U.S. patent application number 14/791666 was filed with the patent office on 2015-10-29 for methods of monitoring physiological properties.
The applicant listed for this patent is Valencell, Inc.. Invention is credited to Michael Edward Aumer, Steven Francis LeBoeuf, Jesse Berkley Tucker.
Application Number | 20150305682 14/791666 |
Document ID | / |
Family ID | 40583733 |
Filed Date | 2015-10-29 |
United States Patent
Application |
20150305682 |
Kind Code |
A1 |
LeBoeuf; Steven Francis ; et
al. |
October 29, 2015 |
Methods of Monitoring Physiological Properties
Abstract
A method of monitoring at least one physiological property of an
organism includes directing energy at a first skin region of the
organism and at a second skin region adjacent the first skin
region, and detecting an energy response signal from the first skin
region and an energy response signal from the second skin region,
wherein both energy response signals contain information about
blood flow and skin motion. The energy response signals are
processed to produce an extracted energy response signal containing
cleaner blood flow information. The extracted energy response
signal may be compared with a physiological model to assess a
physiological condition of the organism.
Inventors: |
LeBoeuf; Steven Francis;
(Raleigh, NC) ; Tucker; Jesse Berkley;
(Youngsville, NC) ; Aumer; Michael Edward;
(Raleigh, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Valencell, Inc. |
Raleigh |
NC |
US |
|
|
Family ID: |
40583733 |
Appl. No.: |
14/791666 |
Filed: |
July 6, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13566269 |
Aug 3, 2012 |
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14791666 |
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12256793 |
Oct 23, 2008 |
8251903 |
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13566269 |
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61000181 |
Oct 25, 2007 |
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Current U.S.
Class: |
600/480 ;
600/479 |
Current CPC
Class: |
A61B 2562/046 20130101;
A61B 5/14552 20130101; A61B 5/1455 20130101; A61B 5/6815 20130101;
A61B 5/0295 20130101; A61B 5/021 20130101; A61B 5/02116 20130101;
A61B 5/0261 20130101; A61B 5/02141 20130101; A61B 5/6838 20130101;
A61B 5/721 20130101; A61B 2562/0233 20130101 |
International
Class: |
A61B 5/00 20060101
A61B005/00; A61B 5/0295 20060101 A61B005/0295; A61B 5/021 20060101
A61B005/021; A61B 5/026 20060101 A61B005/026 |
Claims
1. A method of monitoring at least one physiological property of an
organism, comprising: directing energy at a first skin region of
the organism and at a second skin region adjacent the first skin
region; detecting an energy response signal from the first skin
region and an energy response signal from the second skin region,
wherein both energy response signals contain information about
blood flow and skin motion; and processing the energy response
signals to produce an extracted energy response signal containing
cleaner blood flow information, wherein the directing, detecting
and processing steps are performed by a device worn by the
organism.
2. The method of claim 1, further comprising comparing the
extracted energy response signal with a physiological model to
assess a physiological condition of the organism.
3. The method of claim 1, further comprising telemetrically
communicating the extracted energy response signal to a portable
communication device, and displaying the energy response signal via
the portable communication device in real time.
4. The method of claim 1, wherein processing the energy response
signals to produce an extracted energy response signal comprises
subtracting the energy response signal from the second skin region
from the energy response signal from the first skin region.
5. The method of claim 1, further comprising differentially
amplifying the energy response signal from the first skin region
and the energy response signal from the second skin region prior to
the processing step.
6. The method of claim 2, further comprising amplifying the
extracted energy response signal prior to the comparing step.
7. The method of claim 1, further comprising transmitting the
extracted energy response signal to a remote device.
8. The method of claim 7, wherein transmitting the extracted energy
response signal to the remote device comprises wirelessly
transmitting the extracted energy response signal.
9. The method of claim 7, wherein the remote device is selected
from the group consisting of computing devices, communication
devices, and entertainment devices.
10. The method of claim 1, further comprising transmitting the
extracted energy response signal to the organism.
11. The method of claim 1, wherein directing energy at the first
skin region and the second skin region comprises directing
electromagnetic radiation via at least one optical emitter.
12. The method of claim 11, wherein the at least one optical
emitter is selected from the group consisting of laser diodes
(LDs), light-emitting diodes (LEDs), and organic light-emitting
diodes (OLEDs).
13. The method of claim 11, wherein the at least one optical
emitter comprises at least one array of optical emitters.
14. The method of claim 1, wherein detecting an energy response
signal from the first skin region and an energy response signal
from the second skin region comprises detecting via at least one
detector selected from the group consisting of acoustic detectors,
auscultatory detectors, motion detectors, optical detectors,
thermal detectors, and piezoelectric detectors.
15. The method of claim 2, wherein the physiological condition of
the organism includes properties of skin, blood, and/or blood
vessels of the organism.
16. The method of claim 2, wherein the physiological condition of
the organism comprises one or more of the following: blood
pressure; volume of blood flow through a blood vessel, and size of
at least one blood vessel.
17. The method of claim 1, wherein the first skin region comprises
vascular and non-vascular tissue, and wherein the second skin
region is dominated by non-vascular tissue.
18. The method of claim 1, wherein directing energy at the first
skin region comprises directing electromagnetic radiation via at
least one optical emitter and wherein detecting energy response
signals from the first skin region and the second skin region
comprises electrically biasing at least one optical emitter to
operate as an optical detector.
19. The method of claim 13, wherein the at least one array of
optical emitters comprises at least one monolithic array of optical
emitters.
20. The method of claim 13, wherein the at least one array of
optical emitters comprises at least one partially monolithic array
of optical emitters.
21. The method of claim 1, wherein directing energy at the first
skin region comprises directing electromagnetic radiation at
different wavelengths.
22. The method of claim 1, wherein detecting the energy response
signal from the first skin region and the energy response signal
from the second skin region comprises detecting electromagnetic
radiation at different wavelengths.
23. The method of claim 22, further comprising measuring blood flow
in the organism by detecting electromagnetic radiation at a first
wavelength and measuring motion of the organism by detecting
electromagnetic radiation at a second wavelength that is shorter
than the first wavelength.
24. The method of claim 1, wherein the device is a wearable device
that comprises a plurality of emitters and a plurality of
detectors.
25. A method of monitoring at least one physiological property of
an organism, comprising: directing energy at a first skin region of
the organism; detecting an energy response signal from the first
skin region and an energy response signal from a second skin region
adjacent the first skin region, wherein both energy response
signals contain information about blood flow and skin motion; and
processing the energy response signals to produce an extracted
energy response signal containing cleaner blood flow information,
wherein the directing, detecting and processing steps are performed
by a device worn by the organism.
26. The method of claim 25, wherein processing the energy response
signals to produce an extracted energy response signal containing
cleaner blood flow information comprises subtracting the energy
response signal from the second skin region from the energy
response signal from the first skin region.
27. The method of claim 25, further comprising comparing the
extracted energy response signal with a physiological model to
assess a physiological condition of the organism.
28. The method of claim 27, further comprising telemetrically
communicating the extracted energy response signal to a portable
communication device, and displaying the energy response signal via
the portable communication device in real time.
29. A method of monitoring at least one physiological property of
an organism, comprising: directing energy at a skin region of the
organism; detecting a first energy response signal from the skin
region that contains information about blood flow and a second
energy response signal from the skin region that contains
information about skin motion; and processing the first and second
energy response signals to produce an extracted energy response
signal containing cleaner blood flow information, wherein the
directing and detecting steps are performed by a device worn by the
organism.
30. The method of claim 29, wherein detecting the first and second
energy response signals comprises detecting via at least one
detector selected from the group consisting of acoustic detectors,
auscultatory detectors, motion detectors, optical detectors,
thermal detectors, and piezoelectric detectors.
31. The method of claim 29, wherein detecting the first and second
energy response signals comprises detecting electromagnetic
radiation at different wavelengths.
Description
RELATED APPLICATION
[0001] This application is a continuation application of pending
U.S. patent application Ser. No. 13/566,269, filed Aug. 3, 2012,
which is a continuation application of U.S. patent application Ser.
No. 12/256,793, filed Oct. 23, 2008, now U.S. Pat. No. 8,251,903,
which claims the benefit of and priority to U.S. Provisional Patent
Application No. 61/000,181, filed Oct. 25, 2007, the disclosures of
which are incorporated herein by reference as if set forth in their
entireties.
FIELD OF THE INVENTION
[0002] The present invention relates generally to health and, more
particularly, to health monitoring.
BACKGROUND OF THE INVENTION
[0003] Noninvasive qualification and quantification of
physiological properties via wearable sensors may be executed by
exciting a physiological region with energy and monitoring the
response to that energy with one or more sensors. In wearable pulse
oximetry, for example, optical energy from one or more
light-emitting diodes (LEDs) excites a region of the body rich with
blood vessels (such as a finger tip), and a photodiode senses
scattered optical energy relating to blood flow through these blood
vessels. Physiological information extracted via such wearable
sensor devices may be confounded by a variety of unavoidable
factors. Firstly, the extraction of important physiological
information may be obscured by unwanted motion artifacts. These
motion artifacts may generate false signals that distort
physiological information extracted from the wearable sensors.
Secondly, the physiological information of interest may be
overpowered by unwanted information from neighboring physiological
features. For example, pulse oximetry data regarding blood oxygen
levels in a blood vessel may be distorted by optical scatter from
the skin or blood vessels themselves. Other factors may also
confound the physiological information of interest.
SUMMARY
[0004] In view of the above discussion, methods and apparatus for
qualifying and quantifying excitation-dependent physiological
information extracted from wearable sensors in the midst of
interference from unwanted sources are provided. According to some
embodiments of the present invention, an organism is interrogated
with at least one excitation energy, energy response signals from
two or more distinct physiological regions are sensed, and these
signals are processed to generate an extracted signal. The
extracted signal is compared with a physiological model to qualify
and/or quantify a physiological property. Additionally, important
physiological information can be qualified and quantified by
comparing the excitation wavelength-dependent response, measured
via wearable sensors, with a physiological model.
[0005] According to some embodiments of the present invention, a
method of monitoring at least one physiological property (e.g.,
properties associated with the skin, blood, and/or blood vessels,
etc.) of an organism includes directing energy at a target region
of the organism; detecting an energy response signal from the
target region and an energy response signal from a region adjacent
to the target region; processing the detected signals to produce an
extracted energy response signal; and comparing the extracted
energy response signal with a physiological model to assess a
physiological condition of the organism. Energy directed at a
target region may include electromagnetic radiation, mechanical
energy, acoustical energy, electrical energy, and/or thermal
energy.
[0006] Processing the detected signals to produce an extracted
energy response signal may include subtracting the energy response
signal from the region adjacent to the target region from the
energy response signal from the target region. In some embodiments,
the energy response signal from the target region and the energy
response signal from a region adjacent to the target region may be
differentially amplified prior to processing. In some embodiments,
the extracted energy response signal may be amplified prior to
comparing the extracted signal with a physiological model. The
extracted energy response signal may be transmitted (e.g.,
wirelessly, etc.) to a remote device, such as a computing device,
communication device, entertainment device, etc.
[0007] According to some embodiments of the present invention,
directing energy at a target region of the organism includes
directing electromagnetic radiation via one or more optical
emitters, such as laser diodes (LDs), light-emitting diodes (LEDs),
organic light-emitting diodes (OLEDs), etc. In some embodiments,
one or more arrays of optical emitters may be utilized to direct
energy at a target region. Monolithic and partially monolithic
arrays may be utilized. In some embodiments, optical emitters may
be configured to direct electromagnetic radiation at different
wavelengths, and the detectors may be configured to detect
electromagnetic radiation at different wavelengths.
[0008] According to some embodiments of the present invention,
detecting an energy response signal from the target region and an
energy response signal from a region adjacent to the target region
includes detecting via one or more detectors, such as acoustic
detectors, auscultatory detectors, motion detectors, optical
detectors, thermal detectors, piezoelectric detectors, etc. In some
embodiments, one or more arrays of detectors can be utilized.
[0009] According to some embodiments of the present invention, an
apparatus that monitors at least one physiological property of an
organism includes at least one energy emitter configured to direct
energy at a target region of the organism; at least one detector
configured to detect an energy response signal from the target
region and an energy response signal from a region adjacent to the
target region; and a processor. The processor is configured to
process the detected signals to produce an extracted energy
response signal, and to compare the extracted energy response
signal with a physiological model to assess a physiological
condition (e.g., skin properties, blood flow properties, blood
pressure, blood vessel properties, etc.) of the organism. The
processor is configured to subtract the energy response signal from
the region adjacent to the target region from the energy response
signal from the target region to produce an extracted energy
response signal. In some embodiments, the processor differentially
amplifies the energy response signal from the target region and the
energy response signal from a region adjacent to the target region
prior to producing the extracted energy response signal. In some
embodiments, the processor amplifies the extracted energy response
signal prior to comparing the extracted energy response signal with
a physiological model to assess a physiological condition of the
organism.
[0010] Energy emitters that direct electromagnetic radiation,
mechanical energy, acoustical energy, electrical energy, and/or
thermal energy may be utilized. In some embodiments, the at least
one energy emitter comprises one or more optical emitters, such as
LDs, LEDs, OLEDs, etc. In some embodiments, at least one array of
optical emitters are utilized to direct energy at a target region.
Monolithic and partially monolithic arrays may be utilized. In some
embodiments, optical emitters may be configured to direct
electromagnetic radiation at different wavelengths, and the
detectors may be configured to detect electromagnetic radiation at
different wavelengths.
[0011] Detectors utilized to detect an energy response signal from
the target region and an energy response signal from a region
adjacent to the target region may include auscultatory detectors,
motion detectors, optical detectors, thermal detectors,
piezoelectric detectors, etc. In some embodiments, one or more
arrays of detectors can be utilized. In some embodiments, one or
more detectors are utilized to detect an energy response signal
from the target region and one or more other detectors are utilized
to detect an energy response signal from a region adjacent to the
target region. For example, at least one array of detectors may be
utilized to detect an energy response signal from the target region
and at least one array of detectors may be utilized to detect an
energy response signal from a region adjacent to the target
region.
[0012] Apparatus according to some embodiments of the present
invention may include a transmitter in communication with the
processor that is configured to transmit (e.g., wirelessly, etc.)
the extracted energy response signal to a remote computing device,
communication device, and/or entertainment device.
[0013] According to other embodiments of the present invention,
wearable apparatus for monitoring at least one physiological
property of an organism are provided. For example, a wearable
apparatus includes a housing configured to be worn by the organism;
at least one energy emitter attached to the housing that is
configured to direct energy at a target region of the organism; at
least one detector attached to the housing that is configured to
detect an energy response signal from the target region and an
energy response signal from a region adjacent to the target region;
and a processor attached to the housing. The processor is in
communication with the at least one detector and is configured to
process detected signals to produce an extracted energy response
signal, and to compare the extracted energy response signal with a
physiological model to assess a physiological condition of the
organism. In some embodiments, the wearable apparatus is an
earpiece that is configured to be attached to an ear of the
organism.
[0014] According to other embodiments of the present invention, an
apparatus that monitors at least one physiological property of an
organism includes a processor, and one or more optical emitters
configured to direct electromagnetic radiation at a target region
of the organism. The optical emitters are configured to be
electrically biased by the processor so as to detect an energy
response signal from the target region and an energy response
signal from a region adjacent to the target region. The processor
is configured to process the detected signals to produce an
extracted energy response signal, and to compare the extracted
energy response signal with a physiological model to assess a
physiological condition of the organism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a block diagram of a device for noninvasively
monitoring a physical property of an organism, according to some
embodiments of the present invention.
[0016] FIG. 2 illustrates the excitation-sensor module of FIG. 1
aligned over a physiological region of interest.
[0017] FIG. 3 illustrates an excitation-sensor module comprising a
monolithic array of optical emitters operating as emitters or
detectors depending on the electrical bias, according to some
embodiments of the present invention.
[0018] FIG. 4 illustrates an excitation-sensor module comprising an
array of piezoelectric sensors operating as both mechanical energy
generators as well as mechanical energy sensors depending on the
electrical bias, according to some embodiments of the present
invention.
[0019] FIGS. 5A-5B illustrate flexible piezoelectric arrays that
may be utilized in accordance with embodiments of the present
invention.
[0020] FIG. 6 illustrates an excitation-sensor array, accord to
some embodiments of the present invention, being used to qualify
and/or quantify physiological properties of a blood vessel and/or
blood, such as blood pressure or metabolic status of the blood.
[0021] FIG. 7 is a graph that illustrates the spectral reflectance
response of melanin, bilirubin, and hemoglobin.
[0022] FIG. 8A is a top plan view of a device for exciting at least
one region with multiple wavelengths of electromagnetic radiation
and sensing the response related to each wavelength for comparison
with a physiological model, according to some embodiments of the
present invention.
[0023] FIG. 8B is side elevation view of the device of FIG. 8A,
taken along lines 8B-8B.
[0024] FIG. 9 is a graph that illustrates the spectral extinction
coefficient of various forms of hemoglobin.
[0025] FIG. 10 is a block diagram of a wearable telemetric device,
according to some embodiments of the present invention.
[0026] FIG. 11 is an exploded perspective view of a telemetric
hands-free audio headset capable of both telemetric personal
communications and/or/entertainment and physiological monitoring,
that can be utilized to implement various embodiments of the
present invention.
[0027] FIG. 12 illustrates the anatomy of the human ear.
[0028] FIG. 13 illustrates the hands-free headset of FIG. 11 being
worn by a person.
DETAILED DESCRIPTION
[0029] The present invention now is described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0030] Like numbers refer to like elements throughout. In the
figures, the thickness of certain lines, layers, components,
elements or features may be exaggerated for clarity.
[0031] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0032] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the specification and relevant art and
should not be interpreted in an idealized or overly formal sense
unless expressly so defined herein. Well-known functions or
constructions may not be described in detail for brevity and/or
clarity.
[0033] It will be understood that when an element is referred to as
being "on", "attached" to, "connected" to, "coupled" with,
"contacting", etc., another element, it can be directly on,
attached to, connected to, coupled with or contacting the other
element or intervening elements may also be present. In contrast,
when an element is referred to as being, for example, "directly
on", "directly attached" to, "directly connected" to, "directly
coupled" with or "directly contacting" another element, there are
no intervening elements present. It will also be appreciated by
those of skill in the art that references to a structure or feature
that is disposed "adjacent" another feature may have portions that
overlap or underlie the adjacent feature.
[0034] Spatially relative terms, such as "under", "below", "lower",
"over", "upper" and the like, may be used herein for ease of
description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is inverted, elements
described as "under" or "beneath" other elements or features would
then be oriented "over" the other elements or features. Thus, the
exemplary term "under" can encompass both an orientation of "over"
and "under". The device may be otherwise oriented (rotated 90
degrees or at other orientations) and the spatially relative
descriptors used herein interpreted accordingly. Similarly, the
terms "upwardly", "downwardly", "vertical", "horizontal" and the
like are used herein for the purpose of explanation only unless
specifically indicated otherwise.
[0035] The term "monitoring" refers to the act of measuring,
quantifying, qualifying, estimating, sensing, calculating,
interpolating, extrapolating, inferring, deducing, or any
combination of these actions. More generally, "monitoring" refers
to a way of getting information via one or more sensing elements.
For example, "blood health monitoring" includes monitoring blood
gas levels, blood hydration, and metabolite/electrolyte levels.
[0036] The term "physiological" refers to matter or energy of or
from the body of a creature (e.g., humans, animals, etc.). In
embodiments of the present invention, the term "physiological" is
intended to be used broadly, covering both physical and
psychological matter and energy of or from the body of an organism.
However, in some cases, the term "psychological" is called-out
separately to emphasize aspects of physiology that are more closely
tied to conscious or subconscious brain activity rather than the
activity of other organs, tissues, or cells.
[0037] The term "body" refers to the body of a person (or animal)
that may utilize an earpiece module according to embodiments of the
present invention. Monitoring apparatus, according to embodiments
of the present invention may be worn by humans and animals.
[0038] Referring to FIG. 1, methods and apparatus for qualifying
and quantifying one or more physiological properties of an
organism, according to some embodiments of the present invention,
are illustrated. An extracted signal indicative of the
physiological energy response from two or more distinct regions of
an organism is generated following the excitation of at least one
region via one or more forms of excitation energy. In the
illustrated embodiment, an excitation-sensor module 101 is
configured to generate and direct excitation energy towards at
least one surface 120 of an organism and to sense the energy
response from at least two distinct regions of the surface 120. The
signal from the excitation-source module may be passed to a signal
extractor 102 for processing and/or subtracting the signals to
generate at least one extracted signal more closely related to a
physiological property of interest. This extracted signal may then
be sent to a transmitter 104 for wirelessly transmitting the
desired information 106 to another device or network and/or to a
signal processor 105 for processing the extracted signal, comparing
the processed extracted signal with at least one physiological
model, and sending a physiological assessment to the transmitter
104.
[0039] The excitation-sensor module 101 may include of one or more
excitation source(s) 110, 112, having similar or different
excitation elements and/or excitation configurations, as well as
one more sensor element(s) 111 having similar or different sensor
elements and/or sensor configurations. These elements (110, 112,
and 111) are positioned in contact with, or near to, a surface 120
of an organism. The excitation source(s) 110, 112 can generate
energy such as, but not limited to, electromagnetic radiation,
mechanical energy, acoustical energy, electrical energy, and/or
thermal energy, etc. The sensors 111 can detect one or more of
these types of energy.
[0040] In some embodiments, an excitation source is a solid-state
source, such as a light-emitting diode (LED), laser diode (LD),
lamp, radio or microwave transmitter, etc. In some embodiments, a
sensor is an acoustic/auscultatory sensor, motion sensor, optical
sensor, thermal sensor, etc.
[0041] In some embodiments, the excitation sources and sensors are
integrated into a wearable device. This wearable device can be
configured to process information from the sensors and send
processed information telemetrically to another device or network.
This other device may be a portable device such as a mobile phone,
portable computer, portable entertainment device, embedded
computer, or the like. The wearable device may also include at
least one communication module for communicating information to the
organism and/or entertaining the organism.
[0042] FIG. 2 illustrates an excitation-sensor module 101
positioned noninvasively over the surface 120 (i.e., the skin) of
an organism such that an optical emitter 212 is positioned over an
area largely covering or completely covering a blood vessel and an
optical emitter 210 is positioned over an area near, but not
covering, the blood vessel. Optical detectors 211 are arranged to
detect scattered excitation light from two separate regions and
generate at least two separate electrical signals. Signals related
to light scattered from the region lacking a blood vessel can be
subtracted from signals related to light scattered from the region
covering a blood vessel (e.g., via an electronic circuit). These
signals can be subtracted in raw analog form through analog mixers,
and these signals can also be digitized first and subtracted in
digital form. Regardless, the extracted signal contains "cleaner"
information about scattered light coming from the blood vessel
itself as compared to light scattered by the blood vessel and
neighboring skin tissue. Similarly, as the excitation-sensor module
101 is physically one unit, the effects of motion artifacts can
also be subtracted because changes in scattered light at each
region will typically happen in unison.
[0043] The term "blood vessel", as used herein refers to veins,
arteries, capillaries, and the like.
[0044] The optical emitters 210, 212 and optical detectors 211 can
be solid state devices. For example, the optical emitters 210, 212
can include, but are not limited to, a light-emitting diode (LED),
a laser diode (LD), a miniature incandescent lamp, a miniature
mercury lamp, a light guide delivering light from an outside source
(such as the sun or other light source), a multiwavelength source,
a microplasma source, an arc source, a combination of these
sources, and the like. Special variants of light-emitting diodes,
such as resonant-cavity light emitting diodes (RCLEDs),
superluminescent LEDs (SLEDs), organic LEDs (OLEDs), and the like
can also be utilized. The optical detectors include, but are not
limited to, photodiodes (PDs), avalanche photodiodes (APDs),
photomultipliers, or other compact optical detectors.
[0045] Though only two optical emitters and optical detectors are
shown in FIG. 2, it should be understood that multiple optical
emitters and optical detectors can be arranged in an array. The
greater the number of optical emitters and detectors in an array,
the higher resolution of physiological features and properties that
can be extracted. For example, the intensity of optical scatter
from a blood vessel at multiple points along the surface of skin
covering that blood vessel can be used to judge the size of that
blood vessel, without having to calibrate a single optical source
for each blood vessel. Unfortunately, increasing the number of
optical arrays can increase the fabrication costs of an optical
module 101. Additionally, it can become difficult to align and
package individual optical sources and detectors on a module for
quantifying the size of a blood vessel.
[0046] One methodology for reducing the cost and complexity of a
high-density optical array is to incorporate a monolithic solid
state optical array, such as an LED or LD array. A key benefit of
such an array is that solid state optical emitters can alternately
operate as optical emitters or optical detectors depending on the
electrical biasing. Because these devices can be fabricated
monolithically down to the limits of state-of-the-art lithography,
a highly dense array of individually controlled LED mesas can be
fabricated in a single wafer fabrication run. Thus, an array of
optical emitters/detectors can be fabricated self-aligned without
needing separate packaging techniques. With such a dense array, the
optical emitters can be alternately biased forward and reverse to
operate as optical emitters and detectors respectively. For
example, for neighboring LED mesas, one LED mesa can be
forward-biased to generate light whereas a neighboring LED mesa can
be reverse-biased to detect light. When the monolithic array is in
proximity to the surface of an organism, the number of mesas
detecting significant optical scatter related to a blood vessel can
then be used gauge the size of that blood vessel. Similarly, the
intensity of optical scatter at each mesa can be used to gauge the
size of that blood vessel.
[0047] FIG. 3 illustrates an exemplary monolithic optical emitter
array 312 containing individually controlled optical emitters 313
which can also be biased as optical detectors. Though a variety of
techniques can be used to control the bias through each mesa, one
technique is to bond the metal contacts of each individual mesa to
a mounting package 314 having metal bumps aligned to the monolithic
array 313 and having circuitry for controlling each individual mesa
separately. This packaging forms a module 300 with the array. FIG.
6 shows how an excitation-sensor array module 612, such as a
monolithic optical emitter array module 300, may be aligned to a
blood vessel 620 for gauging the size or shape of the blood vessel,
as well as extracting a cleaner signal relating physiological
information about the blood vessel 620.
[0048] The fabrication of solid-state monolithic optical arrays is
well known to those skilled in the art. Solid-state monolithic
optical arrays can be semiconductor optical arrays, such as LED or
LD arrays, organic LED arrays, such as OLEDs and the like. OLED
arrays can offer a benefit of being flexed, as shown in FIGS.
5A-5B, at least partially around a blood vessel. OLEDs can also be
dual-based as optical emitters and detectors, but separate optical
detectors can also be printed within an array. The print-style
manufacturing technique for fabricating organic electronics makes
the manufacture of organic/polymer device arrays potentially less
costly and tedious than that of traditional LED arrays. Because of
the ability to "print" device components for organic electronics,
OLED arrays, organic photodetector arrays, and organic
piezoelectric arrays can be deposited in the same module and
interlaced in the same array. This adds higher-level physiological
sensing functionality by increasing the number of
physiological-related parameters that can be monitored at the same
time.
[0049] Piezoelectric arrays can also be employed for noninvasively
monitoring the physiological properties of an organism, according
to some embodiments of the present invention. This allows
mechanical energy from some piezoelectric elements to couple with a
region of the organism while other piezoelectric elements measure
the response. The processing of this information to generate
information on physiological dimensions or physiological properties
can be the same as that described for monolithic LED arrays
312.
[0050] Many polar semiconductors contain piezoelectric properties,
and thus several types of device arrays on several types of
semiconductors can be used as piezoelectric sensors and/or
actuators, according to embodiments of the present invention. For
example, metal arsenides and metal nitrides, such as aluminum
indium gallium arsenide or aluminum indium gallium nitride alloys,
and the like, can be used to fabricate piezoelectric arrays. The
elements of these arrays can be micro-manufactured or
nano-manufactured as cantilevers, membranes, flexible rods, or the
like using standard microelectromechanical systems (MEMS) and
nanoelectromechanical (NEMS) fabrication techniques. Similarly,
simple device structures such as field effect transistors,
resistors, and even light-emitting diodes can be operated as
piezoelectric sensors. Thus, an LED array can be used as both an
optical emitter-detector array or piezoelectric sensing array
depending on the biasing of the array. Methods of fabricating
piezoelectric arrays are well known to those skilled in the art.
The monolithic piezoelectric actuator-sensor array 400 of FIG. 4
can be fabricated as an array 412 of metallic contacts 413 on a
semiconductor surface, where the surface may or may not be defined
into individual mesas. The packaging module 414 can be employed in
the same manner as package 314 of FIG. 3.
[0051] As described earlier, flexible organic/polymer arrays can
also be employed for physiological monitoring as shown in FIG. 6.
The array elements (e.g., 513, FIG. 5A) can come from any number of
optical emitting (OLED), optical detecting (OLED or organic
photodetector), piezoelectric (such as polarized fluoropolymers),
or other sensing elements. A secondary screen-printed (or similar)
film 523 (FIG. 5B), which may be deposited on the organic polymer
array layer 512 or on a separate layer 522, can be used to
electrically access each device element 513. In the case of a
polymer piezoelectric array 500, polarized polymers, such as
polyvinylidene fluoride (PVDF), can be used as an active
piezoelectric element for generating and/or sensing mechanical
energy from an organism. For example, by generating mechanical
energy with one filament in the array and detecting the mechanical
energy response coming from the organism at other filaments, a
physiological map of a feature, such as a blood vessel, can be
processed. This can be used to gauge the size of a blood vessel
opening and closing in time.
[0052] Embodiments of the present invention can be used to assess
blood pressure or blood pressure properties in a blood vessel. For
example, the information on the size of a blood vessel, as well as
the change in size of a blood vessel during blood flow, can be
combined with information regarding the total flow of blood to
assess blood pressure. Namely, the size and change of size in a
blood vessel can relate the area of a blood vessel, and this can be
combined with the volumetric flow rate of blood to gauge or
estimate blood pressure.
[0053] Referring to FIG. 6, reflective pulse oximetry can be
combined with blood vessel size estimation via optical scatter
detection, according to some embodiments of the present invention.
For example, an optical emitter generating blue light can be used
to generate an optical scatter signal more closely related to the
size of a blood vessel, shown by .DELTA.y in FIG. 6. An optical
emitter generating IR light can be used to generate an optical
scatter signal more closely related to the blood flow in the blood
vessel, shown by 630 in FIG. 6. A third and fourth optical emitter,
violet and red respectively, may be located near (but not covering)
the blood vessel, for example in an arrangement as that illustrated
in FIG. 2. Optical scatter signals from these sources are more
closely related to optical scatter from the skin or other tissue.
Thus, when these skin-related optical scatter signals are
differentially amplified with respect to their blood-vessel-related
counterparts, at least two extracted signals can be generated that
are more closely related to the size of a blood vessel and the
blood flow rate through a blood vessel. These extracted signals can
then be digitized, processed, and compared with a physiological
model related to blood pressure to qualify and quantify blood
pressure in real time.
[0054] The aforementioned IR scatter signal more closely related to
the blood flow in the blood vessel may also contain some
information related to the optical scatter from the expanding blood
vessel wall. Thus, differentially amplifying the aforementioned
blue scatter signal more closely related to the size of a blood
vessel with respect to the aforementioned IR scatter signal can
help subtract artifacts associated with expanding blood vessel size
from the desired blood flow information. Thus, second order affects
can be alleviated, to at least some degree, from the overall
assessment of blood pressure.
[0055] Embodiments of the present invention can be utilized for
qualifying and quantifying a variety of physiological properties in
physiological tissue and fluids. For example, the optical scatter
signal associated with blood glucose in a blood vessel can be more
accurately and/or precisely extracted. In another embodiment, blood
hemoglobin components, such as oxyhemoglobin, methemoglobin,
carboxyhemoglobin, and the like, can be more accurately and/or
precisely extracted. In these embodiments, the optical scatter
response associated with the skin is subtracted from the optical
scatter response associated with skin+blood metabolites to generate
a clean extracted signal more closely related to blood metabolite
quality and quantity. In each case, the optical signal associated
with scatter from the skin tissue is separated from the optical
signal associated with the blood vessel or blood components. This
embodiment utilizes multiple emitters, multiple detectors, or both,
with each emitter and detector located in a distinct region in the
vicinity of a blood vessel--either directly over the blood vessel
or near but not covering the blood vessel. If the optical emitters
and detectors are located too far apart from the region of
interest, it can be difficult to extract the desired
physiological-related signal. This is because optical scatter from
separate areas can be too dissimilar for successful differential
amplification and extraction of a clear physiologically related
signal.
[0056] In some embodiments of the present invention, the same
sensors, sensor configurations, and processing, can be used to
extract signals related to the physiological properties of the
skin. For example, information related to the size of a blood
vessel or flow of blood through a blood vessel can be subtracted
from an optical scatter signal reflected from the skin. This will
yield cleaner information more closely related to the physiological
properties of the skin, such as skin metabolite levels, hydration,
elasticity, and the like.
[0057] As described above, the scatter intensity of light for each
wavelength of electromagnetic excitation can be used to qualify
and/or quantify a particular physiological parameter. For example,
in humans, shorter wavelength optical radiation (blue-UV) reflects
largely from the skin, whereas longer wavelength radiation (red-IR)
can penetrate through blood vessels (FIG. 7). Thus, an approach for
qualifying and/or quantifying at least one physiological property
of an organism according to some embodiments of the present
invention is to generate at least two extracted signals, each
indicative of at least one physiological energy response from at
least one region of the organism following the electromagnetic
excitation of at least one region with at least two wavelengths of
electromagnetic excitation. The wavelength-dependent energy
response from each region can then be sensed by at least one
neighboring sensor and/or sensor array and converted into at least
two electrical signals. This energy response can be mechanical,
acoustical/auscultatory, electrical, or thermal in origin. The two
or more electrical signals can be converted into extracted signals
by filtering out each signal with respect to noise, as described
earlier. These extracted signals are each indicative of at least
one physiological energy response to at least one wavelength of
electromagnetic energy. These extracted signals can then be
amplified, compared, processed, and compared with at least one
physiological model to qualify and/or quantify at least one
physiological property of the organism. One specific example of
physiological properties that can be extracted, such as blood
metabolites, is shown in FIG. 9.
[0058] A specific embodiment of noninvasively qualifying and/or
quantifying a particular physiological parameter is shown in FIGS.
8A-8B. In this embodiment, the electromagnetic excitation sources,
810, 812, are optical emitters. Optical emitter 810 generates long
wavelength radiation and optical emitter 812 generates short
wavelength radiation. The optical detector 811 converts the optical
scatter from the optical emitters 810, 812 into an electrical
signal. The short wavelength optical emitter 812 generates optical
radiation which is reflected from the surface of the blood vessel
820, whereas the long wavelength optical emitter 810 generates
optical radiation which is at least partially reflected from the
blood inside the blood vessel. If the optical emitters 810, 812 are
pulsed and synchronized in time with the optical detector 811, at
least two separate signals can be extracted for each excitation
wavelength. For example, the electrical signal associated with the
short wavelength optical energy from the optical source 812 is more
closely associated with the size of the blood vessel 820, whereas
the electrical signal associated with the long wavelength optical
energy from the optical source 810 is more closely associated with
the blood flow through the blood vessel. Thus, as described
earlier, by comparing these independent signals, an assessment of
blood pressure can be estimated.
[0059] Embodiments of the present invention described herein can be
quite useful when integrated into a wearable device, such as a
wearable telemetric device. In some embodiments, a wearable device
can communicate telemetrically with a portable computer or portable
communication device, such as a cellular phone, personal digital
assistant, or the like. Thus, a person wearing the device can view
a real-time assessment of personal vital signs through a portable
view screen. In some embodiments, this telemetric information can
be transmitted through a cellular network and onto the
world-wide-web for storage in a database. This stored data can then
be accessed through the web. Devices according to embodiments of
the present invention can be comprised of compact, low-power
solid-state devices, such as LEDs, photodiodes, piezoelectric
elements, microphones, NEMS/MEMS devices, or the like. As such,
embodiments of the present invention can be integrated into
wearable monitors.
[0060] FIG. 10 illustrates the use of excitation-sensor modules
1012 in a wearable physiological monitor 1000. The modules 1012 can
be integrated into a flexible circuit board or flexible connector,
connected to a Bluetooth processing board. Flexible circuit boards
are typically fabricated from a polymer with integrated copper
electrodes and circuit paths.
[0061] In a particular embodiment, the wearable physiological
monitor 1000 can be integrated into the main body 1205 of a
telemetric earpiece, as shown in FIG. 11. FIG. 11 illustrates
details about the location of sensors in certain parts of an
earpiece module 1205, according to embodiments of the present
invention. The ear support 1201 contains a pinna (helix) cover 1202
that may contain sensors for monitoring physiological and
environmental factors. This structure is particularly useful for
sensing methodologies which require energy to be transmitted
through the thin layers of the pinna (the outer ear). Though any
portion of the pinna can be covered and/or contacted, in some
embodiments, the pinna cover 1202 overlaps at least a part of the
helix or a part of the scapha of an ear (FIG. 12 illustrates a
human ear). Likewise, an optical absorption detector, composed of
an optical emitter and optical detector, can be integrated into the
pinna cover 1202 for monitoring, for example, hydration, dosimetry,
skin temperature, inductive galvanometry, conductive galvanometry,
and the like. Galvanometry, the measurement of electrical
properties of the skin, can be measured inductively, through
contactless electromagnetic induction without contacts, or
conductively, with two, three, four, or more conductivity probes.
Additionally, a 4-point conductivity probe technique, such as that
used for measuring the conductivity of semiconductor wafers, can be
applied. A variety of sensors can be integrated into the earpiece
fitting 1208. For example, a galvanometric device can be integrated
into the surface 1209 of the earpiece fitting where the earpiece
fitting touches the skin of the outer ear. A particularly strong
pulse response can be monitored with excitation-sensor modules such
as those described above mounted in the earpiece fitting region
1209, touching the acoustic meatus (FIG. 12). Additionally, an
inductive device, such as an inductive coil 1214, can be integrated
along the earpiece fitting body to measure movements of the
tympanic membrane inductively. The inductive impedance can also be
measured with the inductive coil 1214 or another inductive sensor,
and this can be applied towards contactless galvanometry. The
inductive coil 1214 can include one or more coils arranged in any
orientation, and a core material, such as an iron-containing
material, may be used to improve the sensitivity of the response.
In some cases, multiple coils may be used to facilitate the
canceling of stray electromagnetic interference. Sensors can also
be integrated into the end tip 1212 of the earpiece fitting 1208 to
measure physiological properties deeper into the ear canal. For
example, the modules of FIGS. 2-4 and 5A-5B may be located in, at,
or near the end tip region 1212 in a module 1213. The sensors on
the module 1213 in this region are carefully arranged so as not to
prevent the transmission of sound (from the built-in communication
module) and to not be distorted during earpiece placement and
removal. The end tip sensor module 1213 can contain several types
of sensors for generating multiple types of energy and detecting
multiple types of energy, and this module can be integrated into
the speaker module (part of the communication module) inside the
earpiece fitting 1208 that is used for sound transmission to the
user during telemetric conversations. In some embodiments, the
speaker module can be used as a microphone to measure auscultatory
signals from the body. This may be especially useful for measuring
low frequency signals less than 1000 Hz. Employing the speaker as a
microphone may require impedance matching to maximize the
auscultatory signal extraction. The modules of FIGS. 2-4 and 5A-5B
can be located in, at, or near other parts of the earpiece module,
such as the earpiece fitting 1208 surface 1209, the ear support
1201, or the earpiece body 1205.
[0062] Another multifunctional earpiece module 1500, according to
embodiments of the present invention, is illustrated in FIG. 13.
The illustrated earpiece module 1500 includes the embodiments
illustrated in FIG. 11, such as a pinna cover 1502, an ear support
1501, a mouthpiece 1516, an earpiece body 1505, and the like.
Additionally, the earpiece module 1500 may contain an extension
1511 with sensors for monitoring jaw motion, arterial blood flow
near the neck, or other physiological and environmental factors
near the jaw and neck region.
[0063] The person illustrated in FIG. 15 is also wearing an earring
monitor 1514 according to embodiments of the present invention.
Because at least one portion of an earring may penetrate the skin,
earring monitor 1514 may contain sensors and telemetric circuitries
that provide access to various blood analytes through iontophoresis
and electrochemical sensing that may not be easily accessible by
the other portions of the earpiece module 1500. Additionally, the
earring monitor 1514 may provide a good electrical contact for ECG
or skin conductivity.
[0064] The foregoing is illustrative of the present invention and
is not to be construed as limiting thereof. Although a few
exemplary embodiments of this invention have been described, those
skilled in the art will readily appreciate that many modifications
are possible in the exemplary embodiments without materially
departing from the teachings and advantages of this invention.
Accordingly, all such modifications are intended to be included
within the scope of this invention as defined in the claims. The
invention is defined by the following claims, with equivalents of
the claims to be included therein.
* * * * *