U.S. patent application number 16/400729 was filed with the patent office on 2020-09-10 for devices and methods for detection of internal bleeding and hematoma.
The applicant listed for this patent is Yaron BAR-ILAN, Ilan BEN OREN, Shmuel CHEN, Yaron ILAN, Dean NAHMAN. Invention is credited to Yaron BAR-ILAN, Ilan BEN OREN, Shmuel CHEN, Yaron ILAN, Dean NAHMAN.
Application Number | 20200281483 16/400729 |
Document ID | / |
Family ID | 1000005047046 |
Filed Date | 2020-09-10 |
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United States Patent
Application |
20200281483 |
Kind Code |
A9 |
NAHMAN; Dean ; et
al. |
September 10, 2020 |
DEVICES AND METHODS FOR DETECTION OF INTERNAL BLEEDING AND
HEMATOMA
Abstract
A device for detection of internal bleeding in a patient's body
is provided. An optical interface for transmitting IR light through
an area of a skin of a patient and to collect IR light from the
area of the skin, is provided. In some embodiments the optical
interface includes one or more delivery components and one or more
collection components. The delivery component includes a plurality
of first optical channels configured to transmit the IR light
through a plurality of respective first sub-areas on the area of
the skin, into an internal layer of the body. The collection
component includes a plurality of second optical channels,
configured to collect IR light from a plurality of respective
second sub-areas on the area of the skin.
Inventors: |
NAHMAN; Dean; (JERUSALEM,
IL) ; ILAN; Yaron; (KEFAR TAVOR, IL) ; BEN
OREN; Ilan; (MODIIN, IL) ; BAR-ILAN; Yaron;
(KFAR-TAVOR, IL) ; CHEN; Shmuel; (JERUSALEM,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NAHMAN; Dean
ILAN; Yaron
BEN OREN; Ilan
BAR-ILAN; Yaron
CHEN; Shmuel |
JERUSALEM
KEFAR TAVOR
MODIIN
KFAR-TAVOR
JERUSALEM |
|
IL
IL
IL
IL
IL |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20190254536 A1 |
August 22, 2019 |
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|
Family ID: |
1000005047046 |
Appl. No.: |
16/400729 |
Filed: |
May 1, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14569396 |
Dec 12, 2014 |
10292598 |
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16400729 |
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PCT/IL2013/050509 |
Jun 13, 2013 |
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14569396 |
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61658933 |
Jun 13, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/6833 20130101;
A61B 5/02042 20130101; A61B 5/4875 20130101; A61B 2505/05 20130101;
A61B 5/0075 20130101 |
International
Class: |
A61B 5/02 20060101
A61B005/02; A61B 5/00 20060101 A61B005/00 |
Claims
1.-20. (canceled)
21. An optical interface configured to be attached to a patient's
body and to facilitate detection of internal bleeding in the
patient's body, the optical interface comprising: at least one
first optical channel configured to transmit IR light through an
area of the patient's skin, into an internal layer of the body, and
one or more collection component, comprising at least one second
optical channel, configured to collect IR light reflected from the
area of the skin, and to deliver the collected IR light to an IR
light detector; a reference signal source configured to generate a
radio-Frequency (RF) reference signal at a frequency of about 0.5
MHz-3 MHz; a reference signal detector configured to detect the
reference signal; and a reference signal interface configured to
directly and independently from the transmitted IR light, deliver
through said area of the skin, the reference signal from said
reference signal source into the internal layer and to collect and
deliver a collected reference signal to said reference signal
detector.
22. The optical interface of claim 21, further comprising a signal
processing module comprising a processor configured to normalize
measurement results of the detected IR light, according to
measurement results of the detected reference signal.
23. The optical interface of claim 22, wherein the processor is
further configured to detect internal bleeding in the patient's
body based on the normalized measurement results of the detected IR
light.
24. The optical interface of claim 22, wherein said measurement
results of said detected IR light comprise a measured parameter of
said detected IR light selected from the group consisting of
spectral line width, spectral content and spectral distribution of
power.
25. The optical interface of claim 22, wherein said signal
processing module is further configured to controllably modulate
said IR light generated by said IR light source so that said at
least one first optical channel delivers modulated IR light, and to
modulate said collected IR light synchronously with said modulation
of said generated IR light.
26. The optical interface of claim 21, wherein said reference
signal interface comprises a first electrical contact configured to
be attached to said area of the skin, and said reference signal
interface further comprises a second electrical contact configured
to be attached to the skin at a location different from said area,
wherein at least one of said first electrical contact and second
electrical contact is functionally associated with said reference
signal source for delivering said reference signal into said
internal layer.
27. The optical interface of claim 21, wherein said at least one
first optical channel comprises an optical fiber and a beam
splitter associated with said optical fiber.
28. The optical interface of claim 21, wherein said one or more
collection component comprises at least one lens optically
associated with said at least one optical fiber so that said IR
light is transmitted and collected through said lens, wherein said
lens has a diameter between 10 um and 2 mm.
29. The optical interface of claim 21, wherein said one or more
collection component comprises a waveguide assembly comprising a
plurality of mirrors spatially separated across the waveguide,
thereby being configured to transmit said IR light at a plurality
of sub-areas, and to collect said reflected IR light from said
subareas.
30. The optical interface of claim 29, wherein said waveguide
assembly comprises an array of optic fibers disposed in said
waveguide assembly, wherein each optic fiber is optically
associated with one of a plurality of mirrors so that IR light
delivered by said optic fibers is deflected by said mirrors to each
of said sub-areas, and IR light reflected from each of said
sub-areas is deflected by said plurality of mirrors into said
associated optic fiber.
31. The optical interface of claim 21, wherein said optical
interface comprises a disposable adhesive pad for attaching said
optical interface to said area of the skin.
32. The optical interface of claim 21, wherein said at least one
first and/or second optical channel comprises an optical fiber and
a beam splitter associated with said optical fiber.
33. The optical interface of claim 32, comprising a plurality of IR
light detectors, each associated with a plurality of beam
splitters, and further comprising a plurality of IR light
detectors, each associated with one of said plurality of beam
splitters, so that each beam splitter is configured to deliver IR
light from an IR light source substantially to said associated
optical fiber, and to deliver IR light from said associated optical
fiber substantially to an IR light detector.
34. The optical interface of claim 21, further comprising plurality
of lenses, each lens being optically associated with one of said at
least one first optical channels or said at least one second
optical channel.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to devices and methods for
detection of internal bleeding and hematoma.
BACKGROUND OF THE INVENTION
[0002] Internal bleeding (also known as internal hemorrhage),
namely the leaking of blood from the vascular system into body
cavities or spaces, is a major, potentially life-threatening
complication associated with invasive medical procedures.
[0003] Examples of invasive and minimally invasive medical
procedures that are associated with a profound risk of internal
bleeding include coronary angiography and catheterization,
percutaneous coronary intervention, a caesarean section,
percutaneous biopsies (e.g. liver, kidney, lung), laparoscopic
procedures and coronary artery bypass grafting.
[0004] Post-operative surgical site bleeding is another major cause
of concern. Intra peritoneal bleeding after an abdominal surgery
may lead to unnoticed hypo-volemic shock. Pericardial bleeding
after cardiac surgery may lead to space occupying hematoma and
pericardial tamponade.
[0005] Internal bleeding may also occur as a result of internal
trauma and injuries of the human body. Internal bleeding may also
result from medical conditions associated with an increased risk of
bleeding. For example, a medical condition in which development of
internal bleeding is a serious risk is a cranial intra-ventricular
hemorrhage (IVH) in premature neonates. Several studies estimated
that the risk for IVH in very low birth weight neonates is 20-25%;
many of these will suffer severe neurodevelopmental sequelae. Early
diagnosis of IVH may allow early treatment and late disability
prevention.
[0006] Diagnosis of internal bleeding is often problematic, since
symptoms may not be evident until a significant amount of blood is
lost and/or a blood clot is formed that is large enough to press
adjacent organs and disrupt their proper functioning. Furthermore,
after medical procedures, most patients suffer physical pain and
blurred awareness which overcome the sings of internal bleeding. In
addition to internal bleeding, invasive procedures may lead to
additional changes to the body tissues at the operation area,
including for example edema, which may complicate the detection and
correct diagnosis of bleeding and hematoma. Early detection of
internal bleeding is desired, as it may facilitate optimal
treatment and prevention of mortality.
[0007] Hemoglobin in red blood cells absorbs near infra-red (NIR)
light. Extra-vascular blood is more concentrated compared to
intra-vascular, thus absorbing more NIR light. Several blood
analytes, including for example urea, triglycerides, cholesterol,
glucose, total protein and albumin, are known to absorb mid
infra-red (MIR) light. MIR at certain wavelengths is generally not
absorbed by the surrounding tissue (Shaw and Mantsch 2008 "Infrared
spectroscopy in clinical and diagnostic analysis"; In: Encyclopedia
of Analytical Chemistry, edited by Robert A. Meyers, John Wiley
& Sons Ltd, Chichester, pp. 1-19; Klonoff et al. 1998 IEEE
Photonics Society, vol. 12(2) April Newsletter; Hazama et al. 2008
"High-energy pulsed tunable mid-infrared laser aids biomedical
applications", SPIE Newsroom; and Arai et al. 1990 "infrared
absorption spectra ranging from 2.5 to 10 .mu.m at various layers
of human normal abdominal aorta and fibrofatty atheroma in vitro",
Lasers in Surgery and Medicine, 10(4); 357-362).
[0008] Water content in body tissues affects dielectric properties
of the tissues, reflected in their varying interaction with
radio-frequency (RF) radiation (Werber et al. 2006 "Investigation
of RF transmission properties of human tissues", Advances in Radio
Science, 4: 357-360; Smith et al. 1985 "Dielectric properties of
low-water-content tissues" Phys Med Biol. 30(9):965-73; and Hofmann
et al. 2011 Proc. IEEE Int. Symp. Medical Meas. Applications, Bari,
Italy, pp. 39-42).
[0009] U.S. Pat. No. 5,694,938 discloses non-invasive near infrared
optical medical imaging devices for both hematoma detection in the
brain and early tumor detection in the breast. This is achieved
using image reconstruction which allows a mapping of the position
dependent contrast diffusive propagation constants, which are
related to the optical absorption coefficient and scattering
coefficient in the tissue, at near infrared wavelengths.
[0010] U.S. Pat. No. 5,954,053 is directed, inter alia, to
detection of brain hematoma and discloses systems that utilize
differential measurement of radiation that has migrated through
migration paths between two source-detector pairs placed on the
head in a manner that each path is localized in a portion of one
hemisphere of the brain.
[0011] U.S. Pat. No. 6,175,759 discloses a non-invasive
multispectral energy system made up of a transilluminating
radiating means that illuminates soft tissues that have been
treated with a contrast agent using first and second near-IR
illuminating signals to produce thereby a first and second near-IR
multispectral images; means for optically combining the first and
second near-IR multispectral images into a combined tissue image;
and a means for processing the combined tissue image to detect
cancer and tumors and internal bleeding.
[0012] U.S. Pat. No. 6,233,479 discloses a non-invasive device
designed to detect and localize blood pooling and clots near the
outer surface of the body. While being geared towards finding
sub-dural and epi-dural hematomas, the device can be used to detect
blood pooling anywhere near the surface of the body. The device is
based on low power pulsed microwave technology combined with a
specialized antenna, signal processing/recognition algorithms and a
disposable cap worn by the patient which will facilitate accurate
mapping of the brain and proper function of the instrument.
[0013] U.S. Pat. No. 6,875,176 discloses systems and methods for
assessment of tissue properties, noninvasively, by acquiring data
relating to at least one aspect of intrinsic and/or induced tissue
displacement, or associated biological responses. Data relating to
tissue displacement and associated biological changes may be
acquired by detecting acoustic properties of tissue using
ultrasound interrogation pulses, preferably in a scatter or Doppler
detection mode. In some embodiments, detection techniques,
including near-infrared spectroscopy (NIRS), magnetic resonance
techniques, acoustic hydrophones and the like, are also used.
[0014] US 2009/0221919 (now U.S. Pat. No. 8,060,189) discloses,
inter alia, a device for intra cranial hematoma detection, in head
trauma settings, using the differences in NIR light absorbance
between the two cranial hemispheres that may appear when blood
accumulates in one cranial hemisphere.
[0015] JP 2009136436 discloses an internal hemorrhage detecting
apparatus comprising an armrest for placing an arm, a near infrared
LED for irradiating the arm rested on the armrest with near
infrared rays, and a near infrared camera for continuously imaging
a position of the arm to which the near infrared rays are applied.
An analysis range is extracted from a comparison image captured by
the near infrared camera, and the area of the position where the
luminance is lower than a prescribed threshold is found. Blood is
determined to be present in other regions than veins if the area is
increased by a prescribed quantity.
[0016] There is still a need in the art for devices, systems and
methods for early detection of internal bleeding and hematoma
formation in body parts of interest, particularly following
invasive procedures. For example, it would be highly beneficial to
have devices, systems and methods for non-invasively monitoring a
patient following an invasive procedure in order to detect internal
bleeding as early as possible after it begins, while distinguishing
between bleeding and other changes to tissues, such as formation of
edema.
SUMMARY OF THE INVENTION
[0017] The present invention in embodiments thereof provides
devices and methods for non-invasive detection of internal bleeding
and hematoma formation within an internal body part of a patient.
The devices and methods disclosed herein, in some embodiments,
deliver and collect Infra-Red (IR) light having a wavelength
absorbed substantially exclusively by blood, for example near-IR
absorbed substantially exclusively by hemoglobin, to and from an
internal body part of a patient, through an area on the skin of the
patient. In some embodiments, the devices and methods further
deliver and collect a reference signal having a wavelength which is
not absorbed substantially exclusively by blood, to and from the
internal body part of a patient, through substantially the same
area on the skin of the patient. According to some embodiments, the
devices and methods track and detect changes, such as temporal
changes, in parameters of the two signals as collected from the
skin area, thereby detecting bleeding while filtering noise and
differentiating between bleeding and other changes to tissues, such
as edema formation.
[0018] As used herein, "internal bleeding" refers to the leaking of
blood from blood vessels into spaces and cavities within the body.
The term "internal" indicates that the bleeding is generally not
visible when looking at the patient from the outside. The patient
according to embodiments of the present invention is a subject,
including but not limited to a human subject, at risk of developing
an internal bleeding. In some embodiments, the patient is a subject
who has undergone an invasive or minimally invasive medical
procedure or surgical intervention. In additional embodiments, the
patient is a subject suffering from a medical condition associated
with an increased risk of internal bleeding. The patient according
to embodiments of the present invention is in need of monitoring of
internal bleeding, if occurs, preferably as early as possible after
it begins. In some embodiments, there is a need to monitor the
patient over a relatively long period of time, as bleeding may
develop several hours, or several dozens of hours following an
invasive procedure. In addition, there is a need for a sensitive
yet specific detection of bleeding, as invasive or minimally
invasive medical procedures may cause changes to body tissues in
the operation area, as well as in areas adjacent to the operation
area, which are not associated with bleeding. For example, in
addition to the risk of bleeding and accumulation of blood in
internal body cavities, interstitial fluids may accumulate and form
edema. Such changes may affect the interaction of the tissues with
electromagnetic radiation, as employed by the devices and methods
of the present invention. Thus, there is a need to filter out the
effects of changes not associated with bleeding on collected
signals and differentiate between variation of signals collected
from the body due to bleeding and variation due to other changes
not associated with bleeding.
[0019] In order to meet the above needs, the devices of the present
invention, according to some embodiments, conduct continuous
monitoring, and integrate data collected over a period of time in
order to identify changes and variations in the signals. In
addition, the devices of the present invention, in some
embodiments, employ a reference signal in order to differentiate
between changes in the main signal that are due to bleeding and
changes in the main signal due to other causes, such as
accumulation of fluids other than blood. In addition, the devices
of the present invention, in some embodiments, are configured such
that they cover a large area where bleeding may occur. In some
embodiments, the devices comprise a plurality of channels, each
covers a sub-area within the tested area, and the plurality of
channels collectively covers a broad area, thereby facilitating the
detection of internal bleeding.
[0020] Advantageously, the devices of the present invention,
according to some embodiments, enable delivery of IR and reference
signals to deep layers of the body, for example to a depth of about
2 cm or more, 5 cm or more, 10 cm or more from the surface of the
skin, as well as collection of signals reflected from such deep
layers, where internal bleeding may occur.
[0021] By employing a plurality of substantially separated
channels, the devices of the present invention enable, in some
embodiments, identifying the locality of the bleeding within the
internal body part. Thus, in some embodiments, the devices of the
present invention provide an indication regarding a particular
location of the detected bleeding within an internal body part of a
patient.
[0022] In some embodiments, the devices are employed for the
detection of internal bleeding within a limb, abdominal cavity,
chest cavity or digestive tract.
[0023] According to an aspect of some embodiments there is provided
a device for detection of internal bleeding in a patient's body,
the device comprises: an IR light source configured to generate
light in the Infra-Red (IR) spectral range; an IR light detector
configured to detect light in the Infra-Red (IR) spectral range; an
optical interface comprising one or more delivery component
comprising at least one first optical channel, and configured to
deliver IR light generated by said IR light source and to transmit
said IR light through an at least one respective first sub-area, on
an area of a skin of said patient, into an internal layer of the
body, and one or more collection component comprising at least one
second optical channel, configured to collect IR light from an at
least one respective second sub-area, on said area of said skin,
and deliver said collected IR light to said IR light detector; a
reference signal source configured to generate a reference signal
and a reference signal detector configured to detect said reference
signal and a reference signal interface configured to deliver
through the skin of the patient a reference signal from said
reference signal source into said internal layer and to collect and
deliver a collected reference signal to said reference signal
detector, wherein an IR light detected by said IR detector has a
wavelength .lamda.1 and a reference signal detected by said
reference signal detector has wavelength .lamda.2 substantially
different from .lamda.1; and a signal processing module comprising
a processor configured to compare measurement results of detected
IR light, detected by said IR detector, and measurement results of
detected reference signal, detected by said reference signal
detector, thereby detecting an internal bleeding in a patient's
body.
[0024] According to an aspect of some embodiments there is provided
an optical interface for transmitting IR light to an area of a skin
of a patient and to collect IR light from said area of the skin,
configured to be attached to the patient's body at said area or
proximal thereto and comprising: one or more delivery component,
comprising a plurality of first optical channels configured to
transmit said IR light through a plurality of respective first
sub-areas, on said area of the skin, into an internal layer of the
body; and one or more collection component, comprising a plurality
of second optical channels, configured to collect IR light from a
plurality of respective second sub-areas on said area of the
skin.
[0025] According to an aspect of some embodiments there is provided
a method for detecting internal bleeding in a patient's body,
comprising: providing the device of any one of the preceding
claims; transmitting IR light at a sub area on an area of a skin of
said patient, into an internal layer of the body; collecting and
detecting IR light scattered from a sub-area on the area of the
skin; delivering a reference signal through the skin of said
patient, into said internal layer of the body; collecting and
detecting said reference signal from said body of the patient, and
comparing measurement results of said detected IR light and
measurement results of said detected reference signal.
[0026] According to an aspect of some embodiments there is provided
a method for detecting internal bleeding in a patient's body,
comprising: measuring detected IR light, IBL, associated with
absorption in blood, at a first point in time t=0; measuring
detected reference signal, RefBL, at t=0; establishing
(calculating) a normalized signal SBL=IBL/RefBL; measuring detected
IR light, IT, associated with absorption in blood, at a later point
in time t=T; measuring detected reference signal, RefT, at t=T;
establishing (calculating) a normalized signal ST=IT/RefT;
comparing ST to SBL; if the comparison in the previous step
indicates detection of bleeding, activating an alarm; and returning
to the steps of measuring detected IR light, IT, and measuring
detected reference signal, RefT, at yet a later point in time.
[0027] These and further aspects and features of the present
invention will become apparent from the figures, detailed
description and claims which follow.
BRIEF DESCRIPTION OF THE FIGURES
[0028] Exemplary embodiments are illustrated in referenced figures.
Dimensions of components and features shown in the figures are
generally chosen for convenience and clarity of presentation and
are not necessarily shown to scale. It is intended that the
embodiments and figures disclosed herein are to be considered
illustrative rather than restrictive. The figures are listed
below:
[0029] FIG. 1 schematically depicts a device for detection of
internal bleeding according to exemplary embodiments of the current
invention;
[0030] FIG. 2 schematically depicts a device for detection of
internal bleeding according to some exemplary embodiments of the
current invention;
[0031] FIG. 3 schematically depicts a configuration of components
within a device for detection of internal bleeding according to an
exemplary embodiment of the current invention;
[0032] FIGS. 4A-4B schematically depict configurations of optical
fibers for use in an optical interface in devices for detection of
bleeding according to exemplary embodiments of the current
invention;
[0033] FIG. 5 schematically depicts a configuration of components
within a device for detection of internal bleeding according to an
exemplary embodiment of the current invention;
[0034] FIG. 6 schematically depicts a configuration of components
within a device for detection of internal bleeding according to an
exemplary embodiment of the current invention;
[0035] FIG. 7 schematically depicts a configuration of components
within a device for detection of internal bleeding according to an
exemplary embodiment of the current invention;
[0036] FIGS. 8A-8B schematically depict an optical interface
according to exemplary embodiments of the current invention;
[0037] FIG. 9 shows frequency dependence of the imaginary part of
the dielectric constant for free and bound water. 1--free water
(salinity S=0 o/oo); 2--free water (salinity S=2 o/oo); 3--bound
water;
[0038] FIGS. 10A-10B schematically depict devices for detecting
internal bleeding whereas the reference signal is RF radiation
according to exemplary embodiments of the current invention;
[0039] FIGS. 11A-11B schematically depict devices for detecting
bleeding in an internal layer of the body, whereas the reference
signal comprises an RF signal according to exemplary embodiments of
the current invention;
[0040] FIG. 12 schematically illustrates a method for detecting
internal bleeding in a body of a patient according to an exemplary
embodiment of the current invention; and
[0041] FIG. 13 schematically illustrates a method for detecting
internal bleeding in a body of a patient according to an exemplary
embodiment of the current invention.
DETAILED DESCRIPTION OF THE INVENTION
[0042] The present invention relates to devices and methods for
detection of internal bleeding in a body part of a patient.
[0043] Reference is now made to FIG. 1 which schematically depicts
a device for detection of internal bleeding according to exemplary
embodiments of the current invention. The device (100) includes a
control unit (110) and an optic interface (120) comprising an
adhesive pad and attached to a patient's body (130).
[0044] The control unit may include a signal processing module
comprising a processor configured to analyze data collected from
the patient. The control unit may include a user interface such as
keyboard, mouse, display, switches and/or operating knobs. The
control unit is associated with the optical interface and allows a
user to activate the device. In the illustrated embodiment, a wire
(140) connects between the control unit and the optic interface. In
some embodiments, one or more optic fibers connect between the
control unit and the optic interface. In some embodiments, the
control unit comprises signal sources and detectors. In other
embodiments, signal sources and detectors are included within the
optic interface unit that is attached to the patient's skin. The
optic interface typically comprises delivery components and
collection components for delivering and collecting signals to and
from the skin of the patient.
[0045] Reference is now made to FIG. 2, which schematically depicts
a device for detection of internal bleeding according to some
exemplary embodiments of the current invention, in association with
a body part to be scanned or monitored for the presence of bleeding
or hematoma. The illustrated device (200) includes a signal
processing module (210) comprising a processor (202), an Infra-Red
(IR) light source (232) and a reference signal source (238). The IR
light source and/or the reference signal source may be LED(s) or
laser(s), such as a diode laser. The IR light source is configured
to generate light in the IR spectral range at one or more
wavelengths .lamda.s, absorbed substantially exclusively by blood.
For example The IR light source is configured to generate IR light
that is absorbed by hemoglobin. For example, The IR light source is
configured to generate IR light having a wavelength including but
not limited to, about 760 nm, about 780 nm, about 830 nm and/or
about 850 nm or any combination thereof. Alternatively, the IR
light source is configured to generate a wide-spectrum light having
a spectral width selected from the group consisting of about 30,
50, 100 and 200 nm within the IR spectral range. The reference
signal source is configured to generate a reference signal having a
wavelength not absorbed by hemoglobin. The illustrated device
further includes an IR light detector (234) and a reference signal
detector (236). The IR light detector and/or the reference signal
detector may be CCD and/or CMOS.
[0046] The illustrated device further includes an optical interface
(240). The illustrated optical interface comprises a delivery
component (246) configured to deliver the IR light generated by the
IR light source and transmit it at an area of the skin of the
patient (228), into an internal layer of the patient's body (220).
The device according to embodiments of the present invention
typically covers a skin area of about 2.times.2-10.times.10
cm.sup.2, for example about 2.times.2-5.times.5 cm.sup.2. The light
is typically transmitted into an internal layer of the patient's
body, to a depth of about 0-10 cm, for example about 0-1 cm, about
1-10 cm, about 2-10 cm. The illustrated delivery component
comprises a plurality of optical channels (for example, an array of
three optical channels (242a,b,c) as in the illustrated
embodiment). According to some embodiments the delivery component
comprises optic fibers, each fiber is configured to transmit light
at a location, or sub-area (222,a,b or c), within the skin area.
According to some embodiments the delivery component comprises a
lens (not shown in the figure) through which IR light is
transmitted to the sub area. In some embodiments the delivery
component comprises an optically neutral component such as a
transparent window through which IR light is transmitted to the sub
area.
[0047] The illustrated optical interface further includes a
collection component (248) configured to collect IR light from
sub-areas (224a,b,c) within the skin area, which in this example
have only partial overlap with the sub-areas (222a,b,c) at which IR
light is delivered by the delivery component. Thus, in this
example, the optic channels of the delivery component are
configured to transmit light at a first plurality of sub-areas
within the skin area, and the optic channels of the collection
component are configured to collect light from a second plurality
of sub-areas within the skin area.
[0048] The collection component is further configured to deliver
the collected light to the IR light detector. Similar to the
illustrated delivery component, the illustrated collection
component comprises a plurality of optical channels (for example,
an array of three optical channels (244,a,b,c) as in the
illustrated embodiment). In some embodiments, the collection
component comprises optic fibers, each fiber is configured to
collect light from a location, or sub-area, within the skin area.
In some embodiments, the collection component comprises a lens (not
shown in the figure) through which IR light is collected from sub
area. In some embodiments the collection component comprises an
optically neutral component such as a transparent window through
which IR light is collected from the sub area.
[0049] The reference signal source (238) is configured to generate
a reference signal having a wavelength .lamda.ref; different from
.lamda.s, which is not absorbed substantially exclusively by blood.
According to some embodiments, the reference signal is selected so
as to be absorbed by water. According to some embodiments, the
reference signal is selected so as to be absorbed by interstitial
fluid. According to some embodiments, the reference signal is
selected to be absorbed substantially similarly by blood and by any
liquid that may accumulate in body tissue following a surgical
intervention, such as interstitial fluid.
[0050] According to some embodiments the illustrated device
comprises a reference signal source configured to generate a
reference signal as described above. The illustrated device further
comprises a reference signal detector configured to detect the
reference signal. The illustrated device further comprises a
reference signal interface (250), configured to deliver through the
skin of the patient a reference signal from the reference signal
source into the internal layer, and to collect and deliver a
collected reference signal to the reference signal detector.
[0051] Thus, according to some embodiments the reference signal is
a NIR signal having a wavelength not selectively absorbed by
hemoglobin. According to some embodiments the reference signal is a
Mid-IR signal having a wavelength not selectively absorbed by
hemoglobin. According to some embodiments the reference signal is a
radio-frequency (RF) signal having a wavelength not selectively
absorbed by hemoglobin. By "not selectively absorbed" it is meant
that a signal at that wavelength and signals at neighboring
wavelengths are substantially similarly absorbed (e.g. by
hemoglobin).
[0052] According to some embodiments a NIR light source is used a
source for the NIR light as described above and also as a reference
signal source. In some embodiments the NIR light source is
configured to generate a NIR signal comprising continuously
substantially two or more discrete wavelengths, or a wide spectrum
NIR signal wherein one or more wavelengths are substantially
exclusively absorbed by blood, e.g. by hemoglobin, and the other
wavelengths are absorbed substantially similarly by blood and by
other body liquids such as water or interstitial fluid. Further,
NIR light collected from the area of the skin by the collection
component is filtered so that a spectral component comprising
.lamda.s, selectively absorbed by blood, is delivered to the IR
light detector. The NIR light collected from the area of the skin
by the collection component is also filtered so that a spectral
component not comprising .lamda.s is delivered to the reference
signal detector. In such embodiments, the NIR light source is used
also as a reference signal source, and the optical interface is
used also as the reference signal interface.
[0053] According to some embodiments the NIR light source is
configured to generate a NIR light having a time-varying wavelength
according to a pre-defined variation scheme, e.g. by continuous
scanning of a wavelength range or by generating a NIR signal at
substantially two or more alternating discrete wavelengths. In such
embodiments the NIR light source may be used also as a reference
signal source, the optical interface unit may used also as the
reference signal interface unit, and the NIR detector may be used
also as a reference signal detector. In such embodiments the
transmitted NIR light is substantially exclusively absorbed in
blood at specific points in time, defined by the wavelength
variation scheme of the light, whereas at other points in time it
is not substantially exclusively absorbed in blood, thereby being
fit to be used as a reference signal. Thus, according to the
wavelength variation scheme of the light, measurement results of
the detected NIR light at some points in time are considered as a
signal indicative of presence of blood in the internal layer of the
body, whereas measurement results of the detected NIR light at
other points in time are considered as a reference signal.
[0054] The illustrated device further comprises a signal processing
module (210) comprising a processor (202). According to some
embodiments the signal processing module is configured to control
the IR light source and the IR light detector, the reference signal
source and the reference signal detector. The signal processing
module is further configured to obtain measurement results of the
detected IR light and of the detected reference signal. Such
measurement results may include measurement of parameters such as
magnitude, amplitude, power, spectral line width, spectral content
and spectral distribution of power. The processor is configured to
compare results of measured parameters of the detected IR light, to
measurement results of measured parameters of the detected
reference signal. According to some embodiments, the processor is
further configured to obtain a time-dependent sequence of such
measurement results and it may further obtain desired functions of
the results or mathematical manipulations thereof or desired
calculations using such results, as is further detailed herein.
[0055] According to some embodiments the signal processing module
is configured to controllably modulate the IR light generated by
the IR light source, so that the associated optical channels
deliver modulated IR light to the skin of the patient. The
processing module may controllably modulate the IR light e.g. by
providing a modulating signal directly to the IR light source or,
according to some embodiments, by providing a modulating signal to
a modulating device (not shown in this figure) in the optic
channels of the delivery component. According to some embodiments
the signal processing module is further configured to modulate the
collected IR light synchronously with the modulation of generated
IR light. According to some embodiments the signal processing
module may employ known techniques of matched filtering to the
detected IR light, using the modulation of the transmitted IR light
and/or the modulation of the detected IR light, to enhance the
signal-to-noise ratio (SNR) of the measurements.
[0056] In some embodiments, the optical interface is configured to
be attached to the skin of the patient. In some embodiments, the
optical interface comprises an adhesive pad for attaching the
optical interface to the skin of the patient. In some embodiments,
the device comprises an adhesive pad housing the optical interface
and configured for attaching the optical interface to the skin of
the patient.
[0057] It is to be understood that every part of the device can be
designed for single or multiple uses. For example, an optical
interface configured to be attached to the skin of the patient in
the form of a pad may be configured for single use (disposable).
The pad may be flexible. The pad may include a series of lenses,
such as micro-lenses, and/or means for coupling optical fibers.
[0058] As illustrated in the figure, the tested body part (220)
contains a hematoma (226) below sub-areas 222c and 224c. As further
illustrated in the figure, light (marked by arrows) is delivered to
and from the internal body part. The light collected from the
hematoma area (dashed line) differ in its parameters from light
collected from the adjacent areas (solid lines), and this
difference will be identified by analysis of the signals collected
from the skin. In some embodiments, different spectrum of diffusive
reflection is obtained from the hematoma area, due to accumulation
of hemoglobin in hematoma as compared to flowing blood.
[0059] Reference is now made to FIG. 3, which schematically depicts
a configuration of components within a device for detection of
internal bleeding according to an exemplary embodiment of the
current invention. Further shown is a body part to be scanned for
the presence of bleeding or hematoma. The configuration shown in
FIG. 3 is based on fibers and fiber optic splitter (beam
splitter).
[0060] The illustrated configuration includes a light source (332),
a light detector (334) and an optical interface (340) comprising a
plurality of optic fibers (three optic fibers, 342a,b,c) for the
delivery of light generated by the light source to a plurality of
sub-areas (322a,b,c) within a skin area (328) and into an internal
layer of the body part (320), and light collected from the
plurality of sub-areas of the skin to the light detector. In this
example, the delivery and collection of light to and from a
particular sub-area is performed through the same optical channel,
namely by a single optic fiber. In the illustrated embodiment, a
plurality of beam splitters (three beam splitters 360a,b,c), one
for each optic fiber, is functionally disposed between the optical
interface comprising the fibers, and the light source and detector.
In other embodiments, the beam splitters may be included within the
optical interface. Each beam splitter is configured to deliver
light from the light source to its respective optic fiber, and to
deliver light from the respective optic fiber to the light
detector. A first spatial light modulator (370a) is functionally
disposed between the plurality of beam splitters and the light
source, the first spatial light modulator is configured to
controllably and selectively deliver light from the light source to
each of the plurality of beam splitters. A second spatial light
modulator (370b) is functionally disposed between the plurality of
beam splitters and the light detector, the second spatial light
modulator is configured to controllably and selectively deliver
light from each of the plurality of beam splitters to the light
detector. In some embodiments, the one or more of the spatial light
modulators can be included within the optical interface unit.
[0061] Reference is now made to FIGS. 4A-B, which schematically
depict configurations of optical fibers for use in an optical
interface in devices for detection of bleeding according to
exemplary embodiments of the current invention
[0062] The configuration shown in FIG. 4A is based on a dual fiber
assembly (442a,b) which may help diagnosing internal bleeding by a
simplified method wherein minimal optics is used to deliver the
light into the tissue from the fiber exit and to collect the back
reflected light. The light transmitted to the tissue (420) is
configured to enter the body surface at an angle lower than
90.degree., such as about 45.degree.. This configuration increases
the amount of scattered light that reaches the detector and also
enables larger area coverage.
[0063] In some embodiments employing this configuration, the
illumination and light collection is done with channels that are
not perpendicular to the skin surface area. Light from one channel
is scattered and reflected and collected also by neighbor channels.
In accordance with this embodiment, light emitted from channel "n"
is scattered by the tissue and collected by the neighboring
channels and similarly channel "n" collects not just the light
back-emitted from itself but from neighboring channels as well.
[0064] According to some embodiments such configuration may employ
a dual fiber assembly essentially without further optics. The
fibers used have a large core diameter and a large numerical
aperture, therefore no optics for manipulation of light from the
fiber and for collection is necessary.
[0065] Reference is now made to FIG. 4B, depicting schematically an
optical fiber (442) and an optically associated lens (450),
configured to transmit IR light (460) through the skin into an
internal layer of a body (420). The optical fiber and the lens are
further optically configured for optimized collection of IR light
scattered from internal layers of the body, thereby enabling or
facilitating detecting bleeding in layers of the body that are as
deep as a few centimeters--e.g. 5 cm or 7 cm or even 10 cm--inside
the body. According to the illustrated embodiment the lens focuses
the light beam that emerges from the optical fiber to allow a
transmitted beam angle as small as 2-5 degrees, instead of a beam
angle of 10-20 degrees typical to an optical fiber without a lens.
Moreover, the lens, having a diameter significantly larger than the
core diameter of the fiber, is configured to collect light from a
region inside the body (426) having a larger cross-section and
smaller opening angle, relative to the region from which light may
be collected using a fiber without a lens.
[0066] Reference is now made to FIG. 5, which schematically depicts
a configuration of components within a device for detection of
internal bleeding according to an exemplary embodiment of the
current invention. In this configuration, a waveguide assembly
(550) comprising mirrors (552a,b,c) and lenses (570a,b,c) is used
for the delivery and collection of light to and from the skin of
the patient. In some embodiments, the waveguide comprises an
adhesive part (580) configured to attach the waveguide assembly to
the skin of the patient. The adhesive part may be an integral part
of the waveguide assembly or the waveguide assembly itself may be
adhesive. The illustrated configuration includes a light source
(532), a light detector (534) and an optical interface (540)
comprising a waveguide assembly. A beam splitter (560) is
functionally disposed between the waveguide assembly, and the light
source and detector. The beam splitter is configured to deliver
light from the light source to the waveguide assembly, and to
deliver light from the waveguide assembly to the light detector.
The illustrated waveguide assembly comprises a plurality of optical
channels (542a,b,c), each optical channel is configured to deliver
light to and from a sub-area within a skin area of the patient. The
waveguide can be built with one or more reflective elements, such
as mirrors (552a,b,c), as shown in the figure. In the illustrated
embodiment, the mirrors are partial/small mirrors arranged such
that they are spatially separated across the waveguide. More
specifically, the mirrors are arranged at different distances from
the point in which light from the beam splitter enters the
waveguide, and at different heights within the waveguide. Each
mirror is configured to receive light from the beam splitter and
deflect light towards a sub-area within an area of a skin of the
patient, and into an internal part of the body of the patient. Each
mirror is further configured to receive light from that sub-area
and deflect the light towards the beam splitter. The spatial
division of the mirrors within the waveguide creates a plurality of
optical channels that are spatially distinct thus allowing spatial
resolution of the signals delivered and collected from the skin
area covered. Spatial resolution of the signals is maintained both
when the signals are delivered to the skin and when collected from
the skin. In some embodiments, each mirror is optically associated
with a respective lens (570a,b,c), such as a mini- or micro-lens,
for the delivery and collection of light towards and from the skin
sub-area. In some embodiments, the waveguide assembly further
comprises a plurality of optic fibers (544a,b,c), each is
configured to deliver light to and from a sub-area within the skin
area. In some embodiments, an array of optic fibers is used, where
the fibers are spatially separated to maintain spatial resolution
of the delivered and collected signals. For example, the optic
fibers may be arranged at different heights within the waveguide.
Each optic fiber may be optically associated with a respective
mirror and optionally with a respective lens, to direct light
towards a sub-area within the skin area, and collect light from the
sub-area.
[0067] Reference is now made to FIG. 6, which schematically depicts
a configuration of components within a device for detection of
internal bleeding according to an exemplary embodiment of the
current invention. Similar to FIG. 5, a waveguide assembly (650)
comprising mirrors (652a,b,c) and lenses (670a,b,c), such as mini-
or micro-lenses, is used to deliver light to and from an area of
the skin of the patient. In the illustrated embodiment, the mirrors
are semi-reflective/semi-transparent mirrors, arranged at different
distances from the point in which light from the beam splitter
(660) enters the waveguide, at the same height within the
waveguide. This configuration enables delivery of light to a
plurality of sub-areas within an area of the skin of the subject.
Each mirror is configured to reflect light towards a sub-area
within an area of the skin of the subject, receive light from that
sub-area and reflect the light towards the beam splitter. Each
mirror is further configured to transmit a portion of the light
received by the mirror to an adjacent mirror. In some embodiments,
each mirror is optically associated with a respective lens
(670a,b,c), such as a mini- or micro-lens, for the delivery and
collection of light towards and from the skin sub-area. Other
features may be similar to those described in FIG. 5.
[0068] Reference is now made to FIG. 7, which illustrates detection
of blood accumulated post-operatively in an area next to a surgical
wound area, for example, a few centimeters (cm) from the surgical
wound area, using a configuration of components similar to that
depicted in FIG. 6. The figure schematically depicts a top view of
a configuration of components within a device for detection of
bleeding using a waveguide assembly (750), according to some
exemplary embodiments of the current invention. Further shown is a
body part (720) to be scanned for the presence of bleeding or
hematoma, which contains a surgical wound area (728) and a hematoma
area (726). The illustrated configuration includes a light source
(732), a light detector (734) and a waveguide (750) divided to a
plurality of optical channels (742). The illustrated configuration
further includes a beam splitter (760) functionally disposed
between the waveguide assembly, and the light source and detector.
The beam splitter is configured to deliver light from the light
source to the waveguide assembly, and to deliver light from the
waveguide assembly to the light detector. The illustrated waveguide
assembly comprises a plurality of optical channels, each optical
channel is configured to deliver light to and from a sub-area
within a skin area of the patient. The waveguide comprises
reflective elements, such as mirrors (752). The mirrors are
arranged such that they are spatially separated across the
waveguide. In the illustrated embodiment, an array of mirrors one
next to the other is disposed in the waveguide, where the mirrors
are arranged at different distances from the point in which light
from the beam splitter enters the waveguide. In some embodiments,
the mirrors are disposed at the same height, and form a planar
configuration in the waveguide. In other embodiments, the mirrors
are disposed at different heights in the waveguide. Each mirror is
configured to receive light from the beam splitter and deflect
light towards a sub-area within an area of a skin of the patient,
and into an internal part of the body of the patient. Each mirror
is further configured to receive light from that sub-area and
deflect the light towards the beam splitter. The spatial division
of the mirrors within the waveguide creates a plurality of optical
channels that are spatially distinct thus allowing spatial
resolution of the signals delivered and collected from the skin
area covered. In some embodiments, each mirror is optically
associated with a respective lens, such as a mini- or micro-lens
(not shown in the figure), for the delivery and collection of light
towards and from the skin sub-area.
[0069] In some embodiments, the waveguide assembly further
comprises a plurality of optic fibers, each is configured to
deliver light to and from a sub-area within the skin area. In some
embodiments, an array of optic fibers is used, where the fibers are
spatially separated to maintain spatial resolution of the delivered
and collected signals. For example, an array of optic fibers one
next to the other may be disposed within the waveguide, as shown in
the figure. The plurality of fibers collectively covers an area of
the skin of the subject surrounding a surgical wound. Each optic
fiber may be optically associated with a respective mirror and
optionally with a respective lens, to direct light towards a
sub-area within the skin area, and collect light from the sub-area.
Each fiber and respective mirror and lens are configured to deliver
light to and from a sub-area within the skin area, thus allowing
spatial resolution of the signals delivered and collected from the
skin area covered. Spatial resolution of the signals is maintained
both when the signals are delivered to the skin and when collected
from the skin. In the illustrated embodiment, the fibers (742) are
of varying lengths. In other embodiments, the fibers may be of the
same length. In the illustrated embodiments, the fibers are
disposed at the same height, and form a planar configuration in the
waveguide. In other embodiments, the fibers may be disposed at
different heights in the waveguide.
[0070] Differences between the parameters measured from the optical
channels corresponding to the bleeding sub-areas and the parameters
measured from the optical channels corresponding to other sub-areas
are analyzed by a processor (not shown in the figure), which is
configured to provide an indication of the existence of bleeding
based on the analysis, and optionally provide an indication of the
bleeding location.
[0071] According to some embodiments, implementation of the
waveguide may be based on materials such as plastic or silicone and
in particular based on photonic band gap crystals.
[0072] Reference is now made to FIG. 8A, which schematically
depicts an optical interface (800) according to some embodiments.
The illustrated optical interface comprises an array of IR light
sources (832) configured to transmit IR light directly through the
skin into an internal layer of a body, and an array of adjacent IR
light detectors (834) configured to detect IR light reflected from
the body. According to some embodiments lenses, optically
associated with the IR sourced, may be used for focusing the
transmitted light into the internal layers (not shown in the
figure). Alternatively or additionally, lenses, optically
associated with the IR detectors, may be used enhancing collecting
efficiency of reflected IR light.
[0073] Reference is now made to FIG. 8B, which schematically
depicts the optical interface (800) attached to a body (830) for
detecting an internal bleeding therein. The optical interface is
disposed so that the array of light sources and the array of light
detectors do not substantially contact the skin and are
substantially arranged at a small distance D from the skin. Thus,
each light source generates an illuminated sub-area on the skin,
defined by the cross-section of the light beam of the light source
at the distance of the skin from the light source. Further, the
detector may efficiently collect IR light which is reflected from
the illuminated regions, and particularly from internal layers of
the body, substantially underneath the sub-area illuminated by the
respective adjacent light source. The optical interface may
functionally communicate e.g. using electrical wires (840), or
wirelessly, with a signal processing module housed in a housing
situated near the patient. According to some embodiments the
transmitted IR light comprises wavelengths absorbed substantially
exclusively by blood, and further comprises wavelengths not
absorbed substantially exclusively by blood. IR light at
wavelengths which are not absorbed substantially exclusively by
blood may be used as a reference signal as is described in detail
hereinabove, thereby rendering unnecessary an additional reference
signal source, reference signal detector and reference signal
interface unit. According to some embodiments, the optical
interface further comprises the signal processing module. According
to some embodiments, the optical interface may be used as a
stand-alone, easily portable device (requiring only power supply,
either from an external source such a wall outlet or from a
portable power source such as a battery), for detecting internal
bleeding in a patient's body.
[0074] In some embodiments there is use of RF radiation as a
reference signal to detect changes in dielectric characteristics
which are typically due to changes in the water content in the area
of interest. RF radiation in the range of about 100 MHz to about 10
GHz may be used. Biological tissues are known to enable significant
RF penetration. Changes in dielectric characteristics include the
imaginary part of the dielectric constant. FIG. 9 illustrates the
sensitivity of the dielectric constant to water and compares
frequency dependence of the imaginary part of the dielectric
constant for free and bound water. "1" represents free water
(salinity S=0.Salinity.); "2" represents free water (salinity
S=2.Salinity.); and "3" represents bound water. It is appreciated
that a substantially minute variation in water characteristics
(e.g. 2.Salinity. salinity) generates such a different absorption
spectrum e.g. between 0.1-1 GHz. Subsequently, RF signal may be
used, at a selected wavelength, as a reference signal, having a
similar absorption spectrum in blood and in other fluids known to
accumulate in the body following a surgical intervention.
[0075] FIGS. 10A and 10B illustrate two embodiments of devices
(1000, 1002) for detecting internal bleeding whereas the reference
signal is RF radiation having a wavelength corresponding to a
frequency in the range of 0.1-10 GHz. An optical interface (1020)
comprising an adhesive pad is attached to a patient's body (1030).
The optical interface comprises a delivery component configured to
transmit IR light through the skin of the patient to an internal
layer of the body, and a collecting component, as is described and
detailed above (not shown in the figure). A control unit (1010),
comprising a user interface such as keyboard, mouse, display,
switches and/or operating knobs is associated with the optical
interface and allows a user to activate the device. The control
unit may include in some embodiments IR light source, IR light
detector and a signal processing module (all not shown in this
figure). Additionally or alternatively, all or some of these
components of the device are included in the optical interface
unit.
[0076] The illustrated device in FIG. 10A further includes a
transmitting antenna (1052), situated and configured to transmit an
RF reference signal towards the area of the skin which is
illuminated by the IR light, and towards the internal layer
underneath the area. The device further includes a receiving
antenna (1054) situated and configured to receive RF signal
transmitted through the body, and/or scattered by the body,
possibly following absorption by the internal layer. According to
some embodiments, the transmitting antenna and the receiving
antenna may be situated in a sequence of positions in a trial and
error process of finding an optimized position. Additionally or
alternatively, the antennas may be situated in a pre-defined
sequence of positions, whereas each position allows for obtaining a
reference signal associated with a particular area or internal
layer under the skin area.
[0077] An RF reference signal source (not shown in this figure)
generates the RF reference signal transmitted by the transmitting
antenna. In some embodiments the RF source may be housed in the
control unit, and an RF signal is delivered from the source to the
transmitting antenna using the illustrated wired connection (1050)
between them. In some embodiments the RF source is substantially
attached to the transmitting antenna, in which embodiments the
control unit supplies to the antenna power and control
commands.
[0078] An RF reference signal detector (not shown in this figure)
is functionally associated with the receiving antenna for detecting
RF reference signal collected by the receiving antenna. In some
embodiments the RF detector may be housed in the control unit, and
a received RF signal is delivered from the receiving antenna to the
reference signal detector using the illustrated wired connection
(1060) between the receiving antenna and the control unit. In some
embodiments the RF detector is substantially attached to the
receiving antenna, in which embodiments the control unit supplies
to the receiving antenna power and control commands.
[0079] According to some embodiments one of the transmitting
antenna and the receiving antenna may be substantially integrated
with the pad of the optical interface. In some embodiments both
transmitting antenna and receiving antenna are integrated with the
pad of the optical interface unit. In such embodiments the device
may have appearance as illustrated in FIG. 1 above, wherein a
control unit is connected to a pad attached to the body,
substantially using a single cable (1040) between them.
[0080] The illustrated device may be used substantially as
described above. The IR signal may be used to monitor internal
accumulation of fluids in the monitored internal layer, and
particularly accumulation of blood due to an internal bleeding
event. The RF reference signal may be used to monitor liquids
accumulated in the monitored internal layer. By normalizing or
adjusting or compensating the detected IR signal according to the
detected RF reference signal and according to the teachings herein
above, detection of internal bleeding may be obtained. Further, by
comparing such normalized measurement results over time, namely
comparing normalized results obtained at t=T to normalized results
obtained at a prior time t=0, according to the teachings herein
above, variation in blood content in the internal layer may be
detected.
[0081] FIG. 10B illustrates an embodiment of a device for detecting
bleeding in an internal layer of the body. The illustrated device
is different from the device of FIG. 10A in having only a single
antenna (1056) instead of two antennas in FIG. 10A. The antenna of
the illustrated device is both a transmitting antenna and a
receiving antenna. The antenna is positioned and configured to
transmit an RF reference signal towards the area of the skin
illuminated by the IR light transmitted, and to receive an RF
reference signal substantially backscattered from the internal
layer towards the antenna. According to some embodiments the
antenna may be substantially integrated with the pad of the optical
interface (1020), as is described above in FIG. 13.
[0082] FIGS. 11A and 11B illustrate an embodiment of a device for
detecting bleeding in an internal layer of the body, whereas the
reference signal comprises an RF signal having a wavelength
corresponding to a frequency in the range of 0.5-3 MHz. The
illustrated device (1100) comprises a reference signal interface
(1150) comprising a first electrical contact (1120) and a second
electrical contact (1124). The first electrical contact is
configured to be attached to the body on the area of the skin being
illuminated by the IR light, or proximal thereto. The second
electrical contact is configured to be attached to the body at a
location different from that area of the skin. FIG. 11A
schematically depicts an embodiment of an electrical contact such
as the first electrical contact or the second electrical contact,
according to some embodiments. The electrical contact comprises a
pad (1126), possibly an adhesive pad, which is configured to attach
to the skin, and an array of electrical contacts (1122), all being
electrically connected together, and configured to touch the skin
and assure good electrical contact with the skin. An electrical
connection (1140) associates the electrical contact with the
control unit. According to some embodiments the control unit
includes an RF signal source which is configured to generate an RF
reference signal, to be delivered to the body by the first
electrical contact. According to some embodiments the control unit
further comprises an RF reference signal detector, functionally
associated with the second electrical contact, and configured to
detect the RF signal received by the second electrical contact.
According to some embodiments the RF signal generator, or the RF
signal detector, or both, may be attached to the corresponding
electrical contacts, respectively substantially as described above
in FIG. 11A.
[0083] In use the RF reference signal in the described embodiment
may generate an RF current passing through the patient's body
substantially between the first electrical contact and the second
electrical contact. It is appreciated that at the frequency range
of 0.5 MHz to 3 MHz associated with the described embodiment the
received reference signal is associated with RF voltage (between
the first electrical contact and the second electrical contact) and
with RF current contact (therebetween), rather than with radiation.
The impedance of the body to RF signal in the specified frequency
range is generally strongly affected by the contents of liquid in
the body along the electrical path of the RF current. Thus, by
measuring the RF voltage and RF current, and obtaining the body
impedance therefrom, and possibly performing such measurements at
several positions of the second electrical contact and/or of the
first electrical contact, a mapping of the body impedance may be
obtained. Subsequently, by mapping regions of a low impedance and
regions of high impedance, regions in the body with high content of
fluid may be identified. Further, by monitoring the time-variation
of the received RF signal and the resultant RF impedance of the
body when the first electrical contact and the second electrical
contact are fixed in respective positions on the skin, a reference
signal indicating the time variation fluid accumulated in the body
may be obtained. Such time varying signal may further be used for
normalizing and/or adjusting and/or compensating the IR signal
measurement results, to obtain an efficient detection of internal
bleeding in the body, as substantially described above.
[0084] FIG. 12 schematically illustrates an embodiment of a method
for detecting internal bleeding in a body of a patient. The method
comprises providing a device, for detecting internal bleeding
substantially as described herein (1210); transmitting IR light
through the skin into an internal layer (1224); delivering a
reference signal through the skin into the internal layer (1222);
collecting and detecting IR light scattered from the skin (1234);
collecting and detecting the reference signal from the body of the
patient (1232); and comparing measurement results of the detected
IR light and measurement results of the detected reference signal
(1240).
[0085] FIG. 13 schematically illustrates another embodiment of a
method for detecting internal bleeding in a body of a patient. The
method comprises measuring detected IR light, I.sub.BL, associated
with absorption in blood, at first point in time t=0 (1324);
measuring detected reference signal, Ref.sub.BL, at t=0 (1322);
establishing (calculating) a normalized signal
S.sub.BL=I.sub.BL/Ref.sub.BL (1330); measuring detected IR light,
I.sub.T, associated with absorption in blood, at a later point in
time t=T (1344); measuring detected reference signal, Ref.sub.T, at
t=T (1342); establishing (calculating) a normalized signal
S.sub.T=I.sub.T/Ref.sub.T (1350); comparing S.sub.T to S.sub.BL
(1360); if the comparison in the previous step indicates detection
of bleeding, activating an alarm (1370); and returning to the steps
of measuring detected IR light, I.sub.T and measuring detected
reference signal, at yet a later point in time. According to some
embodiments, if an alarm, indicating a detection of internal
bleeding is activated, the rate at which subsequent measurements
are performed, is increased.
[0086] According to an aspect of some embodiments there is provided
a device (FIG. 2, 200) for detection of internal bleeding (226) in
a patient's body (220). The device comprises an IR light source
(232) configured to generate light in the Infra-Red (IR) spectral
range and an IR light detector (234) configured to detect light in
the Infra-Red (IR) spectral range. The device further comprises an
optical interface (240) comprising one or more delivery component
(246) and one or more collection component (248). The delivery
component comprises at least one first optical channel (242a, 242b,
242c), and configured to deliver IR light generated by the IR light
source and to transmit the IR light through an at least one
respective first sub-area (222a, 222b, 222c), on an area (228) of a
skin of the patient, into an internal layer of the body. The
collection component comprises at least one second optical channel
(244a, 244b, 244c), configured to collect IR light from an at least
one respective second sub-area (224a, 224b, 224c), on the area of
the skin, and to deliver the collected IR light to the IR light
detector;
[0087] The device further comprises a reference signal source (238)
configured to generate a reference signal, and a reference signal
detector (236) configured to detect the reference signal. The
device further comprises a reference signal interface (250)
configured to deliver through the skin of the patient a reference
signal from the reference signal source into the internal layer and
to collect and deliver a collected reference signal to the
reference signal detector.
[0088] The device further comprises a signal processing module
(210) comprising a processor (202). The processor is configured to
compare measurement results of IR light at a wavelength .lamda.1,
detected by the IR detector, to measurement results of reference
signal at a wavelength .lamda.2, detected by the reference signal
detector, thereby detecting an internal bleeding (226) in a
patient's body.
[0089] According to some embodiments at least one second optical
channel comprises a plurality of second optical channels (244a,
244b, 244c), configured to collect IR light from a respective
plurality of second sub-areas (224a, 224b, 224c), and deliver the
collected IR light to the IR light detector. According to some
embodiments at least one first optical channel comprises a
plurality of first optical channels (242a, 242b, 242c) configured
to deliver and to transmit IR light at a first respective plurality
of first sub-areas (222a, 222b, 222c).
[0090] According to some embodiments the measurement results of the
detected IR light comprise a measured parameter of the detected IR
light selected from the group consisting of magnitude, amplitude,
power, spectral line width, spectral content and spectral
distribution of power. According to some embodiments the
measurement results of the detected reference signal comprise a
measured parameter of the detected reference signal selected from
the group consisting of magnitude, amplitude, power, spectral line
width, spectral content and spectral distribution of power.
[0091] According to some embodiments the measurement results of the
detected IR light comprise a time dependent sequence of the
measured parameter of the IR light. According to some embodiments
the measurement results of the detected reference signal comprise a
time dependent sequence of the measured parameter of the reference
signal. According to some embodiments the processor is configured
to detect an internal bleeding in a patient's body by analyzing
time dependent sequences of measured parameters.
[0092] According to some embodiments the processor is configured to
obtain, for each of the at least one second optical channels, a
first measurement of an IR light parameter and of a reference
signal parameter, I.sub.BL and Ref.sub.BL, respectively, and at a
later time a second measurement of the IR light parameter and of
the reference signal parameter, I.sub.T and Ref.sub.T, respectively
and to compute a corresponding function F(I.sub.BL, Ref.sub.BL,
I.sub.T, Ref.sub.T). According to some embodiments the function is
I.sub.BL/Ref.sub.BL-I.sub.T/Ref.sub.T. According to some
embodiments the processor is configured to detect an internal
bleeding (226) and a location thereof by identifying a sub-area
(224) respective of an optical channel (244a) for which the
function is equal to, or greater than or smaller than, a
pre-determined threshold or a pre-determined value.
[0093] According to some embodiments the signal processing module
is configured to controllably modulate the IR light generated by
the IR light source so that the at least one first optical channel
delivers modulated IR light. According to some embodiments the
signal processing module is configured to modulate the collected IR
light synchronously with the modulation of generated IR light.
[0094] According to some embodiments the reference signal comprises
a Near IR (NIR) or a Mid IR (MIR) light or a Radio-Frequency (RF)
signal. According to some embodiments the reference signal source
is configured to generate a Radio-Frequency (RF) signal at a
frequency in a range between about 0.1 to about 10 GHz. According
to some embodiments the reference signal interface (250) comprises
a transmitting RF antenna (FIG. 2, 252; FIG. 10A, 1052) for
delivering the reference signal through the skin into the internal
layer, and a receiving RF antenna (FIG. 2, 254; FIG. 10A, 1054)
configured for collecting the reference signal. According to some
embodiments the transmitting RF antenna comprises the receiving RF
antenna (FIG. 10B, 1056).
[0095] According to some embodiments the reference signal source is
configured to generate a Radio-Frequency (RF) signal at a frequency
in a range between about 0.5 to about 3 MHz. According to some
embodiments the reference signal interface (FIG. 11, 1150)
comprises a first electrical contact (1120) configured to be
attached to the area of the skin, and the reference signal
interface further comprises a second electrical contact (1124)
configured to be attached to the skin at a location different from
the area. At least one of the first electrical contact and second
electrical contact is functionally associated (1140) with the
reference signal source for delivering the reference signal into
the internal layer.
[0096] According to some embodiments the IR light comprises a Near
IR (NIR) or a Mid IR (MIR) light. According to some embodiments the
IR light consists of a substantially single spectral line having a
wavelength about .lamda.1. According to some embodiments the
substantially single spectral line is an absorption line of
hemoglobin. According to some embodiments .lamda.1 is selected from
the group consisting of 760 nm, 780 nm, 830 nm and 850 nm.
[0097] According to some embodiments the IR light comprises a
wide-spectrum light having a spectral width selected from the group
consisting of about 30 nm, 50, 100 nm and 200 nm within the IR
spectral range. According to some embodiments the IR light
comprises a Mid IR (MIR) light having a wavelength in a spectral
range of 4-6 um.
[0098] According to some embodiments the collection component
comprises the delivery component (FIG. 5, 540; FIG. 6, 640; FIG. 7,
750). According to some embodiments the second optical channel(s)
(742) of the collection component (750) comprise the first optical
channel(s) (742) of the delivery component. According to some
embodiments the respective first sub-areas substantially overlap,
respectively, with the respective second sub-areas (FIG. 3, 322a,
322b, 322c).
[0099] According to some embodiments the second optical channels
(FIG. 2, 244a, 244b, 244c; FIG. 7, 742) of the collection component
(248, 750) comprise optical fibers, respectively, configured to
collect IR light from the respective second sub-areas (224a, 224b,
224c). According to some embodiments the first optical channels
(FIG. 2, 242a, 242b, 242c; FIG. 7, 742) of the delivery component
(246, 750) comprise optical fibers, respectively, configured to
transmit the IR light through the respective first sub-areas (222a,
222b, 222c), into an internal layer of the body.
[0100] According to some embodiments the collection component (FIG.
5, 540) comprises at least one optical fiber (544a, 544b, 544c),
configured to deliver the IR light generated by the IR light source
(532), and also to deliver the collected IR light to the IR light
detector (534). According to some embodiments the collection
component (540) comprises at least one lens (570a, 570b, 570c)
optically associated with the at least one optical fiber (544a,
544b, 544c) so that the IR light is transmitted and collected
through the lens. According to some embodiments the lens is a
mini-lens having a diameter between 100 um and 2 mm. According to
some embodiments the lens is a micro-lens having a diameter between
10 um and 100 um.
[0101] According to some embodiments the collection component (FIG.
5, 540) comprises a waveguide assembly (550) comprising a mirror
(552a, 552b, 552c) configured to deflect light generated by the IR
source (532), thereby transmitting the IR light onto the sub area.
The mirror is further configured to deflect light reflected from
the sub area, thereby collecting the reflected IR light to the
waveguide assembly. According to some embodiments the waveguide
assembly (550) comprises a plurality of mirrors (552a, 552b, 552c)
spatially separated across the waveguide thereby being configured
to transmit the IR light at a plurality of sub-areas, and to
collect the reflected IR light from the sub-areas. According to
some embodiments the waveguide assembly (550) comprises an array of
optic fibers (544a, 544b, 554c) disposed in the waveguide assembly
wherein each optic fiber is optically associated with one of the
plurality of mirrors (552a, 552b, 552c) so that IR light generated
by the IR light source is delivered by the optic fibers and
deflected by the mirrors to each of the sub-areas, respectively,
and IR light reflected from each of the sub-areas is deflected by
the respective mirror into the associated optic fiber to be
delivered to the IR detector (534).
[0102] According to some embodiments the plurality of second
optical channels comprises the plurality of first optical channels
(FIG. 3, 342a, 342b, 342c). According to some embodiments each of
the plurality of second optical channels comprises an optical
fiber. According to some embodiments the plurality of first
sub-areas comprise the plurality of second sub-areas (322a, 322b,
322b).
[0103] According to some embodiments the plurality of second
optical channels (FIG. 3, 342a, 342b, 342c) are substantially
optically isolated from one another thereby being configured to
deliver IR light collected from each of the plurality of respective
second sub-areas (322a, 322b, 322b), independently from one
another. According to some embodiments the measurement results of
the detected IR light comprise a measured parameter of the light
detected independently from each of the plurality of second optical
channels. According to some embodiments the device further
comprises a spatial light modulator (370b) functionally disposed
between the collection component and the IR detector, and
configured to controllably and selectively deliver IR light from
each of the plurality of second optical channels to the IR
detector.
[0104] According to some embodiments the IR detector comprises a
spatial array of light detecting elements. According to some
embodiments the IR detector is selected from the group consisting
of CCD, CMOS sensor, Linear Contact Image Sensor (CIS),
Two-Dimensional CIS and 3D image sensor.
[0105] According to some embodiments the device further comprises
at least one beam splitter (FIG. 3, 360a, 360b, 360c; FIG. 5, 560;
FIG. 6, 660; FIG. 7, 760) functionally disposed between the optical
interface (340, 540, 640, 750) and the IR light source (332, 532,
632, 732) and the IR detector (334, 534, 634, 734). The beam
splitter is configured to deliver IR light from the IR light source
to the plurality of second optical channels and to deliver light
from the plurality of second optical channels to the IR
detector.
[0106] According to some embodiments the optical interface (FIG. 1,
120; FIGS. 10A and 10B, 1020, FIG. 11, 1120) is configured to be
attached to the area of the skin. According to some embodiments the
optical interface comprises an adhesive pad for attaching the
optical interface to the area of the skin. According to some
embodiments the adhesive pad is disposable.
[0107] According to an aspect of some embodiments there is provided
an optical interface (FIG. 1, 120; FIG. 2, 240) for transmitting IR
light through an area 228 of a skin of a patient and to collect IR
light from the area of the skin. The optical interface is
configured to be attached to the patient's body at the area of the
skin or proximal thereto and comprises one or more delivery
component (246) and one or more collection component (248). The
delivery component comprises a plurality of first optical channels
(242a, 242b, 242c) configured to transmit the IR light through a
plurality of respective first sub-areas (222a, 222b, 222c), on the
area of the skin, into an internal layer of the body. The
collection component comprises a plurality of second optical
channels (244a, 244b, 244c), configured to collect IR light from a
plurality of respective second sub-areas (224a, 224b, 2242c) on the
area of the skin.
[0108] According to some embodiments the plurality of first optical
channels are configured to transmit the IR light so that the
plurality of respective first sub-areas (222a, 222b, 222c) are
substantially distinct from one another. According to some
embodiments the plurality of second optical channels are configured
to collect the IR light so that the plurality of respective second
sub-areas (224a, 224b, 2242c) are substantially distinct from one
another.
[0109] According to some embodiments the optical interface
comprises an IR light source (FIG. 5, 532; FIG. 6, 632; FIG. 7,
732) functionally associated with the delivery component (540, 640,
740). According to some embodiments the optical interface (FIG. 8,
800) comprises a plurality of IR light sources (FIG. 8, 832), each
associated with one of the plurality of first optical channels.
[0110] According to some embodiments the optical interface
comprises an IR light detector (FIG. 5, 534; FIG. 6, 634; FIG. 7,
734) functionally associated with the collection component (540,
640, 740). According to some embodiments the optical interface
(FIG. 8, 800) comprises a plurality of IR light detectors, each
associated with one of the plurality of second optical
channels.
[0111] According to some embodiments the collection component (FIG.
5, 540; FIG. 6, 640; FIG. 7, 740) comprises the delivery component
so that each of the plurality of second optical channels is further
configured to transmit the IR light through the respective second
sub-areas on the area of the skin, into the internal layer of the
body. According to some embodiments each of the optical channels
comprises an optical fiber.
[0112] According to some embodiments the optical interface
comprises a plurality of beam splitters (FIG. 3, 360a, 360b, 360c),
each associated with one of the optical fibers (342a, 342b and
342c). According to some embodiments the optical interface
comprises a plurality of IR light detectors, each associated with
one of the plurality of beam splitters, and further comprising a
plurality of IR light detectors, each associated with one of the
plurality of beam splitters, so that each beam splitter is
configured to deliver IR light from an IR light source
substantially to the associated optical fiber, and to deliver IR
light from the associated optical fiber substantially to an IR
light detector.
[0113] According to some embodiments the optical interface
comprises a plurality of lenses (FIG. 5, 570, FIG. 6, 670), each
lens being optically associated with one of the plurality of first
optical channels or second optical channels.
[0114] According to some embodiments the collection component
comprises a waveguide assembly FIG. 5, 550; FIG. 6, 650; FIG. 7,
750). According to some embodiments the waveguide assembly
comprises a plurality of mirrors (552, 652, 752), each associated
with one of the optical channels and configured to deflect IR light
of the optical channel to transmit the IR light through a
respective sub-area, and to deflect IR light reflected from the
respective sub-area thereby collecting the reflected IR light to
the respective optical channel. According to some embodiments the
optical interface comprises a plurality of lenses (FIG. 5, 570,
FIG. 6, 670), each being optically associated with one of the
plurality of mirrors (FIG. 5, 552, FIG. 6, 652) so that the IR
light is transmitted and collected through the lens.
[0115] According to an aspect of some embodiments there is provided
a method for detecting internal bleeding in a patient's body,
comprising:
[0116] providing a device according to the teachings herein (FIG.
12, 1210);
[0117] transmitting IR light through a sub area of an area of a
skin of the patient, into an internal layer of the body (1224);
[0118] collecting and detecting IR light scattered from a sub-area
of the area of the skin (1234);
[0119] delivering a reference signal through the skin of the
patient, into the internal layer of the body (1222);
[0120] collecting and detecting the reference signal from the body
of the patient (1234), and
[0121] comparing measurement results of the detected IR light and
measurement results of the detected reference signal (1240).
[0122] According to an aspect of some embodiments there is provided
a method for detecting internal bleeding in a patient's body,
comprising:
[0123] measuring detected IR light, I.sub.BL, associated with
absorption in blood, at a first point in time t=0 (FIG. 13,
1324);
[0124] measuring detected reference signal, RefBL, at t=0
(1322);
[0125] establishing (calculating) a normalized signal
S.sub.BL=I.sub.BL/Ref.sub.BL (1330);
[0126] measuring detected IR light, I.sub.T, associated with
absorption in blood, at a later point in time t=T (1344);
[0127] measuring detected reference signal, Ref.sub.T, at t=T
(1342);
[0128] establishing (calculating) a normalized signal
S.sub.T=I.sub.T/Ref.sub.T (1350);
[0129] comparing S.sub.T to S.sub.BL (1360);
[0130] activating an alarm, if the comparison above indicates
detection of bleeding (1370); and
[0131] returning to the steps of measuring detected IR light,
I.sub.T, and measuring detected reference signal, Ref.sub.T, at yet
a later point in time (1342, 1344).
[0132] According to some embodiments the method further comprise
increasing the rate at which subsequent measurements of detected IR
light and detected reference signal are performed, if an alarm,
indicating a detection of internal bleeding, is activated.
[0133] The foregoing description of the specific embodiments will
so fully reveal the general nature of the invention that others
can, by applying current knowledge, readily modify and/or adapt for
various applications such specific embodiments without undue
experimentation and without departing from the generic concept,
and, therefore, such adaptations and modifications should and are
intended to be comprehended within the meaning and range of
equivalents of the disclosed embodiments. It is to be understood
that the phraseology or terminology employed herein is for the
purpose of description and not of limitation. The means, materials,
and steps for carrying out various disclosed functions may take a
variety of alternative forms without departing from the
invention.
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