U.S. patent application number 17/086008 was filed with the patent office on 2021-08-12 for methods and apparatuses for measuring multiple vital signs based on arterial pressure waveforms.
The applicant listed for this patent is OSLERMD, INC.. Invention is credited to John Richard Gelm, Bahman Khatam.
Application Number | 20210244289 17/086008 |
Document ID | / |
Family ID | 1000005553021 |
Filed Date | 2021-08-12 |
United States Patent
Application |
20210244289 |
Kind Code |
A1 |
Khatam; Bahman ; et
al. |
August 12, 2021 |
METHODS AND APPARATUSES FOR MEASURING MULTIPLE VITAL SIGNS BASED ON
ARTERIAL PRESSURE WAVEFORMS
Abstract
Vital sign sensor apparatuses which measures vital signs based
on arterial pressure waveforms are described. In some embodiments,
the apparatus includes an infrared sensor configured to capture at
least a portion of an arterial pulse pressure waveform from a user.
The apparatus further includes a processor configured to determine
a maximum point for each of a plurality of peaks of the arterial
pulse pressure waveform, and a corresponding first timestamp. The
processor also determines one or more vital signs (e.g., a heart
rate for a user, a heart rate variation of the user, a respiration
rate of the user, and/or an arterial pulse pressure of the user)
based at least in part on the plurality of maximum points and the
plurality of corresponding timestamps. Related systems, methods,
and articles of manufacture are also described.
Inventors: |
Khatam; Bahman; (Escondido,
CA) ; Gelm; John Richard; (Coronado, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OSLERMD, INC. |
San Diego |
CA |
US |
|
|
Family ID: |
1000005553021 |
Appl. No.: |
17/086008 |
Filed: |
October 30, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15249257 |
Aug 26, 2016 |
10856743 |
|
|
17086008 |
|
|
|
|
62258694 |
Nov 23, 2015 |
|
|
|
62211604 |
Aug 28, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/7278 20130101;
A61B 5/14552 20130101; A61B 5/0816 20130101; A61B 5/02405 20130101;
A61B 5/0205 20130101; A61B 5/318 20210101; A61B 5/02416 20130101;
A61B 5/02108 20130101; A61B 5/02028 20130101; A61B 5/6826 20130101;
A61B 5/14551 20130101; A61B 5/02433 20130101; A61B 5/0245 20130101;
A61B 5/7282 20130101 |
International
Class: |
A61B 5/0205 20060101
A61B005/0205; A61B 5/02 20060101 A61B005/02; A61B 5/00 20060101
A61B005/00; A61B 5/021 20060101 A61B005/021 |
Claims
1-21. (canceled)
22. An apparatus for remotely monitoring a health of a user, the
apparatus comprising: a sensor configured to capture an electrical
signal from the user, the electrical signal comprising a plurality
of groups of related points; and a processor coupled to the sensor,
the processor configured to cause operations comprising:
determining whether to calculate a maximum pressure value or a
minimum pressure value for each of the plurality of groups of
related points; determining, based on a determination to calculate
the maximum pressure value, the maximum pressure value for each of
the plurality of groups of related points, wherein the
determination of the maximum pressure value comprises: determining
for a current group of the plurality of groups of related points of
the electrical signal, whether a current sample has a current
maximum pressure value that is greater than a prior maximum
pressure value from a prior sample within the current group of
related points that was previously received by the sensor; storing
the current maximum pressure value when the current maximum
pressure value is greater than the prior maximum pressure value;
and setting the stored current maximum pressure value as the
maximum pressure value when the current maximum pressure value of a
threshold number of samples is not greater than the stored current
maximum pressure value; determining, based at least in part on the
maximum pressure values, vital sign information indicative of the
health of the user; determining, based on the vital sign
information, that an alert condition is met; and providing, to at
least a member of a medical team of the user and based on the
determination that the alert condition is met, an alert indicating
that the alert condition has been met.
23. The apparatus of claim 22, wherein the electrical signal
comprises an arterial pulse pressure waveform.
24. The apparatus of claim 22, wherein the vital sign information
comprises one or more of a heart rate of the user, a heart rate
variation of the user, and a respiration rate of the user.
25. The apparatus of claim 24, wherein determining the vital sign
information comprises generating a plurality of peak rates by at
least subtracting, for each of the plurality of groups of related
points, a first timestamp of the maximum pressure value of an
immediately preceding group of related points from a second
timestamp of the maximum pressure value of an immediately
subsequent group of related points.
26. The apparatus of claim 25, wherein determining the vital sign
information further comprises averaging the plurality of peak
rates.
27. The apparatus of claim 25, wherein determining the vital sign
information comprises: determining a maximum rate from the
plurality of peak rates; determining a minimum rate from the
plurality of peak rates; and determining a standard deviation from
the plurality of peak rates.
28. The apparatus of claim 24, wherein determining the vital sign
information comprises determining a fundamental frequency of the
electrical signal.
29. The apparatus of claim 22, wherein the operations further
comprise: determining to calculate the minimum pressure value;
determining, for each of a plurality of troughs of the electrical
signal, the minimum pressure value; determining, for each of the
minimum pressure values, a first timestamp; and wherein the
determining the vital sign information is further based at least in
part the plurality of minimum pressure values and the first
timestamp of each of the minimum pressure values.
30. The apparatus of claim 22, wherein the sensor is configured to
capture the electrical signal from the user's finger by providing
signals from a light emitting diode; and measuring reflections via
a phototransistor.
31. The apparatus of claim 30, further comprising: a peripheral
capillary oxygen saturation sensor configured to measure oxygen
saturation from the user's second finger; and one or more
electrocardiography sensors configured to measure an
electrocardiography waveform from the user's third finger.
32. The apparatus of claim 23, wherein the operations further
comprise: determining, based at least in part on the arterial
pressure waveform, an arterial audio waveform; and determining,
based at least in part on the arterial pressure waveform and the
arterial audio waveform, one or more cardiac events of the user,
wherein the one or more cardiac events comprises at least one of an
aortic valve opening or closing, a mitral valve opening or closing,
an isovolumetric contraction or relaxation, an ejection, a rapid
inflow, diastasis, and an atrial systole.
33. The apparatus of claim 22, wherein the alert condition
comprises a vital sign value being greater than or equal to a
predefined threshold vital sign value.
34. A method for remotely monitoring a health of a user, the method
comprising: capturing, via a sensor, an electrical signal from the
user, the electrical signal comprising a plurality of groups of
related points; determining, via a processor in communication with
the sensor, whether to calculate a maximum pressure value or a
minimum pressure value for each of the plurality of groups of
related points; determining, based on a determination to calculate
the maximum pressure value, the maximum pressure value for each of
the plurality of groups of related points, wherein the
determination of the maximum pressure value comprises: determining
for a current group of the plurality of groups of related points of
the electrical signal, whether a current sample has a current
maximum pressure value that is greater than a prior maximum
pressure value from a prior sample within the current group of
related points that was previously received by the sensor; storing
the current maximum pressure value when the current maximum
pressure value is greater than the prior maximum pressure value;
and setting the stored current maximum pressure value as the
maximum pressure value when the current maximum pressure value of a
threshold number of samples is not greater than the stored current
maximum pressure value; determining, based at least in part on the
maximum pressure values, vital sign information indicative of the
health of the user; determining, based on the vital sign
information, that an alert condition is met; and providing, to at
least a member of a medical team of the user and based on the
determination that the alert condition is met, an alert indicating
that the alert condition has been met.
35. The method of claim 34, wherein the electrical signal comprises
an arterial pulse pressure waveform.
36. The method of claim 34, wherein the vital sign information
comprises one or more of a heart rate of the user, a heart rate
variation of the user, and a respiration rate of the user.
37. The method of claim 36, wherein determining the vital sign
information comprises generating a plurality of peak rates by at
least subtracting, for each of the plurality of groups of related
points, a first timestamp of the maximum pressure value of an
immediately preceding group of related points from a second
timestamp of the maximum pressure value of an immediately
subsequent group of related points.
38. The method of claim 37, wherein determining the vital sign
information further comprises averaging the plurality of peak
rates.
39. The method of claim 37, wherein determining the vital sign
information comprises: determining a maximum rate from the
plurality of peak rates; determining a minimum rate from the
plurality of peak rates; and determining a standard deviation from
the plurality of peak rates.
40. The method of claim 34, wherein the alert condition comprises a
vital sign value being greater than or equal to a predefined
threshold vital sign value.
41. A non-transitory computer program product storing instructions
which, when executed by at least one hardware data processors,
result in operations comprising: capturing, via a sensor, an
electrical signal from the user, the electrical signal comprising a
plurality of groups of related points; determining, via a processor
in communication with the sensor, whether to calculate a maximum
pressure value or a minimum pressure value for each of the
plurality of groups of related points; determining, based on a
determination to calculate the maximum pressure value, the maximum
pressure value for each of the plurality of groups of related
points, wherein the determination of the maximum pressure value
comprises: determining for a current group of the plurality of
groups of related points of the electrical signal, whether a
current sample has a current maximum pressure value that is greater
than a prior maximum pressure value from a prior sample within the
current group of related points that was previously received by the
sensor; storing the current maximum pressure value when the current
maximum pressure value is greater than the prior maximum pressure
value; and setting the stored current maximum pressure value as the
maximum pressure value when the current maximum pressure value of a
threshold number of samples is not greater than the stored current
maximum pressure value; determining, based at least in part on the
maximum pressure values, vital sign information indicative of the
health of the user; determining, based on the vital sign
information, that an alert condition is met; and providing, to at
least a member of a medical team of the user and based on the
determination that the alert condition is met, an alert indicating
that the alert condition has been met.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/211,604 filed Aug. 28, 2015 and entitled
APPARATUS USING AN INFRARED SENSOR TO ACQUIRE, PROCESS, ANALYZE,
AND EXTRACT CARDIOVASCULAR AND PULMONARY BIOMETRICS FROM AN
ARTERIAL PRESSURE WAVEFORM and U.S. Provisional Application No.
62/258,694 filed Nov. 23, 2015 and entitled INTEGRATING MULTIPLE
MEDICAL VITAL SIGNS SENSORS INTO A WIRELESS HEALTH AND MEDICAL
APPARATUS PLATFORM IN CONJUNCTION WITH MEDICAL DEVICES, SMART
APPLICATION, CLOUD STORAGE, AND BACKEND DATABASE, the disclosures
of which are incorporated herein by reference.
FIELD
[0002] The subject matter disclosed herein relates to wireless
medical sensors for monitoring a user's health and/or vital signs
and/or infrared monitoring of cardiovascular and pulmonary
biometrics from arterial pressure waveforms.
BACKGROUND
[0003] With the rapid growth in the field of mobile health and
telemedicine there is an increasing demand for more integrated,
less fragmented, with little, or no, calibration required, as well
as non-invasive ways to collect patients' health and medical vital
signs from the onboard sensors quickly such as in less than 30
seconds after the valid detection of signals in various settings or
use environment.
[0004] Extracting and monitoring medical signs from hemodynamic
waveforms can provide insight to the quality of heart functioning
and the detection of current and impending cardiac and pulmonary
conditions. Early detection can enable a quicker realization of an
unhealthy heart condition thus triggering early intervention and
preventative strategies
SUMMARY
[0005] Vital sign sensor apparatuses which measures vital signs
based on arterial pressure waveforms are described. In some
embodiments, the apparatus includes an infrared sensor configured
to capture at least a portion of an arterial pulse pressure
waveform from a user. The apparatus further includes a processor
configured to determine, for each of a plurality of peaks of the
arterial pulse pressure waveform, a maximum point. The processor is
further configured to determine, for each of the maximum points, a
corresponding first timestamp. The processor is further configured
to determine one or more vital signs based at least in part on the
plurality of maximum points and the plurality of corresponding
timestamps. In various embodiments, the one or more vital signs
includes at least one of a heart rate for a user, a heart rate
variation of the user, a respiration rate of the user, and an
arterial pulse pressure of the user.
[0006] In some embodiments, the above-noted aspects may further
include features described herein, including one or more of the
following: determining the heart rate by generating a plurality of
peak rates by subtracting, for each of the plurality of peaks, the
corresponding first timestamp of a most recent peak from the
corresponding first timestamp of the current peak; determining the
heart rate by averaging the plurality of peak rates; determining
the heart rate by determining a maximum rate from the plurality of
peak rates, determining a minimum rate from the plurality of peak
rates, and/or determining a standard deviation from the plurality
of peak rates; determining the respiration rate by determining a
fundamental frequency of the arterial pulse pressure waveform. In
some embodiments, determining the maximum point includes
determining, for a plurality of subsequent samples of the arterial
pulse pressure waveform, whether a current sample is greater in
pressure than a prior sample, storing the current sample when the
current sample is greater in pressure than the prior sample,
determining whether a threshold number of subsequent samples are
not greater than the maximum point, and setting the stored sample
as the maximum point when the threshold number of subsequent
samples are not greater than the maximum point.
[0007] In various embodiments, the processor can be further
configured to determine, for each of a plurality of troughs of the
arterial pulse pressure waveform, a minimum point, determine, for
each of the minimum points, a corresponding second timestamp,
and/or determine the one or more vital signs based at least in part
the plurality of minimum points and the plurality of corresponding
second timestamps. In certain embodiments, the infrared sensor is
configured to capture the at least the portion of the arterial
pulse pressure waveform from the user's finger via providing
signals from a light emitting diode and measuring reflections via a
phototransistor. Additionally or alternatively, the apparatus
further includes a peripheral capillary oxygen saturation sensor
configured to measure oxygen saturation from a user's second
finger, and one or more electrocardiography sensors configured to
measure an electrocardiography waveform from a user's third finger,
wherein the one or more electrocardiography sensors are further
configured to measure one or both of the respiration rate and the
heart rate from a user's fourth finger.
[0008] The above-noted aspects and features may be implemented in
systems, apparatuses, methods, and/or computer-readable media
depending on the desired configuration. The details of one or more
variations of the subject matter described herein are set forth in
the accompanying drawings and the description below. Features and
advantages of the subject matter described herein will be apparent
from the description and drawings, and from the claims. In some
example embodiments, one of more variations may be made as well as
described in the detailed description below and/or as described in
the following features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates an example of a system in which a sensor
device for determining vital signs may be implemented, in
accordance with some example embodiments;
[0010] FIG. 2A illustrates a functional block diagram of the sensor
device of FIG. 1, in accordance with some example embodiments;
[0011] FIG. 2B illustrates an example of the sensor device and
computing device of FIG. 1, in accordance with some example
embodiments;
[0012] FIG. 3 illustrates an example of a computing apparatus which
may be used to implement one or more of the described devices
and/or components, in accordance with some example embodiments;
[0013] FIG. 4A illustrates an aerial view of an example of a sensor
which may be used for determining vital signs, in accordance with
some example embodiments;
[0014] FIG. 4B illustrates a side view of an example of a sensor
which may be used for determining vital signs, in accordance with
some example embodiments;
[0015] FIG. 4C illustrates an example use of a sensor for
determining vital signs, in accordance with some example
embodiments;
[0016] FIG. 4D illustrates an example of a diagram of operation of
the sensor for determining vital signs, in accordance with some
example embodiments;
[0017] FIG. 4E illustrates an example of a diagram of a circuit for
obtaining an arterial pressure waveform and/or arterial audio
waveform, in accordance with some example embodiments;
[0018] FIG. 5A illustrates an example of an arterial pressure
waveform, in accordance with some example embodiments;
[0019] FIG. 5B illustrates example timing diagram of cardiac event
waveforms, in accordance with some example embodiments;
[0020] FIG. 6A illustrates an example of a method of using a sensor
device to for determining multiple vital signs, in accordance with
some example embodiments;
[0021] FIG. 6B illustrates an example of a method of determining
one or more vital sign, in accordance with some example
embodiments;
[0022] FIG. 7 illustrates an example of a method of determining
vital signs based on an arterial pressure waveform, in accordance
with some example embodiments; and
[0023] FIG. 8 illustrates an example of a method of using a sensor
device to for determining one or more vital sign, in accordance
with some example embodiments.
[0024] Where practical, like labels are used to refer to the same
or similar items in the figures.
DETAILED DESCRIPTION
[0025] FIG. 1 illustrates an example system 100 in which a sensor
device 102 for determining vital signs may be implemented, in
accordance with some example embodiments. In some aspects, the
sensor device 102 may be an electronic device capable of measuring
a person's (referred to herein as a "user") vital signs through the
use of one or more sensors. The vital signs may include traditional
vital signs and/or additional health signs. For example, the vital
signs tested/determined can be one or more of body temperature,
weight, oxygen saturation, glucose level, pulse/heart rate, heart
rate fluctuation, respiration rate, blood pressure, pulse pressure,
and/or the like. Similarly, certain waveforms may be
detected/measured in order to aid in the determination of vital
signs measurements, such as an arterial pressure waveform and/or a
cardio audio waveform. The sensors may be one or more of resistive
sensor(s), surface acoustic sensor(s), capacitive sensor(s),
infrared sensor(s), electrocardiography (ECG) sensor(s), peripheral
capillary oxygen saturation (SpO2) sensor(s), optical sensor(s),
pressure sensor(s), ultrasonic sensor(s), humidity sensor(s), gas
sensor(s), motion sensor(s), acceleration sensor(s), displacement
sensor(s), force measurement sensor(s), and/or color sensor(s).
[0026] Before, during, and/or after measuring a user's vital signs,
the sensor device 102 may communicate with a computing device 106.
In some aspects, the sensor device 102 may connect with the
computing device 106 via one or more of Bluetooth (e.g., low
energy) communications, Near-field communications (NFC), ZigBee
communications, a universal serial bus (USB), wireless USB,
device-to-device communications, and/or the like. As illustrated,
the computing device 106 may be in communication with a database
108, which may be used to store vital sign information, user data,
and/or the like. In some embodiments, the computing device 106 may
be used to initialize measurement of the user's vital signs (e.g.,
by accepting information about the user), and/or may be used to
display resulting measurements of the user's vital signs. For
example, a user may place their hand(s) on the sensor device and
may see one or more visualizations of their vital signs in real
time and/or after their vital signs have been properly scanned.
[0027] Although the sensor device 102 and the computing device 106
are illustrated as separate, in some embodiments, the computing
device 106 may be part of the sensor device 102, and therefore the
sensor device 102 may access and/or provide information to the
database 108.
[0028] As further illustrated, the sensor device 102 and/or the
computing device 106 may communicate over a network 110 (e.g., with
each other and/or with others). In various aspects, the network 110
can include one or more of a local area network (LAN), a wireless
LAN (WLAN), a personal area network (PAN), a wide area network
(WAN), a cellular network, the internet, and/or the like. As
further illustrated, one or more user device 104 may also utilize
the network 110, and may therefore be in communication with the
sensor device 102 and/or the computing device 106. User devices 104
may be computing devices which are capable of controlling,
accessing, and/or communicating with other computing device. For
example, in some aspects, a user device 104 may be used to provide
information to and/or receive information from the sensor device
102, such as updates, maintenance information, user data, test
results, and/or the like.
[0029] In some aspects, the computing device 106 may provide
backend services/software for the sensor device 102. For example,
in various embodiments, the sensor device 102 and/or the computing
device 106 may utilize cloud-based storage (e.g., via database 108
or physical and/or virtual storage located elsewhere). In some
embodiments, the computing device 106 may be a phone, tablet,
personal computer, or other device. In accordance with these
embodiments, the computing device may operate according to an iOS,
Android, Mac, Windows, Linux, or other operating system. The
computing device 106 may access one or more cloud-computing
services that are running on a secure HIPPA-compliant server (e.g.,
over the internet).
[0030] In some aspects, one or more of the sensor device 102, the
user device(s) 104, the computing device, and/or the database 108
may be used by a healthcare professional, and therefore these
persons may also be referred to as users.
[0031] FIG. 2A illustrates a functional block diagram of the sensor
device 102 of FIG. 1, in accordance with some example embodiments.
As illustrated, the sensor device 102 may include a surface 202, a
first input module 204, a second input module 206, and one or more
sensors 210-215. One or more of the sensors 210-215 may be
configured to capture information based on a portion of a user's
hand, and the captured information can be processed according to
signal and/or data processing algorithms. In some aspects, the
surface 202 may be a plastic, metal, glass, or other covering,
which may be designed to allow for a comfortable and/or secure
placement of a user's hands on the sensor device 102. For example,
FIG. 2B illustrates an example embodiment of the sensor device 102
where the surface 202 is curved and/or contoured in shape to allow
for the placement of the user's hands on the curved portion, and
also contains recessed portions which contain the sensors 210-213
so that the user's fingers can stay in place with less effort.
[0032] Referring back to FIG. 2A, as noted above, the sensors
210-213 may include many different forms of sensors. In an example
embodiment, sensor 210 includes an peripheral capillary oxygen
saturation (SpO2) sensor, sensors 211 and 212 include
electrocardiography (ECG) sensors, and/or sensor 213 includes an
infrared (IR) sensor. In accordance with related embodiments, the
user's left middle finger may be used to determine the user's
oxygen saturation and/or heart/pulse rate based on measurements
taken by the sensor 210, the user's left index finger may be used
to determine an ECG waveform, the user's pulse rate, and/or the
user's respiration rate based on measurements taken by the sensors
211 and/or 212, and the user's right middle finger may be used to
determine an arterial pressure waveform and/or a cardio audio
waveform based on measurements taken by the sensor 213.
[0033] In various embodiments, the sensor device 102 may utilize
one or both of the first and second input modules 204 and 206 to
communicate with another device (or other devices), to receive
power, and/or the like. For example, the sensor device 102 may
optionally receive inputs from auxiliary/external tethered sensors
for additional vital sign information, such as temperature, weight,
cuff blood pressure, glucometer, and/or the like. Similarly, the
sensor device 102 may communicate with the computing device 106 via
one or more of the input modules 204 or 206. In some aspects, one
or both of the input modules 204 or 206 may be a universal serial
bus (USB) connection or some other data connection. Although some
operations are described as being wired, wireless communication is
also possible, depending upon the device with which the sensor
device 102 is communicating. In some aspects, information
transmitted to/from the sensor device 102 may be encrypted.
[0034] In some aspects, one or both of the sensors 214 and 215 may
be utilized to obtain identification about the user. For example,
one or both of the sensors may capture information about a user's
palm print, which may be used to uniquely identify the user.
Therefore, in some embodiments, a user may be allowed to place both
hands on top of the sensor device 102, which in turn measures
multiple vital signs at the same time and/or identifies the user.
In some embodiments, biometric and/or health information obtained
from one or more of the sensors 210-215 may be used to define
and/or obtain an aggregate signature for identification of the
user. The resulting measurements may be displayed to the user, for
example, via the computing device 106. In some embodiments,
aggregate health information may be used to characterize a medical
condition of a person.
[0035] In various embodiments, the computing device 106 may utilize
a software application to display the sensor readings and/or vital
sign information. For example, the sensor device 102 may be in
communication with the computing device 106 running the software
application, and the software application may be used to
control/direct the sensor device 102 to some degree (e.g., to turn
on/off one or more of the sensors 210-215). In some aspects, the
computing device 106 may be configured to transmit the vital sign
information to a secure cloud storage via the network 110 or
provide the vital sign information locally to the database 108. In
some aspects, the vital sign information can be attached to the
user's health records, processed in post-collection analysis
algorithms (e.g., based on the user's health history), provided for
further analysis by health and medical professionals, and/or the
like.
[0036] Although specific measurements are described with respect to
specific fingers, specific sensor types, and specific sensor
locations other combinations are possible. For example, one of the
sensors 210-213 may additionally or alternatively be used to obtain
a user's fingerprint and/or one of the sensors 214 or 215 may be
used to obtain oxygen saturation, heart/pulse rate, respiration, an
ECG waveform, an arterial pressure waveform, and/or a cardio audio
waveform.
[0037] FIG. 3 illustrates an example computing apparatus 300 which
may be used to implement one or more of the described devices
and/or components, in accordance with some example embodiments. For
example, at least a portion of the computing apparatus 300 may be
used to implement the sensor device 102, the computing device 106,
and/or one or more of the user devices 104. Computing apparatus 300
may perform one or more of the processes described herein.
[0038] As illustrated, computing apparatus 300 may include one or
more processors such as processor 310 to execute instructions that
may implement operations consistent with those described herein.
Apparatus 300 may include memory 320 to store executable
instructions and/or information. Memory 320 may include solid-state
memory, solid-state disk drives, magnetic disk drives, or any other
information storage device. In some aspects, the memory 320 may
provide storage for at least a portion of a database. Apparatus 300
may include a network interface 340 to a wired network or a
wireless network, such as the network 110 of FIG. 1. Wireless
networks may include WiFi, WiMax, and cellular networks
(2G/3G/4G/5G), and/or any other wireless network. In order to
effectuate wireless communications, the network interface 340, for
example, may utilize one or more antennas, such as antenna 380.
[0039] Apparatus 300 may include one or more user interface, such
as user interface 350. The user interface 350 can include hardware
or software interfaces, such as a keyboard, mouse, or other
interface, some of which may include a touchscreen integrated with
a display 330. The display 330 may be used to display visual
representations of health information (e.g., vital sign
statistics), provide prompts to a user, receive user input, and/or
the like. In various embodiments, the user interface 350 can
include one or more of the peripheral devices described herein
and/or the user interface 350 may be configured to communicate with
these peripheral devices.
[0040] In some aspects, the user interface 350 may include one or
more of the sensors described herein. The operation of these
sensors may be controlled at least in part by a sensor module 360.
The apparatus 300 may also comprise and input and output filter
370, which can filter information received from the sensors or
other user interfaces, received and/or transmitted by the network
interface, and/or the like. For example, signals detected through
the sensors can be passed through the filter 370 for proper signal
conditioning, and the filtered data may then be passed to the
microcontroller sensor module 360 and/or processor 310 for
validation and processing (e.g., before transmitting results via
the network interface 340). The apparatus 300 may be powered
through the use of one or more power sources, such as power source
390. As illustrated, one or more of the components of the apparatus
300 may communicate through a system bus.
[0041] FIG. 4A illustrates an aerial view of an example sensor
component 400 which may be used for determining vital signs, in
accordance with some example embodiments. As illustrated, the
sensor component 400 may include a sensor portion 410 and a surface
portion 420. In various embodiments, the sensor portion 410 can
include one or more physical sensors, such as an infrared sensor.
The surface portion 420 may be used such that a user's finger
remains stationary while the sensor portion 410 is used to collect
information from the finger.
[0042] FIG. 4B illustrates a side view of the sensor component 400
of FIG. 4A, in accordance with some example embodiments. As
illustrated, the sensor portion 410 may be positioned between two
opposite, interior surfaces of the surface portion 420 (e.g.,
inset). In some aspects, the sensor portion 410 may be flush with
the surface portion 420, slightly protruding above the level of the
surface portion 420, and/or slightly recessed to a point that is
lower than the surface portion 420. As further illustrated, the
sensor component 400 can contain a base 430 which supports the
sensor portion 410. In various embodiments, the base 430 may
include circuitry configured to obtain data from the sensor portion
410 for analysis. For example, the base 430 can include a printed
circuit board (PCB), and/or the sensor portion 410 may be
electrically attached by the leads to the base 430. The base 430
may include additional circuitry to collect the output of the
sensor, portion 410 digitize it, and/or format the resulting
digitized information. This information may be analyzed and/or
transmitted to another device, such as the computing apparatus 106,
and or a cloud server.
[0043] In some aspects, the sensor portion 410 may be fixed in
place or may be moveable (e.g., may be arranged so that it can be
pushed down). In some aspects, the surface portion 420 and/or the
base 430 may be considered a mechanical platform. In various
embodiments, the sensor portion 410 can include a reflective object
sensor.
[0044] FIG. 4C illustrates an example use of the sensor component
400 for determining vital signs, in accordance with some example
embodiments. As illustrated, a user may place their finger 190 on
sensor component 400. In some aspects, the finger 190 may be one of
the user's middle fingers or index fingers. In some embodiments,
the user may place the finger-tip 195 of their finger 190 directly
on top of the sensor portion 410 so that the sensor portion 410 may
collect data relating to the user's vital signs. In some aspects,
the finger-tip 195 includes the center part of the fingerprint area
of the user's finger. The user's finger 190 or finger-tip 195 may
cover the sensor portion 410, which transmits IR light and/or
responds to the reflection of the signal off of the finger 190. In
various embodiments, additional or alternative portions of a user's
body where an artery is close to the skin may be used to obtain
measurements described herein.
[0045] For example, FIG. 4D illustrates an example diagram of IR
sensing in operation, in accordance with some example embodiments.
As illustrated, the sensor portion 410 can include an LED 412 and
phototransistor 414. In various embodiments, the LED 412 is used to
transmit IR light onto the user's finger-tip 195, and/or the
phototransistor 414, based upon the reflection, is configured to
output a voltage V.sub.OUT proportional to the displacement of the
reflection caused by digital arterial pressure. Specifically, the
pulse pressure from the digital artery 185 in the finger 190 causes
a reflective displacement between the IR light emitting diode 412
and the phototransistor 414 from the surface of the skin that
results in a proportional voltage output V.sub.OUT corresponding to
the time domain signal from which a digital arterial pressure
and/or a digital audio can be extracted.
[0046] In some embodiments, the output voltage V.sub.OUT is
amplified and/or conditioned with a low-pass filter and/or
high-pass filter to produce an electrical signal that correlates to
arterial pressure. The filtered output voltage V.sub.OUT can
thereby include a waveform that is representative of the pressure,
over time, of the digital artery 185. An example arterial pressure
waveform 500 is illustrated in FIG. 5A, which spans the time frame
of approximately twenty seconds.
[0047] FIG. 4E illustrates an example of a diagram of a circuit 450
for obtaining an arterial pressure waveform and/or arterial audio
waveform, in accordance with some example embodiments. As noted
above, in some aspects, an audio waveform for the digital artery
185 may additionally or alternatively measured. For example, in
some aspects, low-pass and/or high-pass filtering may be performed
on the output voltage V.sub.OUT to produce a voltage corresponding
to the amplitude of the digital arterial pressure audio waveform.
Overdriving an audio amplifier can produce visible pulses
coincident with cardiac events, producing a waveform similar to a
phonocardiogram. These pulses can identify the beginning of a
Systole and/and or Diastole. Thus, a one or more of the arterial
pressure, ECG, and/or the audio output can be used determine the
phases of the cardiac cycle.
[0048] For example, a way to determine the audio waveform can
include feeding the output of the IR sensor into a high-pass filter
(HPF) circuit 452. As illustrated, HPF circuit 452 can be
configured to remove DC to 0.1 Hz. The high-pass-filtered output
may then be amplified via an amplifier 454 with a gain of 140 dB.
The amplified output may then be provided to a low pass filter
(LPF) circuit 456. As illustrated, the LPF circuit 456 can be an
8th order LPF with a cutoff frequency of 240 Hz. The resulting,
low-pass-filtered output may be indicative of the arterial pressure
waveform, which can be fed to an analog-to-digital (A/D) converter
to be digitized for further processing as described herein.
[0049] In some aspects, the filtered output of the LPF circuit 456
may also be provided to another HPF circuit 460. As illustrated,
the HPF circuit 460 may be a 4.sup.th order HPF with a cutoff
frequency of 40 Hz. The high-pass-filtered output may then be
provided as an input to an amplifier 462, which may utilize a gain
of 10 dB (or more). Amplifying this signal with the amplifier can
result in the amplifier 462 being saturated. This may cause a
ringing with sharp signal transitions fed to it. The resulting,
amplified output may be indicative of the arterial audio waveform,
which can be fed to an analog-to-digital (A/D) converter to be
digitized for further processing as described herein. Although
specific values are illustrated and described, other values may be
utilized. For example, to get a less saturated (e.g., clean) audio
signal or phonocardiogram, the gain of the amplifier 454 and/or the
amplifier 462 can be decreased. With the arterial pressure waveform
as input in this configuration, a signal similar to the
phonocardiagram signal waveform 565 illustrated in the Wiggers
diagram 550 of FIG. 5B may be generated.
[0050] The Wiggers diagram 550 illustrates a timing diagram of an
aortic pressure waveform 560, an atrial pressure waveform 561, a
ventricular pressure waveform 562, a ventricular volume waveform
563, an electrocardiogram signal waveform 564, and a
phonocardiogram signal waveform 565. In some embodiments, the
arterial pressure waveform described herein can be a waveform
resulting from the superposition of each of the aortic pressure
waveform 560, the atrial pressure waveform 561, and/or the
ventricular pressure waveform 562. The electrocardiogram signal
waveform 564 may correspond to a signal obtained from an ECG
sensor, as described herein.
[0051] As noted above, the configuration of the circuit 450 of FIG.
4E can be used to generate a signal similar to the phonocardiagram
signal waveform 565. While the signal generated by the circuit 450
may not be a clearly audible phonocardiagram signal, the ringing
transitions may be used for processing and/or analysis, as they can
be coincident with other cardiac event timings as shown in the
Wiggers diagram 550. Such cardiac event timings can include one or
more of an aortic valve opening or closing, a mitral valve opening
or closing, isovolumetric contraction or relaxation, ejection,
rapid inflow, diastasis, and/or atrial systole. Thus, in some
aspects, one or more of the arterial pressure waveform, the
arterial audio waveform, and or the ECG waveforms may be used
individually or in combination with each other to extract the
timing and/or the magnitude of cardiac events. Such extraction
methods may provide non-invasive systems and methods for
determining vital signs, such as determining a user's blood
pressure through a sensor without the use of a cuff. Other
measurements related to relative blood pressure and/or blood
pressure variations over time may additionally or alternatively
determined.
[0052] Referring back to FIG. 4E, the measured and/or filtered
signals can be sampled with an A/D converter (e.g., within the PCB
430), to produce a stream of integers that can be plotted to
display resulting waveforms of arterial pressure and/or arterial
pressure audio. This data may be collected from the output of the
A/D by processor circuitry (which may be implemented at, our
coupled to, the PCB 430). In some aspects, the data may be
formatted by the sensor device 102 and/or transmitted to the
computing device 106. In some embodiments, the sensor device 102
and/or the computing device 106 may include software (e.g., an
application) that plots the arterial pressure waveform and/or the
arterial audio waveform for viewing by the user. The resulting
waveforms may be recorded, stored, and relayed, by the sensor
device 102 and/or computing device 106, to another device, such as
a remote server coupled to the Internet (for example, a cloud-based
server/computing device). In some aspects, the sensor device 102
and/or the computing device 106 may be configured to determine one
or more of the user's vital signs, as described herein.
[0053] FIG. 6A illustrates an example method 600 of using a sensor
device for determining multiple vital signs, in accordance with
some example embodiments. In some embodiments, the sensor device
102 and/or the computing device 106 of FIG. 1 may be utilized as
part of the method 600. Although a specific sequence of operations
of method 600 are illustrated and described with respect to
particular devices and/or components, in various embodiments, not
all of operations may be present, additional operations may be
present, the order of the operations may alter, and/or the
operations may be performed by different devices and/or
components.
[0054] As illustrated, method 600 may begin at operational block
610, where the sensor device 102, for example, is powered on.
Powering on the sensor device 102 may include powering on one or
more of the sensors 210-215 described herein. Method 600 may
proceed to operational block 620 where the computing device 106,
for example, may launch application software. Method 600 may then
proceed to operational block 630 where the sensor device 102, for
example, may pair with the computing device 106, for example. In
some aspects, the pairing may occur via a Bluetooth connection, a
USB connection, and/or the like. In various embodiments, the
pairing and/or connection between devices may be automatic.
[0055] Method 600 may then proceed to operational block 640, where
the sensor device 102, for example, starts detecting and measuring
data for the determination of multiple vital signs. In various
embodiments, this data may be measured through one or more of a
user's fingertips. Method 600 may proceed to operational block 650
where the sensor device 102, for example, transmits captured data
to the computing device 106. Additionally or alternatively, the
computing device 106 may transmit the data over the network 110 to
another device for storage and/or analysis. As illustrated, this
data can be transmitted through the use of the application running
on the computing device 106. As described herein, additional
information from peripheral devices may be used in conjunction with
data obtained from the sensors.
[0056] Method 600 may then proceed to operational block 660 where
the sensor device 102 (and/or the computing apparatus 106), for
example, evaluates whether the detected data is valid or not. In
some aspects, the data validation process can be achieved through
correlation and calculation of multiple heart rate measurements
from the SPO2, ECG waveform, and peripheral arterial pressure
waveform. For example, a valid range of heart rate (e.g., minimum
to maximum) may be predefined (e.g., based on the user, based on
other people with the same/similar health, and/or based on a
desired rate). As heartrate can be obtained from all three
waveforms (e.g., SpO2, ECG, and arterial pressure) the measured
heart rate from all three can be calculated and compared with
range, and then compared to each other to evaluate the proper
finger placement (e.g., two of the measurements are within the
range but a third is not, indicating that the finger placed over
the associated sensor is not properly placed). If data is
determined to be invalid, this can indicate that the user's fingers
are not correctly placed on the sensors. In this case, method 600
may return to operational block 640. Additionally or alternatively,
the sensor device 102 and/or the computing device may provide an
error message.
[0057] If the data is instead determined to be valid, method 600
may next proceed to operational block 670 where the computing
device 106, for example, stores the data in a secure storage device
(which may be compliant with Health Insurance Portability and
Accountability Act (HIPAA) or other privacy regulations). For
example, the computing device 106 may store the data in a locally
accessible database 108 and/or another device which received the
data over the network 110 may store the data in a database
accessible to that device. Method 600 may then proceed to
operational block 680, where the computing device 106, for example,
may apply signal processing and/or algorithms for analysis of the
stored data. Method 600 may next proceed to operational block 690,
where the computing device 108, for example, may control (e.g.,
update, revise, or the like) the user's medical records based on
the stored data. Additionally or alternatively, a device which
receives the data from the computing device 108 may perform one or
both of operational blocks 680 and 690.
[0058] As a non-limiting example of a benefit, the use of method
600 may provide for the integration of multiple sensors into one
apparatus, a non-intrusive method of sensing a person's vital
signs, the ability to detect, measure, and/or wirelessly transmit
collected data from onboard and auxiliary/external sensors under
thirsty seconds, and/or collecting and correlating data via a
user's finger or palm print unique biometric identification,
without requiring any manual or operational calibration.
[0059] FIG. 6B illustrates an example method 605 for collecting
vital sign information. In some embodiments, the sensor device 102,
the computing device 106, and/or one or more of the client devices
104 of FIG. 1 may be utilized as part of the method 605. Although a
specific sequence of operational blocks of method 605 are
illustrated and described with respect to particular devices and/or
components, in various embodiments, not all of operations may be
present, additional operations may be present, the order of the
operations may alter, and/or the operations may be performed by
different devices and/or components. In some aspects, one or more
of the operations (or a portion thereof) of method 600 may be
integrated into method 605.
[0060] As illustrated, method 605, may start at operational block
615 where the computing device 106, for example, receives waveform
(e.g., arterial pressure waveform) samples. In some aspects, these
waveform samples may be received from a sensor device 102. In some
aspects, the waveform samples may be received via a user's finger,
such as a middle index, placed over a sensor, as discussed herein.
In some aspects, before method 605 begins, the computing device may
wait until high enough quality samples are received. Once this is
achieved, the sample recording process can start, either
automatically or manually by the operator.
[0061] Method 605 may next proceed to operational block 625 where
the computing device 106, for example, categorizes the waveform
samples. In some embodiments, the waveform samples may be
categorized according to distinct phenomenon areas to analyze, such
as heart rate variability, pulse pressure, arterial elasticity,
and/or fluid volume status. In some aspects, heart rate variability
can relate to frequency and time duration measurements of the
cardiac cycle, pulse pressure can relate to the amplitude of the
waveform, arterial elasticity can relate to slope and distortions
of the waveform, and/or fluid volume status can relate to ejection
ratio calculations and integration integrals of the arterial
waveform. Therefore, the waveform samples may be categorized
accordingly. In some embodiments, method 605 may wait until a
certain amount of time (e.g., 20 seconds, 25 seconds, 30 seconds,
or the like) has passed before proceeding to operational block
625.
[0062] Method 605 may next proceed to operational block 635 where
the computing device 106, for example, correlates the samples and
detects vital signs. For example, the computing device 106 may
calculate one or more vital signs for a user, based on the
categorized data, by using specific algorithms.
[0063] Method 605 may next proceed to operational block 645 where
the computing device 106, for example, may associate vital signs
with a user. In some aspects, the user may be identified by a
unique identifier, such as a patient ID, a screen name, social
security number, fingerprint, and/or the like.
[0064] Method 605 may next proceed to operational block 655 where
the computing device 106, for example, conducts reporting. In some
aspects, reporting may include transmitting the vital sign
information over the network 110 to a client device 104. Reporting
may include outputting at least a portion of the results to a
reporting function which formats the results for analysis.
[0065] Method 605 may next proceed to operational block 665 where
the computing device 106, for example, may determine whether an
alert condition is met. For example, the computing device 106 may
determine whether the user's heart rate or pulse pressure is above
a certain threshold. Alert limits may be set by the patient's
medical team and/or may suggest a propensity to a specific medical
condition that would require immediate attention.
[0066] If so, method 605 may next proceed to operational block 675
where the computing device 106, for example, provides an alert. In
some aspects, alerts may be customized per user. If an alert
condition occurs, specific members of a medical team and/or
emergency contact list determined by the alert algorithm, can be
immediately notified for example by email, SMS, phone call, and/or
the like, depending on how the alert conditions are set up.
[0067] Method 605 may next proceed to operational block 685 where
the computing device 106, for example, stores the resulting vital
sign information. If instead, it is determined at operational block
665 that an alert condition is not met, then method 605 may instead
proceed to directly to operational block 685.
[0068] Method 605 may next proceed to operational block 695 where
the computing device 106, for example, provides results via a
secure portal. In some aspects, secure may refer to a portal that
is HIPPA compliant. Providing the results via the secure portal can
include allowing a user to log into a secure web portal to access
their vital sign information (and/or the vital sign information of
a patient).
[0069] Method 605 may next proceed to operational block 699 where
the computing device 106, for example, may modify medical records.
For example, if medical records are stored in an electronic format,
the computing device 106 may have access to the records, and may
add more information, alter information, and/or remove information
from a user's medical record.
[0070] In various embodiments, one or more of the operations of
method 605 may be performed by a device other than the computing
device 106. For example, one or more of operational blocks 665-699
may be performed by a cloud computing device, such as a client
device 104.
[0071] In some aspects, method 605 may additionally or
alternatively involve providing a visual display of a peripheral
arterial pressure waveform, audio waveform, and/or vital sign
information. Similarly, method 605 may include displaying visual
indications of whether the signal(s) is/are being received at a
quality level needed to make an appropriately accurate
interpretation of one or more vital signs.
[0072] In some embodiments, the disclosed systems and/or methods
may provide an end-to-end solution by encompassing the necessary
system components in one platform including the wireless sensor
unit, the smart application software, the secure cloud storage, the
signal processing and algorithms to calculate and extrapolate
various vital signs, and/or the backend data base to provide the
final results that can be used by the patients/users or the
professionals.
[0073] FIG. 7 illustrates an example method 700 of determining
information related to an arterial pressure waveform, in accordance
with some example embodiments. In some embodiments, the sensor
device 102 and/or the computing device 106 of FIG. 1 may be
utilized as part of the method 700. Although a specific sequence of
operations of method 700 are illustrated and described with respect
to particular devices and/or components, in various embodiments,
not all of operations may be present, additional operations may be
present, the order of the operations may alter, and/or the
operations may be performed by different devices and/or
components.
[0074] As illustrated, method 700 may start at operational block
705 where a sensor device 102, for example, receives an input
sample. In some aspects, the input sample may be a digitized sample
of arterial pressure at index "i" (e.g., ap[i]). In various
embodiment, each time the index parameter "i" is incremented, a new
sample is introduced for processing. Method 700 may next proceed to
decision block 710 where the sensor device 102, for example,
determines whether a maximum or a minimum peak (or trough) is
currently sought. In some embodiments, a parameter "MaxSeek" may be
set to "0" if the sensor device 102 is looking for the minimum
value and/or may be set to "1" if the sensor device 102 is looking
for the maximum value.
[0075] If the sensor device 102, for example, determines that it is
looking for the max value, process 700 may proceed to decision
block 715 where the sensor device 102, for example, determines
whether the current sample (e.g., ap[i]) is higher than the
previous sample (e.g., ap[i-1]). If so, method 700 may proceed to
operational block 720 where the sensor device 102, for example, can
set the current max to the current sample value and reset the
minimum counter (e.g., a counter of successive minimum
evaluations). In some aspects, the minimum counter may be used to
determine whether a threshold number of successive points are lower
than the current max, signifying that the actual (or approximate)
max has already passed. Method 700 may next proceed to operational
block 780 where the sensor device 102, for example, increments the
sample counter (e.g., increments i). Thereafter, method 700 may
return to operational block 705.
[0076] If instead, at decision block 715 the sensor device 102, for
example, determines that the current sample (e.g., ap[i]) is not
higher than the previous sample (e.g., ap[i-1]), then method 700
may instead proceed to operational block 725 where the sensor
device 102, for example, may increment the maximum counter (e.g.,
add one). Thereafter, method 700 may proceed to decision block 730
where the sensor device 102, for example, may determine whether the
maximum counter is at or above a threshold. If not, then method 700
may proceed to operational block 780. If instead it is determined
that the maximum counter is at or above the threshold, then method
700 may instead proceed to operational block 735. At operational
block 735, the sensor device 102, for example may record the
current max as the max for the current peak, record the
corresponding timestamp for the maximum, reset the minimum counter
(e.g., to a value of 0), and/or may seek the minimum for the next
sample (e.g., set MaxSeek to equal 0). Thereafter, method 700 may
proceed to operational block 780.
[0077] If instead, at decision block 710 the sensor device 102, for
example, determines that it is looking for a min value, then method
700 may proceed to decision block 745 where the sensor device 102,
for example, determines whether the current sample (e.g., ap[i]) is
lower than the previous sample (e.g., ap[i-1]). If so, method 700
may proceed to operational block 750 where the sensor device 102,
for example, can set the current min to the current sample value
and reset the maximum counter (e.g., a counter of successive
maximum evaluations). In some aspects, the maximum counter may be
used to determine whether a threshold number of successive points
are higher than the current min, signifying that the actual (or
approximate) min has already passed. Method 700 may next proceed to
operational block 780.
[0078] If instead, at decision block 745 the sensor device 102, for
example, determines that the current sample (e.g., ap[i]) is not
lower than the previous sample (e.g., ap[i-1]), then method 700 may
instead proceed to operational block 755 where the sensor device
102, for example, may increment the maximum counter (e.g., add
one). Thereafter, method 700 may proceed to decision block 760
where the sensor device 102, for example, may determine whether the
minimum counter is at or above a threshold. If not, then method 700
may proceed to operational block 780. If instead it is determined
that the maximum counter is at or above the threshold, then method
700 may instead proceed to operational block 765. At operational
block 765, the sensor device 102, for example may record the
current min as the min for the current trough, record the
corresponding timestamp for the minimum, reset the maximum counter
(e.g., to a value of 0), and/or may seek the maximum for the next
sample (e.g., set MaxSeek to equal 1). Thereafter, method 700 may
proceed to operational block 780.
[0079] In some embodiments, the sensor device 102 may conduct an
initialization procedure. For example, upon start-up, the sensor
device 102 may evaluate whether the samples taken are increasing,
thus approaching a peak, or decreasing, thus approaching a trough.
If the sample values are increasing, then the sensor device 102 may
determine that it is initially seeking a max (e.g., setting MaxSeek
to a value of 1), or vice versa. In some aspects, the minimum
counter and/or the maximum counter may both be initialized to a
value of 0.
[0080] In some embodiments, as long as the integrity of the
waveform is intact, the algorithm may be able to correctly evaluate
the parameters. If, however, there is an aberration in the signal
(e.g., excessive noise or finger movements) where the integrity of
the signal is compromised, the resulting calculations may be
distorted beyond the ability to calculate. This case can be handled
by setting a criteria check for the calculations to be within a
specified range (e.g., a range of reasonably expected values). In
addition, if the heart rate is calculated redundantly by other
sensors (e.g., SpO2 and/or ECG), the calculations may be checked
against the IR measurements to determine whether the estimates are
within a certain threshold range of each other (e.g., estimates
based on IR are a specified percentage away from one or more of the
other estimates based on other sensors). If errors or unreliable
data are determined to exist, the arterial pressure cycle
measurement(s) in question can be removed from the heart rate
calculation.
[0081] The shape and modulation of the waveform can be effected by
a number of cardiac events and disturbances due to such conditions
as arterial hardening, heart murmurs, operation of the heart
valves, etc. Thus, from the waveform, there are multiple vital
signs calculations that can be produced. For example, relative
pulse pressure (e.g., the difference between the magnitudes of the
systolic blood pressure and the diastolic blood pressure) may be
calculated based on the waveform. Although an absolute value of
systolic pressure and/or diastolic pressure may not be directly
calculated from the waveform in some embodiments, a pulse pressure
value, which is the difference between the two values, may be
evaluated.
[0082] Additionally, heart rate (e.g., beats per minute) may be
calculated. In some embodiments, in order to calculate the heart
rate, a more traditional method might be to perform a discrete
Fourier analysis of the waveform samples to extract the fundamental
frequency with DC removed and the lower frequency component(s)
which is caused by/correlates with the respiration rate. This
fundamental frequency value can be equivalent to the inverse of the
temporal value of the cyclic period of the arterial pressure
waveform, and may be a close representation of the average value of
the heart rate.
[0083] Another approach is to find and utilize the length of the
period of each cycle by establishing the temporal positions of the
start of each repeating cycle. Any arbitrary point on the waveform
could be used, however the particular value and/or temporal
position of any given peak may be more readily established. From
this, one or more additional calculations may be established.
[0084] The temporal values of the peak positions can be used to
calculate an instantaneous heart rate every cycle where peak[n] is
the time stamp in seconds at the first peak, peak[n+1] is the time
tamp in seconds at the following peak, and the instantaneous heart
rate value HR is equal to [60 seconds/minute/(peak[n+1]-peak[n])
seconds] in heart beats/minute. Although peaks are described, other
related points may additionally or alternatively be used, such as
troughs and/or zero-crossing points.
[0085] Heart rate fluctuation/variation (e.g., how the rate varies
from beat to beat) may also be determined. A human heart rate may
normally have some variation, but abnormal variations can be caused
by atrial fibrillation, heart murmurs, and/or the like. Therefore,
accurately determining this measurement may be beneficial.
[0086] If instantaneous heart rate calculations are performed for
each observed cycle, heart rate fluctuation can be readily
monitored. For example, how the successive values of heart rate
vary over the recording series may be monitored/determined. In
order to determine the heart rat variations, a maximum heart rate,
minimum heart rate, average heart rate, standard deviation, and/or
the like may be calculated. In some aspects, the sensor device 102
may be set to monitor a user for longer and/or continuous (e.g.,
similar to a Holter monitor) monitoring, which may allow for
detection of momentary heart fluctuations.
[0087] As noted above, respiration rate (e.g., breath cycles per
minute) may be calculated. Looking back to the waveform 500 of FIG.
5, a lower frequency component, upon which the arterial pressure
cycles are modulated, can be seen. These recorded cycles can have a
low frequency offset superimposed on the waveform which corresponds
to the respiration rate. So using the same/similar algorithm that
is used to calculate the heart rate, the waveform corresponding to
a temporal plotted value of the peaks can be processed to determine
the fundamental frequency, which may be the value of respiration.
In the same/similar manner as in the case of the heart rate
calculation the instantaneous frequency may be measured for for
each cycle. As in the case of the heart rate calculation, a
maximum, a min, an average, a standard deviation, and/or the like
may be calculated from the series.
[0088] In some aspects, the longer the series of samples collected,
the more accurate an average respiration and/or heart rate may be
obtained. As the respiration rate is slower more samples may be
needed to provide an accurate/reliable calculation compared to
heart rate. Therefore, in some embodiments, at least twenty seconds
of reliable samples may be recorded to process enough samples for a
respiration calculation. The sensor device 102 can be programmed
via a user-entered entry to record this waveform for any length of
time.
[0089] FIG. 8 illustrates a method 800 of calculating one or more
vital signs. In some embodiments, the sensor device 102, the
computing device 106, and/or one or more of the client devices 104
of FIG. 1 may be utilized as part of the method 800. Although a
specific sequence of operations of method 800 are illustrated and
described with respect to particular devices and/or components, in
various embodiments, not all of operations may be present,
additional operations may be present, the order of the operations
may alter, and/or the operations may be performed by different
devices and/or components.
[0090] Method 800 may start at operational block 810 where the
sensor device 102, for example, may capture at least a portion of
an arterial pulse pressure waveform for a user.
[0091] Method 800 may proceed to operational block 820 where the
sensor device 102, for example, may determine, for each of a
plurality of peaks of the arterial pulse pressure waveform, a
maximum point. In some embodiments, determining the maximum points
includes determining, for a plurality of subsequent samples of the
arterial pulse pressure waveform, whether a current sample is
greater in pressure than a prior sample, storing the current sample
when the current sample is greater in pressure than the prior
sample, determining whether a threshold number of subsequent
samples are not greater than the stored sample, and setting the
stored sample as the maximum point (e.g., for the current peak
(e.g., peak[n])) when the threshold number of subsequent samples
are not greater than the stored sample.
[0092] Method 800 may proceed to operational block 830 where the
sensor device 102, for example, may determine, for each maximum
point, a corresponding timestamp. For example, determining the
corresponding timestamp may include checking a clock and/or storing
the clock value related to the maximum point (e.g., peak[n]).
[0093] Method 800 may proceed to operational block 840 where the
sensor device 102, for example, may determine, for each of a
plurality of troughs of the arterial pulse pressure waveform, a
minimum point. In some embodiments, determining the minimum points
includes determining, for a plurality of subsequent samples of the
arterial pulse pressure waveform, whether a current sample is lower
in pressure than a prior sample, storing the current sample when
the current sample is lower in pressure than the prior sample,
determining whether a threshold number of subsequent samples are
not lower than the stored sample, and setting the stored sample as
the minimum point (e.g., for the current trough (e.g., trough[n]))
when the threshold number of subsequent samples are not lower than
the stored sample. Although peaks, troughs, maximum points, and/or
minimum points are illustrated and described, other related points
may be used. For example, a zero-crossing (rising or falling)
pressure point may be determined.
[0094] Method 800 may proceed to operational block 850 where the
sensor device 102, for example, may determine, for each maximum
point, a corresponding timestamp.
[0095] Method 800 may proceed to operational block 860 where the
sensor device 102, for example, may determine one or more vital
signs based at least in part on the plurality of maximum points and
corresponding timestamps, and/or the plurality of minimum points
and corresponding timestamps, the one or more vital signs including
at least one of a heart rate of the user, a heart rate variation of
the user, a respiration rate of the user, and an arterial pulse
pressure of the user.
[0096] Method 800 may proceed to operational block 870 where the
sensor device 102, for example, may provide the one or more vital
signs for display. In various embodiments, determining the heart
rate includes generating a plurality of peak rates by at least
subtracting, for each of the plurality of related points (e.g.,
maximum, minimum, and/or other), the corresponding first timestamp
of a most recent related point from the corresponding first
timestamp of a current related point. In some aspects, determining
the heart rate further includes averaging the plurality of peak
rates.
[0097] In some embodiments, method 800 may additionally or
alternatively include determining an arterial audio waveform based
at least in part on the arterial pressure waveform (e.g., through
the use of one or more filter and/or one or more amplifier). Method
800 can similarly include determining one or more cardiac events of
the user based at least in part on the arterial pressure waveform,
the arterial audio waveform, and or an electrocardiography
waveform. The one or more cardiac events can include an aortic
valve opening or closing, a mitral valve opening or closing, an
isovolumetric contraction or relaxation, an ejection, a rapid
inflow, diastasis, and/or an atrial systole.
[0098] In related embodiments, determining the heart rate variation
includes determining a maximum rate from the plurality of peak
rates, determining a minimum rate from the plurality of peak rates,
and/or determining a standard deviation from the plurality of peak
rates. In some embodiments, determining the respiration rate
includes determining a fundamental frequency of the arterial pulse
pressure waveform.
[0099] In some embodiments, the infrared sensor is configured to
capture the at least the portion of the arterial pulse pressure
waveform from the user's finger via providing signals from a light
emitting diode and measuring reflections via a phototransistor. In
some embodiments, the sensor device 102, for example, may also
include a peripheral capillary oxygen saturation sensor configured
to measure oxygen saturation from a user's second finger, and one
or more electrocardiography sensors configured to measure an
electrocardiography waveform from a user's third finger, wherein
the one or more electrocardiography sensors are further configured
to measure one or both of the respiration rate and the heart rate
from a user's fourth finger.
[0100] In some embodiments, the disclosed systems may be used as a
platform in broad range of application where there is a need to
collect multiple key vital signs simultaneously and seamlessly at
local or remote settings. In some embodiments, the disclosed system
may be configured into stationary units, or portable/mobile units,
or wearable units, or various kiosk units and can include
integrated or separated tablet or mobile device for display.
[0101] The subject matter described herein may be embodied in
systems, apparatus, methods, and/or articles depending on the
desired configuration. For example, the systems, apparatus,
methods, and/or articles described herein can be implemented using
one or more of the following: electronic components such as
transistors, inductors, capacitors, resistors, and the like, a
processor executing program code, an application-specific
integrated circuit (ASIC), a digital signal processor (DSP), an
embedded processor, a field programmable gate array (FPGA), and/or
combinations thereof. These various example embodiments may include
embodiments in one or more computer programs that are executable
and/or interpretable on a programmable system including at least
one programmable processor, which may be special or general
purpose, coupled to receive data and instructions from, and to
transmit data and instructions to, a storage system, at least one
input device, and at least one output device. These computer
programs (also known as programs, software, software applications,
applications, components, program code, or code) include machine
instructions for a programmable processor, and may be implemented
in a high-level procedural and/or object-oriented programming
language, and/or in assembly/machine language. As used herein, the
term "machine-readable medium" refers to any computer program
product, computer-readable medium, computer-readable storage
medium, apparatus and/or device (for example, magnetic discs,
optical disks, memory, Programmable Logic Devices (PLDs)) used to
provide machine instructions and/or data to a programmable
processor, including a machine-readable medium that receives
machine instructions. Similarly, systems are also described herein
that may include a processor and a memory coupled to the processor.
The memory may include one or more programs that cause the
processor to perform one or more of the operations described
herein.
[0102] Although a few variations have been described in detail
above, other modifications or additions are possible. In
particular, further features and/or variations may be provided in
addition to those set forth herein. Moreover, the example
embodiments described above may be directed to various combinations
and subcombinations of the disclosed features and/or combinations
and subcombinations of several further features disclosed above. In
addition, the logic flow depicted in the accompanying figures
and/or described herein does not require the particular order
shown, or sequential order, to achieve desirable results. Other
embodiments may be within the scope of the following claims.
* * * * *