U.S. patent application number 14/926073 was filed with the patent office on 2016-07-14 for apparatus and method for simultaneously detecting surface pressure and blood volume.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Jaemin KANG, Sunkwon KIM, Younho KIM, Yongjoo KWON, Sangyun PARK.
Application Number | 20160198962 14/926073 |
Document ID | / |
Family ID | 56366626 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160198962 |
Kind Code |
A1 |
PARK; Sangyun ; et
al. |
July 14, 2016 |
APPARATUS AND METHOD FOR SIMULTANEOUSLY DETECTING SURFACE PRESSURE
AND BLOOD VOLUME
Abstract
An apparatus for simultaneously detecting surface pressure and
blood volume of an object and a method of detecting the same are
provided. The apparatus includes a printed circuit board (PCB); a
light emitter disposed on the PCB which emits light of a first
wavelength and light of a second wavelength; a first light receiver
which detects light of the first wavelength and a second light
receiver which detects light of the second wavelength; a
transparent elastic body on the PCB which covers the light emitter,
the first light receiver, and the second light receiver; and a
dichroic coating formed on the transparent elastic body. The
dichroic coating reflects light of the first wavelength and
transmits light of the second wavelength.
Inventors: |
PARK; Sangyun; (Hwaseong-si,
KR) ; KANG; Jaemin; (Seoul, KR) ; KWON;
Yongjoo; (Yongin-si, KR) ; KIM; Sunkwon;
(Suwon-si, KR) ; KIM; Younho; (Hwaseong-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
56366626 |
Appl. No.: |
14/926073 |
Filed: |
October 29, 2015 |
Current U.S.
Class: |
600/480 ;
600/476 |
Current CPC
Class: |
A61B 5/0295 20130101;
A61B 5/6826 20130101; A61B 5/6843 20130101; A61B 5/02416 20130101;
A61B 5/0261 20130101; A61B 5/6816 20130101; A61B 2562/166 20130101;
A61B 5/02141 20130101 |
International
Class: |
A61B 5/021 20060101
A61B005/021; A61B 5/0295 20060101 A61B005/0295; A61B 5/00 20060101
A61B005/00; A61B 5/026 20060101 A61B005/026 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 2015 |
KR |
10-2015-0004448 |
Claims
1. An apparatus for simultaneously detecting a surface pressure and
a blood volume of an object, the apparatus comprising: a printed
circuit board (PCB); a light emitter disposed on the PCB, the light
emitter configured to emit light of a first wavelength and light of
a second wavelength, different from the first wavelength; a first
light receiver disposed on the PCB, the first light receiver
configured to detect light of the first wavelength; a second light
receiver disposed on the PCB, the second light receiver configured
to detect light of the second wavelength; a transparent elastic
body disposed on the PCB and covering the light emitter, the first
light receiver, and the second light receiver; and a dichroic
coating disposed on the transparent elastic body, wherein the
dichroic coating reflects light of the first wavelength and
transmits light of the second wavelength.
2. The apparatus of claim 1, wherein the first wavelength is
shorter than the second wavelength.
3. The apparatus of claim 2, wherein the light of the first
wavelength is green light and the light of the second wavelength is
orange light.
4. The apparatus of claim 1, wherein the light emitter is a laser
diode.
5. The apparatus of claim 1, wherein the transparent elastic body
comprises one of silicon and a styrenic block copolymer.
6. The apparatus of claim 5, wherein the transparent elastic body
has a thickness in a range of about 2 mm to about 10 mm.
7. The apparatus of claim 5, wherein the dichroic coating comprises
metal.
8. The apparatus of claim 7, wherein the dichroic coating comprises
aluminum.
9. The apparatus of claim 1, wherein the first light receiver
comprises a first color filter disposed thereon, wherein the first
color filter selectively transmits light of the first wavelength,
and the second light receiver comprises a second color filter
disposed thereon, wherein the second color filter selectively
transmits light of the second wavelength.
10. The apparatus of claim 1, wherein the light emitter comprises a
first light emitter configured to emit light of the first
wavelength and a second light emitter configured to emit light of
the second wavelength.
11. The apparatus of claim 10, wherein the first light receiver and
the second light receiver are a single light receiver configured to
detect both light of the first wavelength and light of the second
wavelength; the first light emitter and the second light emitter
are configured to alternately emit light of the first wavelength
and light of the second wavelength; and the single light receiver
is configured to generate a first electrical signal in response to
receiving the light of the first wavelength and is configured to
generate a second electrical signal, distinguishable from the first
electrical signal, in response to receiving light of the second
wavelength.
12. The apparatus of claim 1, wherein the object is a body part of
a patient and the apparatus is configured to be wearable on the
body part of the patient.
13. A method of simultaneously detecting surface pressure and blood
volume of an object, the method comprising: positioning a detecting
apparatus such that a dichroic coating of the detecting apparatus
is in contact with a skin of the object: irradiating the dichroic
coating with light of a first wavelength and irradiating the skin
of the object, via the dichroic coating with light of a second
wavelength, different form the first wavelength; calculating a
surface pressure of the object by detecting the light of the first
wavelength that is reflected by the dichroic coating; and
calculating a blood volume by detecting the light of the second
wavelength light that is scattered by the skin of the object and
reflected back to the apparatus.
14. The method of claim 13, wherein the calculating the surface
pressure comprises measuring a curvature of the skin of the object
by measuring an optical path of the detected light of the first
wavelength based on an intensity of the detected light of the first
wavelength.
15. The method of claim 13, wherein the calculating the blood
volume comprises calculating a change in the blood volume based on
a change in an intensity of the detected light of the second
wavelength.
16. The method of claim 13, wherein the light of the first
wavelength is green light, and the light of the second wavelength
is orange light.
17. A detecting apparatus comprising: a light emitter configured to
emit light of a first wavelength and light of a second wavelength,
different from the first wavelength; a detector configured to
detect light of the first wavelength and light of the second
wavelength; a transparent elastic body covering the light emitter
and the detector; and a dichroic coating disposed on the
transparent elastic body, wherein the dichroic coating reflects
light of the first wavelength emitted from the light emitter and
transmits light of the second wavelength emitted from the light
emitter.
Description
RELATED APPLICATION
[0001] This application claims priority from Korean Patent
Application No. 10-2015-0004448, filed on Jan. 12, 2015, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND
[0002] 1. Field
[0003] Apparatuses and methods consistent with exemplary
embodiments relate to an apparatus for simultaneously detecting a
surface pressure and a blood volume of an object and a method of
detecting the same.
[0004] 2. Description of the Related Art
[0005] In order to detect various characteristic of a
cardiovascular system, a patient's blood flow may be detected
through the surface of the skin. Methods of detecting the blood
flow may be largely divided into two types of methods: a method of
detecting blood pressure at the surface of the skin by using a
pressure sensor, and a method of detecting a change in blood flow
under the surface of the skin by using light.
[0006] In the case of detecting blood pressure at the surface of
the skin, by analyzing the shape of a pressure profile of the skin
surface, the elasticity of a blood vessel can be calculated, and
thus, the age of the blood vessel or the health of the patient's
cardiovascular system may be determined.
[0007] In the case of detecting a change in blood flow using light,
a ratio of oxyhemoglobin to deoxyhemoglobin is estimated by using
light having at least two different wavelengths, and thus, a degree
of oxygen saturation may be estimated.
[0008] The two methods described above respectively measure
pressure at the surface of the skin and blood volume, and this
information may be more useful when synchronized with information
regarding the patient's pulse. However, a combined sensor,
including two sensors respectively used in the two methods, may be
complicated to use because a location at which the pressure at the
surface of the skin is to be detected may differ from a location at
which the blood volume-change is to be detected. Also,
miniaturization of such a sensor for simultaneously detecting the
body surface pressure and the blood volume may also be
difficult.
SUMMARY
[0009] One or more exemplary embodiments may provide an apparatus
for simultaneously detecting a skin surface pressure and a blood
volume by using an optical device and a method of detecting the
same.
[0010] Additional exemplary aspects will be set forth in part in
the description which follows and, in part, will be apparent from
the description, or may be learned by practice of the presented
exemplary embodiments.
[0011] According to an aspect of an exemplary embodiment, an
apparatus for simultaneously detecting surface pressure and blood
volume of an object may include: a printed circuit board (PCB); a
light emitter disposed on the PCB and configured to emit light of a
first wavelength and light of a second wavelength; a first light
receiver and a second light receiver disposed on the PCB, the first
light receiver configured to detect the light of the first
wavelength and the second light receiver configured to detect light
of the second wavelength; a transparent elastic body on the PCB and
covering the light emitter, the first light receiver, and the
second light receiver; and a dichroic coating disposed on the
transparent elastic body and configured to reflect the light of the
first wavelength and to transmit the light of the second
wavelength.
[0012] The first wavelength may be shorter than the second
wavelength.
[0013] The light of the first wavelength may be green light and the
light of the second wavelength light may be orange light.
[0014] The light emitter may be a laser diode.
[0015] The transparent elastic body may be formed of silicon or a
styrenic block copolymer.
[0016] The transparent elastic body may have a thickness in a range
of about 2 mm to about 10 mm.
[0017] The dichroic coating may be a metal coating.
[0018] The dichroic coating may be formed of aluminum.
[0019] The first light receiver may include a first color filter
formed thereon and the first color filter selectively transmits
light of the first wavelength; and the second light-receiving unit
may include a second color filter formed therein and the second
color filter selectively transmits light of the second wavelength
light.
[0020] According to an aspect of another exemplary embodiment, the
light emitter may include a first light emitter that emits light of
the first wavelength light and a second light emitter that emits
light of the second wavelength light.
[0021] According to an aspect of another exemplary embodiment, the
first light receiver and the second light receiver may be a single
light receiver which detects both light of the first wavelength and
light of the second wavelength; the first and second light emitters
may alternately emit light of the first wavelength and light of the
second wavelength; and the single light receiver may generate
electrical signals distinguishable from each other in response to
alternately receiving light of the first wavelength and light of
the second wavelength.
[0022] The apparatus may be wearable on the object.
[0023] According to an aspect of another exemplary embodiment, a
method of simultaneously detecting surface pressure and blood
volume of an object by using the apparatus described above, the
method includes: positioning the apparatus such that the dichroic
coating is in contact with a skin of the object in order to
transmit a curvature of the skin that occurs due to blood flow
variation in a blood vessel under the skin to the dichroic coating:
irradiating the skin of the object with light of the first
wavelength and light of the second wavelength; calculating a
surface pressure of the object by detecting light of the first
wavelength that is reflected by the dichroic coating; and
calculating blood volume by detecting light of the second
wavelength that is returned back to the apparatus after passing
through the dichroic coating and being scattered in the skin and
passing through the dichroic coating toward the apparatus.
[0024] The calculating of the body-surface pressure may include
measuring the curvature of the skin of the object by measuring an
optical path of light of the first wavelength to the skin based on
an intensity of the detected light of the first wavelength.
[0025] The calculating of the blood volume may include calculating
a change in the blood volume based on a change in an intensity of
the detected light of the second wavelength.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and/or other exemplary aspects and advantages will
become apparent and more readily appreciated from the following
description of exemplary embodiments, taken in conjunction with the
accompanying drawings in which:
[0027] FIG. 1 is a schematic block diagram showing a configuration
of an apparatus for simultaneously detecting a surface pressure and
a blood volume of an object, according to an exemplary
embodiment;
[0028] FIG. 2 is a schematic cross-sectional view of a biosignal
detecting unit of an apparatus for simultaneously detecting a
surface pressure and a blood volume of an object, according to an
exemplary embodiment;
[0029] FIG. 3 is a schematic cross-sectional view for explaining a
method of simultaneously detecting a surface pressure and a blood
volume of an object, according to an exemplary embodiment;
[0030] FIG. 4 is a flow diagram of a method of simultaneously
detecting a surface pressure and a blood volume of an object,
according to an exemplary embodiment;
[0031] FIG. 5 is a schematic cross-sectional view of a biosignal
detecting unit of an apparatus for simultaneously detecting a
surface pressure and a blood volume of an object, according to an
exemplary embodiment; and
[0032] FIG. 6 is a schematic cross-sectional view of a biosignal
detecting unit of an apparatus for simultaneously detecting a
surface pressure and a blood volume of an object, according to an
exemplary embodiment.
DETAILED DESCRIPTION
[0033] Reference will now be made in detail to exemplary
embodiments which are illustrated in the accompanying drawings. In
the drawings, the thicknesses of layers and regions are exaggerated
for clarity. The embodiments described below are merely exemplary,
and thus, may be embodied in many different forms.
[0034] It will be understood that when an element or layer is
referred to as being "above" or "on" another element or layer, the
element or layer may be directly on another element or layer or
intervening elements or layers.
[0035] It will be understood that, although the terms "first",
"second", etc. may be used herein to describe various elements,
these elements should not be limited by these terms. These terms
are only used to distinguish one element from another element.
[0036] The singular forms include the plural forms unless the
context clearly indicates otherwise. It will be understood that
when a part "comprise(s)" a constituent element, the constituent
element is not excluded but may further include the constituent
element unless there is a specifically contradict element.
[0037] Also, the terminology " . . . unit" or "module" used in the
specification denotes a unit that processes at least one function
or operation, and the unit may be realized as hardware or software,
or a combination of hardware and software.
[0038] FIG. 1 is a schematic block diagram showing a configuration
of an apparatus 100 for simultaneously detecting a surface pressure
and a blood volume of an object, according to an exemplary
embodiment.
[0039] Referring to FIG. 1, the apparatus 100 for simultaneously
detecting a surface pressure and a blood volume of an object
includes a biosignal detecting unit 200 and a processor 310 that
controls the biosignal detecting unit 200 and performs various
processes for analyzing bio-information based on the detected
result. The apparatus 100 for simultaneously detecting a surface
pressure and a blood volume of an object may further include a
memory 320 and a user interface 330.
[0040] The biosignal detecting unit 200 includes a light emitter
220 and a light receiver 230. The light emitter 220 irradiates an
object OBJ with light, and the light receiver 230 detects light
scattered by and reflected from the object OBJ. The detected
optical signal is used in various ways for analyzing bio
information, which will be described below.
[0041] The object OBJ may be a biological element, for example a
body part of a patient through which a pulse wave measurement is
possible using photoplethysmography (PPG), that may contact or be
located adjacent to the biosignal detecting unit 200 of the
apparatus 100. For example, the body part of the patient may be a
surface of a patient's wrist adjacent to a radial artery. When a
pulse wave is detected at the skin surface of the patient's wrist
through which the radial artery passes, the effect of external
factors, such as the thickness of the skin of the inner wrist, that
may cause detection errors, may be lessened. The radial artery is a
blood vessel that is located in a position of a patient's body
enabling blood pressure to be measured more accurately from the
radial artery than from other blood vessels in the wrist. However,
the object OBJ is not limited thereto, and may be any of a number
of other peripheral body parts of a patient in which a blood vessel
density is high, such as a patient's fingers, toes, or ear
lobes.
[0042] The apparatus 100 may be a wearable device that may be worn
on the object under examination OBJ. For example, the apparatus 100
may be a wrist watch type, a bracelet type, a wrist band type, or a
hair band type, but is not limited thereto.
[0043] Alternately, rather than the whole apparatus 100, a portion
of the apparatus 100, for example, the biosignal detecting unit
200, may be configured as a wearable device to be worn on the
object OBJ.
[0044] FIG. 2 is a schematic cross-sectional view of the biosignal
detecting unit 200 of the apparatus 100, according to an exemplary
embodiment.
[0045] Referring to FIG. 2, the biosignal detecting unit 200 of the
apparatus 100 includes a light emitter 220, a first light receiver
231, and a second light receiver 232, that are disposed on a
printed circuit board (PCB) 210, and a transparent elastic body 240
that covers the light emitter 220, the first light receiver 231,
and the second light receiver 232 on the PCB 210. The first light
receiver 231 and the second light receiver 232 correspond to the
light receiver 230 of FIG. 1. A dichroic coating 250 may be formed
on the transparent elastic body 240. The PCB 210 may be mounted on
a pressing band 260. The pressing band 260 may apply a
predetermined amount of pressure to the transparent elastic body
240 so that the transparent elastic body 240 tightly contacts a
skin of the object OBJ. The pressing band 260 may be a cuff.
[0046] The PCB 210 may be a flexible substrate. The PCB 210
supplies power to the light emitter 220, the first light receiver
231, and the second light receiver 232 and transmits an electrical
signal to the processor 310 (refer to FIG. 1) after receiving the
electrical signal from the first light receiver 231 and the second
light receiver 232. The processor 310 calculates the surface
pressure and the blood volume of an object based on the received
electrical signal.
[0047] The light emitter 220 may emit light of a first wavelength
and light of a second wavelength. The first wavelength may be
shorter than the second wavelength. For example, the light of the
first wavelength may be green light, and the light of the second
wavelength may be orange light. However, exemplary embodiments are
limited thereto, and the light of the first wavelength may be red
light and the light of the second wavelength may be infrared light.
The light emitter 220 may be formed of a laser diode or a
light-emitting device.
[0048] The first light receiver 231 detects the light of the first
wavelength. The first light receiver 231 may be a photodiode, a
photo transistor, or a charge-couple device (CCD). A first color
filter 233 may be disposed on the first light receiver 231 to
selectively transmit the light of the first wavelength.
[0049] The second light receiver 232 detects the light of the
second wavelength. The second light receiver 232 may be a
photodiode, a photo transistor, or a charge-couple device (CCD). A
second color filter 234 may be disposed on the second light
receiver 232 to selectively transmit the light of the second
wavelength.
[0050] The transparent elastic body 240 may be formed of a material
that tightly contacts a patient's skin under which a blood vessel
passes. When a predetermined pressure is applied to the transparent
elastic body 240 by the pressure of a blood vessel under the
patient's skin, a curvature of the surface of the transparent
elastic body 240 changes according to the pressure in the blood
vessel. For example, the transparent elastic body 240 may be formed
of silicon or a styrenic block copolymer. Alternately, the
transparent elastic body 240 may be formed of a thermoplastic
elastomer.
[0051] The transparent elastic body 240 may be formed to be thin so
that the surface of the transparent elastic body 240 moves in
accordance with even very small movements of the skin surface of
the object OBJ.
[0052] The dichroic coating 250 may be formed of a material that
reflects light of the first wavelength and transmits light of the
second wavelength. The dichroic coating 250 may be a metal coating,
for example, an aluminum coating. The dichroic coating 250 may be
formed to a thickness in a range from about 10 .mu.m to about 500
.mu.m. However, the dichroic coating 250 according to exemplary
embodiments is not limited thereto. The dichroic coating 250 may be
a metal, such as silver or gold, a dielectric material, such as
magnesium fluoride, silicon dioxide, tantalum pentoxide, zinc
sulfide, or titanium dioxide, or a combination of these materials.
Alternately, the dichroic coating 250 may be formed as multiple
layers of these materials.
[0053] The dichroic coating 250 may be formed using a physical
vapor deposition method such as sputtering, evaporative deposition,
and ion beam deposition, a chemical vapor deposition method, and
molecular beam epitaxy method.
[0054] Referring to FIG. 1, a program for processing and
controlling the processor 310 may be stored in the memory 320, and
data that is inputted thereto and outputted therefrom may be
stored. For example, a program for analyzing bio-information
performed in the processor 310 may be stored as code. Also,
detection results that are detected by the biosignal detecting unit
200 and are required for processing in the processor 310 may be
stored in the memory 320.
[0055] The memory 320 may include at least one type of storage
medium, for example, a flash memory, a hard disk, a multimedia card
micro, a card memory (for example, secure digital (SD) or extreme
digital (XD) memory etc.), a random access memory (RAM), a static
random access memory (SRAM), a read-only memory (ROM), an
electrically erasable programmable read-only memory (EEPROM), a
programmable read-only memory (PROM), a magnetic memory, a magnetic
disc, an optical disc, or another type of memory as would be
understood by one of skill in the art.
[0056] The user interface 330 is an interface between the apparatus
100 and the user and/or an external device, and includes an input
unit and an output unit. The user may be an object OBJ, bio
information of which is to be detected, and also may be a person or
a specialist who uses the apparatus 100, that is, the term "user"
is intended to be broader than the object OBJ. Information required
for operating the apparatus 100 is inputted thereto and analyzed
results are outputted therefrom through the user interface 330. The
user interface 330 may include, for example, a button, a connector,
or a display unit, and also, may further include a device, such as
an acoustic output unit and a vibrating motor.
[0057] The apparatus 100 may further include a communication unit
340 for transmitting analyzed results to an external device. The
external device may be medical equipment that uses the analyzed bio
information, a printer for printing the analyzed result, or a
display device for displaying the analyzed result. Additionally,
the external device may be a smart phone, a mobile phone, a
personal digital assistant (PDA), a laptop, a personal computer
(PC), and mobile or non-mobile computer equipment, but the
exemplary embodiments are not limited thereto.
[0058] The communication unit 340 may be connected to an external
device via a wireless method or wires. The communication unit 340
may communicate with the external devices via, for example, a
bluetooth communication unit, a bluetooth low energy (BLE)
communication unit, a near field communication unit, a WLAN (wifi)
communication unit, a zigbee communication unit, an infrared Data
Association (IrDA) communication unit, a WFD(Wi-Fi Direct)
communication unit, an ultra wideband (UWB) communication unit, or
another device as would be understood by one of skill in the
art.
[0059] Using the apparatus 100, for simultaneously detecting
surface pressure and blood volume of an object, since the surface
pressure and blood volume of an object may be detected at the same
position on the skin of the object OBJ, an additional
characteristic of the patient's cardiovascular system may be
detected. For example, the blood pressure and the elasticity of the
blood vessel may both be accurately detected by detecting a pulse
wave at the patient's wrist using the apparatus 100.
[0060] Hereinafter, a method of simultaneously detecting a surface
pressure and a blood volume of an object will be described with
reference to FIGS. 3 and 4.
[0061] FIG. 3 is a schematic cross-sectional view for explaining a
method of simultaneously detecting surface pressure and blood
volume of an object, according to an exemplary embodiment. FIG. 4
is a flow diagram of a method of simultaneously detecting surface
pressure and blood volume of an object, according to an exemplary
embodiment.
[0062] Referring to FIGS. 3 and 4, the transparent elastic body 240
of the biosignal detecting unit 200 is positioned to tightly
contact an object 280 (S401). Thus, the dichroic coating 250 is in
contact with the skin of the object 280. At this point, a
predetermined pressure is applied to the transparent elastic body
240 so that the surface curvature of the skin of the object 280 is
transmitted to the transparent elastic body 240. For example, the
transparent elastic body 240 is tightly contacted with the skin of
the object 280 by using the pressing band 260.
[0063] Next, light is irradiated onto a blood vessel, for example a
radial artery 290 in the skin of the object 280, from the light
emitter 220 (S402). The emitted light may have a wide range of
wavelengths. For example, the emitted light may include green light
and orange light. In this example, the green light is the light of
the first wavelength L1 and the orange light is the light of the
second wavelength L2. The light of the first wavelength L1 is
reflected at the dichroic coating 250 and is detected by the first
light receiver 231 (S403), and the light of the second wavelength
L2 is transmitted through the dichroic coating 250. A portion of
the light of the second wavelength L2 is absorbed by blood in a
blood vessel in the skin of the object 280, and another portion of
the light of the second wavelength L2 is reflected and is detected
by the second light receiver 232 after passing through the dichroic
coating 250 (S404).
[0064] A surface pressure is calculated from the detected light of
the first wavelength L1 (S405). The light of the first wavelength
L1 that is reflected at the dichroic coating 250 is inputted into
the first light receiver 231. The light reflected towards the first
light receiver 231 may include light having a wide range of
wavelengths. Of the reflected light, the light of the first
wavelength L1 enters into the first light receiver 231 after
passing through the first color filter 233 formed on an upper
surface of the first light receiver 231. The first light receiver
231 generates an electrical signal in response to the quantity of
the detected light of the first wavelength L1 and transmits the
electrical signal to the processor 310 (refer to FIG. 1).
[0065] When the light of the first wavelength L1 is irradiated onto
a region of skin which is convex due to a blood flow in the blood
vessel therebelow, the light of the first wavelength L1 is
reflected at the dichroic coating 250 on the convex region of skin,
and thus, the optical path of the light of the first wavelength
received by the first light receiver 231 is shorter than an
instance in which the light of the first wavelength L1 is reflected
from a planar region of skin. The light of the first wavelength L1,
having a relatively shorter optical path has a relatively higher
optical intensity, and the light of the first wavelength L1 having
a relatively longer optical path has a relatively lower optical
intensity. Thus, the height of the convex region of the skin may be
determined from the intensity of the received light of the first
wavelength L1. Also, when a frequency of the appearance of the
convex region is detected, a number of pulses may be determined.
Accordingly, a surface pressure may be obtained from the light of
the first wavelength L1.
[0066] A blood volume is calculated from the detected light of the
second wavelength L2 (S406). The light of the second wavelength L2
emitted from the light emitter 220 enters into the skin through the
dichroic coating 250. The light of the second wavelength L2
incident on the skin is scattered by the skin, and some of the
light of the second wavelength L2 is absorbed by blood components
and a remaining portion of the light of the second wavelength light
L2 is reflected to the second light receiver 232. Of the reflected
light of the second wavelength L2, only light which is the same
color as that of the second color filter 234 is incident onto the
second light receiver 232. The second light receiver 232 generates
an electrical signal in response to the detected light of the
second wavelength L2 and transmits the electrical signal to the
processor 310. The processor 310 calculates a blood volume from the
received light of the second wavelength L2.
[0067] According to this exemplary method of simultaneously
detecting surface pressure and blood volume of an object, the
surface pressure and blood volume of an object may be
simultaneously detected by emitting light toward the same position
of a skin by using the same light emitter 220.
[0068] FIG. 5 is a schematic cross-sectional view of a biosignal
detecting unit 202 of an apparatus 100 for simultaneously detecting
surface pressure and blood volume of an object, according to an
exemplary embodiment. Like reference numerals are used to indicate
elements that are substantially identical to the elements of FIG.
2, and thus the detailed description thereof will not be
repeated.
[0069] Referring to FIG. 5, the biosignal detecting unit 202 of the
apparatus 100 includes a first light emitter 221 that emits light
of a first wavelength, a second light emitter 222 that emits light
of a second wavelength, a first light receiver 231 that detects the
light of the first wavelength, and a second light receiver 232 that
detects the light of the second wavelength. The first light emitter
221, the second light emitter 222, the first light receiver 231,
and the second light receiver 232 are disposed on a PCB 210. A
transparent elastic body 240 is formed on the PCB 210 to cover the
first light emitter 221, the second light emitter 222, the first
light receiver 231, and the second light receiver 232. A dichroic
coating 250 facing the PCB 210 is formed on the transparent elastic
body 240. The first and second light emitters 221 and 222
correspond to the light emitter 220 of FIG. 1.
[0070] The PCB 210 may be a flexible substrate. The PCB 210
supplies power to the first light emitter 221, the second light
emitter 222, the first light receiver 231, and the second light
receiver 232 and transmits electrical signals to the processor 310
(refer to FIG. 1) after receiving the electrical signals from the
first light receiver 231 and the second light receiver 232. The
processor 310 calculates a surface pressure and a blood volume of
an object based on the received electrical signal.
[0071] The first wavelength may be shorter than the second
wavelength. For example, the first wavelength may be green light,
and the second wavelength may be orange light. The first light
emitter 221 and the second light emitter 222 may each be a laser
diode or a light-emitting device.
[0072] The biosignal detecting unit 202 of the apparatus 100,
according to an exemplary embodiment, includes light emitters that
separately emit the light of the first wavelength and the light of
the second wavelength, and thus, the light emitted from the light
emitters may be easily controlled.
[0073] The operation of the apparatus 100 may be readily understood
from the exemplary embodiments described above, and thus, the
description thereof will not be repeated.
[0074] FIG. 6 is a schematic cross-sectional view of a biosignal
detecting unit 204 of an apparatus 100 for simultaneously detecting
surface pressure and blood volume of an object, according to an
exemplary embodiment. Like reference numerals are used to indicate
elements that are substantially identical to the elements of FIG.
2, and thus the detailed description thereof will not be
repeated.
[0075] Referring to FIG. 6, the biosignal detecting unit 204 of the
apparatus 100 includes a first light emitter 221 that emits light
of a first wavelength, a second light emitter 222 that emits light
of a second wavelength, and a light receiver 230 that detects the
light of the first wavelength and the light of the second
wavelength. The first light emitter 221, the second light emitter
222, and the light receiver 230 are disposed on a PCB 210. A
transparent elastic body 240 is formed on the PCB 210 to cover the
first light emitter 221, the second light emitter 222, and the
light receiver 230. A dichroic coating 250 facing the PCB 210 is
formed on the transparent elastic body 240.
[0076] The first light emitter 221 and the second light emitter 222
may alternately emit the light of the first wavelength and the
light of the second wavelength, as controlled by the processor 310.
The light receiver 230 may receive the light of the first
wavelength and the light of the second wavelength at given
predetermined times. The light receiver 230 generates a first
electrical signal in response to the intensity of the light of the
first wavelength and a second electrical signal in response to the
intensity of the light of the second wavelength, and transmits the
first electrical signal and the second electrical signal to the
processor 310.
[0077] The operation of the apparatus 100 for simultaneously
detecting surface pressure and blood volume of an object may be
readily understood from the exemplary embodiments described above,
and thus, the description thereof will not be repeated.
[0078] The biosignal detecting unit 204 of the apparatus 100,
according to an exemplary embodiment includes light emitters that
distinctively emit light of a first wavelength and light of a
second wavelength and a single light receiver that alternatively
receives the light of the first wavelength and the light of the
second wavelength, and thus, a color filter is unnecessary on the
light receiver.
[0079] According to one or more of the above-described exemplary
embodiments, the apparatus for simultaneously detecting surface
pressure and blood volume of an object may detect a surface
pressure and a blood volume of an object at the same position on
the skin of an object, and thus, an additional accurate
characteristic of a patient's cardiovascular system may be
detected.
[0080] Also, an exemplary apparatus for simultaneously detecting
surface pressure and blood volume of an object is configured of a
single optical sensor without using an additional pressure
measuring device, and thus, the apparatus may be miniaturized and
used on a wearable device.
[0081] While one or more exemplary embodiments have been described
with reference to the figures, it will be understood by those of
ordinary skill in the art that various changes in form and details
may be made therein without departing from the spirit and scope as
defined by the following claims.
* * * * *