U.S. patent application number 14/507620 was filed with the patent office on 2015-04-09 for regional oximetry sensor.
The applicant listed for this patent is MASIMO CORPORATION. Invention is credited to Yassir Abdul-Hafiz, Ammar Al-Ali, Kevin Forrest, Sujin Hwang, Pete Mangosing, Walter M. Weber.
Application Number | 20150099950 14/507620 |
Document ID | / |
Family ID | 51842849 |
Filed Date | 2015-04-09 |
United States Patent
Application |
20150099950 |
Kind Code |
A1 |
Al-Ali; Ammar ; et
al. |
April 9, 2015 |
REGIONAL OXIMETRY SENSOR
Abstract
A regional oximetry sensor has a sensor head attachable to a
patient skin surface so as to transmit optical radiation into the
skin and receive that optical radiation after attenuation by blood
flow within the skin. The sensor includes windows that press into
the skin to maximize optical transmission. A stem extending from
the sensor head transmits electrical signals between the sensor
head and an attached cable. In a peel resistant configuration, the
stem is terminated interior to the sensor head and away from a
sensor head edge so as to define feet along either side of the stem
distal the stem termination. The stem interior termination
transforms a peel load on a sensor head adhesive to less
challenging tension and shear loads on the sensor head
adhesive.
Inventors: |
Al-Ali; Ammar; (San Juan
Capistrano, CA) ; Forrest; Kevin; (Rancho Santa
Margarita, CA) ; Abdul-Hafiz; Yassir; (Irvine,
CA) ; Weber; Walter M.; (Laguna Hills, CA) ;
Mangosing; Pete; (Santa Ana, CA) ; Hwang; Sujin;
(Irvine, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MASIMO CORPORATION |
Irvine |
CA |
US |
|
|
Family ID: |
51842849 |
Appl. No.: |
14/507620 |
Filed: |
October 6, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62012170 |
Jun 13, 2014 |
|
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|
61887878 |
Oct 7, 2013 |
|
|
|
61887856 |
Oct 7, 2013 |
|
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61887883 |
Oct 7, 2013 |
|
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Current U.S.
Class: |
600/323 |
Current CPC
Class: |
A61B 5/14542 20130101;
A61B 5/6833 20130101; A61B 2562/227 20130101; A61B 2562/228
20130101; A61B 5/14551 20130101; A61B 5/14557 20130101; A61B
2562/225 20130101; A61B 5/7275 20130101; A61B 2562/22 20130101;
A61B 2562/222 20130101; H01R 2201/12 20130101; A61B 5/742 20130101;
A61B 5/746 20130101; H01R 13/5224 20130101; A61B 5/14553 20130101;
A61B 5/14552 20130101; A61B 5/1455 20130101 |
Class at
Publication: |
600/323 |
International
Class: |
A61B 5/1455 20060101
A61B005/1455; A61B 5/00 20060101 A61B005/00 |
Claims
1. A regional oximetry sensor comprising: a face tape layer; a base
tape layer adhesively attachable to a patient skin surface; at
least one emitter configured to transmit optical radiation into the
patient skin surface; a near-field detector configured to detect
the optical radiation after attenuation by tissue of the patient; a
far field detector also configured to detect the optical radiation
after attenuation by tissue of the patient; and at least one focus
element associated with at least one of the at least one emitter,
the near-field detector and the far field detector.
2. The regional oximetry sensor of claim 1, wherein the focus
element comprises a half-dome shape.
3. The regional oximetry sensor of claim 2, wherein the focus
element comprises a rectangular planar base.
4. The regional oximetry sensor of claim 1, wherein the focus
element comprises a three dimensional shape that allows the focus
element to press into the patient skin surface.
5. The regional oximetry sensor of claim 1, wherein the focus
element increases optical transmission with the patient skin
surface.
6. The regional oximetry sensor of claim 1, further comprising at
least a second focus element.
7. The regional oximetry sensor of claim 6, wherein at least one
focus element is associated with the near-field detector and at
least one focus element is associated with the far field
detector.
8. The regional oximetry sensor of claim 7, wherein the focus
element associated with the near field detector is smaller than the
focus element associated with the far field detector.
9. The regional oximetry sensor of claim 6, further comprising a
third focus element associated with the at least one emitter.
10. A regional oximetry sensor comprising: a face tape layer; a
base tape layer adhesively attachable to a patient skin surface; at
least one emitter configured to transmit optical radiation in to
the patient skin surface; a near-field detector configured to
detect the optical radiation after attenuation by tissue of the
patient; a far field detector also configured to detect the optical
radiation after attenuation by tissue of the patient; and wherein
the face tape layer and the base tape layer cooperate together and
include a plurality of notches forming a plurality of cutouts.
11. The regional oximetry sensor of claim 10, wherein the plurality
of notches forming the plurality of cutouts are formed on a
periphery of the base and face tape layers.
12. The regional oximetry sensor of claim 11, wherein the cutouts
are mechanically decoupled from each other.
13. The regional oximetry sensor of claim 12, wherein the cutouts
allow for ease of patient movement of the measurement site.
14. A peel-off resistant regional oximetry sensor comprising: a
sensor head attachable to a patient skin surface and configured to
transmit optical radiation into the skin and receive that optical
radiation after attenuation by blood flow within the skin; and a
stem extending from the sensor head and configured to transmit
electrical signals between the sensor head and an attached cable;
wherein the stem is terminated interior to the sensor head and away
from an edge of the sensor head so as to define feet along either
side of the stem distal the stem termination.
15. The regional oximetry sensor of claim 14, wherein the sensor
head and stem form a single continuous body.
16. The regional oximetry sensor of claim 14, wherein the sensor
head and stem are substantially flat.
17. The regional oximetry sensor of claim 14, wherein the stem
extends radially outward from the sensor head.
18. A peel-off resistant regional oximetry sensor comprising: a
face tape layer; a base tape layer adhesively attachable to a
patient skin surface, the face tape layer and base tape layer
cooperating to form a sensor head and stem, the sensor head
including notches on either side of the stem at the junction of the
sensor head and stem, the notches mechanically decoupling the
sensor stem from a radial edge of the sensor head; at least one
emitter configured to transmit optical radiation in to the patient
skin surface; a near-field detector configured to detect the
optical radiation after attenuation by tissue of the patient; and a
far field detector also configured to detect the optical radiation
after attenuation by tissue of the patient.
19. The regional oximetry sensor of claim 18, wherein the sensor
head and stem form a single continuous body.
20. The regional oximetry sensor of claim 18, wherein the sensor
head and stem are substantially flat.
21. The regional oximetry sensor of claim 18, wherein the stem
extends radially outward from a distal portion of the sensor head.
Description
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS
[0001] Any and all applications for which a foreign or domestic
priority claim is identified in the Application Data Sheet as filed
with the present application are hereby incorporated by reference
under 37 CFR 1.57. The present application claims priority benefit
under 35 U.S.C. .sctn.119(e) to U.S. Provisional Patent Application
Ser. No. 62/012,170, filed Jun. 13, 2014, titled Peel-Off Resistant
Regional Oximetry Sensor, U.S. Provisional Patent Application Ser.
No. 61/887,878 filed Oct. 7, 2013, titled Regional Oximetry Pod;
U.S. Provisional Patent Application Ser. No. 61/887,856 filed Oct.
7, 2013, titled Regional Oximetry Sensor; and U.S. Provisional
Patent Application Ser. No. 61/887,883 filed Oct. 7, 2013, titled
Regional Oximetry User Interface; all of the above-referenced
provisional patent applications are hereby incorporated in their
entireties by reference herein.
FIELD
[0002] The present disclosure relates to the field of optical based
physiological sensors.
BACKGROUND
[0003] Regional oximetry, also referred to as tissue oximetry and
cerebral oximetry, enables the continuous assessment of the
oxygenation of tissue. The measurement is taken by placing one or
more sensors on a patient, frequently on the patient's left and
right forehead. Regional oximetry estimates regional tissue
oxygenation by transcutaneous measurement of areas that are
vulnerable to changes in oxygen supply and demand. Regional
oximetry exploits the ability of light to penetrate tissue and
determine hemoglobin oxygenation according to the amount of light
absorbed by hemoglobin.
[0004] Regional oximetry differs from pulse oximetry in that tissue
sampling represents primarily (70-75%) venous, and less (20-25%)
arterial blood. The technique uses two photo-detectors with each
light source, thereby allowing selective sampling of tissue beyond
a specified depth beneath the skin. Near-field photo-detection is
subtracted from far-field photo-detection to provide selective
tissue oxygenation measurement beyond a pre-defined depth.
Moreover, regional oximetry monitoring does not depend upon
pulsatile flow.
[0005] Regional oximetry is a useful patient monitoring technique
to alert clinicians to dangerous clinical conditions. Changes in
regional oximetry have been shown to occur in the absence of
changes in arterial saturation or systemic hemodynamic
parameters.
SUMMARY
[0006] The present disclosure provides a regional oximetry sensor.
The regional oximetry sensor includes, for example, a face tape
layer and a base tape layer adhesively attachable to a patient skin
surface. The regional oximetry sensor also includes at least one
emitter configured to transmit optical radiation into the patient
skin surface, a near-field detector configured to detect the
optical radiation after attenuation by tissue of the patient and a
far field detector also configured to detect the optical radiation
after attenuation by tissue of the patient. In an embodiment, the
regional oximetry sensor also includes one or more focus elements
associated with one or more of the emitter, the near-field detector
and the far field detector. In an embodiment any or all of the
emitter, near-field detector and far field detector can be provided
with a focus element. The focus element improves optical
transmissions by gently pushing into the skin and providing
improved optical coupling with the skin.
[0007] The focus element can include a half-dome shape or any three
dimensional shape that gently pushes into the skin to improve
optical coupling. The focus element can also have a rectangular
planar base in order to provide a support structure for cooperating
with the face tape layer and/or other portions of the regional
oximetry sensor. In an embodiment, the focus element associated
with the near-field detector is smaller than the focus element
associated with the far field detector. For example, the near field
detector includes a square shape whereas the far field detector
includes a larger rectangular shape.
[0008] In an embodiment of the regional oximetry sensor, the
regional oximetry sensor can have a face tape layer and a base tape
layer adhesively attachable to a patient skin surface as discussed
above. The sensor can also have at least one emitter configured to
transmit optical radiation into the patient skin surface, a
near-field detector configured to detect the optical radiation
after attenuation by tissue of the patient, and a far field
detector also configured to detect the optical radiation after
attenuation by tissue of the patient. In some embodiments, the face
tape layer and the base tape layer include a plurality of notches
forming a plurality of cutouts. The plurality of cutouts can be
formed in a portion of a periphery or across the entire periphery
of the base and face tape layers, for example. The cutouts are
mechanically decoupled from each other. Due to the mechanical
decoupling, the cutouts allow for greater ease of patient movement
of the measurement site. This reduces patient discomfort while
wearing the regional sensor.
[0009] In an embodiment, a peel-off resistant regional oximetry
sensor is disclosed. The peel-off resistant regional oximetry
sensor includes a head attachable to a patient skin surface and
configured to transmit optical radiation into the skin and receive
that optical radiation after attenuation by blood flow within the
skin and a stem extending from the sensor head and configured to
transmit electrical signals between the sensor head and an attached
cable. The stem is terminated interior to the sensor head and away
from an edge of the sensor head so as to define feet along either
side of the stem distal the stem termination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The drawings and following associated descriptions are
provided to illustrate embodiments of the present disclosure and do
not limit the scope of the claims. Corresponding numerals indicate
corresponding parts, and the leading digit of each numbered item
indicates the first figure in which an item is found.
[0011] FIG. 1 is a depiction of a patient monitoring system
including regional oximetry sensors and a processing and display
unit.
[0012] FIGS. 2A-C are top and bottom perspective views and a
connector-end view, respectively, of a regional oximetry
sensor;
[0013] FIGS. 3A-C are top exploded, bottom partially-exploded and
bottom assembled perspective views, respectively, of regional
oximetry sensor head, stem and shell assemblies;
[0014] FIG. 4 is a bottom plan view a sensor cable and sensor flex
circuit interconnection;
[0015] FIGS. 5A-H are a top plan view, top and bottom perspective
views, first side and first side cross-sectional views, second side
and second side cross-sectional views and a bottom view,
respectively, of a near-field detector lens;
[0016] FIGS. 6A-H are a top plan view, top and bottom perspective
views, first side and first side cross-sectional views, second side
and second side cross-sectional views and a bottom view,
respectively, of a far-field detector lens;
[0017] FIG. 7 is a cross-sectional view of a regional oximetry
sensor attached to a tissue site and corresponding near-field and
far-field emitter-to-detector optical paths;
[0018] FIGS. 8A-B are a regional oximetry monitor display of sensor
placement options for an adult and a child, respectively; and
[0019] FIG. 8C is an exemplar regional oximetry monitor display
using two regional sensors.
[0020] FIGS. 9A-B are top perspective views of a regional oximetry
sensor being inadvertently peeled from a skin-surface
monitoring-site due to a pulling force applied to the sensor stem
and interconnecting sensor cable;
[0021] FIG. 10 is a top perspective view of a peel-off resistant
regional oximetry sensor;
[0022] FIGS. 11 A-B are top perspective views of a peel-off
resistant regional oximetry sensor adhering to a skin-surface
monitoring site despite a pulling force applied to the sensor stem
and interconnecting sensor cable; and
[0023] FIGS. 12A, 12B, 13A and 13B are side-by-side, top
perspective views of a regional oximetry sensor and a peel-off
resistant regional oximetry sensor subjected to like pulling forces
and the corresponding impact of anti-peel feet extending from the
cable-side of the peel-off resistant regional oximetry sensor.
DETAILED DESCRIPTION
[0024] Aspects of the disclosure will now be set forth in detail
with respect to the figures and various embodiments. One of skill
in the art will appreciate, however, that other embodiments and
configurations of the devices and methods disclosed herein will
still fall within the scope of this disclosure even if not
described in the same detail as some other embodiments. Aspects of
various embodiments discussed do not limit the scope of the
disclosure herein, which is instead defined by the claims following
this description.
[0025] FIG. 1 is a physiological monitoring system 100 configured
to measure and display regional oximetry measurements. The
physiological monitoring system 100 includes at least a display 103
and a processor (not shown) for processing and displaying
physiological measurements. The physiological monitoring system 100
also includes at least one sensor 200 for detecting physiological
information and providing that physiological information to the
processor of the physiological monitoring system 100. In the
embodiment of FIG. 1, the physiological monitoring system includes
a removable hand held physiological monitor 105. The physiological
monitoring system 100 of FIG. 1 also includes a sensor cable system
106 that includes wiring 107 and a sensor connector 109. Sensor
connector 109 includes ports for two or more sensors. The sensors
are described in more detail with respect to FIGS. 2A-2C.
[0026] FIGS. 2A-C illustrate a regional oximetry sensor 200
embodiment having a sensor head 210, stem 220, shell 230, cable 240
and connector 250. The sensor head 210 houses an emitter 282, a
near-field detector 284 and a far-field detector 288 within a
layered tape having a top side 211 and an adhesive bottom side 212
disposed on a release liner 260. The release liner 260 is removed
so as to adhere the bottom side 212 to a skin surface. The sensor
head 210 also includes notches or channels 291 that form cutouts
293. The cutouts 293 are independently flexible from other
neighboring cutouts. Because of the various placement locations of
the sensors on the human body and the movement forces placed on
regional oximetry sensors, the cutouts 293 allow the sensor head
210 to be relatively large to increase the measurement area and
adhesive surface area without greatly inhibiting patient movement.
Thus, for example, when a patient moves their forehead with a
sensor 200 adhesively attached, the sensor allows for some movement
of the underlying skin so that the patient is more comfortable, yet
provide a large enough surface area to provide good measurement and
adhesive qualities.
[0027] The regional oximetry sensor 200 is substantially flat,
allowing the sensor to adhere to the patient without significant
bulges. The stem 220 extends out radially outward from the sensor
head 210. The stem is positioned to extend from a radial edge in
order to provide a clean exit from the body for wiring and cables.
The radial placement also provides for streamlined sensor
construction and prevents unnecessary bending or wrapping of
internal or external wires.
[0028] The emitter 282 and detectors 284, 288 have a lens that
protrudes from the bottom side 212, advantageously providing a
robust optics-skin interface. The top side 211 has emitter/detector
indicators 272-278 so as to aid precise sensor placement on a
patient site. The shell 230 houses the stem 220 to cable 240
interconnect, described in detail with respect to FIGS. 3A-C,
below. The connector 250 is a 12-pin, D-shaped plug.
[0029] FIGS. 3A-C illustrate an assembly of a regional oximetry
sensor portion including a head assembly (FIG. 3A) and a sensor
cable to flex circuit interconnect (FIGS. 3B-C). As shown in FIG.
3A, a sensor head assembly 301 has a face tape 310, a flex circuit
320, a sensor cable 330, a stem tape 340, a base tape 350, a shell
top 360 and a shell base 370. The face tape 310 and base tape 350
encase the flex circuit 320 and corresponding emitter and
detectors. The shell top and base 360, 370 encase the sensor cable
330 to flex circuit 320 interconnect, described in further detail
with respect to FIGS. 4A-B, below. The stem tape 340 encases the
flex circuit 320 below the base tape 350.
[0030] FIG. 4 illustrates sensor flex circuit 320 to sensor cable
330 interconnection. The flex circuit 320 is positioned on mounting
pins in the top shell 360 (FIG. 3B). As shown in FIG. 4, cable 330
wires are soldered to flex circuit pads 410, 420. Cable 330 Kevlar
bundles are wrapped around a shell post 430 for strain relief and
secured with adhesive. A detector shield flap 440 is folded over
detector wires soldered to the detector pads 410 and secured with
Kapton tape. The base shell 370 (FIG. 3B) is then glued in place
over the top shell 360 (FIG. 3B). In the embodiment of FIG. 4, the
connections to the flex circuit 320 include four emitter anode
conductors controlling four different wavelength emitters, a common
emitter cathode conductor and an emitter shield, two near-field
detector conductors, two far-field detector conductors and a
detector shield. In an embodiment, the emitter and detector
connections are physically separated between different circuit
pads, for example, pads 410 and 420. This reduces and/or prevents
cross talk and noise between the emitter lines and the detector
lines. Of course a person of skill in the art will understand from
the present disclosures that different numbers and types of
connectors can be used with the presently described connection
system.
[0031] FIGS. 5A-H illustrate an emitter lens and a near-field
detector lens 500 having a generally half-dome focus element 501
and a generally rectangular, planar base 502. As described above,
the lens base 502 is disposed over the flex-circuit-mounted emitter
and near-field detector in order to focus emitted and detected
light. Also as described above, the lens focus element 501 is
configured to gently press into a tissue site when applied to the
patient in order to maximize optical transmission via the skin
surface. The focus elements can also use different three
dimensional shapes as well in order to improve optical coupling
with the skin and the present disclosure is not limited to the
specific embodiments disclosed herein. For example, the lens can be
spherical, cubed, rectangular, square, circular oblong or any other
shape to increase optical transmission with the skin.
[0032] FIGS. 6A-H illustrate a far-field detector lens 600 having a
generally oblong, half-dome focus element 601 and a generally
oblong, planar base 602. As described above, the lens base 602 is
disposed over the flex-circuit-mounted far-field detector so as
focus detector received light. Also as described above, the lens
focus element 601 gently presses into a tissue site in order to
maximize optical transmission via the skin surface. Also, as
described above with respect to FIG. 5, the present disclosure is
not limited to the specific dimensions and shape described herein
which are provided for illustrative purposes. Rather, as discussed
above, the present disclose extends to other shapes and sizes of a
focus element that will improve optical coupling. Moreover, the
focus element 601 can comprise two or more different focus elements
instead of a single larger focus element.
[0033] FIG. 7 illustrates a regional oximetry sensor 700 attached
to a tissue site 70 so as to generate near-field 760 and far-field
770 emitter-to-detector optical paths through the tissue site 70.
The resulting detector signals are processed so as to calculate and
display oxygen saturation (SpO.sub.2), delta oxygen saturation
(.DELTA.SpO.sub.2) and regional oxygen saturation (rSO.sub.2), as
shown in FIG. 8C, below. The regional oximetry sensor 700 has a
flex circuit layer 710, a tape layer 720, an emitter 730, a
near-field detector 740 and a far-field detector 750. The emitter
730 and detectors 740, 750 are mechanically and electrically
connected to the flex circuit 710. The tape layer 720 is disposed
over and adheres to the flex circuit 710. Further, the tape layer
720 attaches the sensor 700 to the skin 70 surface.
[0034] As shown in FIG. 7, the emitter 730 has a substrate 732
mechanically and electrically connected to the flex circuit 710 and
a lens 734 that extends from the tape layer 720. Similarly, each
detector 740, 750 has a substrate 742, 752 and each has a lens 744,
754 that extends from the tape layer. In this manner, the lenses
734, 744, 754 press against the skin 70, advantageously increasing
the optical transmission and reception of the emitter 730 and
detectors 740, 750 through improved optical coupling. The lenses
press into the skin and provide a more direct angle of light
propagation through the skin between the emitter and detectors.
[0035] FIGS. 8A-B illustrate regional oximetry monitor embodiments
for designating adult and child sensor placement sites. As shown in
FIG. 8A, an adult form 801 is generated on a user interface
display. Between one and four sensor sites can be designated on the
adult form 801, including left and right forehead 810, forearm 820,
chest 830, upper leg 840, upper calf 850 and calf 860 sites.
Accordingly, between one and four sensors 200 (FIGS. 2A-C) can be
located on these sites. A monitor in communication with these
sensors then displays between one and four corresponding regional
oximetry graphs and readouts, as described with respect to FIG. 8C,
below. As illustrated in FIGS. 8A-8C, the sensor can be positioned
on a patient so that the sensor stem 220 and attached cabling can
extend radially out from the body on the various regional oximetry
sensor sites. This configuration reduces patient discomfort by
preventing wiring from crossing or crisscrossing over a patient
face, torso or lower body. This configuration also reduces the
potential for entanglement of wires from the multiple sensors and
associated cabling.
[0036] As shown in FIG. 8B, a child form 802 is generated on a user
interface display. Between one and four sensor sites can be
designated on the child form 802, including left and right forehead
810, left and right renal 870, and left and right abdomen 880
sites. Any number of regional oximetry sensors can be deployed on a
patient at the same time, but generally, between one and four
sensors 200 (FIGS. 2A-C) are located on these sites at a given
time. A monitor in communication with these sensors then displays
between a corresponding regional oximetry graphs and readouts for
each sensor, as described with respect to FIG. 8C, below. The
displays of FIGS. 8A and 8B can also be selectively shown such
that, for example, only an upper torso portion of the graphic is
shown to prevent confusion by a care provider.
[0037] FIG. 8C illustrates a regional oximetry display 800
embodiment for monitoring parameters derived from between one and
four regional oximetry sensors 200 (FIGS. 2A-C). This particular
example is a two sensor display for monitoring, for example, a
forehead left 811 site and a forehead right 831 site. In an upper
display portion, the forehead left 812 site displays, for example,
an SpO.sub.2 graph 812, an rSO.sub.2 graph 814 and an rSO.sub.2
readout 816. Similarly, the forehead right 831 site displays, for
example, an SpO.sub.2 graph 832, an rSO.sub.2 graph 834 and an
rSO.sub.2 readout 836.
[0038] Also shown in FIG. 8C, in a lower display portion, the
forehead left 851 site displays, for example, an SpO.sub.2 readout
852, a .DELTA.SO.sub.2 readout 854 and a .DELTA..sub.base readout
856. Similarly, the forehead right 830 site displays, for example,
an SpO.sub.2 readout 872, a .DELTA.SO.sub.2 readout 874 and a
.DELTA..sub.base readout 876.
[0039] FIGS. 9A-B illustrate a problem that arises with a regional
oximetry sensor 200 during use. The connector 250 is fixedly
connected to a physiological monitor (not shown) that provides a
read-out of parameters derived from the sensor 200. Patient
movement away from the monitor may occur in a manner that pulls on
the cable (not shown) and bends the attached stem 220 up and/or
over the sensor head 210 (FIG. 9A). Continued patient movement away
from the monitor may cause a portion of the sensor head 901 to peel
off of the patient's skin (FIG. 2B), disrupting accurate parameter
measurements. Indeed, continued patient movement may completely
dislodge the sensor head 210 from the patient.
[0040] A peel-off resistant regional oximetry sensor has a sensor
head attachable to a patient skin surface so as to transmit optical
radiation into the skin and receive that optical radiation after
attenuation by blood flow within the skin. A stem extending from
the sensor head transmits electrical signals between the sensor
head and an attached cable. The stem is terminated interior to the
sensor head and away from a sensor head edge so as to define feet
along either side of the stem distal the stem termination. The stem
interior termination substantially transforming a peel load on a
sensor head adhesive to less challenging tension and shear loads on
the sensor head adhesive.
[0041] FIG. 10 illustrates an advantageous peel-off resistant
regional oximetry sensor 1000 embodiment having a sensor head 1010,
stem 1020, shell 230, cable 240 and connector 250. The sensor head
1010 houses an emitter, a near-field detector and a far-field
detector within a layered tape having a top side and an adhesive
bottom side disposed on a release liner, similar to that described
with respect to FIGS. 2A-B, above. The peel-off resistant regional
oximetry sensor 1000 has peel-resistant feet 1012 proximately
disposed on either side of the stem. The feet are defined by stem
slots 1014 separating the feet from the stem. This configuration
advantageously moves the stem 1020 base from the edge of the sensor
head (e.g. 210 FIG. 2A) to the interior of the sensor head 1010. As
a result, potential peel loads on the sensor head adhesive
resulting from the stem 1020 being pulled over the sensor head are
substantially reduced, as described with respect to FIGS. 12A-13B,
below.
[0042] FIGS. 11A-B illustrate a peel-off resistant regional
oximetry sensor 1000 adhering to a skin-surface monitoring site
despite a pulling force applied to the sensor stem 1020 and
interconnecting sensor cable. Patient movement relative to
connected monitor tends to cause the stem 1020 to peel up the
sensor head (see FIG. 2B, above). The sensor head feet 1012,
however, advantageously extend away from the point where the stem
1020 begins applying a load to the sensor head adhesive, thus
counteracting the peel away force. Further the resulting adhesive
loads are different in kind and magnitude than the adhesive loads
on the sensor head shown and described with respect to FIG. 2,
above. Comparative adhesive loads are described in detail with
respect to FIGS. 12A-13B, below.
[0043] FIGS. 12A-13B illustrate comparative adhesive loads applied
to a regional oximetry sensor and a peel-off resistant regional
oximetry sensor resulting from cable forces applied to the sensor
head stems 220 (FIGS. 12A-B), 1020 (FIGS. 13A-B). As shown in FIGS.
12A-B, the stem 220 applies a substantial peel load 221 to the
sensor head 210 adhesive 222, and the peel load 221 is distributed
over a relatively small area 223 of the sensor head 210. It is
well-know that a peel load 221 is a substantial challenge to any
adhesive, and the milder adhesives used on skin cannot easily
overcome this challenge. As such, it is relatively easy for the
sensor head 210 to become dislodged or completely detached from the
patient.
[0044] As shown in FIGS. 13A-B, the stem 1020 applies different
loads 1021 to the sensor head 310 adhesive 322, 323, 324 than
described with respect to FIGS. 12A-B. In particular, there is a
marginal peel load on the adhesive as the result of the adhesive
feet 1012 positioned opposite the connection point of the stem 1020
to the sensor head 1010. The sheer load due to the stem force 1021
is much less challenging to the feet adhesive 1024 compared to a
peel load. Likewise, the tension load due to the stem force 1021 is
less challenging to the feet adhesive 1022, 1023, compared to a
peel load, and that tension load is distributed on both sides of
the stem-to-head connection point. That is, the cumulative effect
of positioning the stem 1020 somewhat to the interior of the sensor
head 1010 and behind the feet 1021 is a greatly diminished adhesive
peel load and much less challenging shear and tension loads
distributed over a larger adhesive footprint. The advantageous
result is a sensor head-to-cable stem interface that is much less
likely to dislodge the sensor head from the patient when forces are
applied to the sensor cable. Further, more skin-friendly adhesives
can be utilized for sensor head attachment as a result of lowered
adhesive loads.
[0045] A peel-off resistant regional oximetry sensor has been
disclosed in detail in connection with various embodiments. These
embodiments are disclosed by way of examples only and are not to
limit the scope of this disclosure or the claims that follow. One
of ordinary skill in art will appreciate many variations and
modifications.
Terminology
[0046] Embodiments have been described in connection with the
accompanying drawings. However, it should be understood that the
figures are not drawn to scale. Distances, angles, etc. are merely
illustrative and do not necessarily bear an exact relationship to
actual dimensions and layout of the devices illustrated. In
addition, the foregoing embodiments have been described at a level
of detail to allow one of ordinary skill in the art to make and use
the devices, systems, etc. described herein. A wide variety of
variation is possible. Components, elements, and/or steps can be
altered, added, removed, or rearranged. While certain embodiments
have been explicitly described, other embodiments will become
apparent to those of ordinary skill in the art based on this
disclosure.
[0047] Conditional language used herein, such as, among others,
"can," "could," "might," "may," "e.g.," and the like, unless
specifically stated otherwise, or otherwise understood within the
context as used, is generally intended to convey that certain
embodiments include, while other embodiments do not include,
certain features, elements and/or states. Thus, such conditional
language is not generally intended to imply that features, elements
and/or states are in any way required for one or more embodiments
or that one or more embodiments necessarily include logic for
deciding, with or without author input or prompting, whether these
features, elements and/or states are included or are to be
performed in any particular embodiment.
[0048] Depending on the embodiment, certain acts, events, or
functions of any of the methods described herein can be performed
in a different sequence, can be added, merged, or left out
altogether (e.g., not all described acts or events are necessary
for the practice of the method). Moreover, in certain embodiments,
acts or events can be performed concurrently, e.g., through
multi-threaded processing, interrupt processing, or multiple
processors or processor cores, rather than sequentially.
[0049] The various illustrative logical blocks, engines, modules,
circuits, and algorithm steps described in connection with the
embodiments disclosed herein can be implemented as electronic
hardware, computer software, or combinations of both. To clearly
illustrate this interchangeability of hardware and software,
various illustrative components, blocks, modules, circuits, and
steps have been described above generally in terms of their
functionality. Whether such functionality is implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system. The described
functionality can be implemented in varying ways for each
particular application, but such implementation decisions should
not be interpreted as causing a departure from the scope of the
disclosure.
[0050] The various illustrative logical blocks, modules, and
circuits described in connection with the embodiments disclosed
herein can be implemented or performed with a general purpose
processor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA) or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general purpose processor can be a microprocessor, but in the
alternative, the processor can be any conventional processor,
controller, microcontroller, or state machine. A processor can also
be implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0051] The blocks of the methods and algorithms described in
connection with the embodiments disclosed herein can be embodied
directly in hardware, in a software module executed by a processor,
or in a combination of the two. A software module can reside in RAM
memory, flash memory, ROM memory, EPROM memory, EEPROM memory,
registers, a hard disk, a removable disk, a CD-ROM, or any other
form of computer-readable storage medium known in the art. An
exemplary storage medium is coupled to a processor such that the
processor can read information from, and write information to, the
storage medium. In the alternative, the storage medium can be
integral to the processor. The processor and the storage medium can
reside in an ASIC. The ASIC can reside in a user terminal. In the
alternative, the processor and the storage medium can reside as
discrete components in a user terminal.
[0052] While the above detailed description has shown, described,
and pointed out novel features as applied to various embodiments,
it will be understood that various omissions, substitutions, and
changes in the form and details of the devices or algorithms
illustrated can be made without departing from the spirit of the
disclosure. As will be recognized, certain embodiments of the
inventions described herein can be embodied within a form that does
not provide all of the features and benefits set forth herein, as
some features can be used or practiced separately from others. The
scope of certain inventions disclosed herein is indicated by the
appended claims rather than by the foregoing description. All
changes which come within the meaning and range of equivalency of
the claims are to be embraced within their scope.
* * * * *