U.S. patent application number 13/672506 was filed with the patent office on 2013-11-21 for foldable sensor device and method of using same.
This patent application is currently assigned to Nonin Medical, Inc.. The applicant listed for this patent is Nonin Medical, Inc.. Invention is credited to Vladimir Grubac, Peter R. Rosendahl.
Application Number | 20130310667 13/672506 |
Document ID | / |
Family ID | 39716706 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130310667 |
Kind Code |
A1 |
Grubac; Vladimir ; et
al. |
November 21, 2013 |
FOLDABLE SENSOR DEVICE AND METHOD OF USING SAME
Abstract
A physiologic sensor device configured to be placed on an
appendage. The sensor device includes a foldable portion designed
to be deformed around the tip of the appendage. In some embodiments
the foldable portion is a soft compressible material. In other
embodiments a stabilization component is provided to isolate
sensing elements from external forces. Some embodiments also
include a deformable frame that folds in response to a bending
force as the sensing device is placed on the appendage. The
deformable frame holds the sensor device in place until another
bending force is applied. In other embodiments the frame and/or
sensor elements are removable and disposable relative to other
components of the sensor device.
Inventors: |
Grubac; Vladimir; (Plymouth,
MN) ; Rosendahl; Peter R.; (Plymouth, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nonin Medical, Inc. |
Plymouth |
MN |
US |
|
|
Assignee: |
Nonin Medical, Inc.
Plymouth
MN
|
Family ID: |
39716706 |
Appl. No.: |
13/672506 |
Filed: |
November 8, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11679595 |
Feb 27, 2007 |
8326392 |
|
|
13672506 |
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Current U.S.
Class: |
600/323 ; 29/428;
600/300; 600/476 |
Current CPC
Class: |
A61B 5/6824 20130101;
A61B 5/0002 20130101; A61B 5/14551 20130101; A61B 5/14552 20130101;
A61B 2562/164 20130101; Y10T 29/49826 20150115; A61B 5/6838
20130101; A61B 5/6826 20130101 |
Class at
Publication: |
600/323 ;
600/300; 600/476; 29/428 |
International
Class: |
A61B 5/00 20060101
A61B005/00; A61B 5/1455 20060101 A61B005/1455 |
Claims
1. A sensor device comprising: a foldable member carrying one or
more sensor elements; a communications link configured to transmit
data from said one or more sensor elements; and a frame engaging
said foldable member, together said frame and foldable member
adapted to be deformed from an initial shape into a customized form
providing said one or more sensor elements in a desired orientation
relative to a tissue field, with said frame maintaining said
foldable member in said customized form.
2. The sensor device of claim 1 further comprising: a flexible
cover material connected to the foldable member, said flexible
cover material covering a skin surface engaging material.
3. The sensor device of claim 1 further comprising: a stabilization
component between a lead of said communications link and said one
or more sensors elements.
4. The sensor device of claim 3 wherein the stabilization component
comprises: a first aperture through said foldable member and
disposed between said one or more sensor elements and said
lead.
5. The sensor device of claim 4 wherein the stabilization component
further comprises: a second aperture through said foldable member
and disposed between said first aperture and said one ore more
sensor elements; and a bridge disposed between said first aperture
and second aperture.
6. The sensor device of claim 3 wherein the stabilizing component
comprises: an elongated tail.
7. The sensor device of claim 6 wherein the tail is configured to
wrap around a finger and forearm of a user.
8. The sensor device of claim 1 wherein said one or more sensor
elements further comprises: a light source; and a light detector
configured to receive light from said light source through said
tissue field.
9. The sensor device of claim 1 wherein the foldable member is
removable from said one or more sensor elements.
10. The sensor device of claim 1 wherein said communications link
is a wired link to a remote site.
11. The sensor device of claim 1 wherein said communications link
is a wireless link.
12. The sensor device of claim 1 wherein said foldable member
further comprises: a first material disposed on a bottom portion of
the device; and a second material disposed on a top portion of the
device.
13. The sensor device of claim 12 wherein the first material is a
compressible material.
14. The sensor device of claim 13 wherein the first material is a
polyurethane foam.
15. The sensor device of claim 12 wherein the second material is
denser than the first material.
16. The sensor device of claim 12 wherein said frame is disposed
between the first material and second material.
17. The sensor device of claim 16 wherein said frame is separable
and disposable from said foldable component.
18. The sensor device of claim 1 wherein said frame is of malleable
material.
19. The sensor device of claim 1 wherein the foldable member has a
plurality of apertures arranged to provide air circulation to said
tissue field covered by said foldable component.
20. The sensor device of claim 1 further comprising: an alignment
aperture adapted to be engaged by an appendage tip prior to folding
of said foldable member.
21. The sensor device of claim 20 wherein the aperture has a first
radius and a second radius, the first radius and the second radius
corresponding to radii of said appendage tip.
22. The sensor device of claim 1 wherein the foldable member
further comprises: a curved portion configured to interface with a
bottom portion of an appendage and to allow movement of the
appendage when the device is folded.
23. The sensor device of claim 22 wherein the curved portion define
portions of a pair of winglets configured to fold around sides of
the appendage.
24. The sensor device of claim 1 wherein a rear section of the
foldable member further comprises a stabilization component.
25. The sensor device of claim 24 wherein the stabilization
component comprises a first aperture, wherein an appendage is
placed through the first aperture prior to folding the device.
26. The sensor device of claim 25 wherein the stabilization
component further comprises: a second aperture proximate to the
first aperture; a bridge disposed between the first and second
aperture; and wherein the appendage is inserted through the second
aperture over the bridge and through the first aperture such that
the appendage
27. The sensor device of claim 24 wherein the stabilization
component comprises a wrapping tail, the wrapping tail having a
length sufficient to wrap around a forearm.
28. A sensor device configured to be placed on an appendage of an
animal, comprising: a foldable member carrying one or more sensor
elements; and a pliant frame connected to said foldable member,
said frame and foldable member being configured by a deforming
force to conform to an appendage, said frame and foldable member
positioning said one or more sensor elements proximate to a tissue
field of said appendage, and said frame maintaining said foldable
member in a deformed orientation upon release of the deforming
force.
29. The sensor device of claim 28 wherein the foldable member
comprises: a first material; a second material; and wherein the
first material and second material overlap such that when folded
the first material engages a surface of said tissue field and the
second material is generally disposed on an outside of the folded
member.
30. The sensor device of claim 29 wherein the first material is a
foam-type material.
31. The sensor device of claim 30 wherein the first material is a
polyurethane foam.
32. The sensor device of claim 29 wherein the second material is
comprised of a foam like material, the second material being denser
than the first material.
33. The sensor device of claim 32 wherein the second material
defines a protective layer for the sensor device.
34. The sensor device of claim 28 wherein said foldable member is
separable from said frame.
35. The sensor device of claim 28 further comprising: a
communications link providing communication between said one or
more sensors and a remote device.
36. The sensor device of claim 35 wherein the communications link
includes a wired component.
37. The sensor device of claim 35 wherein the communication link
includes a wireless component.
38. The sensor device of claim 28 wherein the foldable member
further comprises: an alignment aperture adapted to be engaged by a
tip of said appendage prior to folding of said foldable member.
39. The sensor device of claim 38 wherein the aperture has a first
radius and a second radius, the first radius and the second radius
corresponding to radii of said appendage tip.
40. The sensor device of claim 28 wherein the foldable member
further comprises: a curved portion, said curved portion configured
to interface with a bottom portion of the appendage and to allow
movement of the appendage when the device is folded.
41. The sensor device of claim 40 wherein the curved portion
comprises portions of two winglets, the winglets configured to fold
around sides of the appendage.
42. The sensor device of claim 28 wherein a rear section of the
foldable member further comprises a stabilization component.
43. The sensor device of claim 42 wherein the stabilization
component comprises a first aperture, wherein the appendage is
placed through the first aperture prior to folding the device.
44. The sensor device of claim 43 wherein the stabilization
component further comprises: a second aperture proximate to the
first aperture; a bridge disposed between the first and second
aperture; and wherein the appendage is inserted through the second
aperture over the bridge and through the first aperture during
application of said sensor device.
45. The sensor device of claim 42 wherein the stabilization
component comprises a wrapping tail, the wrapping tail having a
length sufficient to wrap around a forearm.
46. The sensor device of claim 28 wherein the sensor comprises: a
pair of light emitting diodes disposed on the foldable member; a
photodiode disposed on the foldable member; and wherein the LED and
the photodiode are arranged on foldable member such that when
folded the LED and photodiode are on opposite sides of the
appendage.
47. A method of attaching a foldable sensor device to an appendage
comprising: placing the sensor device at a portion of the
appendage; folding the sensor device over said appendage portion
into a folded orientation; and biasing the sensor device in the
folded orientation so as to retain said appendage portion within
said folded sensor device.
48. The method of claim 47 further comprising: placing a portion of
the appendage into an alignment aperture, said aperture being sized
to correspond with a tip of the appendage.
49. The method of claim 48 further comprising: providing
stabilization of the sensor device using portions of said appendage
for stabilization.
50. The method of claim 49 wherein providing stabilization
comprises: inserting the appendage through a first aperture in the
sensor device.
51. The method of claim 50 further comprising: inserting the
appendage through a second aperture in the sensor device; and
placing the appendage over a bridge located between the first and
second apertures.
52. The method of claim 47 wherein providing stabilization
comprises: wrapping a portion of the sensor device around the
appendage.
53. The method of claim 52 wherein wrapping the portion of the
sensor device, further comprises: wrapping the portion around a
forearm of a patient.
54. The method of claim 47 wherein said folding comprises: bending
a rigid deformable frame disposed in a portion of said sensor
device.
55. The method of claim 54 wherein the frame is initially provided
in a flat form prior to being folded before use.
56. A method of attaching a foldable sensor device to an appendage
comprising: bending a deformable sensor device over an appendage
portion so as position optical sensor elements on either side of
the appendage; and biasing said sensor device in a bent position so
as to retain said appendage portion within said sensor device.
57. The method of claim 56 further comprising: placing a tip
portion of the appendage into an alignment aperture of said sensor
device.
58. The method of claim 56 further comprising: isolating said
optical sensor elements with a stabilization component, said
stabilization component transferring an external force to the
appendage away from the optical sensor elements.
59. The method of claim 58 wherein said isolating comprises:
inserting the appendage through a first aperture in the sensor
device.
60. The method of claim 59 further comprising: inserting the
appendage through a second aperture in the sensor device; and
placing the appendage over a bridge located between the first and
second apertures.
61. The method of claim 58 wherein said isolating comprises:
wrapping a tail portion of the sensor device around the
appendage.
62. The method of claim 61 wherein wrapping the portion of the
sensor device, further comprises: wrapping the portion around a
forearm of a patient.
63. The method of claim 56 wherein the frame is initially provided
in a flat form prior to being folded before use.
64. The method of claim 62 wherein said biasing is performed by a
malleable frame engaging foldable material in contact with said
apendage.
65. A method of adapting an oximeter sensor to an appendage
comprising: bending a deformable sensor device over an appendage
into a customized form so as conform portions of said sensor device
to said appendage and position elements of a light sensor at a
tissue field of the appendage; and maintaining said sensor device
in said customized form with a biasing element so as to retain said
sensor device upon said appendage and said light sensor elements at
the tissue field.
66. The method of claim 65 further comprising: isolating said
optical sensor elements with a stabilization component, said
stabilization component transferring an external force to the
appendage away from the optical sensor elements.
67. The method of claim 66 wherein said isolating comprises:
inserting the appendage through a first aperture in the sensor
device.
68. The method of claim 67 further comprising: inserting the
appendage through a second aperture in the sensor device; and
placing the appendage over a bridge located between the first and
second apertures.
69. The method of claim 65 wherein said isolation comprises:
wrapping a tail portion of the sensor device around the
appendage.
70. The method of claim 65 wherein said biasing element is a
deformable frame.
71. The method of claim 70 wherein said frame is enclosed within at
least a portion of the sensor device.
72. An assembly comprising: a plurality of preformed sensor devices
each having a deformable body, optical sensor components and a
communications link, each sensor device being customized prior to
use by deformation of said body from a preformed shape into a form
fit to a unique patient morphology, and each sensor having a frame
for maintaining said sensor in said form during a sensor
process.
73. The assembly of claim 72 wherein the sensors are provided in a
preformed shape which is generally flat.
74. The assembly of claim 72 wherein the patient morphology is
defined upon an appendage of the patient.
75. A method of customizing a sensor device to a unique user
comprising: applying a bending force to a preformed sensor device
having a deformable body, optical sensor components and a
communications link, said bending force causing the body to deform
into a shape unique to an appendage of said user; and biasing said
deformable body in said unique shape upon removal of said bending
force, said biasing relying at least in part on a frame deformed by
said bending force.
76. The method of claim 75 wherein said applying a bending force
results in a portion of said body being bent over a finger tip with
winglet portions being bent around the finger tip.
77. A method of manufacturing a sensor device comprising: attaching
optical sensor elements to a flexible substrate, said substrate
sized to conform to at least a portion of a patient appendage;
coupling said optical sensor elements to a communications link
extending away from said substrate; and connecting a deformable
frame to the substrate, said frame being sized to maintain the
substrate to said portion of the patient appendage.
78. The method of claim 77 wherein said connecting includes
encompassing said frame within said substrate.
79. The method of claim 77 wherein said substrate includes multiple
plies of material.
80. A sensor device comprising: a foldable member carrying one or
more sensor elements; and deformable means connected to said
foldable member, said deformable means and foldable member being
reconfigured by a deforming force to conform to an appendage, said
deformable means and foldable member positioning said one or more
sensor elements proximate to a tissue field of said appendage, and
said deformable means providing forces tending to maintain the
foldable member in a deformed orientation upon release of said
deforming force.
81. The sensor device of claim 80 wherein said deformable means
includes a malleable frame adapted to be bent around a tip of the
appendage.
82. The sensor device of claim 81 wherein a portion of the
malleable frame is bent along a longitudinal axis of the appendage
and another portion of the malleable frame is bent along an axis
perpendicular to the longitudinal axis.
Description
PRIORITY
[0001] This application is a continuation of and claims the benefit
of priority under 35 U.S.C. .sctn.120 to U.S. patent application
Ser. No. 11/679,595, entitled "FOLDABLE SENSOR DEVICE AND METHOD OF
USING SAME," filed on Feb. 27, 2007, which is hereby incorporated
by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present disclosure is directed to physiologic sensors.
More specifically, the present disclosure is directed to a sensor
device that can be folded to conform about an appendage by a
patient or care provider.
BACKGROUND OF THE INVENTION
[0003] Pulse oximetry involves the non-invasive monitoring of
oxygen saturation level in blood-profused tissue indicative of
certain vascular conditions. Pulse oximetry is typically used to
measure various blood flow characteristics including, but not
limited to, the blood-oxygen saturation of hemoglobin in arterial
blood, the volume of individual blood pulsations supplying the
tissue, and the rate of blood pulsations corresponding to each
heartbeat of a patient. Measurement of these characteristics has
been accomplished by use of a non-invasive sensor which passes
light through a portion of the patient's tissue where blood
perfuses the tissue, and photoelectrically senses the absorption of
light in such tissue. The amount of light absorbed is then used to
calculate the amount of blood constituent being measured. Oxygen
saturation may be calculated using some form of the classical
absorption equation know as Beer's law. The light passed through
the tissue is typically selected to be of one or more wavelengths
that are absorbed by the blood in an amount representative of the
amount of the blood constituent present in the blood. The amount of
transmitted light passed through the tissue will vary in accordance
with the changing amount of blood constituent in the tissue and the
related light absorption. For measuring blood oxygen level, such
sensors have been provided with light sources and photodetectors
that are adapted to operate at two or more different wavelengths,
in accordance with known techniques for measuring blood oxygen
saturation.
[0004] Known pulse oximetry sensors include an optical element
which uses a pair of light emitting diodes (LEDs) to direct light
through blood-perfused tissue, with a photodetector receiving light
which has not been absorbed by the tissue. Accurate pulse oximeter
measurements require relatively stable positioning of the sensor on
an appendage, as well as proper alignment between the light source
and light detector.
[0005] Accurate measurement of oxygen saturation levels are
predicated upon optical sensing in the presence of arterial blood
flow. A finger provides a convenient access to a body part through
which light will readily pass. Other body appendages may also be
used, e.g., toes and ears. Local vascular flow in a finger is
dependent on several factors which affect the supply of blood.
Blood flow may be affected by centrally mediated vasoconstriction,
which must be alleviated by managing the perceived central causes.
Peripheral constriction via external compression, however, can be
induced by local causes. One such cause of local vasocompression is
the pressure exerted by the sensor on the finger.
[0006] Many currently available pulse oximetry finger sensors have
a hard shell which is maintained upon the finger tip by spring
action. Since excess pressure on the finger can distort or
eliminate the pulsation in the blood supply to the finger, these
springs are intentionally relatively weak. The result of this
compromise is that the spring-held sensors readily fall off the
finger. Resilient polymer sensors are also known, such as disclosed
in US Patent Publication No. 20060106294, incorporated by reference
herein and assigned to Nonin Medical, Inc., the assignee of the
present application. One limitation of these types of sensors has
been user discomfort, particularly during extended periods of
sensor use.
[0007] Many known non-disposable oximeter sensors are relatively
bulky and exhibit a relatively high inertia of the housing relative
to the finger. This results in a susceptibility to disturbance
between the sensor and the finger surface as the patient's hand is
moved. This relative motion manifests itself as motion artifacts in
the detected signal. Motion artifacts, for example caused by
tension on the lead wire, are especially problematic for pulse
oximeter systems.
[0008] Pulse oximeter sensors are used in a number of applications
where they are susceptible to being disturbed or displaced entirely
from the appendage. Many oximeter finger sensors locate the lead
wire from the sensor over a central portion of a patient's finger.
When the patient flexes or curls his finger, the lead wire is often
pulled against the sensor causing the light elements to be
displaced.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is directed to a medical sensor device
configured to be placed on an appendage of, for example, a patient.
The sensor device is adapted to conform to an appendage upon
application of an external folding force. The sensor device
includes a portion designed to fold around the appendage and
position optical sensor elements on or near a tissue surface of the
appendage. In some embodiments the foldable portion includes a soft
compressible material. In some embodiments a stabilization
component is provided. The stabilization component helps keep the
sensor device in place when inadvertently disturbed, for example,
by an external force. Some embodiments also include a flexible
stiffening portion or frame that is folded over as the sensor
device is folded on the appendage. The flexible stiffening portion
or frame tends to maintain the sensor device comfortably in place
until it is repositioned or removed.
[0010] The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the invention that follows may be better
understood. Additional features and advantages of the invention
will be described hereinafter which form the subject of the claims
of the invention. It should be appreciated by those skilled in the
art that the conception and specific embodiment disclosed may be
readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the present
invention. It should also be realized by those skilled in the art
that such equivalent constructions do not depart from the spirit
and scope of the invention as set forth in the appended claims. The
novel features which are believed to be characteristic of the
invention, both as to its organization and method of operation,
together with further objects and advantages will be better
understood from the following description when considered in
connection with the accompanying figures. It is to be expressly
understood, however, that each of the figures is provided for the
purpose of illustration and description only and is not intended as
a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a more complete understanding of the present invention,
reference is now made to the following descriptions taken in
conjunction with the accompanying drawing, in which:
[0012] FIG. 1A is a top view of a sensor device according to one
illustrative embodiment;
[0013] FIG. 1B is a cut away view of the sensor device;
[0014] FIG. 1C is a bottom view of the sensor device;
[0015] FIG. 1D is a partially exploded top view of the sensor
device;
[0016] FIG. 2 is a diagrammatic view of the sensor device in place
over a finger;
[0017] FIG. 3A is a is a diagrammatic view of a pulse oximeter
according to an alternative embodiment;
[0018] FIG. 3B illustrates the pulse oximeter on a finger according
to one embodiment;
[0019] FIG. 4A is a is a diagrammatic view of a pulse oximeter
according to an alternative embodiment;
[0020] FIG. 4B illustrates the pulse oximeter on a finger according
to one embodiment
DETAILED DESCRIPTION OF THE INVENTION
[0021] FIG. 1A is a top view of a sensor according to one
illustrative embodiment. FIG. 1B is a side view of the sensor cut
taken along line B-B of FIG. 1A. FIG. 1C is a bottom view of the
sensor. FIG. 1D is a partially exploded top view of the sensor. For
purposes of this discussion FIGS. 1A, 1B, 1C and 1D will be
discussed together. In one embodiment, sensor 100 is a pulse
oximeter sensor utilized within a pulse oximetry system. For the
purposes of explanation only, sensor 100 is configured for the
measurement of oxygen saturation through known oximetric
transmittance techniques. As one skilled in the art can readily
appreciate, the present invention is easily adaptable to
accommodate a number of different physiological monitoring
applications and configurations, including but not limited to,
other optical sensors, reflective sensor, etc.
[0022] Sensor 100 includes foldable portion (or member or
substrate) 130, optical sensor elements 150, 155 and a
communications link including lead 140 which couples sensor 100,
for example, to a monitor. A pulse oximeter system is configured to
measure blood oxygenation levels by fitting sensor 100 over at
least a portion of a phalange (such as a finger or toe) of the
body. Sensor 100 could also be placed on other body parts, e.g.,
ears and nose.
[0023] Foldable portion 130 in some embodiments is made from two
different materials. These two materials are designated as a top
material 133 and bottom material 137. However, other arrangements
can be envisioned. Top material 133 is disposed on a top portion of
foldable portion 130. Conversely, bottom material 137 is disposed
on a bottom portion of foldable portion 130. When folded around an
appendage the top material 133 forms the outside of the pulse
oximeter, and bottom material 137 forms the inside of the sensor in
direct contact with the finger surface.
[0024] Foldable materials for use in foldable portion 130 include,
but are not limited to, foams, plastics, fabrics, leathers, papers
and other materials in cellular form. In some embodiments materials
133 and 137 have different material properties that allow sensor
100 to be both resilient and provide cushioning. In one embodiment
material 137 is a readily compressible polyethylene foam. However,
other cushioning, compressible or foam materials can be used for
bottom material 137. Top material 133 is, in one embodiment, also a
polyethylene foam. However, unlike bottom material 137, the
polyethylene foam of top material 133 is significantly more dense
and less compressible than bottom material 137. Further, in some
embodiments, top material 133 can include a protective layer or
coating on an outside portion 134 that both protects the underlying
material(s). Again, other materials can be used for top material
133. In other embodiments the top and bottom materials can be the
same material with no noticeable differentiation between the two
materials.
[0025] Disposed at an interface 136 between materials 133 and 137
is a deformable frame 131. However, in other embodiments frame 131
can be located elsewhere, such as on the outside of either material
133 or 137. Frame 131 is in one embodiment a rigid material (as
compared to materials 133 or 137) that is readily folded over and
deformed from a flat form into a curved shape. Once bent into a
shape, such as during application of sensor 100 to a finger, frame
131 tends to substantially maintain its shape until such time as an
additional bending force is applied. In one embodiment, frame 131
is initially generally flat so that sensor 100 can be shipped flat
and then deformed into positioned over the finger prior to use.
Preferably, frame 131 and materials 133, 137 together combine to
minimize disturbances of optical sensor elements 150, 155 in
response to external forces. As a result, a reduction in motion
artifacts is provided along with improved user comfort. In one
embodiment frame 131 is a metal wire that is disposed near an outer
perimeter of sensor 100. However, frame 131 can utilize other
materials or be of different cross-sectional shape. For example,
frame 131 may include a metal stamping or die-cut part. Frame 131
may be a disposable component within a sensor device kit. Frame 131
is preferably formed from a malleable material.
[0026] Disposed within foldable portion 130 is the pair of optical
sensor elements 150 and 155. In one embodiment, element 150
includes a pair of light emitting diodes (LED) and element 155 is a
photodiode. Other illumination methods can be used. In one
embodiment LEDs 150 include one LED emitting red light having a
wavelength of 660 nm, and a second LED emitting infrared light
having a wavelength of 910 nm. However, other wavelengths that
produce red and infrared light can be used. In alternative
embodiments of sensor 100, alternative or additional LEDs can be
used.
[0027] Photodiode 155 is arranged to receive light signals from
LEDs 150 during an optical sensing process. In one embodiment,
photodiode 155 receives both red and infrared light that has passed
from LEDs 150 through the finger. Photodiode 155 provides a signal
coupled through lead 140 to, for example, a remote monitor for
further processing and interpretation. In alternative embodiments,
LEDs 150 can be collocated next to or near photodiode 155. For
example, LEDs 150 and photodiode 155 may be provided adjacent each
other to facilitate a reflectance-type optical sensing process
instead of the above described transmittance-type sensing.
[0028] In some embodiments sensor elements 150 and 155 can be
provided on a flexible sheet which is initially separate from
foldable portion 130. When such elements are disposed on a separate
sheet, foldable portion 130 may have a slit or other opening to
allow the insertion of sensor elements 150, 155. Such an
arrangement allows for the reuse of optical sensor elements 150,
155. Similarly, in some embodiments frame 131 can be provided as a
disposable component which is inserted or otherwise engaged with
foldable portion 130 during use and subsequently removed and
disposed. In yet another embodiment, frame 131, foldable portion
130 and sensor elements 150, 155 may be separately provided and
combined prior to use, with one or all being disposable.
[0029] In some embodiments foldable portion 130 also includes a
finger hole 120 used to assist in proper positioning of sensor 100
upon a finger. More particularly, finger hole 120 can assist in
proper alignment of sensor elements 150, 155 upon the finger.
Finger hole 120 is in one embodiment an aperture through foldable
portion 130. Finger hole 120 is defined in some embodiments by two
separate radii 121 and 122. These radii generally correspond to the
radii of a bottom and top radii found on a finger. However, in some
embodiments, finger hole 120 can be replaced with an indent or bump
within foldable portion 130. This indent or bump can be present in
bottom material 137 or top material 133 and felt by a patient upon
application of sensor device 100 on a finger.
[0030] Foldable portion 130 in some embodiments includes a number
of holes or apertures 135. Holes 135 are arranged in foldable
portion 130 to allow for air flow circulation across finger
surfaces covered by sensor 100. Depending on the selection of
materials of foldable portion 130, in some embodiments apertures
135 are not needed as the materials of foldable portion 130 are
selected to provide sufficient breathability to covered finger
surfaces.
[0031] In some embodiments foldable portion 130 of sensor 100
includes a curved portion 110. Curved portion 110 is shaped such
that when sensor 100 is folded over a finger the curved portion is
positioned, in one embodiment, between the first and second knuckle
of the finger which allows for natural movement of the finger, yet
resists rotation of sensor 100 upon the finger. However, this
feature need not be present in all embodiments. Additionally,
depending on the size of the finger, the location of curved portion
110 relative to the finger knuckles can change.
[0032] In some embodiments foldable portion 130 includes deformable
"winglet" ends 112 near, for example, curved portion 110 which can
be deformed to provide a more secure attachment of sensor 100 to
the finger or other appendage. Winglet ends 112, in one embodiment,
are embodied as a widened portion of sensor 100 as compared to a
width proximate to finger hole 120. As shown in FIGS. 2 and 4B,
winglet ends 112 can be configured in one embodiment to allow
sensor 100 to be folded over upon a finger tip with portions of
soft foam material 137 engaging each other without respective
portions of harder cover material 133 engaging each other.
[0033] Lead 140 is in one embodiment a series of wires that are
connected to a remote monitoring device. The remote monitoring
device can be in the same room as the patient or can be located
elsewhere. However, in some embodiments a wireless communication
component may be provided upon or within sensor 100 to communicate
to a remote monitor via one of many known medical device wireless
protocols (e.g., BLUETOOTH).
[0034] FIG. 2 is a diagrammatic view of sensor 100 upon a finger
200. In this figure, sensor 100 has been folded over the finger.
Curved portion 110 is illustrated interfacing with the bottom of
the finger between the first and second knuckle. Lead 140 is shown
following along the hand and away from the body. The tip of the
finger can be observed protruding slightly from aperture 120. Frame
131 is holding sensor 100 in the desired position.
[0035] For purposes of completeness a brief description of a
process of using sensor 100 will be provided. In one embodiment,
sensor 100 is provided in a generally flat form. A finger tip then
engages the flattened sensor 100 at finger hole 120. Once the
finger tip has been aligned with the finger hole 120 (assisted, for
example, by dual radii 121, 122) the user or caregiver then folds
sensor 100 over and around the finger. During this folding process
frame 131 is deformed around the finger. The bending process
deforms frame 131 and foldable portion 130 and allows sensor 100 to
remain comfortably in place upon the finger.
[0036] FIG. 3A is a diagrammatic view of a pulse oximeter 300
according to an alternative embodiment of the present invention.
For purposes of simplicity, reference numbers in FIG. 3A that
correspond to reference numbers in FIGS. 1A-1D refer to the same or
similar features.
[0037] Sensor 300 includes curved portion 110, foldable portion
130, communications lead 140, and stabilization component 350. In
such an embodiment sensor 300 is configured to provide additional
stabilization to resist disturbance of optical sensor elements 150,
155 from external forces during use. For example, an external force
may be transferred to sensor 300 through lead 140, e.g., by pulling
on lead 140. Such contact with lead 140 may cause sensor elements
150, 155 to be displaced or entirely removed from the finger.
[0038] Stabilization component 350 helps prevent the inadvertent
movement of sensors 150 and 155 in response to an external force
applied to sensor 300. Stabilization component 350 includes first
aperture 353, second aperture 357 and bridge portion 355. In some
embodiments, frame 131 is present as well within stabilization
component 350. Apertures 353, 357 are sized such that a finger can
pass through during placement. When placing sensor 300 on a
patient, a finger is inserted from the bottom of sensor 300 through
aperture 353, over support bridge 355 and then through aperture
357. Once the finger is placed through apertures 353 and 357, the
fingertip is then directed into finger hole 120. Foldable portion
130 is then folded over the finger, as described above, such that a
desired application is provided.
[0039] FIG. 3B illustrates sensor 300 on a finger according to one
embodiment. In this configuration stabilization component 350
engages upper and lower finger surfaces away from optical sensor
elements 150, 155 to help stabilize sensor 300 upon the finger. In
one embodiment, forces applied to communications link 140 are
transferred through the stabilization component 350 to the finger.
For a small external force, the stabilization component 350
transfers the force to finger surfaces engaged by the stabilization
component 350 without causing disturbance to sensor elements 150,
155. For many external forces applied to sensor 300, the
stabilization component 350 isolates the optical sensor elements
150, 155 from displacement, leading to a reduction in motion
artifacts.
[0040] FIGS. 4A and 4B illustrate yet another embodiment of a
sensor 400 in accordance with the present invention. The components
of pulse oximeter 400 are similar to those of pulse oximeter 100 in
FIGS. 1A-1D. Pulse oximeter 400 is in one embodiment designed to be
used in sleep studies. In sleep studies it is often desirable to
measure the patient's pulse rate and oxygenation levels while they
sleep. Further, sensor devices should be non-invasive and as
comfortable as possible so as not to disrupt the participant's
sleep. However, in most sleep studies it is extremely difficult to
maintain a sensor device in place through all sleep cycles. Tossing
and turning of the study participant during sleep often results in
the sensor device being pulled off or displaced.
[0041] Sensor 400 is provided with a wrapping tail 410 as a
stabilizing component to reduce the likelihood that the sleep study
participant will dislodge sensor 400 while sleeping. In one
embodiment, wrapping tail 410 extends from a front portion 412 of
sensor 400. Wrapping tail 410 preferably has a length that is
sufficient to permit tail 410 to be wrapped a number of times
around the finger and wrist of the participant, as illustrated by
FIG. 4B. By so wrapping tail 410 around the finger and wrist,
sensor 400 provides a stable platform for sensor elements 150, 155
which is resistant to forces transferred through lead 140. In one
application, as shown in FIG. 4B, at tail 410 is wrapped a full
turn around the finger, preferably between the 2.sup.nd and
3.sup.rd knuckles prior to being wrapped around the wrist.
[0042] In some embodiments frame 131 is provided within wrapping
tail 410 to further assist in maintaining sensor 400 in place. In
other embodiments, an adhesive or hook-and-loop type fastener upon
tail 410 may be utilized to secured sensor 400 in place. Tail 410
may be a different material from foldable portion 130. For example,
tail 410 may be a flexible fabric strap. While the embodiment of
FIG. 4 has been described in relation to a sleep study participant,
it should be appreciated that sensor 400 may have a variety of
other uses.
[0043] As shown in FIG. 4B, a portion of the malleable frame 131 is
bent along a longitudinal axis of the appendage and another portion
of the malleable frame 131 is bent along an axis perpendicular to
the longitudinal axis.
[0044] Although the present invention and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the invention as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure of the present invention, processes, machines,
manufacture, compositions of matter, means, methods, or steps,
presently existing or later to be developed that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized according to the present invention. Accordingly, the
appended claims are intended to include within their scope such
processes, machines, manufacture, compositions of matter, means,
methods, or steps.
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