U.S. patent application number 14/794504 was filed with the patent office on 2017-01-12 for wireless sensors and corresponding systems and methods for intra-operative nerve root decompression monitoring.
The applicant listed for this patent is Warsaw Orthopedic, Inc.. Invention is credited to Richard L. Brown, Todd A. Kallmyer, Randal Schulhauser.
Application Number | 20170007146 14/794504 |
Document ID | / |
Family ID | 53901135 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170007146 |
Kind Code |
A1 |
Schulhauser; Randal ; et
al. |
January 12, 2017 |
WIRELESS SENSORS AND CORRESPONDING SYSTEMS AND METHODS FOR
INTRA-OPERATIVE NERVE ROOT DECOMPRESSION MONITORING
Abstract
A sensor including an array of pins, a sensing element, a
control module, and a physical layer module. The array of pins or
needles is configured to be inserted in tissue of a patient. The
sensing element is separate from the array of pins or needles and
is configured to (i) detect a first parameter of the tissue, and
(ii) generate a first signal indicative of the first parameter. The
control module is configured to (i) receive the first signal, (ii)
monitor a second parameter of the tissue based on a second signal
received from the array of pins or needles, and (ii) generate a
third signal based on the first signal and the second parameter,
where the third signal is indicative of a level of decompression of
a nerve of the patient. The physical layer module is configured to
wirelessly transmit the third signal from the sensor to a console
interface module or a nerve integrity monitoring device.
Inventors: |
Schulhauser; Randal;
(Phoenix, AZ) ; Brown; Richard L.; (Mesa, AZ)
; Kallmyer; Todd A.; (Tempe, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Warsaw Orthopedic, Inc. |
Warsaw |
IN |
US |
|
|
Family ID: |
53901135 |
Appl. No.: |
14/794504 |
Filed: |
July 8, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/0492 20130101;
A61M 2230/42 20130101; A61M 2205/502 20130101; A61M 2205/8206
20130101; A61B 5/0002 20130101; A61M 2205/3569 20130101; A61B
5/7475 20130101; A61M 16/0443 20140204; A61B 5/024 20130101; A61B
5/04012 20130101; A61B 5/6843 20130101; A61B 1/2673 20130101; A61B
5/1107 20130101; A61B 5/0008 20130101; A61B 5/04017 20130101; A61M
2230/06 20130101; A61B 1/00036 20130101; A61B 1/00004 20130101;
A61B 5/0816 20130101; A61B 5/0488 20130101; A61B 5/1473 20130101;
A61B 5/4041 20130101; A61B 1/00016 20130101; A61B 5/02055 20130101;
A61M 2230/60 20130101; A61B 5/0084 20130101; A61B 5/01 20130101;
A61M 2205/52 20130101; A61B 5/4848 20130101; A61N 1/36031 20170801;
A61B 5/6848 20130101; A61B 5/6852 20130101; A61B 5/6833 20130101;
A61M 2230/50 20130101; A61N 1/36034 20170801; A61M 2230/63
20130101; A61B 5/0004 20130101; A61B 5/14539 20130101; A61M
2205/3592 20130101; A61B 5/11 20130101; A61B 2562/0209 20130101;
A61B 5/0024 20130101; A61B 2560/0209 20130101; A61M 16/04 20130101;
A61M 2205/36 20130101 |
International
Class: |
A61B 5/0492 20060101
A61B005/0492; A61B 5/1473 20060101 A61B005/1473; A61B 5/04 20060101
A61B005/04; A61B 5/00 20060101 A61B005/00; A61B 5/11 20060101
A61B005/11; A61B 5/01 20060101 A61B005/01; A61B 5/145 20060101
A61B005/145 |
Claims
1. A sensor comprising: an array of pins or needles configured to
be inserted in tissue of a patient; a first sensing element
separate from the array of pins or needles and configured to (i)
detect a first parameter of the tissue, and (ii) generate a first
signal indicative of the first parameter; a control module
configured to (i) receive the first signal, (ii) monitor a second
parameter of the tissue based on a second signal received from the
array of pins or needles, and (ii) generate a third signal based on
the first signal and the second parameter, wherein the third signal
is indicative of a level of decompression of a nerve of the
patient; and a physical layer module configured to wirelessly
transmit the third signal from the sensor to a console interface
module or a nerve integrity monitoring device.
2. The sensor of claim 1, wherein: the control module is configured
to determine the level of decompression based on the first signal
and the second signal; and the third signal indicates the level of
decompression.
3. The sensor of claim 1, further comprising: a power source; and a
front end module configured to (i) receive power from the power
source, and (ii) generate a stimulation signal to be applied to the
tissue via the array of pins or needles, wherein the second signal
is an evoked response to the stimulation signal.
4. The sensor of claim 1, wherein: the first signal is indicative
of a temperature of the tissue, an oxygen level of the tissue, or a
pH level of the tissue; and the second signal is an
electromyography signal.
5. The sensor of claim 1, further comprising: a motion sensing
element configured to generate a motion signal; and a pH sensing
element configured to generate a pH signal indicative of a pH level
of the tissue, wherein the first signal is indicative of a
temperature of the tissue, and the control module is configured to
determine a perfusion level based on the first signal or the second
signal, determine a conduction speed based on the second signal and
a time when a stimulation signal was previously generated, receive
the motion signal, and generate the third signal based on the
motion signal, the pH level, the perfusion level, and the
conduction speed.
6. The sensor of claim 1, further comprising: a light emitting
device configured to emit light at the tissue; and a photodiode
configured to (i) detect portions of the light reflected off of the
tissue, and (ii) generate a fourth signal indicative of a
wavelength and corresponding intensity of the light reflected off
of the tissue, wherein the control module is configured to generate
the third signal based on the fourth signal.
7. The sensor of claim 1, comprising a sensing array, wherein: the
sensing array comprises a first substrate, wherein at least a
portion of the first substrate is transparent, the array of pins or
needles attached to the first substrate, a second substrate
connected to the first substrate by conductive elements, an
illuminating device configured to emit light through the at least a
portion of the first substrate and at the tissue, and a photodiode
configured to (i) detect a reflected portion of the light reflected
back through the first substrate, and (ii) generate a fourth
signal; and the control module is configured to generate the third
signal based on the fourth signal.
8. The sensor of claim 7, further comprising a base, wherein: the
conductive elements include a first set of conductive balls; and
the second substrate is connected to the base via a second set of
conductive balls.
9. The sensor of claim 8, further comprising: a control layer
comprising the control module; and an interposer layer disposed
between the control layer and the base, wherein the control module
is connected to the sensor and the second set of conductive balls
via interconnections within the interposer layer.
10. The sensor of claim 1, further comprising a second array of
pins or needles, wherein the control module is configured to (i)
monitor the second parameter or a third parameter of the tissue
based on a fourth signal received from the second array of pins or
needles, and (ii) generate the third signal based on the second
parameter or the third parameter.
11. The sensor of claim 10, wherein the control module is
configured to (i) monitor the second parameter and the third
parameter of the tissue based on the fourth signal, and (ii)
generate the third signal based on the second parameter and the
third parameter.
12. A system comprising: the sensor of claim 1; and the console
interface module or the nerve integrity monitoring device.
13. The system of claim 12, comprising the nerve integrity
monitoring device, wherein the nerve integrity monitoring device
comprises: a second control module configured to generate a payload
request, wherein the payload request (i) requests a data payload
from the sensor in a wireless nerve integrity monitoring network,
and (ii) indicates whether a stimulation probe device is to
generate a stimulation pulse; and a second physical layer module
configured to (i) wirelessly transmit the payload request to the
sensor and the stimulation probe device, or (ii) transmit the
payload request to the console interface module, and in response to
the payload request, (i) receive the data payload from the sensor,
and (ii) receive stimulation pulse information from the stimulation
probe device, wherein the third signal includes the data payload,
wherein the data payload includes data corresponding to an evoked
response of the patient, and wherein the evoked response is
generated based on the stimulation pulse.
14. The system of claim 12, comprising the console interface
module, wherein the console interface module comprises: a second
control module configured to (i) receive a payload request from the
nerve integrity monitoring device, and (ii) generate a
synchronization request including information in the payload
request, wherein the synchronization request (i) requests a data
payload from the sensor in a wireless nerve integrity monitoring
network, and (ii) indicates whether a stimulation probe device is
to generate a stimulation pulse; and a second physical layer module
configured to wirelessly transmit the synchronization request to
the sensor and the stimulation probe device, and in response to the
synchronization request, (i) wirelessly receive the data payload
from the sensor, and (ii) wirelessly receive stimulation pulse
information from the stimulation probe device, wherein the third
signal includes the data payload, wherein the data payload includes
data corresponding to an evoked response of the patient, and
wherein the evoked response is generated based on the stimulation
pulse.
15. The system of claim 12, wherein the console interface module or
the nerve integrity monitoring device is configured to: determine
baseline values for the first parameter and the second parameter;
during or subsequent to a surgery, compare the baseline values
respectively to the first parameter and the second parameter; and
based on the comparisons, generating the third signal or indicating
whether positive results exist for tasks performed during the
surgery.
16. A method of operating a sensor, the method comprising:
detecting a first parameter of a tissue of a patient via a first
sensing element of the sensor; generating a first signal indicative
of the first parameter; monitoring a second parameter of the tissue
based on a second signal received from an array of pins or needles,
wherein the array of pins or needles is configured to be inserted
in the tissue, and wherein the array of pins or needles are
separate from the first sensing element; generating a third signal
based on the first signal and the second parameter, wherein the
third signal is indicative of a level of decompression of a nerve
of the patient; and wirelessly transmitting the third signal from
the sensor to a console interface module or a nerve integrity
monitoring device.
17. The method of claim 16, further comprising: receiving power
from a power source within the sensor and at a front end module;
and generating a stimulation signal to be applied to the tissue via
the array of pins or needles, wherein the first signal is
indicative of a temperature of the tissue, an oxygen level of the
tissue, or a pH level of the tissue, the second signal is an evoked
response to the stimulation signal and is an electromyography
signal.
18. The method of claim 16, further comprising: generating a motion
signal indicative of muscle activity; generating a pH signal
indicative of a pH level of the tissue, wherein the first signal is
indicative of a temperature of the tissue; determining a perfusion
level based on the first signal or the second signal; determining a
conduction speed based on the second signal and a time when a
stimulation signal was previously generated; receiving the motion
signal; emitting light via a light emitting device at the tissue;
detecting portions of the light reflected off of the tissue;
generating a fourth signal indicative of a wavelength and
corresponding intensity of the light reflected off of the tissue;
and generating the third signal based on the motion signal, the pH
level, the perfusion level, the conduction speed and the fourth
signal.
19. The method of claim 16, further comprising: emitting light
through the at least a portion of a first substrate and at the
tissue, wherein the array of pins or needles are included in a
sensing array, and wherein the sensing array comprises the first
substrate attached to the array of pins or needles, wherein at
least a portion of the first substrate is transparent, and a second
substrate connected to the first substrate by conductive elements;
detecting a reflected portion of the light reflected back through
the first substrate; generating a fourth signal based on the
detected reflected portion of the light reflected back through the
first substrate; and generating the third signal based on the
fourth signal.
20. The method of claim 16, further comprising: monitoring the
second parameter and a third parameter of the tissue based on a
fourth signal received from a second array of pins or needles; and
generating the third signal based on the second parameter and the
third parameter.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present disclosure is related to U.S. patent application
Ser. No. 14/455,258 filed on Aug. 8, 2014, U.S. patent application
Ser. No. 14/455,285 filed on Aug. 8, 2014, and U.S. patent
application Ser. No. 14/455,313 filed on Aug. 8, 2014. The entire
disclosures of the applications referenced above are incorporated
herein by reference.
FIELD
[0002] The present disclosure relates to nerve integrity monitoring
systems and devices.
BACKGROUND
[0003] The background description provided herein is for the
purpose of generally presenting the context of the disclosure. Work
of the presently named inventors, to the extent the work is
described in this background section, as well as aspects of the
description that may not otherwise qualify as prior art at the time
of filing, are neither expressly nor impliedly admitted as prior
art against the present disclosure.
[0004] Prior to and/or during surgery, nerves may be compressed.
During and/or subsequent to surgery the nerves may then be
decompressed due to removal of material compressing the nerve
and/or surrounding tissue. For example, when a channel of a nerve
root is being compressed due to a degenerative or split disc, the
disc can be removed and a spacer may be inserted to increase the
size of the channel allowing decompression of the nerve root. A
current standard of care for spinal nerve root decompression does
not include intra-operative monitoring techniques to determine how
much decompression of a nerve is required to achieve a positive
outcome. Traditionally, spinal surgeons relieve pressure on a nerve
root in a subjective manner and arbitrarily determine "how much"
decompression provides a positive outcome based on surgical
experience. One technique that has been suggested for monitoring
decompression includes monitoring electromyographic (EMG) nerve
root potentials. This includes using EMG sensors attached to a
patent and wired to an EMG monitoring device to detect EMG
activity. This technique has associated limitations and
disadvantages. EMG signals generated by the EMG sensors tend to be
noisy due to the wires connecting the EMG sensors to the EMG
monitoring device. The EMG monitoring device has a low sensitivity
to changes in the EMG signals. Decompression is detected based on
small changes in EMG signals. As a result, decompression estimates
generated based on the monitored changes in the EMG signals can be
inaccurate.
[0005] A nerve integrity monitoring (NIM) system can include a
stimulation probe device, sensors, an electrode connection box, and
an EMG monitoring device. The stimulation probe device is used to
stimulate nerve and/or muscle activity. As an example, a
stimulation probe device may include a stimulating electrode tip. A
surgeon may touch a location on a patient with the electrode tip to
provide a voltage and/or current to the location and stimulate
nerve activity and as a result a muscle response (or muscle
activity). A reference patch may be attached to the patient away
from (i) the sensors, and (ii) an area being stimulated. An
electrode of the reference patch can be at a reference potential.
The sensors can include electrodes that are attached to the patient
and used to monitor the muscle activity. A voltage potential
between the electrode tip of the stimulation probe device and the
reference patch and voltage potentials indicated by outputs of the
sensors may be provided via wires to the electrode connection box.
The wires are plugged into respective jacks in the electrode
connection box. The electrode connection box can have channels
respectively for: a voltage potential of the stimulation probe
device; a voltage potential of the reference patch; and output
voltages of the sensors. The electrode connection box may filter
signals received from the stimulation probe device and sensors and
provide corresponding signals to the EMG monitoring device.
Depending on the surgical procedure being performed, a large number
of cables may be used to transmit information between (i) the
stimulation probe device and sensors and (ii) the electrode
connection box. As an example, 1-32 channels may be used during a
surgical procedure. As an other example, more than 32 channels may
be used. Each of the channels may correspond to a respective
twisted pair cable (each cable having a twisted pair of wires).
Each of the cables connected to the sensors is secured to a patient
via the electrodes of the sensors, extends away from the patient,
and is routed outside of a sterile field (or environment) in which
the patient is located to the EMG monitoring device.
SUMMARY
[0006] A sensor is provided that includes an array of pins, a
sensing element, a control module, and a physical layer module. The
array of pins or needles is configured to be inserted in tissue of
a patient. The sensing element is separate from the array of pins
or needles and is configured to (i) detect a first parameter of the
tissue, and (ii) generate a first signal indicative of the first
parameter. The control module is configured to (i) receive the
first signal, (ii) monitor a second parameter of the tissue based
on a second signal received from the array of pins or needles, and
(ii) generate a third signal based on the first signal and the
second parameter, where the third signal is indicative of a level
of decompression of a nerve of the patient. The physical layer
module is configured to wirelessly transmit the third signal from
the sensor to a console interface module or a nerve integrity
monitoring device.
[0007] In other features, a method of operating a sensor is
disclosed herein. The method includes: detecting a first parameter
of a tissue of a patient via a first sensing element of the sensor;
generating a first signal indicative of the first parameter;
monitoring a second parameter of the tissue based on a second
signal received from an array of pins or needles, where the array
of pins or needles is configured to be inserted in the tissue, and
where the array of pins or needles are separate from the first
sensing element; generating a third signal based on the first
signal and the second parameter, where the third signal is
indicative of a level of decompression of a nerve of the patient;
and wirelessly transmitting the third signal from the sensor to a
console interface module or a nerve integrity monitoring
device.
[0008] Further areas of applicability of the present disclosure
will become apparent from the detailed description, the claims and
the drawings. The detailed description and specific examples are
intended for purposes of illustration only and are not intended to
limit the scope of the disclosure.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a perspective view of a wireless nerve integrity
monitoring (WNIM) system incorporating sensors in accordance with
the present disclosure.
[0010] FIG. 2 is a functional block diagram of a sensing module, a
console interface module and a NIM device in accordance with the
present disclosure.
[0011] FIG. 3 is a functional block diagram of another sensing
module and another NIM device in accordance with the present
disclosure.
[0012] FIG. 4 is a functional block diagram of another sensing
module in accordance with the present disclosure.
[0013] FIG. 5 is a functional block diagram of a stimulation probe
device in accordance with the present disclosure.
[0014] FIG. 6 is a functional block diagram of a portion of the
stimulation probe device in accordance with the present
disclosure.
[0015] FIG. 7 is a top view of a sensor in accordance with the
present disclosure.
[0016] FIG. 8 is a side view of the sensor of FIG. 7.
[0017] FIG. 9 is a side view of the sensor of FIG. 7.
[0018] FIG. 10 is a bottom view of the sensor of FIG. 7.
[0019] FIG. 11 is a perspective view of a sensing array including
sensing elements and devices in accordance with the present
disclosure.
[0020] FIG. 12 is an exploded view of the sensing array of FIG.
11.
[0021] FIG. 13 is a top view of the sensing array of FIG. 11.
[0022] FIG. 14 is a signal flow diagram illustrating a sensor
joining and communicating in a WNIM system in accordance with the
present disclosure.
[0023] FIG. 15 is a signal flow diagram illustrating a stimulation
device joining and communicating in a WNIM system in accordance
with the present disclosure.
[0024] FIG. 16 illustrates an implementation of a sensor and a
sensing array in accordance with an embodiment of the present
disclosure.
[0025] FIG. 17 illustrates a method of operating a sensor and a
console interface module and/or NIM device in accordance with the
present disclosure.
[0026] FIG. 18 illustrates a method of powering-up a sensor in
accordance with the present disclosure.
[0027] FIG. 19 illustrates a WNIM method of operating a stimulation
probe device, one or more sensors, and a console interface module
and/or NIM device in accordance with the present disclosure.
[0028] In the drawings, reference numbers may be reused to identify
similar and/or identical elements.
DESCRIPTION
[0029] Any clutter and/or time inefficiencies in an operating room
that can be eliminated and/or minimized is advantageous to both
hospital personal and a patient. Traditional nerve integrity
monitoring (NIM) systems including EMG sensors have extensive
cabling. Most of the cabling corresponds to transporting or
delivery evoked response signals from sensors to a NIM device, as a
result of stimulated nerve activity in muscles of a patient.
Various techniques are disclosed below, which reduce and/or
eliminate cables used in a NIM system, reduce and/or minimize
certain time inefficiencies associated with current NIM systems,
minimize noise, increase sensitivity to changes in EMG signals, and
minimize power consumption.
[0030] Examples are also disclosed below that provide sensors,
systems and methods including intra-operative monitoring of
relevant physiological parameters to achieve predictive, accurate
and positive decompression outcomes. Nerve integrity monitoring is
performed during spinal decompression to enhance predictive
positive outcomes. Wireless NIM sensors and systems are disclosed
that provide increased sensitivity and signal discrimination.
[0031] FIG. 1 shows a wireless nerve integrity monitoring (WNIM)
system 10. The WNIM system 10, as shown, includes sensors 12, a
stimulation probe device 14, a wireless interface adaptor (WIA) 16
and a NIM device 18. The WIA 16 includes a console interface module
(CIM), which is shown in FIG. 2, and an interface 20 (e.g., a
32-pin connector) for connecting to the NIM device 18. The WIA 16
is shown as being plugged into a back side of the NIM device 18.
Although the WIA 16 is shown as being plugged into the NIM device
18 via the interface 20, the WIA 16 may be separate from the NIM
device 18 and wirelessly communicate with the NIM device 18. The
sensors 12 and the stimulation probe device 14 wirelessly
communicate with the CIM and/or the NIM device 18. In one
embodiment, the WIA 16 is connected to the NIM device 18 and
wirelessly communicates with the sensors 12 and the stimulation
probe device 14. Information described below as being transmitted
from the NIM device 18 to the CIM may then be relayed from the CIM
to the sensors 12 and/or the stimulation probe device 14.
Information and/or data described below as being transmitted from
the sensors 12 and/or the stimulation probe device 14 to the CIM
may then be relayed from the CIM to the NIM device 18.
[0032] The WIA 16: transfers signals between (i) the NIM device 18
and (ii) the sensors 12 and the stimulation probe device 14; and/or
adds additional information to the signals received from the NIM
device 18 prior to forwarding the signals to the sensors 12 and/or
stimulation probe device 14, as described below. The WIA 16 may:
operate essentially as a pass through device; be a smart device and
add and/or replace information provided in received signals; and/or
generate signals including determined information based on received
signals. For example, the WIA 16 may receive a payload request
signal from the NIM device 18 and determine a delay time between
when the payload request was received and when a next
synchronization (SYNC) request signal is to be transmitted. This is
described in further detail with respect to FIGS. 14 and 19. The
WIA 16 allows the NIM device 18 to be compatible with legacy
hardware. The WIA 16 may be unplugged from the NIM device 18 and a
traditional electrode connection box may be connected to the WIA 16
using the same interface of the NIM device 18 as the WIA 16. The
WIA 16 replaces cables traditionally connected between (i) a NIM
device 18 and (ii) sensors 12 and a stimulation probe device 14.
This eliminates wires traversing (extending from within to outside)
a sterile field in which a patient is located.
[0033] As another example, the WIA 16 may receive signals from the
sensors 12 and/or the stimulation probe device 14. The signals from
the sensors 12 and/or the stimulation probe device 14 may indicate
first parameters and/or the WIA device 16 may determine second
parameters based on the received signals. The first parameters may
include, for example, voltages, frequencies, current levels,
durations, amplitudes, temperatures, impedances, resistances,
wavelengths, etc. The second parameters may include, for example,
durations, oxygen levels, temperatures, impedances, pH levels,
accelerations, amplitudes, etc. The received signals and/or the
determined information may be forwarded to the NIM device 18 for
evaluation and/or for display on the screen of the NIM device
18.
[0034] Although one type of sensor 12 is shown in FIG. 1, other
types of sensors and/or configurations of the sensor 12 may be
incorporated in the WNIM system 10. The sensors 12 may include
respective pins and/or needles that are inserted into, for example,
muscle tissue of a patient. The sensors 12 may be adhered to skin
of a patient over, for example, muscle tissue. The sensors 12 may,
for example, be used to detect the first parameters including
voltage potentials and/or current levels passed between pins of the
sensors 12. As shown below, the sensors may include one or more
arrays of pins and/or needles. Voltage potentials, impedances,
and/or current levels between selected pairs of the pins and/or
needles in the arrays may be monitored. This may include monitoring
various pin (and/or needle) combinations in a single array and/or
pin (and/or needle) combinations of pins (and/or needles) in
different arrays. For example, a voltage potential between a first
pin (and/or needle) in a first array and a second pin (and/or
needle) in a second array may be monitored. The sensors 12 may each
include any number of pins and/or needles. The pins and needles may
be referred to as electrodes.
[0035] The sensors 12 are used to digitize nerve and/or muscle
activity and wirelessly transmit this information to the CIM and/or
the NIM device 18. The sensors 12 may alert the CIM and/or the NIM
device 18 of bursts (e.g., increases in voltages of evoked response
signals) in nerve and/or muscle activity. An evoked response signal
refers to a signal generated in a tissue of a patient as a result
of a stimulation signal generated by the stimulation probe device
14.
[0036] The stimulation probe device 14 is used to stimulate nerves
and/or muscle in the patient. The stimulation probe device 14
includes: a housing 30 with a grip 32; one or more electrodes 34
(shown having two electrodes); a switch 36; a control module (an
example of which is shown in FIG. 5); and an input 38 for
connection to a reference pad (or patch) 40, via a cable 42.
Although the stimulation probe device 14 is shown having a
bifurcated tip with two electrodes 34, the stimulation probe device
14 may have one or more electrodes 34. The electrodes 34 are
separated and insulated from each other and may extend within a
tube 44 to the housing 30. The switch 36 may be used to turn ON the
stimulation probe device 14 and/or to apply a stimulation pulse to
the electrodes 34. The stimulation pulse may be manually generated
by actuating the switch 36 or may be generated via the NIM device
18 and/or the WIA 16 via the CIM. The NIM device 18 and/or the CIM
may signal the control module of the stimulation probe device 14 to
generate one or more stimulation pulses to stimulate one or more
nerves and/or muscles in proximity of the electrodes 34. The
reference patch 40 is used to provide a reference voltage
potential. One or more voltage potentials between one or more of
the electrodes 34 and the reference patch 40 may be determined by:
the control module of stimulation probe device 14; a control module
of the NIM device 18 (examples of which are shown in FIGS. 2-3);
and/or a control module of the CIM (examples of which are shown in
FIGS. 2-3).
[0037] The stimulation probe device 14 may wirelessly transmit
information to the CIM and/or NIM device 18. The information may
include: timing information; voltage potentials between the
electrodes 34; voltage potentials between the reference patch 40
and one or more of the electrodes 34; number of stimulation pulses;
pulse identifiers (IDs); voltages and current levels of stimulation
pulses generated; and amplitudes, peak magnitudes and/or durations
of stimulation pulses generated. The timing information may
include: start and end times of stimulation pulses; durations of
stimulation pulses; and/or time between stimulation pulses. In
another embodiment, the WIA 16 is not included in the WNIM system
10. In this embodiment, the NIM device 18 wirelessly communicates
directly with the sensors 12 and the stimulation probe device 14.
This may include communication with the sensors 12 and the
stimulation probe device 14 shown in FIG. 1 and/or communication
with other sensors and/or stimulation devices. The WNIM system 10
may include any number of sensors and/or stimulation probe
devices.
[0038] Referring now to FIGS. 1 and 2, which show a sensing module
50, a CIM 52 and a NIM device 54. The sensing module 50 wirelessly
communicates with the CIM 52 and/or with the NIM device 54 via the
CIM 52. The sensing module 50 may be included in any of the sensors
disclosed herein including the sensors shown in FIGS. 1 and 7-9.
The CIM 52 may be included in the WIA 16 of FIG. 1.
[0039] The sensing module 50 includes a control module 56 (e.g., a
microprocessor), a memory 58, and a physical layer (PHY) module 60
(e.g., a transceiver and/or radio). The control module 56 detects
(i) electromyographic signals generated in tissue of a patient via
sensing elements 61 (e.g., pins, needles, electrodes, and/or
flexible circuit with electrodes), (ii) voltage potentials, current
levels, and/or impedances between selected pairs of the sensing
elements 61. The electromyographic signals may be in the form of
voltage signals having voltage potentials. One or more of the
voltage signals and/or current levels may be from photodiodes
and/or photodetectors, which may be included in the sensing
elements 61. The control module 56 may also drive illuminating
devices 62 (e.g., lasers, light emitting diodes (LEDs), etc.). The
voltage signals and/or current levels generated via the photodiodes
and/or photodetectors may be light emitted by the illuminating
devices 62 and reflected off of tissue of a patient and detected by
the photodiodes and/or photodetectors. The photodiodes may be used
to detect color and/or wavelength of reflected light. Oxygen
content levels may be determined based on amplitudes of the voltage
signals generated by the photodiodes.
[0040] The control module 56 includes a font end receive module 63,
a front end transmit module 64, and a baseband module 66. The front
end receive module 63 may include one or more of each of an
amplifier, a modulator, a demodulator, a filter, a mixer, a
feedback module, and a clock. The front end transmit module 64 may
include one or more of each of a modulator, an amplifier, and a
clock. The baseband module 66 may include an upconverter and a
downconverter. The front end receive module 63 may modulate,
demodulate, amplify, and/or filter signals received from the
sensing elements prior to generating an output for the baseband
module 66. The front end transmit module 64 transmits stimulation
signals to selected ones of the sensing elements 61 (e.g., selected
pins and/or needles) and/or control operation of the illuminating
devices 62. The front end transmit module 64 may modulate
stimulation signals provided to the sensing elements and/or
modulate illumination signals generated by the illuminating devices
62. Stimulation signals and/or illumination signals may not be
modulated. The filtering performed by the front end transmit module
63 may include bandpass filtering and/or filtering out (i)
frequencies of the amplified signals outside of a predetermined
frequency range, and (ii) a direct current (DC) voltage. This can
eliminate and/or minimize noise, such as 60 Hz noise. The front end
receive module 63 generates baseband signals based on the signals
received by the front end receive module 63.
[0041] The baseband module 66 may include an analog-to-digital
(A/D) converting module 70 (e.g., an A/D converter) and convert the
baseband signals (analog signals) to digital baseband (BB) signals.
The BB module 66 and/or the A/D converting module 70 may sample the
output of the front end receive module 63 at a predetermined rate
to generate frames, which are included in the digital BB signals.
By A/D converting signals at the sensor as opposed to performing an
A/D conversion at the CIM 52 or the NIM device 54, opportunities
for signal interference is reduced. The BB module 66 may include a
multiplexer 67 for multiplexing (i) signals generated by the front
end receive module 63, and/or (ii) generated based on the signals
generated by the front end receive module 63.
[0042] The BB module 66 may then upconvert the digital BB signal to
an intermediate frequency (IF) signal. The BB module 66 may perform
direct-sequence spread spectrum (DSSS) modulation during
upconversion from the digital BB signal to the IF signal. The BB
module 66 may include a mixer and oscillator for upconversion
purposes. The BB module 66 and/or the control module 56 may
compress and/or encrypt BB signals transmitted to the PHY module 60
prior to upconverting to IF signals and/or may decompress and/or
decrypt signals received from the PHY module 60.
[0043] The BB module 66 may provide a received signal strength
indication (RSSI) indicating a measured amount of power present in
a RF signal received from the CIM 52. This may be used when
determining which of multiple CIMs the sensor is to communicate
with. The control module 56 may select a CIM corresponding to a
SYNC request signal and/or a payload request signal having the most
power and/or signal strength. This may include (i) selecting a
channel on which the SYNC request signal and/or the payload request
signal was transmitted, and (ii) communicating with the CIM on that
channel. This allows the control module 56 to select the closest
and proper CIM. This selection may be performed when the sensor has
not previously communicated with a CIM, is switching to a different
WNIM network, and/or has been reset such that the sensor does not
have a record of communicating with a CIM. In one embodiment, the
sensors are unable to be reset.
[0044] The memory 58 is accessed by the control module 56 and
stores, for example, parameters 72. The parameters 72 may include
parameters provided in SYNC request signals and/or parameters
associated with signals generated via the sensing elements 61. The
parameters may include voltages, current levels, amplitudes, peak
magnitudes, pulse durations, temperatures, pH levels, frequencies,
impedances, resistances, oxygen levels, perfusion and/or conduction
rates, etc.
[0045] The PHY module 60 includes a transmit path 74 (or
transmitter) and a receiver path 76 (or receiver). The transmit
path 74 includes a modulation module 78 (e.g., a modulator) and an
amplification module 80 (e.g., an amplifier). The modulation module
78 modulates and upconverts the IF signal to generate a radio
frequency (RF) signal. This may include Gaussian frequency-shift
keying (GFSK) modulation. The modulation module 78 may include, for
example, a filter, a mixer, and an oscillator (collectively
identified as 82). The amplification module 80 may include a power
amplifier 84, which amplifies the RF signal and transmits the RF
signal via the antenna 86.
[0046] The receiver path 76 includes a second amplification module
90 and a demodulation module 92 (e.g., a demodulator). The
amplification module 90 may include a low-noise amplifier (LNA) 94.
The second amplification module 90 amplifies RF signals received
from the CIM 52. The demodulation module 92 demodulates the
amplified RF signals to generate IF signals. The IF signals are
provided to the BB module 66, which then downconverts the IF
signals to BB signals. The demodulation module 92 may include, for
example, a filter, a mixer, and an oscillator (collectively
identified as 96). The A/D converting module 70 may include a
digital-to-analog (D/A) converter to convert the BB signals to
analog signals. The RF signals received from the CIM 52 may
include, for example, SYNC request signals or portions thereof.
[0047] The CIM 52 includes a PHY module 100, a control module 102,
a memory 104, and a NIM interface 106 (e.g., 32 pin connector). The
PHY module 100 includes a receive path (or receiver) 108 and a
transmit path (or transmitter) 110. The receive path 108 includes
an amplification module 112 and a demodulation module 114. The
amplification module 112 amplifies RF signals received from the
sensing module 50 and/or from other sensor modules and/or
stimulation probe devices. The amplification module 112 may include
a LNA 115. The demodulation module 114 demodulates and downconverts
the amplified RF signals to generate IF signals. The demodulation
module 114 may include a filter, mixer, and an oscillator
(collectively referred to as 117). The transmit path 110 includes a
modulation module 116 and an amplification module 118. The
modulation module 116 modulates and upconverts IF signals from the
control module 102 to generate RF signals. This may include
Gaussian frequency-shift keying (GFSK) modulation. The modulation
module 116 may include, for example, a filter, a mixer, and an
oscillator (collectively identified as 119). The amplification
module 118 transmits the RF signals to the sensing module 50 via an
antenna 120 and/or to other sensor modules and/or stimulation probe
devices. The amplification module 118 may include a power amplifier
121.
[0048] The control module 102 includes a BB module 124 and a
filtering module 126. The BB module 124 converts IF signals
received from the PHY module 100 to BB signals and forwards the BB
signals to the filtering module 126. The BB module may demultiplex
an IF signal and/or a BB signal to provide multiple IF signals and
BB signals. The BB module 124 also converts BB signals from the
filtering module 126 to IF signals, which are forwarded to the
modulation module 116. The BB module 124 may include a D/A
converting module 128, a demultiplexer 129, and/or a fast Fourier
transform (FFT) module 131.
[0049] The D/A converting module 128 may include an A/D converter
to convert analog signals from the filtering module 126 to digital
signals. The D/A converting module 128 may include a D/A converter
to convert digital signals from the PHY module 100 to analog
signals. In one embodiment, the BB module 124 does not include the
D/A converting module 128 and digital signals are passed between
the filtering module 126 and the PHY module 100. The demultiplexer
129 may demultiplex the analog signals and/or the digital signals.
The FFT module 131 perform a FFT of the analog signals and/or the
digital signals for spectral waveform analysis including frequency
content monitoring.
[0050] The BB module 124 may attenuate signals received from the
demodulation module 114. The filtering module 126 may be a bandpass
filter and remove frequencies of signals outside a predetermined
range and/or DC signals. This can eliminate and/or minimize noise,
such as 60 Hz noise. The BB module 124 and/or the control module
102 may compress and/or encrypt signals transmitted to the
modulation module 116 and/or decompress and/or decrypt signals
received from the demodulation module 114. Although the CIM 52 is
shown as being connected to the NIM device 54 via the NIM interface
106, the CIM 52 may be separate from the NIM device 54 and
wirelessly communicate with the NIM device 54 via the PHY module
100.
[0051] The memory 104 is accessed by the control module 102 and
stores, for example, parameters 130. The parameters 130 may include
parameters provided in SYNC request signals and/or parameters
indicated in and/or generated based on the signals received via the
sensing elements 61. The parameters 130 may include voltages,
current levels, temperatures, oxygen levels, wavelengths, pH
levels, impedances, resistances, acceleration values, amplitudes,
peak magnitudes, pulse durations, etc. and may include or be the
same as the parameters 72. The memory may also store
synchronization requests 132, which are defined below.
[0052] The NIM device 54 may include a control module 140, a PHY
module 142, a CIM interface 144, a display 146 and a memory 148.
The control module 140: generates payload request signals; receives
data payload signals from the sensing module 50 and/or other
sensing modules and stimulation probe devices via the CIM 52; and
displays signals and/or other related information on the display
146. The displayed signals and/or information may include the
parameters 130 and/or information generated based on the parameters
130, which may include oxygen levels, pH levels, and/or other
parameters that may be determined based on the parameters 130. The
PHY module 142 may transmit signals to and receive signals from the
control module 140 via the interfaces 106, 144 as shown or
wirelessly via an antenna (not shown). The memory 148 is accessed
by the control module 140 and stores the parameters 130 and may
store payload requests 150, which are defined below.
[0053] The control modules 56, 126, the BB modules 66, 128, the PHY
modules 60, 100, and/or one or more modules thereof control timing
of signals transmitted between the sensing module 50 and the CIM
52. This is described in further detail below with respect to FIGS.
14-15 and 22. The PHY modules 60, 100 may communicate with each
other in a predetermined frequency range. As an example, the PHY
modules 60, 100 may communicate with each other in 2.0-3.0
giga-hertz (GHz) range. In one embodiment, the PHY modules 60, 100
transmit signals in a 2.4-2.5 GHz range. The PHY modules 60, 100
may communicate with each other via one or more channels. The PHY
modules 60, 100 may transmit data at predetermined rates (e.g., 2
mega-bits per second (Mbps)). The CIM 52 and/or the NIM device 54
may set the frequency range, the number of channels, and the data
rates based on: the number of sensor modules in and actively
communicating in the WNIM system 10; the number of stimulation
probe devices in and actively communicating in the WNIM system 10;
the types of the sensors; the number of channels per sensor; the
speed per channel of each of the sensors; the number of channels
per stimulation probe device, and/or the speed per channel of the
stimulation probe devices.
[0054] Referring now to FIG. 1 and FIG. 3, which shows the sensing
module 50 and a NIM device 162. The sensing module 50 includes the
control module 56, the memory 58 and the PHY module 60. The control
module 56 includes the front end receive module 63, the front end
transmit module 64, and the BB module 66. The control module 56
receives signals from the sensing elements 61 and controls
operation of the illuminating devices 62. The control module 56
reports data associated with the signals to the NIM device 162 via
the PHY module 60. The control module 56 also receives signals
(e.g., synchronization request signals) from the NIM device 162 via
the PHY module 60.
[0055] The NIM device 162 includes a control module 164, a memory
166, a PHY module 168, and the display 146. Functionality of the
CIM 52 of FIG. 2 is included in the NIM device 162. The PHY module
168 includes a receive path 170 (or receiver) and a transmit path
172 (or transmitter). The receive path 170 includes an
amplification module 174 and a demodulation module 176. The
amplification module 174 via a LNA 175 amplifies RF signals
received from the sensing module 50 and/or from other sensor
modules and/or stimulation probe devices. The demodulation module
176 demodulates and downconverts the amplified RF signals to
generate IF signals. The transmit path 172 includes a modulation
module 178 and an amplification module 180. The modulation module
178 and the amplification module 180 may operate similar to the
modulation module 116 and the amplification module 118. The
amplification module 118 may include a power amplifier 182 and
transmits RF signals via an antenna 183 to the sensing module 50
and/or to other sensor modules and/or stimulation probe
devices.
[0056] The control module 164 includes a BB module 184 and a
filtering module 186. The BB module 184 converts IF signals
received from the PHY module 168 to BB signals and forwards the BB
signals to the filtering module 186. The BB module 184 may
demultiplex the IF signals and/or the BB signals. The BB module 184
also converts BB signals from the filtering module 186 to IF
signals, which are forwarded to the modulation module 178. The BB
module 184 may include a D/A converting module 188 and/or a
demultiplexer 185. The D/A converting module 188 may include an A/D
converter to convert analog signals from the filtering module 186
to digital signals. The demultiplexer 185 may demultiplex the
analog and/or the digital signals. The D/A converting module 188
may include a D/A converter to convert digital signals from the PHY
module 168 to analog signals. In one embodiment, the BB module 184
does not include the D/A converting module 188 and digital signals
are passed between the filtering module 186 and the PHY module 168.
The BB module 184 may attenuate signals received from the
demodulation module 176. The filtering module 186 may be a bandpass
filter and remove frequencies of signals outside a predetermined
range and/or DC signals. This can eliminate and/or minimize noise,
such as 60 Hz noise. The BB module 184 and/or the control module
164 may compress and/or encrypt signals transmitted to the
modulation module 178 and/or decompress and/or decrypt signals
received from the demodulation module 176.
[0057] Referring now to FIGS. 2-3, the BB module 66 of the sensing
module 50 may provide a received signal strength indication (RSSI)
indicating a measured amount of power present in a RF signal
received from the NIM device 162. This may be used when determining
which of multiple NIM devices to communicate with. The control
module 56 may select a NIM device corresponding to a SYNC request
signal and/or a payload request signal that has the most power
and/or signal strength. This may include selecting a channel on
which the SYNC request signal and/or the payload request signal was
transmitted and communicating with the CIM 52 and/or the NIM device
162 on that channel. This allows the control module 56 to select
the closest and proper NIM device. This selection may be performed
when the corresponding sensor has not previously communicated with
the NIM device 162 and/or other NIM devices and/or has been reset
such that the sensor does not have a record of communicating with
the NIM device 162 and/or other NIM devices.
[0058] The memory 166 may store the parameters 130, the payload
requests 150 and/or the SYNC requests 132. The memory 166 may store
the SYNC requests and may not store the payload requests. This is
because the NIM device 162 may generate SYNC requests and not
payload requests.
[0059] Referring now to FIGS. 1 and 4, which show a sensing module
200. The sensing module 200 may be included in any of the sensors
(e.g., the sensors 12 of FIG. 1) disclosed herein and/or replace
any of the sensing modules (e.g., the sensing module 50 of FIGS.
2-3) disclosed herein. The sensing module 200 may include the
control module 202, a PHY module 204, a power module 206, a power
source 208, a temperature sensing module 210, an A/D converter 212,
and an accelerometer 214 (e.g., a 3-axis accelerometer) or other
motion sensor (e.g., a gyro). The motion sensor 214 includes motion
sensing elements (e.g., electrodes) 215 for generating a signal
indicative of motion and/or acceleration. Although the sensing
module 200 is shown as having the temperature sensing module 210,
the sensing module 200 may not include the temperature sensing
module 210. The temperature sensing module 210 may be replaced with
a temperature sensor, such as an infrared temperature sensor, as
shown in FIG. 9. In one embodiment, the sensing module 200 includes
the temperature sensing module 210 and the temperature sensor.
Although shown separate from the control module 202, the PHY module
204, the power module 206, the temperature sensing module 210
and/or the A/D converter 212 may be included in and as part of the
control module 202.
[0060] The control module 202 includes the front end modules 63, 64
and the BB module 66 of FIG. 2. The PHY module 204 includes the
modulation module 78, the demodulation module 92 and the
amplification modules 80, 90 of FIG. 2.
[0061] The control module 202, the PHY module 204, the temperature
sensing module 210, and the A/D converter 212 operate based on
power from the power module 206. The power module 206 receives
power from the power source (e.g., a battery). The power module 206
may include a switch 216 as shown (or a pull-tab) to turn ON and/or
OFF the power module 206 and thus turn ON and/or OFF the sensing
module 200 and/or the corresponding sensor. The switch 216 may be
manually operated or may be operated by the power module 206, the
control module 202 and/or the PHY module 204. In one embodiment,
the switch 216 is manually operated and at least partially exposed
on an exterior of the sensing module 200 and/or corresponding
sensor housing. In another embodiment, the switch 216 includes one
or more transistors located in the control module 202, the PHY
module 204, and/or in the power module 206, as shown. If included
in one of the modules 202, 204, 206, the switch 216 is not exposed
on an exterior of the sensing module 200 and/or the corresponding
sensor housing. The state of the switch 216 may be controlled by
the control module 202, the PHY module 204, and/or the power module
206 based on signals received from the sensing elements 61, the CIM
52, and/or the NIM device 162 of FIGS. 2-3. Transitioning the
switch 216 via one of the modules 202, 204, 206 from a first state
to a second state to turn ON at least a portion of the sensor
and/or at least a portion of the one or more of the modules 202,
204, 206 may be referred to as an "auto-start".
[0062] The sensing module 200 may operate in: a high power mode
(fully powered mode), a low (or idle) power mode (partially powered
or transmitting less frequently then when in the high power mode),
a sleep mode, or OFF. Operation in and transition between these
modes may be controlled by one or more of the modules 202, 204,
206. As an example, the sensor may be OFF (or dormant) while being
shipped and/or not in use. The sensor may also be OFF if: not yet
communicated with a CIM and/or NIM device; a connection has not yet
been established between the sensing module 200 and a CIM and/or
NIM device; the sensor has not yet been assigned to a CIM and/or
NIM device; and/or the sensor has not yet been assigned one or more
time slots in which to communicate with a CIM and/or NIM
device.
[0063] Transitioning to the low power mode, the sleep mode and/or
to OFF decreases power consumption and can aid in minimizing size
of the power source 208. While partially powered, the control
module 202 and/or portions of the control module 202 and the PHY
module 204 may be deactivated. The receiver path of the PHY module
204 may remain activated to (i) receive signals from the CIM 52
and/or portions of the control module 202, and (ii) detect
electromyographic signals. The transmit path 74 of the PHY module
204 and/or other portions of the sensor that are not experiencing
activity may be deactivated. Transitioning between the stated modes
is further described below.
[0064] When a surgery is performed, an operating room is generally
kept at a low temperature. This in turn can decrease temperature of
a patient. Studies have shown that if a patient is kept warm (e.g.,
within a predetermined range of a predetermined temperature or a
normal body temperature, such as 98.6.degree. F.) better outcomes
are achieved. To maintain a temperature of a patient, heaters may
be used to blow warm air under the patient and/or heat portions of
a table on which a patient is lying. The patient may also be
covered or wrapped in blankets. If a heater is broken, accidentally
disconnected, not setup properly and/or is operating improperly,
the temperature of the patient can drop. Unfortunately, there can
be a long lag time from when the heaters fail to when a decrease in
the temperature of the patient is detected. By the time the
decrease in the temperature of the patient is detected by, for
example, a surgeon or surgical assistant, the temperature of the
patient may have been below the predetermined range for an extended
period of time.
[0065] To aid in early detection of changes in temperatures of a
patient, a sensor and/or sensing module may include the temperature
sensing module, which may be used to detect a temperature where the
sensor is located. This temperature may be based on or represent a
temperature of a portion of a patient on which the sensor is
attached. While the temperature sensor may not be in direct contact
and/or directly indicate a temperature of the portion of the
patient, the temperature sensor can provide a temperature signal
indicative of an average temperature in a proximate area of the
temperature sensor. The temperature may also be used for other
tasks disclosed herein, such as to determine levels of nerve
decompression, as described below.
[0066] Referring again also to FIG. 1, one or more of the sensors
12 may include a temperature sensing module (e.g., the temperature
sensing module 210) and/or a motion sensor (e.g., an accelerometer
or gyro sensor). By including temperature sensing modules in
sensors, temperatures of various points on a patient may be
monitored. This further aids in early detection of changes in
temperatures of a patient. The sensors provide an earlier
indication of a temperature issue than a sensor used to detect a
change in a core body temperature of the patient, as the limbs or
exterior of the body tends to decrease in temperature quicker than
the core body temperature. The core body temperature may refer to,
for example, an internal temperature within a trunk (or chest) of
the body.
[0067] The temperature sensing module 210 may include a first
transistor 220 and a second transistor 222. The first transistor
220 may be transitioned between states to supply current to the
second transistor 222. This turns ON the temperature sensing module
210. The second transistor 222 is configured to detect a
temperature. As an example, the first transistor 220 may be a
metal-oxide-semiconductor field-effect transistor (MOSFET) and
includes a drain, a gate and a source. The second transistor 222
may be a bipolar junction transistor (BJT) and includes a
collector, a base and an emitter. The transistors 220, 222 are
shown for example purposes only, one or more of the transistors
220, 222 may be replaced with other transistors or other similarly
operating circuitry. The drain is connected to and receives current
from the power module 206. The gate is connected to and receives a
control signal from the control module 202. The source of the first
transistor 220 is connected to the collector and the base. The
collector is connected to a ground terminal 224. The collector and
the emitter are also connected to the A/D converter 212.
[0068] The second transistor 222 is connected in a diode
configuration. Temperature dependence of the base-to-emitter
voltage (Vbe) is the basis for temperature measurement. The
base-to-emitter voltage Vbe is dependent on temperature while (i)
the power source 208 and the power module 206 supply a constant
level of current to the collector via the first transistor 220, and
(ii) a voltage across the base and the collector is zero. The
voltage across the base (or collector) and the emitter is detected
by the A/D converter. The detected voltage is converted to a
temperature via the control module 202. The control module 202
receives a digital signal from the A/D converter and determines the
temperature. The temperature may be determined using, for example,
expression 1, where A is a predetermined multiplier constant and B
is a predetermined offset constant.
AVbe+B [1]
[0069] In addition to detecting signals from the sensing elements
61 and temperature, the sensing module 200 may also detect other
parameters, such as heart rate, respiration rate, and/or muscle
spasms. These parameters may be determined via one or more of the
control modules 202, 102, 140, 164 of the sensor, the CIM 52 and
the NIM devices 54, 162 of FIGS. 2-3. The NIM devices 54, 162 may
generate an alert signal and/or display these parameters on the
display 146. This information may also be used to provide an early
indication that a patient is coming out from anesthesia
prematurely. The sensing elements 61 may be monitored for EMG
purposes as well as for heart rate, respiration rate, and/or muscle
spasms purposes. To detect this information, the sensor may be
attached to (or mounted on) a trunk of a patient.
[0070] A heart rate may be in a same frequency band as an
electromyographic signal. A heart rate is periodic unlike an
electromyographic signal. A voltage potential detected as a result
of a beating heart may have a larger amplitude (or magnitude) than
amplitudes (or magnitudes) of an electromyographic signal. A
respiration rate is typically in a lower frequency band than an
electromyographic signal. A muscle spasm may have a distinguishable
frequency and/or distinguishable frequency band. Thus, one or more
of the control modules 202, 102, 140, 164 may distinguish between
signals or portions of signals corresponding to a heart rate, a
respiration rate, and an electromyographic signal based on these
differences. If the control module 202 of the sensor detects heart
rate, respiration rate, and/or muscle spasms, the control module
202 may wirelessly transmit this information to the CIM 52 and/or
one of the NIM devices 54, 162. The NIM devices 54, 162 may then
display this information and/or generate an alert signal if one or
more of these parameters are outside of respective predetermined
ranges and/or thresholds.
[0071] In addition to or as an alternative to monitoring the
sensing elements 61 to detect heart rate, respiration rate, and/or
muscle spasms, the sensor includes a motion sensor. As similarly
described above, one or more of the control modules 202, 102, 140,
164 may monitor signals from the motion sensor (e.g., acceleration
signals generated by an accelerometer) to detect activity of muscle
firing, heart rate, respiration rate, and/or muscle spasms. The
acceleration information, muscle firing activity, heart rate,
respiration rate, and/or muscle spasm information determined based
on the acceleration signals may be wirelessly transmitted from the
sensor and/or PHY module 204 to the CIM 52 and/or one of the NIM
devices 54, 162.
[0072] As is further described below with respect to FIG. 18, the
sensor may "self-awake". In other words, the sensor may
automatically transition from being OFF or being in the low power
(or sleep) mode to being powered ON and being in the high power
mode when attached to a patient. For example, while not attached to
a patient, there is an "open" circuit between two of the sensing
elements 61. Thus, an impedance between two of the sensing elements
61 is high (e.g., greater than 10 kilo-Ohms (kOhms)). Subsequent to
attaching the sensor to the patient, an impedance between the two
of the sensing elements 61 is low (e.g., less than 1 kOhms) and/or
significantly less then when the sensor was not attached. This
difference in impedance can be detected and cause the power module
206 and/or the control module 202 to switch operating modes.
[0073] In another embodiment, the two of the sensing elements 61
and corresponding impedance between the two of the sensing elements
61 operate as a switch to activate the power module 206. Upon
activation, the power module 206 may supply power to the control
module 202 and/or the PHY module 204.
[0074] In yet another embodiment, the power module 206 (or analog
front end) is configured to generate a DC voltage while the sensor
is not attached to a patient. Generation of the DC voltage may be
based on the impedance between the two of the sensing elements 61.
This DC voltage is detected by the control module 202. The control
module 202 remains in the low power (or sleep) mode while receiving
the DC voltage. The power module 206 ceases to provide the DC
voltage when the electrodes are attached to the patient. This
causes the control module to transition (i) from being OFF to being
in the low power mode or high power mode, or (ii) from being in a
sleep mode to being in the low power mode or the high power
mode.
[0075] The control module 202 and/or the power module 206 may
periodically transition between operating in a low power (or sleep)
mode and the high power mode to check the impedance between the two
of the sensing elements 61 and whether the DC voltage is provided.
This may occur every predetermined period (e.g., 30-60 seconds). In
another embodiment, in response to the two of the sensing elements
61 being attached to a patient, the power module 206 may transition
(i) from not supplying power to the control module 202, the PHY
module 204 and/or portions thereof to (ii) supplying power to the
control module 202, the PHY module 204 and/or portions thereof.
[0076] Although the modules 204, 206, 210 and the A/D converter 212
are shown as being separate from the control module 202, one or
more of the modules 204, 206, 210 and the A/D converter 212 or
portions thereof may be incorporated in the control module 202.
Signal lines 221 are shown between the sensing elements 61 and the
control module 202. A third signal line 223 may be included for
noise feedback cancellation.
[0077] Referring now to FIGS. 1-3 and FIG. 5, a stimulation probe
device 230 is shown, which may be in wireless communication with
the CIM 52 and/or one of the NIM devices 54, 162. The stimulation
probe device 230 provides pulses of current to stimulate nerves.
The stimulation probe device 230 wirelessly receives signals from
the CIM 52 and/or one of the NIM devices 54, 162 indicating timing,
amplitudes and rates for the pulses generated by the stimulation
probe device 230. The stimulation probe device 230 attempts to
provide the pulses with the indicted timing and amplitudes and at
the rate (or rates) indicated. The stimulation probe device 230
also monitors the actual timing, amplitudes and rates of the pulses
and provides feedback of this information to the CIM 52 and/or one
of the NIM devices 54, 162.
[0078] The stimulation probe device 230 includes a control module
232, a memory 234, a PHY module 236, a stimulating module 238,
electrodes 240, a power module 242, and a power source 244. The
stimulating module 238 receives power from the power module 242 and
generates stimulation signals via the electrodes 240, which are
supplied to tissue of a patient. Although the modules 236, 238, 242
are shown as being separate from the control module 232, one or
more of the modules 236, 238, 242 or portions thereof may be
incorporated in the control module 232. The stimulating module 238
may detect a voltage supplied to the electrodes 240 and/or voltage
potentials applied across two of the electrodes 240 and generate
stimulation information signals indicating the same. The
stimulating module 238 may include a current-to-voltage conversion
module 246 for measuring current supplied to one or more of the
electrodes 240 and generate a stimulation information signal
indicating the same. The stimulation information signals may be
provided to the control module 232.
[0079] The control module 232 wirelessly communicates with the CIM
52 and/or one or more of the NIM devices 54, 162 via the PHY module
236 and an antenna 248. The control module 232 includes a filtering
module 250 and a BB module 252. The filtering module 250 may
operate as a bandpass filter and filter out frequencies of the
amplified signals outside of a predetermined frequency range and a
direct current (DC) voltage. This can eliminate and/or minimize
noise, such as 60 Hz noise. The filtering module 250 may receive
stimulation information signals from the stimulating module 238 and
convert the stimulation information signals and/or signals
generated based on the stimulation information signal to BB
signals. The stimulating module 238 may monitor and indicate to the
control module 232 actual voltages, current levels, amplitudes, and
durations of stimulation pulses via the stimulation information
signals. The control module 232 may then transmit this information
via the PHY module 236 to the CIM 52 and/or one of the NIM device
54, 162.
[0080] The BB module 252 may include an analog-to-digital (A/D)
converting module 254 and convert the BB signals from the filtering
module 250 to digital BB signals. The BB module 252 and/or the A/D
converting module 254 may sample the output of the filtering module
250 at a predetermined rate to generate frames, which are included
in the digital BB signal. By A/D converting signals at the sensor
as opposed to performing an A/D conversion at the CIM 52 or one of
the NIM devices 54, 162, opportunities for signal interference is
reduced.
[0081] The BB module 252 may then upconvert the digital BB signal
to an intermediate frequency (IF) signal. The BB module 252 may
perform DSSS modulation during upconversion from the digital BB
signal to the IF signal. The BB module 252 may include a mixer and
oscillator for upconversion purposes. The BB module 252 and/or the
control module 232 may compress and/or encrypt BB signals
transmitted to the PHY module 236 prior to upconverting to IF
signals and/or may decompress and/or decrypt signals received from
the PHY module 236.
[0082] The BB module 252 may provide a received signal strength
indication (RSSI) that indicates a measured amount of power present
in a received RF signal. This may be used when determining which of
multiple CIMs and/or NIM devices to communicate with. The control
module 232 may select a CIM and/or a NIM device corresponding to a
SYNC request signal and/or a payload request signal having the most
power and/or signal strength. This may include selecting a channel
on which the SYNC request signal and/or the payload request signal
was transmitted and communicating with the CIM or the NIM device on
that channel. This allows the control module 232 to select the
closest and proper CIM and/or NIM device. This selection may be
performed when the stimulation probe device has not previously
communicated with a CIM and/or a NIM device and/or has been reset
such that the stimulation probe device does not have a record of
communicating with a CIM and/or a NIM device.
[0083] The memory 234 is accessed by the control module 232 and
stores, for example, parameters 260. The parameters 260 may include
parameters provided in SYNC request signals and/or parameters
associated with stimulation pulses generated via the electrodes
240. The parameters associated with stimulation pulses may include
voltages, wavelengths, current levels, amplitudes, peak magnitudes,
pulse durations, etc.
[0084] The PHY module 236 includes a transmit path 262 (or
transmitter) and a receiver path 264 (or receiver). The transmit
path 262 includes a modulation module 266 and an amplification
module 268. The modulation module 266 modulates the IF signal to
upconvert the IF signal to a RF signal. This may include GFSK
modulation. The modulation module 266 may include, for example, a
filter, a mixer, and an oscillator. The amplification module 268
may include a power amplifier 269, which amplifies the RF signal
and transmits the RF signal via the antenna 248.
[0085] The receiver path 262 includes a second amplification module
270 and a demodulation module 272. The second amplification module
270 may include a LNA 274. The second amplification module 270
amplifies RF signals received from the CIM. The demodulation module
272 demodulates the amplified RF signals to generate IF signals.
The IF signals are provided to the BB module 252, which then
downconverts the IF signals to BB signals. The A/D converting
module 254 may include a D/A converter to convert the BB signals to
analog signals. The RF signals received from the CIM 52 may
include, for example, SYNC request signals or portions thereof.
[0086] The power module 242 receives power from the power source
244 and supplies the power to the stimulating module 238, the
control module 232 and the PHY module 236. The power module 242 may
include a switch 276. The switch 276 may be actuated to generate
stimulation pulses. When the switch 276 is closed or toggled and/or
when the control module 232 generates a control signal commanding
generation of one or more stimulation pulses, the power module 242
and/or the control module 232 signals the stimulating module 238 to
generate the one or more stimulation pulses. The timing, amplitude,
and/or duration of each of the stimulation pulses may be based on
information received from the CIM 52 and/or one of the NIM devices
54, 162. Frequency of the stimulation pulses and/or time between
the stimulation pulses may also be controlled and based on
corresponding information received from the CIM 52 and/or one of
the NIM devices 54, 162.
[0087] Referring also to FIG. 6, which shows a portion 279 of the
stimulation probe device 230. The stimulation probe device 230
includes the control module 232, the stimulating module 238, the
electrodes 240, the power module 242 with the switch 276, and the
power source 244. The control module 232 may be connected to the
reference patch 40. In one embodiment, the stimulating module 238
is connected to the reference patch 40. The stimulating module 238
may include the current-to-voltage conversion module 246, a boost
module 280, and a D/A converter 282. The current-to-voltage
conversion module 246 converts a current supplied to the electrodes
240 to a voltage, which is detected by the control module 232. The
control module 232 may include an A/D converter to convert a
voltage signal received from the current-to-voltage conversion
module 246 to a digital signal.
[0088] The D/A converter 282 may convert an analog control signal
from the control module 232 to a digital control signal. The
digital control signal is provided to the boost module 280 and sets
a current level, a voltage, and a duration of one or more
stimulation pulses to be generated by the boost module 280 via the
electrodes 240. The boost module 280 generates stimulation signals
having the stimulation pulses to be supplied to the electrodes 240.
The stimulation signals have increase voltage, current and/or power
over other signals (e.g., signals transmitted between other modules
and/or RF signals) transmitted in the WNIM system 10. The increased
voltage, current and/or power generates the stimulation pulses to
stimulate tissue (nerve or muscle tissue) of a patient. The boost
module 280 receives power from the power module 242. The control
module 232 may control the power module 242 to supply a selected
amount of current to the boost module 280 for generation of the
stimulation signals.
[0089] The control module 232 controls sampling timing of the A/D
converter 254 and stimulation pulse timing of the D/A converter
282. The control module 232 may also control and/or perform
encryption of data generated by the stimulation probe device 230
prior to transmission of the data to the CIM 52 and/or one or more
of the NIM devices 54, 162. The control module 232 may further
control operation of the PHY module 236.
[0090] Although not shown, the reference patch 40 may be replaced
with and/or configured as a "smart" reference patch that is
configured to wirelessly communicate with the stimulation probe
device 230. The smart reference patch may, for example, be
configured similar to the sensing module 50 of FIGS. 2-3 and may
include one or more electrodes, a control module and a PHY module
having a transmitter path. The control module and the transmitter
path of the reference patch 40 may be configured similar to and
operate similar to the control module 56 and the transmit path 74
of the sensing module 50 of FIG. 2 or 3. The control module of the
reference patch 40 may be connected to the one or more electrodes
and detect and wirelessly transmit a reference voltage at the one
or more electrodes to the stimulation probe device 230. The
reference voltage may be transmitted via the transmitter path of
the reference patch 40. The control module of the reference patch
40 may generate a reference voltage signal that indicates the
reference voltage. The reference voltage may be a constant voltage
or may vary depending on the state of the patient in an area where
the reference patch 40 is attached.
[0091] The stimulating module 238 and/or the stimulation probe
device 230 may generate stimulation signals, which may be detected
via at least some of the sensing elements 61 of FIGS. 2-4 during
decompression of one or more nerves. Conduction speed (sometimes
referred to as conduction velocity or conduction rate) from when a
stimulation signal is provided via the electrodes 240 and/or at
least some of the sensing elements 61 to when a control module
(e.g., one of the control modules 56, 202) detects the stimulation
signal may be monitored. The healthier the nerve and/or tissue,
typically the quicker the conduction speed. The control module may
determine the difference in time from when the stated events occur
and based on this information determine the conduction speed.
[0092] FIGS. 7-10 show a sensor 290 that may replace any of the
sensors 12 of FIG. 1 and includes multiple layers including a top
control layer 292, an interposer layer 294 and a bottom sensing
layer 296. The top control layer 292 may include a power source
298, a control module 300, a radio 302, and/or a motion sensor 304.
The motion sensor 304 includes motion sensing elements 305. The
power sources 298 may supply power to the control module 300, the
radio 302 and/or other components in the sensor 290. The bottom
sensing layer 296 may be attached to tissue of a patient and
include one or more sensors, which may be connected to the control
module 300 by traces, vias, conductive balls, wire bonds, and/or
other conductive elements within the interposer layer 294. The
sensors may include one or more sensing arrays (two sensing arrays
306, 308 are shown) and one or more other sensors (an infrared
temperature sensor 310 and a pH sensor 312 are shown).
[0093] The sensing arrays 306, 308 and/or other sensing arrays
disclosed herein may include pins 314, which are inserted into
tissue of a patient and used to detect voltages, current levels,
impedances, and/or resistances of between selected pairs of the
pins 314 and corresponding portions of the tissue. The pins 314 may
be used to generate electromyography signals. The pins 314 may be
used as stimulation electrodes to provide stimulation pulses to the
selected portions of the tissue. The sensing arrays 306, 308 and/or
other sensing arrays discloses herein may include sensing elements
and/or devices other than the pins 314 (e.g., electrodes, needles,
conductive elements, etc.). Examples of the other sensing elements
are shown in FIGS. 11-13. The sensing arrays 306, 308 and/or other
sensing arrays discloses herein may be of various sizes and have
any number of pins. In one embodiment, the pins of the sensing
arrays 306, 308 are used to detect voltages, current levels,
impedances, and/or resistances. In another embodiment, one of the
sensing arrays 306 is used to detect voltages, current levels,
impedances, and/or resistances while the other sensing array is
used to provide stimulation pulses. In yet another embodiment,
selected pins of each of the sensing arrays 306, 308 are used to
detect voltages, current levels, impedances, and/or resistances
while the same and/or other selected pins of the sensing arrays
306, 308 are used to provide stimulation pulses.
[0094] The infrared temperature sensor 310 has infrared sensing
elements 311 (e.g., diodes capable of detecting infrared energy)
detects temperature of tissue and generates a temperature signal
indicative of the temperature. The infrared temperature sensor 310
may detect infrared energy emitted from the tissue within a
predetermined infrared band. As a nerve is decompressed, perfusion
occurs, which increases blood flow and oxygen levels and as a
result increases temperature of the tissue of and around the nerve.
Thus, the temperature of the tissue is indicative of the state of
decompression and/or level of perfusion of the tissue. In addition
or as an alternative to the infrared temperature sensor 310 a heat
sensitive camera may be used to monitor small temperature changes
associated with changes in perfusion.
[0095] The pH sensor (or neuropathy sensor) 312 includes a needle
316 and a flex circuit 318. The pH sensor 312 detects pH levels in
tissue of a patient. The needle 316 may be inserted in the tissue
when the sensor 290 is attached to the tissue. The needle 316
guides the flex circuit 318 into the patient. The flex circuit 318
may include pH sensing elements (e.g., electrodes 319) between
which current is supplied. The flex circuit 318 performs
electrochemical impedance spectroscopy techniques to measure pH
levels of target tissue. This may include supplying current to the
electrodes and monitoring changes in conductivity levels of the
tissue. Presence of different chemicals in the tissue changes
impedance of the tissue and as a result conductivity of the tissue.
For example, if tissue of a patient exhibits poor perfusion, the
patient may develop neuropathy (or diabetic neuropathy due to lack
of blood flow), which includes accumulation of nitrous oxide and
associated chemicals with nitrogen. This results in an acidic
reaction that is directly related to a pH level, which can be
detected using the flex circuit 318.
[0096] The upper control layer 292 may be covered with a silicone
based overmold material. The interposer layer 294 may be an
insulative layer including an insulative material. The bottom
sensing layer (or base layer) may be a substrate having an adhesive
material on a bottom side for attachment to tissue of a
patient.
[0097] FIGS. 11-13 show an example sensing array 320, which may
replace any of the sensing arrays disclosed in FIGS. 8-10. The
sensing array 320 includes an interposer substrate 322 and a base
substrate 324. The interposer substrate 322 may be connected to the
bottom sensing layer 296 by a first set of conductive balls (or
solder bumps) 326. As an alternative, the sensing array 320 may be
located away from the bottom sensing layer 296 and may be connected
to the bottom sensing layer 296 via conductive elements and/or a
flex circuit. The interposer substrate 322 may be connected to the
base substrate 324 by a second set of conductive balls (or solder
bumps) 328. The second set of conductive balls 328 provide
interconnections between (i) pins 330 on the base substrate 324,
and (ii) conductive elements within the interposer substrate 322.
The sensing array 320 may include any number of pins, which may be
in an array having rows and columns. Each of the rows and columns
has corresponding ones of the pins. One or more of the pins 330 may
be replaced with needles. The pins 330 may be conically-shaped as
shown. Length of the pins and/or needles may be based on whether
the pins and/or needles are being used (i) more as surface
electrodes placed above a nerve bundle of interest, or (ii) more
for selective monitoring and deeper signal detection. The pins
and/or needles may be used for monitoring prior to, during and/or
subsequent to surgery. The shorter the pins and/or needles the more
of an average of signals from a nerve bundle is generated due to
the pins and/or needles being further from, for example, neurons of
the nerve bundle.
[0098] The interposer substrate 322 includes conductive elements
connecting the first set of conductive balls 326 to the second set
of balls 328. One or more of the substrates 322, 324 may be
incorporated in the bottom sensing layer 296 of FIGS. 8-9 and/or a
substrate of the bottom sensing layer 296. The base substrate 324
may be formed of, for example, glass, silicon, sapphire, and/or
other suitable materials. The base substrate 324 and/or a portion
of the base substrate 324 may be transparent to allow for passage
of light.
[0099] The sensing array 320 may include a vertical-cavity
surface-emitting laser (VCSEL) 332 and a photodiode detector (or
other light detecting device) 334 or other optical and/or perfusion
sensor. The VCSEL 332 and the photodiode detector 334 may be
located between the substrates 322, 324 and in an area between some
of the conductive balls in the second set of conductive balls 328.
The base substrate 324 may operate as a translucent lens allowing
light emitted by the VCSEL 332 to pass through the base substrate
324 reflect off of tissue of a patient and be detected by the
photodiode detector 334. The portion of the base substrate 324 that
is transparent may be located in a center of the base substrate
324, as shown. Wire bonds 336 may connect photodiodes and/or
conductive elements of the photodiode detector 334 to conductive
elements in the interposer substrate 322. The photodiode detector
334 may have one or more photodiodes.
[0100] The VCSEL 332 and the photodiode detector 334 may be used to
detect changes in wavelength of light reflected off of tissue
and/or blood. The changes in wavelength correspond to changes in
color, which relates to changes in blood flow, pressure of blood
flow, and/or oxygen levels in the blood. As more blood flows the
pressure of the blood flow increases, which provides an increase in
a pulsified amplitude of a received signal. As another example, the
more red the color of the reflected light, the more blood flowing
in the tissue.
[0101] The sensing array 320 may be used at a skin interface, as
well as within a body of a patient. The sensing array 320 may be in
direct contact with a monitored structure within the patient. The
substrates 322, 324 may have predetermined lengths, widths and
depths (or heights). An example length L, width W, and depth D are
shown in FIG. 13. As an example, lengths and widths of the
substrates 322, 324 may be 4 millimeter (mm).times.4 mm.
[0102] In addition to being used to detect the above-stated
parameters, one or more of the pins 330 may be used to detect
temperature of tissue within the patient. Thus, each of the pins
330 may be used for multiple purposes. The pins may be used for
nerve integrity monitoring, perfusion monitoring, decompression
monitoring, etc. Impedance of tissue changes during perfusion. This
may be detected using the pins 330. Different sets of the pins 330
may be used for different purposes or each set of the pins 330 may
be used for all of the stated purposes. The pins 330 may be
inserted in muscle/tissue being monitored. Each of the pins 330 may
be used for monitoring one or more parameters. In one embodiment, a
respective number of pins are allocated for each parameter
monitored. Each parameter monitored may have a same or different
number of allocated pins.
[0103] Additional details of the wireless protocol are described
below with respect to FIGS. 14 and 15. FIG. 14 shows a signal flow
diagram illustrating a sensor 400 joining a WNIM network and
communicating in a WNIM system with a CIM and/or a NIM device
(collectively designated 402). The sensor 400 may refer to any
sensor disclosed herein. Similarly, the CIM and/or NIM device 402
may refer to any CIM and/or NIM device disclosed herein. Before a
sensor responds to a SYNC request with a data payload, a joining
process is performed. Joining establishes a link between the sensor
and a CIM and/or NIM device and together the sensor and the CIM
and/or NIM device (and/or other sensors and/or stimulation probe
devices linked to the CIM and/or NIM device) provide a WNIM
network. FIG. 14 shows an example sequence of events performed for
the sensor 400 to join the WNIM network and also how different
modes of operation are obtained.
[0104] A SYNC request signal 404 is transmitted from the CIM and/or
NIM device 402 and includes a word for each time slot in a
corresponding SYNC interval and is periodically and/or continuously
updated and transmitted to indicate the statuses of the slots. To
join the WNIM network, the sensor 400 checks all the available
slots and selects the time slot in which to transmit a data payload
signal to the CIM and/or NIM device 402. Prior to transmitting the
data payload, the sensor 400 sends a join request 406 to join the
WNIM network and communicate in the selected time slot. The join
request 406 may be transmitted in the selected time slot and
indicates a sensor unique identifier (SUID) of the sensor, the
selected time slot, the type of the sensor, a minimum data rate,
and/or a maximum data rate of the sensor. In one embodiment, the
sensor 400 sends the SUID in the selected time slot and the CIM
and/or NIM device 402 has a record of the type and data rates of
the sensor.
[0105] Based on the join request 406, the CIM and/or NIM device 402
fills an appropriate slot status word with the SUID from the sensor
400. The CIM and/or NIM device 402 may then send an updated SYNC
request 408 with the updated slot status word indicating
designation of the selected time slot to the sensor 400. The sensor
400 receives the updated SYNC request with the SUID in the
corresponding slot status word and responds by sending a data
payload to the CIM and/or the NIM device 402 in the selected slot.
If more than one slot is selected and/or designated to the sensor
400, the sensor 400 may transmit one or more data payloads in the
slots selected and/or designated to the sensor 400 (data payloads
in slot 1 are designated 410 and data payloads in other slots are
designated 411). The time slots may be associated with one or more
channels of the sensor 400. The transmission of the SYNC requests
and the data payloads may be periodically transmitted over a series
of periodic SYNC intervals (or RF frames). Once linked to the CIM
and/or NIM device 402, the sensor 400 may now be controlled by the
CIM and/or NIM device 402 via transmission of updated SYNC
requests. The CIM and/or NIM device 402 may control, for example,
output data rates and transitions between power modes of the sensor
400. As an example, the CIM and/or NIM device 402 may update the
output data rate from 10 kHz to 5 kHz for the time slot of the
sensor 400 by transmitting an updated SYNC request 412. Sensors
linked to the CIM and/or NIM device 402 inspect control bits (e.g.,
bits of the slot status words) in SYNC requests to determine
respective operating and/or power modes. The sensors then
transition to the indicated operating and/or power modes.
[0106] FIG. 15 shows a signal flow diagram illustrating a
stimulation probe device 420 joining a WNIM network and
communicating in a WNIM system to a CIM and/or NIM device
(collectively designated 422). The stimulation probe device 420 may
refer to any stimulation probe device disclosed herein. The CIM
and/or NIM device 422 may refer to any CIM and/or NIM device
disclosed herein. Generation of stimulation pulses may be initiated
at the NIM device and/or CIM 422. The NIM device may issue a
payload request with bits 15 of status words indicating generation
of a stimulation pulse. The status words may include: a CIM and/or
NIM status word; slot status words; and stimulation probe status
word. Based on the payload request, the CIM may generate a SYNC
request 424 also having bits 15 of status words set to ON to
indicate generation of a stimulation pulse. Both the payload
request and the SYNC request may indicate a delay, an amplitude of
the stimulation pulse, and/or a duration of the stimulation pulse
via corresponding words 13-15. In response to bits 15 indicating a
stimulation pulse is to be generated, one or more sensors
corresponding to the stimulation probe device 420 and/or being used
to monitor the stimulation pulse to be generated may transition to
the HIGH power mode. Upon transitioning to the HIGH power mode, the
sensors may generate and transmit data payloads at predetermined
default frequencies and/or at frequencies indicated by bits 11:10
of the status words of the SYNC request.
[0107] In response to the SYNC request 424, the stimulation probe
device 420 generates a stimulation pulse, which is provided to a
patient. To achieve an accurate timing and measurement of the
stimulation pulse in relationship to an evoked response, the delay
period provided in the SYNC request 424 is monitored by the
stimulation probe device 420. The stimulation probe device 420
generates a response signal 426 indicating the amplitude and
duration of the stimulation pulse as applied to the patient.
[0108] Subsequent to the response signal 426 from the stimulation
probe device 420, the NIM device and/or CIM 422 generates a payload
request (or SYNC request) 428 with the stimulation bits 15 low (or
OFF). In response to the received payload request (or SYNC request)
the stimulation probe device 420 sends an acknowledgement (ACK)
signal 430 to the CIM and/or NIM device 422. Generation of payload
request (or SYNC requests) and ACK signals may be repeated until a
next stimulation pulse is to be generated in which case the
stimulation process may be repeated. The repeated tasks and/or
similar tasks performed by a subsequent process are designated with
the same numbers 424, 426, 428, 430.
[0109] As described above, the CIMs, NIM devices, sensors,
reference patches, and stimulation probe devices disclosed herein
may communicate with each other using bits within payload requests,
SYNCH requests, data payloads, and response signals. The CIMs
and/or NIM devices may initiate communication by a sending a
payload request (SYNC request). The data payload may include one
16-bit word for payload validation. The 16 bit-word may include a
SUID or a stimulator unique identifier (STIMUID). When the CIM
and/or NIM device receives a data payload, the CIM and/or NIM
device compares the SUID or the STIMUID with an expected SUID or
STIMUID stored in memory of the CIM and/or NIM device. The SUID or
STIMUID may have been stored in the memory when the sensor or
stimulation probe device joined the corresponding WNIM network. If
the comparison indicates a match, the data in the data payload may
be displayed at the NIM device.
[0110] Likewise, when the sensor receives the SYNC request, the
sensor compares a console unique identifier (CUID) of the CIM
and/or NIM device provided in the SYNC request with an expected
CUID stored in a memory of the sensor. The CUID may have been
stored in the memory when the sensor joined the corresponding WNIM
network. If the comparison of the CUIDs indicates a match, the
sensor may respond, depending on mode status bits within a slot
status word of the SYNC request, with one or more data payloads in
the appropriate time slots following the SYNC request. The mode
status bits may be the bits of the slot status word indicating a
data rate and/or whether a stimulation pulse is to be
generated.
[0111] FIG. 16 shows an example implementation of the sensor 290
and/or the sensing array 320 for detecting nerve root
decompression. The sensor 290 and/or the sensing array 320 may be
located on peripheral muscle tissue 340 downstream and away from a
nerve root 342 of a nerve 344. The nerve root 342 refers to a
portion of the nerve 344 near a spinal cord 346. Although the
sensor 290 and/or the sensing array 320 are shown as being near
certain neurons 348 of the nerve, the sensor 290 and/or the sensing
array 320 may be located elsewhere. The sensor 290 may wirelessly
communicate with a CIM and/or NIM device. A signal showing this
communication is designated 349.
[0112] A decompression procedure may be performed to relieve nerve
root impingement (designated by arrows 350). Nerve conduction to
associated muscle groups is enhanced during decompression resulting
in minute and/or incremental changes in perfusion and temperature.
These are further enhanced as a healing process progresses. Sensors
disclosed herein are used for nerve integrity monitoring and to
detect these changes in perfusion and temperature.
[0113] For an evoked response, a stimulation signal may be
generated and applied to the nerve root upstream (closer to the
spinal cord) or downstream (further away from the spinal cord) than
the compressed portion of the nerve. As an example, a stimulation
probe device disclosed herein may be used to apply a stimulation
signal to the nerve root (i) between the spinal cord and the
compressed portion of the nerve, or (ii) downstream from the
compressed portion of the nerve.
[0114] The systems, devices and modules disclosed herein may be
operated using numerous methods, in addition to the methods
described above, some additional example methods are illustrated in
FIGS. 17-19. In FIG. 17, a method of operating a sensor and a CIM
and/or NIM device is shown. Although the following tasks are
primarily described with respect to the implementations of FIGS.
1-13 and 16, the tasks may be easily modified to apply to other
implementations of the present disclosure. The tasks may be
iteratively performed.
[0115] The method may begin at 500. The method may begin prior to,
during and/or subsequent to an operation and/or procedure on a
patient being performed. As an example, the method may begin prior
to, during and/or subsequent to a procedure to provide nerve root
decompression and/or decompression of a portion of a nerve. Basic
nerve root compression/decompression physiology and etiology
assumes the nerve root is impinged typically by a degenerative
spinal disc or lamina. To relieve the impingement, there are 3
common types of spinal decompression procedures: (i)
Laminotomy/foraminotomy--shaving off part of a lamina to create a
larger opening to relieve a pinched nerve; (ii)
Laminectomy--complete removal of a lamina (lamina refers to bone
over the nerve root); and (iii) Discectomy--removal of a part of a
disc that is compressing a nerve.
[0116] Nerve root activity prior to, during, and/or subsequent to
decompression is monitored using the wireless NIM systems sensors
and systems disclosed herein including detecting and displaying
changes in spectral content, temperature, acceleration values,
perfusion, pH levels, and nerve conduction speed (or velocity).
Other parameters disclosed above may also be monitored and/or
displayed. Typically, as the impingement is relieved, spectral
content decreases and nerve conduction speed increases. Wireless
NIM provides increased sensitivity to signal changes. This is at
least partially due to the elimination of "antenna effects"
associated with cables/wires of a hardwired system.
[0117] At 501, a control module (e.g., one of the control modules
56, 202) or a front end transmit module (e.g., the front end
transmit module 64) controls one or more illuminating devices
(e.g., the VCSEL 332) to generate illumination signals. The
illumination signals are emitted at tissue of concern.
[0118] At 502, signals are generated via sensing elements (e.g.,
the sensing elements 61 of FIG. 1 and/or the pins, photodiodes,
temperature sensor, motion sensor of the sensor 290 and/or sensing
array 320 of FIGS. 7-13). The signals may include electromyographic
signals, voltage signals, current signals, and/or other signals
indicative of detected parameters disclosed herein. The signals may
be generated due to, for example, generation of one or more
stimulation pulses. The stimulation pulses may be generated and
controlled by a front end transmit module (e.g., the front end
transmit module 64) of the sensor or may be generated by a
stimulation probe device operating according to, for example, the
method of FIG. 19. The stimulation pulses and/or current applied
may be modulated and controlled by the front end transmit module.
The signals are detected by a control module (e.g., one of the
control modules 56, 202). The control module may perform a fast
Fourier transform (FFT) on receive voltage signals to determine
spectral content, frequencies and corresponding amplitudes of the
signals. Predetermined frequency ranges may be monitored to detect
nerve activity (e.g., a frequency range of 10 Hertz (Hz) to 1
kilohertz (kHz) may be monitored).
[0119] At 504, a front end receive module (e.g., the front end
receive module 63) adjusts gain of the signals to generate
amplified signals. At 506, the front end receive module filters the
signals. This may include bandpass filtering amplified signals. The
filtering removes unwanted information. At 508, a BB module (e.g.,
the BB module 66) generates a BB signal based on the filtered and
amplified signals.
[0120] At 509, the baseband module and/or the control module may
determine parameters based on the amplified and/or filtered
signals. This may include determining parameters disclosed above
including impedances, resistances, current levels, voltage
potentials, pulse durations, frequencies, spectral content,
amplitudes, perfusion levels, temperatures, oxygen levels,
decompression levels, etc. The baseband module and/or control
module may quantify energy in a predetermined frequency band (e.g.,
10-1 kHz). The decompression levels may be determined based on (i)
one or more of these parameters, (ii) the quantified energy levels,
and (iii) one or more tables relating the parameters and/or
mathematical relationships between the parameters. Tables and/or
mathematical expressions may be used to determine and/or calculate
the decompression levels based on parameters, the quantified energy
levels and/or the one or more tables relating the parameters and/or
mathematical relationships between the parameters. For example,
decompression levels may be determined based on conduction speeds,
temperatures, perfusion levels, pH levels, motion signals, etc.
[0121] Prior to the baseband module upconverting signals and/or the
parameters determined at 509 and for improved signal
discrimination, any of this information may be modulated at a first
frequency, amplified and then demodulated at a second frequency.
This may be referred to as a neuromodulation process. The second
frequency is different than the first frequency. The control module
and/or baseband module may perform as a frequency selective signal
monitor and utilize a heterodyning chopper-stabilized amplifying
technique to convert a selected frequency band of a physiological
signal to baseband for analysis. The physiological signal may
include a bioelectrical signal, which may be analyzed in one or
more selected frequency bands to select a stimulation electrode
combination. The control module may analyze a characteristic of the
bioelectrical signal in the selected frequency band. The second
frequency may be selected such that the demodulation substantially
centers a selected frequency band of the signal in a baseband
frequency range.
[0122] Impedance of the tissue of concern may be measured using
stimulation currents generated prior to task 502 and modulated at
frequencies in different frequency ranges. In addition, the
stimulation current frequency that is delivered to measure
impedance may differ between patients and may depend on the region
of the patient in which the impedance is measured.
[0123] The front end receive module, front end transmit module
and/or control module may operate as an impedance sensor and
produce an alternative current (AC) modulated signal that is AC
coupled to an amplifier through the tissue of the patient. In this
case, the stimulation current is modulated to modulate amplitude of
a voltage across points of the tissue, thereby chopping the
impedance signal produced by application of the stimulation current
to the tissue. Thus, the patient is not exposed to a direct current
(DC) signal. Moreover, the modulated signal applied to the tissue
may not substantially excite the tissue, thereby decreasing a
likelihood that the patient may experience discomfort or other
detrimental effects from the modulated signal.
[0124] At 510, a modulation module (e.g., the modulation module 78)
may modulate and upconvert the resulting BB signal to generate an
RF signal. At 514, a PHY module (e.g., one of the PHY modules 60,
204) and/or an amplification module (e.g., the amplification module
80) transmits the RF signal from the sensing module to a CIM and/or
NIM device.
[0125] At 516, the CIM and/or NIM device receives the RF signal
from the sensing module and amplifies the RF signal. At 518, a
demodulation module (e.g., one of the demodulation modules 114,
176) downconverts the RF signal to generate a second BB signal. At
522, a BB module (e.g., one of the BB modules 128, 184) at the CIM
and/or NIM device may attenuate the second BB signal, as described
above. At 524, a filtering module (e.g., one of the filtering
modules 126, 186) filters the attenuated second BB signal to
generate a second filtered signal. This may include bandpass or low
pass filtering.
[0126] At 526, the second filtered signal may be provided from the
CIM to the NIM device. At 527, the CIM and/or NIM devices may
determine parameters based on the BB signal and/or filtered signal
generated at 524, 526. This may include determining parameters
disclosed above including impedances, resistances, current levels,
voltage potentials, pulse durations, frequencies, spectral content,
amplitudes, perfusion levels, temperatures, oxygen levels,
decompression levels, conduction speed, etc. The control module may
quantify energy in a predetermined frequency band (e.g., 10-1 kHz).
The decompression levels may be determined based on (i) one or more
of these parameters, (ii) the quantified energy levels, and (iii)
one or more tables relating the parameters and/or mathematical
relationships between the parameters. For example, decompression
levels may be determined based on conduction speeds, temperatures,
perfusion levels, pH levels, motion signals, etc.
[0127] At 528, the CIM and/or NIM devices may display the second
filtered signal, detected parameters and/or parameters determined
based on the detected parameters, such as the parameters determined
at 509 and 527. The filtered signal, the detected parameters,
and/or the determined parameters may be presented graphically
and/or over live images of an area of a patient as to prevent the
surgeon from removing his/her eyes from the surgical site. A plot
of energy in a band of interest may be plotted. One or more tones
of varying frequency may also be generated to indicate one or more
of the filtered signal, the detected parameters, and/or the
determined parameters. This may be done via a display (e.g., the
display 146) and/or other user interface. A numerical score may be
generated by, for example, the control module of the CIM and/or NIM
devices to indicate nerve performance. The numerical score allows a
surgeon to quickly and easily determine nerve performance. The
nerve performance may be based on intrinsic activity of the nerve
and/or external stimulus. The nerve performance may be related to
monitoring naturally occurring nerve activity and/or monitoring the
nerve itself without generation of stimulation pulses/signals. In
addition or alternatively, the nerve performance may be an evoked
response to stimulation pulses/signals. The nerve performance may
be based on EMG activity from an associated muscle group,
mechanical movement (detectable via a motion sensor), temperature
change, color change, etc. As similar method as that shown with
respect to FIG. 17 may be performed for data requested and received
from a stimulation probe device.
[0128] The control modules of the CIM and/or NIM devices may:
determine baseline values for one or more of the parameters
disclosed herein; during or subsequent to a surgery, compare the
baseline values respectively to detected values of the one or more
parameters; and based on the comparisons, generate signals or
indicate whether positive results exist for tasks performed during
the surgery. As an example, a positive result may indicate whether
a certain amount of nerve decompression has occurred. Differences
between the baseline values and the detected values and/or
differences between the baseline values and values generated based
on the detected values may be compared to predetermined values
and/or ranges corresponding to positive results. The baseline
values and detected values may be aggregated and analyzed as a
whole to determine results of a surgery or one or more tasks
performed during surgery. The results may be displayed in real time
during and/or subsequent to the surgery. The predetermined values
and/or ranges may correspond to a degree of nerve decompression,
correspond to full nerve decompression, or other positive result.
As an example, the differences may indicate an extent of nerve
decompression and/or whether nerve decompression has not occurred.
The baseline values may be measured values that are measured prior
to, at a beginning, during, at an end of and/or subsequent to a
surgery and may be based on feedback signals generated by any of
the sensors disclosed herein. The method may end at 530.
[0129] The above-described method of monitoring decompression
subsequent to surgery is beneficial because compressed nerves may
not immediately response to decompression. It may be months after
surgery for a full recovery and the nerves to be fully
decompressed. The described method may also be beneficial to
indicate when nerve recovery has reached a plateau or peak level.
In an intra-operative scenario, there may be an immediate change in
nerve performance. In this case, a surgeon may be notified in real
time using the above-described method of nerve performance.
[0130] In FIG. 18, a method of powering-up a sensor is shown.
Although the following tasks are primarily described with respect
to the implementations of FIGS. 1-13, the tasks may be easily
modified to apply to other implementations of the present
disclosure. The tasks of FIG. 18 may be iteratively performed. The
method may begin at 550.
[0131] At 552, an electromyographic signal is generated and/or an
impedance between electrodes decreases due to attachment of the
sensor to a patient. At 554, a power module (e.g., the power module
206) determines whether the impedance is less than a predetermined
impedance (or threshold). If the impedance is less than the
predetermined impedance, task 560 may be performed as shown, or
alternatively task 556 may be performed. If the impedance is
greater than or equal to the predetermined impedance, one or more
of tasks 560, 561, 562, 564 may be performed. Although tasks 560,
561, 562, 564 are shown, any one of the tasks may not be performed
and/or may be skipped. Also, tasks 560, 561, 562, 564 may be
performed in a different order.
[0132] At 560, a control module (e.g., one of the control modules
56, 202) determines whether a DC voltage (may be referred to as an
output voltage or output voltage signal) has been received from a
power module (e.g., the power module 206), as described above. If a
DC voltage is not received task 556 may be performed. If a DC
voltage is received, task 561 is performed.
[0133] At 556, a sensing module of the sensor transitions to a LOW
power mode or a HIGH power mode, which may include powering ON a
portion, all, or a remaining portion of the control module and/or
the PHY module. As an example, if a stimulation pulse is to be
generated, the power module may transition to the HIGH power mode
and power ON all or a remaining portion of the control module
and/or the PHY module that are not already powered ON. Subsequent
to task 556, the method may end at 558. Subsequent to task 556, the
control module may proceed to, for example, task 504 of FIG.
17.
[0134] At 561, the power module may determine whether a voltage
potential across the electrodes is greater than a predetermined
voltage and/or has a magnitude that is greater than a predetermined
magnitude. If the voltage potential is greater than the
predetermined voltage and/or the magnitude is greater than the
predetermined magnitude, task 556 may be performed; otherwise task
562 may be performed. In one embodiment, a stimulation probe device
is used to activate sensors. The stimulation probe device generates
an initial stimulation pulse to active the sensors. Additional
stimulation pulses may be generated after the sensors are
activated. The power module may detect the initial stimulation
pulse by monitoring the voltage at the electrodes and/or amplified
signals generated based on the voltage detected at the
electrodes.
[0135] At 562, the power module may determine whether an amount of
current received from one of the electrodes is greater than a
predetermined current level. If the amount of current is greater
than the predetermined current level, task 556 may be performed;
otherwise task 564 may be performed. As stated above, a stimulation
probe device may generate an initial stimulation pulse to activate
sensors. The power module may detect the initial stimulation pulse
by monitoring current received from one or more of the electrodes
and/or amplified signals generated based on the current received
from the one or more electrodes. In one embodiment, tasks 561
and/or 562 are performed and tasks 554 and/or 560 are not
performed.
[0136] At 564, the power module refrains from generating the output
voltage (or output signal) and the sensing module refrains from
transitioning to the low power mode or the high power mode and
remains in the sleep mode and/or low power mode. Subsequent to task
564, task 552 may be performed as shown or the method may end at
558.
[0137] In FIG. 19, a WNIM method of operating a stimulation probe
device, one or more sensors, and a console interface module and/or
NIM device is shown. Although the following tasks are primarily
described with respect to the implementations of FIGS. 1-13 and 16,
the tasks may be easily modified to apply to other implementations
of the present disclosure. The tasks of FIG. 19 may be iteratively
performed. The following tasks provide an example of initial
power-ON and continuous and initial generation of periodic SYNC
requests. The method may begin at 600. At 602, sensors and one or
more stimulation probe devices receive one or more SYNC requests
from one or more CIMs and/or NIM devices. The control modules of
the NIM devices may generate payload request signals requesting
data payloads from sensors and stimulation probe devices. The
control modules of the CIMs may each generate a SYNC request
signal, which may be transmitted periodically (e.g., once every
predetermined or SYNC) period).
[0138] At 604, a stimulation probe device selects a broadcast
channel of one of the SYNC requests based on, signal strengths of
the SYNC requests as received by the stimulation probe device. The
stimulation probe device may hop through channels in a table to
receive the SYNC requests. The broadcast channel of the SYNC
request with the greatest signal strength is selected. The
stimulation probe device may determine whether there is more than
one stimulation probe device in the WNIM network of the selected
SYNC request. If there is more than one stimulation probe device,
an available time slot is selected by the stimulation probe device
that is joining the WNIM network. This may be accomplished similar
to how a sensor selects a time slot, as described above.
[0139] At 605, the stimulation probe device joining the WNIM
network determines that a stimulation pulse is not to be generated
based on corresponding status bits of the SYNC request of the
selected broadcast channel. At 606, the stimulation probed device
sends an ACK signal to the CIM and/or a NIM device of the selected
broadcast channel.
[0140] At 607, the stimulation probe device receives an updated
SYNC request from the CIM and/or NIM device of the selected
broadcast channel.
[0141] At 608, the stimulation probe device that has joined the
WNIM network determines whether a stimulation pulse is to be
generated based on corresponding status bits of the updated SYNC
request of the selected broadcast channel. If a stimulation pulse
is requested to be generated, task 610 is performed, otherwise task
609 is performed. At 609, the stimulation pulse device sends an ACK
signal to the CIM and/or NIM device of the selected broadcast
channel.
[0142] At 610, the stimulation pulse device generates a stimulation
pulse signal based on stimulation information words in the SYNC
request. The stimulation pulse signal may be provided to electrodes
(e.g., electrodes 240), which may include pin style electrodes;
"cuff" style electrodes, or other suitable electrodes. The
stimulation pulse signal may be generated according to a delay
period, an amplitude, and/or a duration provided in the SYNC
request. The stimulation pulse signal may include a modulated
stimulation current that creates a voltage potential between points
on tissue of a patient. The modulation of the stimulation current
may be controlled by a control module of the stimulation probe
device. The stimulation pulse signal is applied to evoke a response
from a nerve. Conduction velocity may be determined based on time
between (i) when the stimulation probe signal is generated and/or
applied and (ii) when a sensor (e.g., the sensor 290) detects the
evoked response. The conduction velocity may be determined, for
example during one of the tasks 509, 527.
[0143] At 612, the stimulation probe device reports a measured (or
detected) amplitude and duration of the generated stimulation pulse
to the CIM and/or the NIM device in a designated time slot of the
periodic SYNC interval. This may occur in the same periodic SYNC
interval as the SYNC request. Task 607 may be performed subsequent
to task 612 or the method may end at 630 as shown.
[0144] At 620, each of the sensing modules selects a broadcast
channel of a SYNC request with greatest signal strength. The
sensing modules may hop through channels in tables stored in the
sensing modules to find and select the broadcast channel. At 622,
each of the sensing modules of the sensors selects one or more time
slots and/or checks statuses of time slots as indicated in the SYNC
request of the selected broadcast channel. If a sensing module has
not linked up previously to the CIM and/or the NIM device
communicating the selected broadcast channel, then the sensing
module selects an available time slot. If a sensing module has
previously linked up to the CIM and/or NIM device, then the sensing
module checks a status of the previously selected time slot to
assure that the time slot is still designated to the sensing
module. If the time slot is no longer designated to the sensing
module, the sensing module may select another available time
slot.
[0145] Multiple time slots may be designated to a sensing module
based on a type of the corresponding sensor without the sensing
module having previously requested multiple time slots. For
example, if the sensor has multiple channels and/or is to be
assigned multiple time slots, the CIM and/or NIM device may update
slot status words accordingly based on a single slot request. The
sensing module may then detect that multiple slots have been
assigned during review of slot status words in a subsequent SYNC
request.
[0146] At 624, the sensing modules may send data payloads in the
respectively selected time slots. This serves dual purposes. In
addition to providing data corresponding to signals detected at
electrodes of the sensors, the sent data payloads serve as a
request for the selected time slots. At 626, the sensing modules
may receive a next updated SYNC request from the CIM and/or NIM
device. The next updated SYNC request may indicate SUIDs of the
sensing modules in slot status words. Task 626 may be performed
while task 607 is performed. Tasks 626 and 607 may refer to the
same updated SYNC request.
[0147] At 628, the sensing modules send data payloads in the
designated time slots according to the updated SYNC request to the
CIM and/or NIM device. Task 628 may be performed subsequent to task
610. Task 626 may be performed subsequent to task 628 or the method
may end at 630 as shown. Although not shown in FIG. 19, some of the
tasks may be iteratively performed for subsequent SYNC request
signals and/or generation of additional stimulation pulses.
[0148] The above-described tasks of FIGS. 17-19 are meant to be
illustrative examples; the tasks may be performed sequentially,
synchronously, simultaneously, continuously, during overlapping
time periods or in a different order depending upon the
application. Also, any of the tasks may not be performed or skipped
depending on the implementation and/or sequence of events.
[0149] A method of operating a sensor is disclosed herein. The
method includes: detecting a first parameter of a tissue of a
patient via a first sensing element of the sensor; generating a
first signal indicative of the first parameter; monitoring a second
parameter of the tissue based on a second signal received from an
array of pins or needles, where the array of pins or needles is
configured to be inserted in the tissue, and where the array of
pins or needles are separate from the first sensing element;
generating a third signal based on the first signal and the second
parameter, where the third signal is indicative of a level of
decompression of a nerve of the patient; and wirelessly
transmitting the third signal from the sensor to a console
interface module or a nerve integrity monitoring device.
[0150] The method may include determining the level of
decompression based on the first signal and the second signal,
where the third signal indicates the level of decompression. The
method may further include: receiving power from a power source
within the sensor and at a front end module; and generating a
stimulation signal to be applied to the tissue via the array of
pins or needles, where the first signal is indicative of a
temperature of the tissue, an oxygen level of the tissue, or a pH
level of the tissue, and the second signal is an evoked response to
the stimulation signal and is an electromyography signal.
[0151] The method may include: generating a motion signal
indicative of muscle activity; and generating a pH signal
indicative of a pH level of the tissue, where the first signal is
indicative of a temperature of the tissue; determining a perfusion
level based on the first signal or the second signal; determining a
conduction speed based on the second signal and a time when a
stimulation signal was previously generated; receiving the motion
signal; emitting light via a light emitting device at the tissue;
detecting portions of the light reflected off of the tissue;
generating a fourth signal indicative of a wavelength and
corresponding intensity of the light reflected off of the tissue;
and generating the third signal based on the motion signal, the pH
level, the perfusion level, the conduction speed and the fourth
signal.
[0152] The method may include emitting light through the at least a
portion of a first substrate and at the tissue, where the array of
pins or needles are included in a sensing array, and where the
sensing array includes (i) the first substrate attached to the
array of pins or needles, wherein at least a portion of the first
substrate is transparent, and (ii) a second substrate connected to
the first substrate by conductive elements. The method may further
include: detecting a reflected portion of the light reflected back
through the first substrate; generating a fourth signal based on
the detected reflected portion of the light reflected back through
the first substrate; and generating the third signal based on the
fourth signal.
[0153] The method may include: monitoring the second parameter and
a third parameter of the tissue based on a fourth signal received
from a second array of pins or needles; and generating the third
signal based on the second parameter and the third parameter.
[0154] The method may include: generating a payload request at the
nerve integrity monitoring device, wherein the payload request (i)
requests a data payload from the sensor in a wireless nerve
integrity monitoring network, and (ii) indicates whether a
stimulation probe device is to generate a stimulation pulse;
wirelessly transmitting the payload request to the sensor and the
stimulation probe device or transmitting the payload request to the
console interface module; and in response to the payload request,
(i) receiving the data payload from the sensor at the nerve
integrity monitoring device, and (ii) receiving stimulation pulse
information from the stimulation probe device. The third signal
includes the data payload. The data payload includes data
corresponding to an evoked response of the patient. The evoked
response is generated based on the stimulation pulse.
[0155] The method may include: receiving a payload request from the
nerve integrity monitoring device at the console interface module;
generating a synchronization request including information in the
payload request, wherein the synchronization request (i) requests a
data payload from the sensor in a wireless nerve integrity
monitoring network, and (ii) indicates whether a stimulation probe
device is to generate a stimulation pulse; wirelessly transmitting
the synchronization request to the sensor and the stimulation probe
device; and in response to the synchronization request, (i)
wirelessly receiving the data payload from the sensor, and (ii)
wirelessly receiving stimulation pulse information from the
stimulation probe device. The third signal includes the data
payload. The data payload includes data corresponding to an evoked
response of the patient. The evoked response is generated based on
the stimulation pulse.
[0156] The method may include: determining baseline values for the
first parameter and the second parameter; during or subsequent to a
surgery, comparing the baseline values respectively to the first
parameter and the second parameter; and based on the comparisons,
generating the third signal or indicating whether positive results
exist for tasks performed during the surgery. The systems and
methods disclosed herein may be used for monitoring decompression
pre, during and post an operation and/or procedure. The sensors may
be used on brain tissue, muscle tissue, nerve tissue, and/or other
tissue of a patient. The systems and methods may be used to monitor
decompression of nerves near or at a predetermined distance away
from a spinal cord.
[0157] The wireless communication and corresponding systems and
devices disclosed herein provide several advantages. For example,
the wireless communication and corresponding systems and devices
provide improved signal-to-noise ratios due at least partially to
elimination of large loops of wire associated with traditional
systems. The wireless communication and corresponding systems and
devices also electrically isolate a patient from monitoring
devices. This provides improved safety by minimizing the amount of
electrical current that may be supplied to a patient.
[0158] The wireless communications described in the present
disclosure can be conducted in full or partial compliance with IEEE
standard 802.11-2012, IEEE standard 802.16-2009, IEEE standard
802.20-2008, and/or Bluetooth Core Specification v4.0. In various
implementations, Bluetooth Core Specification v4.0 may be modified
by one or more of Bluetooth Core Specification Addendums 2, 3, or
4. In various implementations, IEEE 802.11-2012 may be supplemented
by draft IEEE standard 802.11ac, draft IEEE standard 802.11ad,
and/or draft IEEE standard 802.11ah.
[0159] The foregoing description is merely illustrative in nature
and is in no way intended to limit the disclosure, its application,
or uses. The broad teachings of the disclosure can be implemented
in a variety of forms. Therefore, while this disclosure includes
particular examples, the true scope of the disclosure should not be
so limited since other modifications will become apparent upon a
study of the drawings, the specification, and the following claims.
It should be understood that one or more steps within a method may
be executed in different order (or concurrently) without altering
the principles of the present disclosure. Further, although each of
the embodiments is described above as having certain features, any
one or more of those features described with respect to any
embodiment of the disclosure can be implemented in and/or combined
with features of any of the other embodiments, even if that
combination is not explicitly described. In other words, the
described embodiments are not mutually exclusive, and permutations
of one or more embodiments with one another remain within the scope
of this disclosure.
[0160] Spatial and functional relationships between elements (for
example, between modules, circuit elements, semiconductor layers,
etc.) are described using various terms, including "connected,"
"engaged," "coupled," "adjacent," "next to," "on top of," "above,"
"below," and "disposed." Unless explicitly described as being
"direct," when a relationship between first and second elements is
described in the above disclosure, that relationship can be a
direct relationship where no other intervening elements are present
between the first and second elements, but can also be an indirect
relationship where one or more intervening elements are present
(either spatially or functionally) between the first and second
elements. As used herein, the phrase at least one of A, B, and C
should be construed to mean a logical (A OR B OR C), using a
non-exclusive logical OR, and should not be construed to mean "at
least one of A, at least one of B, and at least one of C."
[0161] In this application, including the definitions below, the
term "module" or the term "controller" may be replaced with the
term "circuit." The term "module" may refer to, be part of, or
include: an Application Specific Integrated Circuit (ASIC); a
digital, analog, or mixed analog/digital discrete circuit; a
digital, analog, or mixed analog/digital integrated circuit; a
combinational logic circuit; a field programmable gate array
(FPGA); a processor circuit (shared, dedicated, or group) that
executes code; a memory circuit (shared, dedicated, or group) that
stores code executed by the processor circuit; other suitable
hardware components that provide the described functionality; or a
combination of some or all of the above, such as in a
system-on-chip.
[0162] The module may include one or more interface circuits. In
some examples, the interface circuits may include wired or wireless
interfaces that are connected to a local area network (LAN), the
Internet, a wide area network (WAN), or combinations thereof. The
functionality of any given module of the present disclosure may be
distributed among multiple modules that are connected via interface
circuits. For example, multiple modules may allow load balancing.
In a further example, a server (also known as remote, or cloud)
module may accomplish some functionality on behalf of a client
module.
[0163] The term code, as used above, may include software,
firmware, and/or microcode, and may refer to programs, routines,
functions, classes, data structures, and/or objects. The term
shared processor circuit encompasses a single processor circuit
that executes some or all code from multiple modules. The term
group processor circuit encompasses a processor circuit that, in
combination with additional processor circuits, executes some or
all code from one or more modules. References to multiple processor
circuits encompass multiple processor circuits on discrete dies,
multiple processor circuits on a single die, multiple cores of a
single processor circuit, multiple threads of a single processor
circuit, or a combination of the above. The term shared memory
circuit encompasses a single memory circuit that stores some or all
code from multiple modules. The term group memory circuit
encompasses a memory circuit that, in combination with additional
memories, stores some or all code from one or more modules.
[0164] The term memory circuit is a subset of the term
computer-readable medium. The term computer-readable medium, as
used herein, does not encompass transitory electrical or
electromagnetic signals propagating through a medium (such as on a
carrier wave); the term computer-readable medium may therefore be
considered tangible and non-transitory. Non-limiting examples of a
non-transitory, tangible computer-readable medium are nonvolatile
memory circuits (such as a flash memory circuit, an erasable
programmable read-only memory circuit, or a mask read-only memory
circuit), volatile memory circuits (such as a static random access
memory circuit or a dynamic random access memory circuit), magnetic
storage media (such as an analog or digital magnetic tape or a hard
disk drive), and optical storage media (such as a CD, a DVD, or a
Blu-ray Disc).
[0165] The apparatuses and methods described in this application
may be partially or fully implemented by a special purpose computer
created by configuring a general purpose computer to execute one or
more particular functions embodied in computer programs. The
apparatuses and methods may be implemented in, for example, a
handheld instrument, a tablet, a smart phone, a cellular phone,
and/or other computing device. The functional blocks, flowchart
components, and other elements described above serve as software
specifications, which can be translated into the computer programs
by the routine work of a skilled technician or programmer.
[0166] The computer programs include processor-executable
instructions that are stored on at least one non-transitory,
tangible computer-readable medium. The computer programs may also
include or rely on stored data. The computer programs may encompass
a basic input/output system (BIOS) that interacts with hardware of
the special purpose computer, device drivers that interact with
particular devices of the special purpose computer, one or more
operating systems, user applications, background services,
background applications, etc.
[0167] The computer programs may include: (i) descriptive text to
be parsed, such as HTML (hypertext markup language) or XML
(extensible markup language), (ii) assembly code, (iii) object code
generated from source code by a compiler, (iv) source code for
execution by an interpreter, (v) source code for compilation and
execution by a just-in-time compiler, etc. As examples only, source
code may be written using syntax from languages including C, C++,
C#, Objective C, Haskell, Go, SQL, R, Lisp, Java*, Fortran, Perl,
Pascal, Curl, OCaml, Javascript.RTM., HTML5, Ada, ASP (active
server pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby,
Flash.RTM., Visual Basic.RTM., Lua, and Python.RTM..
[0168] None of the elements recited in the claims are intended to
be a means-plus-function element within the meaning of 35 U.S.C.
.sctn.112(f) unless an element is expressly recited using the
phrase "means for," or in the case of a method claim using the
phrases "operation for" or "step for."
* * * * *