U.S. patent application number 16/630620 was filed with the patent office on 2021-01-28 for multifunctional measuring device capable of determining carotid blood pressure.
The applicant listed for this patent is BlV MEDICAL, LTD., Shiming LIN. Invention is credited to Shiming LIN.
Application Number | 20210022624 16/630620 |
Document ID | / |
Family ID | 1000005167532 |
Filed Date | 2021-01-28 |
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United States Patent
Application |
20210022624 |
Kind Code |
A1 |
LIN; Shiming |
January 28, 2021 |
MULTIFUNCTIONAL MEASURING DEVICE CAPABLE OF DETERMINING CAROTID
BLOOD PRESSURE
Abstract
The present invention provides a multifunctional measuring
device capable of determining carotid blood pressure, comprising: a
heartbeat sensing unit to be disposed on a subject's chest in order
to obtain heartbeat signals; a pulse sensing unit to be disposed on
the subject's neck at a position corresponding to the subject's
carotid arteries in order to obtain pulse signals; and a data
calculation unit configured to communicate with the heartbeat
sensing unit and the pulse sensing unit and to process signals
coming from the heartbeat sensing unit and from the pulse sensing
unit; wherein the data calculation unit obtains a mean arterial
pressure of the subject's carotid arteries by calculating with the
heartbeat signals coming from the heartbeat sensing unit and the
pulse signals coming from the pulse sensing unit. The invention can
be used to detect carotid blood pressure and pulse wave velocity,
and the measurement results can be used to assess carotid stenosis
and cerebral blood volume, so as to quickly screen the degree of
carotid stenosis for those who have a high risk of cardiovascular
disease, and respond to a high demand in the global medical device
market.
Inventors: |
LIN; Shiming; (Taipei,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LIN; Shiming
BlV MEDICAL, LTD. |
Taipei
Caotun Township, Nantou County |
|
TW
TW |
|
|
Family ID: |
1000005167532 |
Appl. No.: |
16/630620 |
Filed: |
July 10, 2018 |
PCT Filed: |
July 10, 2018 |
PCT NO: |
PCT/CN2018/095174 |
371 Date: |
January 13, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62604596 |
Jul 13, 2017 |
|
|
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62604656 |
Jul 17, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/6823 20130101;
A61B 7/04 20130101; A61B 5/02007 20130101; A61B 5/02125 20130101;
A61B 5/02438 20130101; A61B 5/0004 20130101; A61B 5/7275
20130101 |
International
Class: |
A61B 5/021 20060101
A61B005/021; A61B 5/024 20060101 A61B005/024; A61B 5/00 20060101
A61B005/00; A61B 5/02 20060101 A61B005/02; A61B 7/04 20060101
A61B007/04 |
Claims
1. A multifunctional measuring device capable of determining
carotid blood pressure, comprising: a heartbeat sensing unit to be
disposed on a subject's chest in order to obtain heartbeat signals;
a pulse sensing unit to be disposed on the subject's neck at a
position corresponding to the subject's carotid arteries in order
to obtain pulse signals; and a data calculation unit configured to
communicate with the heartbeat sensing unit and the pulse sensing
unit and to process signals coming from the heartbeat sensing unit
and from the pulse sensing unit; wherein the data calculation unit
obtains a mean arterial pressure of the subject's carotid arteries
by calculating with the heartbeat signals coming from the heartbeat
sensing unit and the pulse signals coming from the pulse sensing
unit.
2. The multifunctional measuring device of claim 1, wherein the
heartbeat sensing unit is an acoustic wave sensor.
3. The multifunctional measuring device of claim 2, wherein the
heartbeat sensing unit is configured to be disposed on a subject's
chest at a position corresponding to the vicinity of the aortic
valve, the pulmonary valve, the mitral valve, or the tricuspid
valve.
4. The multifunctional measuring device of claim 2, wherein the
pulse sensing unit is a Doppler radar, a piezoelectric sensor, a
piezoresistive pressure sensor, a capacitive pressure sensor, an
acoustic wave sensor, an ultrasound sensor, or a
photoplethysmographic (PPG) sensor.
5. The multifunctional measuring device of claim 4, wherein the
pulse sensing unit is configured to be disposed at a pulse
measuring point on the neck, wherein the pulse measuring point is a
point in a line segment defined as follows: the line segment starts
from a starting point (or 0 cm position) defined as a point that is
to the left or right of, and horizontally spaced apart by 3.+-.0.3
cm from, the peak of the thyroid cartilage, and the line segment
extends from the starting point (or 0 cm position) for 4 cm along a
direction that extends distally at an angle of 135 degrees with
respect to the horizontal direction.
6. The multifunctional measuring device of claim 5, wherein the
mean arterial pressure is obtained through the following equation
(I) or equation (II): mean arterial pressure ( MAP ) = a ( l p t p
a .times. c ) + b ; equation ( I ) mean arterial pressure ( MAP ) =
A ( l p t p a .times. C ) 2 + B ; equation ( II ) ##EQU00008##
where l.sub.p is the length of the path along which the pulse
propagates through the arteries between the aortic valve and the
pulse measuring point; t.sub.pa is the times it takes for a pulse
to reach the pulse measuring point from the aortic valve; and a, b,
c, A, B, and C are correction parameters.
7. The multifunctional measuring device of claim 5, wherein the
pulse sensing unit includes an adhesive patch with a thyroid
cartilage locating portion.
8. The multifunctional measuring device of claim 6, wherein the
multifunctional measuring device further comprises a communication
module connected to the data calculation unit, wherein the
communication module is a Bluetooth communication module, a WIFI
communication module, a radio frequency identification (RFID)
communication module, a near-field communication (NFC) module, a
Zigbee communication module, or a wireless local area network
(WLAN) communication module.
9. The multifunctional measuring device of claim 8, wherein the
data calculation unit is provided in the heartbeat sensing unit,
the pulse sensing unit, and/or a portable device.
10. The multifunctional measuring device of claim 1, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
11. The multifunctional measuring device of claim 2, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
12. The multifunctional measuring device of claim 3, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
13. The multifunctional measuring device of claim 4, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
14. The multifunctional measuring device of claim 5, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
15. The multifunctional measuring device of claim 6, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
16. The multifunctional measuring device of claim 7, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
17. The multifunctional measuring device of claim 8, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
18. The multifunctional measuring device of claim 9, wherein the
multifunctional measuring device can further be used to obtain
heart sound, blood flow sound, pulse wave velocity, and the degree
of carotid stenosis.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
[0001] The present invention relates to a blood pressure measuring
device, and more particularly to a multifunctional measuring device
for determining carotid blood pressure.
2. Description of Related Art
[0002] Cerebrovascular disease has long been among the top five
causes of death in Taiwan and a major cause of physical
disabilities of young adults and is therefore a principal enemy of
the health of the residents in Taiwan. As a cerebrovascular
disease, ischemic strokes stem from insufficient blood supply to
the brain and cause damage to the central nervous system, occurring
typically in those who are 60 to 70 years old. The risk factors of
ischemic strokes include atherosclerosis, hypertension, diabetes,
hyperlipidemia, smoking, family history, and so on. A further
analysis of the causes of atherosclerosis indicates that carotid
stenosis-related occlusion accounts for about 20 % to 25 % of the
cases of atherosclerosis, hypertension-related lacunar infarct
about 20 %, occlusion attributable to atrial fibrillation-related
arrhythmia 25 %, and occlusion of unknown causes 30 %.
[0003] Of the various risk factors, stenosis of the left or right
carotid arteries shows a strong statistical correlation with a
subsequent ischemic stroke that affects the same side of the brain.
Literature has also shown that patients with more than 80 %
stenosis of the carotids are nearly 60 times as likely (92.3 % vs
1.5 %) to suffer ischemic strokes and other complications at a
later time as those with less than 80 % stenosis. Moreover, carotid
stenosis and its damage to the human body aggravate over time.
[0004] It can be known from the above that the detection and
quantitative assessment of carotid stenosis are of paramount
clinical importance to the prevention of strokes. Methods
conventionally used to diagnose carotid stenosis include, among
others, Doppler ultrasound scanning, magnetic resonance angiography
(MRA), and carotid angiography. A brief description of the
aforesaid methods is given below.
[0005] Doppler ultrasound scanning of the neck entails applying the
Doppler effect to the detection of the hemodynamic properties of
each major artery in the cerebral arterial circle and can be used
to observe the blood flow in those arteries. Due to the cranium,
however, carotid Doppler ultrasound has many restrictions in terms
of engineering and clinical application. For example, only a
limited portion of the carotid arteries (i.e., the portion in the
neck) is detectable by Doppler ultrasonography. While the detection
area can be increased by using Doppler ultrasound that can
penetrate the cranium, the improvement is nominal.
[0006] In MRA, the hydrogen atoms in the target body tissues are
temporarily magnetized with an applied magnetic field so that, with
the hydrogen atoms resonating with radio waves, signals generated
by the tissues can be collected with a coil to generate an MRA
image. In other words, MRA uses the vector properties of blood flow
velocity in an applied magnetic field to determine the condition of
the blood vessel under observation. The resulting MRA image,
therefore, is sensitive to blood flow velocity, and this makes it
impossible to observe the anatomical structure of the blood vessel
as precisely as with the conventional angiography.
[0007] Carotid angiography is carried out by inserting a catheter
into a femoral artery or other peripheral artery in the groin,
guiding the catheter into the proximal end of a carotid artery
under radiation-based monitoring, injecting a contrast agent into
the catheter, and irradiating the carotid artery with X rays at
short time intervals in order to capture images inside the artery
(of a cerebral or cervical section of the artery) and thereby
visualize the blood flow condition in the artery. While such
angiography produces images of the blood vessel structure with
relatively high precision, a study comparing angiographic results
against biopsy sections obtained by carotid endarterectomy shows
that carotid angiography has a false negative rate as high as 40
%.
BRIEF SUMMARY OF THE INVENTION
[0008] Patients with high-percentage carotid stenosis are far more
susceptible to ischemic strokes and other complications than those
with low-percentage carotid stenosis. Furthermore, carotid stenosis
affects the cerebral blood volume (CBV), which is closely related
to dementia. To prevent strokes and dementia, therefore, clinical
detection of carotid stenosis is critical. Methods conventionally
used to diagnose carotid stenosis and determine the CBV include
digital subtraction angiography (DSA), MRA, Doppler ultrasound
scanning, etc. of the carotid arteries, but the foregoing clinical
methods for assessing carotid stenosis have their respective
limitations and are time-consuming. Taking Doppler ultrasound--the
simplest of them all--for example, it takes at least 20 minutes to
complete one examination. Angiographic methods such as DSA and MRA
take even longer time and entail risks associated with their
invasive procedures and the use of contrast agents, which may cause
allergic reactions. Computed tomography angiography (CTA), which
has become more and more common in recent years, involves risks
related to radiation as well as contrast agents. According to the
above, the conventional diagnosis methods are not suitable for fast
screening. It is imperative to provide those who are of an advanced
age, who have had a stroke, or who have a high risk of
cardiovascular disease with a carotid stenosis detection device or
technique that is easy to use and enables fast screening. The
development of such a detection device or technique is critical to
the prevention of strokes and dementia and responds to a high
demand in the global medical device market.
[0009] As above, in order to solve the aforementioned problems, the
primary objective of the present invention is to provide a
multifunctional measuring device capable of determining carotid
blood pressure, comprising: a heartbeat sensing unit to be disposed
on a subject's chest in order to obtain heartbeat signals; a pulse
sensing unit to be disposed on the subject's neck at a position
corresponding to the subject's carotid arteries in order to obtain
pulse signals; and a data calculation unit configured to
communicate with the heartbeat sensing unit and the pulse sensing
unit and to process signals coming from the heartbeat sensing unit
and from the pulse sensing unit; wherein the data calculation unit
obtains a mean arterial pressure of the subject's carotid arteries
by calculating with the heartbeat signals coming from the heartbeat
sensing unit and the pulse signals coming from the pulse sensing
unit.
[0010] In a preferred embodiment, the heartbeat sensing unit is an
acoustic wave sensor.
[0011] In a preferred embodiment, the heartbeat sensing unit is
configured to be disposed on a subject's chest at a position
corresponding to the vicinity of the aortic valve, the pulmonary
valve, the mitral valve, or the tricuspid valve.
[0012] In a preferred embodiment, the pulse sensing unit is a
Doppler radar, a piezoelectric sensor, a piezoresistive pressure
sensor, a capacitive pressure sensor, an acoustic wave sensor, an
ultrasound sensor, or a photoplethysmographic (PPG) sensor.
[0013] In a preferred embodiment, the pulse sensing unit is
configured to be disposed at a pulse measuring point on the neck,
wherein the pulse measuring point is a point in a line segment
defined as follows: the line segment starts from a starting point
(or 0 cm position) defined as a point that is to the left or right
of, and horizontally spaced apart by 3.+-.0.3 cm from, the peak of
the thyroid cartilage, and the line segment extends from the
starting point (or 0 cm position) for 4 cm along a direction that
extends distally at an angle of 135 degrees with respect to the
horizontal direction.
[0014] In a preferred embodiment, the mean arterial pressure is
obtained through the following equation (I) or equation (II):
mean arterial pressure ( MAP ) = a ( l p t p a .times. c ) + b ;
equation ( I ) mean arterial pressure ( MAP ) = A ( l p t p a
.times. C ) 2 + B ; equation ( II ) ##EQU00001##
[0015] where l.sub.p is the length of the path along which the
pulse propagates through the arteries between the aortic valve and
the pulse measuring point; t.sub.pa is the times it takes for a
pulse to reach the pulse measuring point from the aortic valve; and
a, b, c, A, B, and C are correction parameters.
[0016] In a preferred embodiment, the pulse sensing unit includes
an adhesive patch with a thyroid cartilage locating portion.
[0017] In a preferred embodiment, the multifunctional measuring
device further comprises a communication module connected to the
data calculation unit, wherein the communication module is a
Bluetooth communication module, a WIFI communication module, a
radio frequency identification (RFID) communication module, a
near-field communication (NFC) module, a Zigbee communication
module, or a wireless local area network (WLAN) communication
module.
[0018] In a preferred embodiment, the data calculation unit is
provided in the heartbeat sensing unit, the pulse sensing unit,
and/or a portable device.
[0019] In a preferred embodiment, the multifunctional measuring
device can further be used to obtain heart sound, blood flow sound,
pulse wave velocity, and the degree of carotid stenosis.
[0020] The present invention provides a multifunctional measuring
device that features non-invasive detection. More specifically, an
acoustic wave sensor is adhesively attached via an adhesive patch
to a subject's body at a position adjacent to one of the subject's
cardiac valves, and a sensing unit selected as needed from a
variety of options is adhesively attached to the subject's neck at
a position adjacent to the carotid arteries. Not only can the
multifunctional measuring device detect carotid blood pressure and
pulse wave velocity, but also the measurement result can be used to
diagnose carotid stenosis and determine the cerebral blood volume.
The multifunctional measuring device of the invention is compact in
size, can be held by hand, is portable, can measure the degree of
carotid stenosis rapidly, and is suitable for use at home as well
as in hospitals (e.g., by a physician for diagnosis purposes),
nursing homes, research centers, and so on. The multifunctional
measuring device of the invention is expected to have a strong
demand in the global medical device market by those who are of an
advanced age, who have had a stroke, or who have a high risk of
cardiovascular disease.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] FIG. 1 is a first block diagram of the multifunctional
measuring device of the present invention.
[0022] FIG. 2 is a second block diagram of the multifunctional
measuring device of the present invention.
[0023] FIG. 3 shows a state of use of a multifunctional measuring
device according to embodiment 1 of the present invention.
[0024] FIG. 4 is an oscillogram of a multifunctional measuring
device according to embodiment 1 of the present invention.
[0025] FIG. 5 shows a state of use of a multifunctional measuring
device according to embodiment 2 of the present invention.
[0026] FIG. 6 is an audiogram for the heart sound in the aortic
valve area about a multifunctional measuring device of embodiment 2
of the present invention.
[0027] FIG. 7 is an oscillogram for the right carotid arteries
about a multifunctional measuring device of embodiment 2 of the
present invention.
[0028] FIG. 8 shows the oscillogram images of embodiment 1 of the
present invention and comparative example 1.
[0029] FIG. 9 is the correlation analysis result of embodiment 1 of
the present invention and comparative example 1.
[0030] FIG. 10 is the first correlation analysis result of
embodiment 1 of the present invention and comparative example
2.
[0031] FIG. 11 is the second correlation analysis result of
embodiment 1 of the present invention and comparative example
2.
[0032] FIG. 12 is the third correlation analysis result of
embodiment 1 of the present invention and comparative example
2.
[0033] FIG. 13 shows the carotid waveforms according to validation
and verification example 3 of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The details and technical solution of the present invention
are hereunder described with reference to accompanying drawings.
For illustrative sake, the accompanying drawings are not drawn to
scale. The accompanying drawings and the scale thereof are not
restrictive of the present invention.
[0035] The use of "comprise" means not excluding the presence or
addition of one or more other components, steps, operations, or
elements to the described components, steps, operations, or
elements, respectively. Similarly, "comprise," "comprises,"
"comprising," "include," "includes," and "including" are
interchangeable and not intended to be limiting. As used herein and
in the appended claims, the singular forms "a," "an," and "the"
include plural referents unless the context dictates otherwise. The
terms "a", "an," "the," "one or more," and "at least one," for
example, can be used interchangeably herein.
[0036] In the following, the present invention will be further
described with detailed descriptions and embodiments. However, it
should be understood that these embodiments are only used to help
make the present invention easier to understand, rather than to
limit the scope of the present invention.
[0037] Please refer to FIG. 1 and FIG. 2 respectively for two block
diagrams of the multifunctional measuring device according to a
preferred embodiment of the present invention.
[0038] The primary objective of the present invention is to provide
a multifunctional measuring device 100 that is capable of
determining carotid blood pressure. The multifunctional measuring
device 100 includes a heartbeat sensing unit 11 to be disposed on a
subject's chest to obtain heartbeat signals, a pulse sensing unit
12 to be disposed on the subject's neck at a position corresponding
to the carotid arteries in order to obtain pulse signals, and a
data calculation unit 13 in communication with the heartbeat
sensing unit 11 and the pulse sensing unit 12 in order to process
signals coming from the heartbeat sensing unit 11 and from the
pulse sensing unit 12. In particular, the data calculation unit 13
calculates with the heartbeat signals coming from the heartbeat
sensing unit 11 and the pulse signals coming from the pulse sensing
unit 12 in order to obtain the mean arterial pressure (MAP) of the
subject's carotid arteries.
[0039] The carotid arteries, which are responsible for supplying
blood to the brain and the neck, can be divided into a left part
and a right part, each part including a common carotid artery
arising from the aorta and two branches (i.e., an external carotid
artery and an internal carotid artery) from the common carotid
artery. The external carotid artery is the major source of facial
blood flow, while the internal carotid artery serves mainly to
supply blood to brain tissues. The carotid arteries are shallow,
easy to detect, and hence a desirable window through which to
discover such diseases as arteriosclerosis.
[0040] As used herein, the term "heartbeat sensing unit 11" refers
to an assembly of components configured to obtain heartbeat signals
in real time. The heartbeat sensing unit 11 may include software as
well as hardware and be further integrated with an auxiliary
component. For example, the heartbeat sensing unit 11 may include a
sensor for measuring heartbeat, a storage device for receiving and
recording data, a data processor, and other related components; the
present invention has no limitation in this regard. The "related
components" may be, but are not limited to, a signal amplifier, a
power supply device, a microcontroller, a communication unit, a
power unit, and a display unit. The aforesaid software may be, but
is not limited to, software for data collection or feature
extraction, software for signal amplification, and software for
data calculation and analysis. The auxiliary component may be, but
is not limited to, an adhesive patch, an electronic adhesive patch,
or an auxiliary component to render the heartbeat sensing unit 11
easy to grip. In one preferred embodiment, the heartbeat sensing
unit 11 is an acoustic wave sensor; in other words, the acoustic
wave sensor is used to obtain the sound/acoustic wave signals (also
known as heart sound signals) generated by pulsation of the heart.
Heart sound signals correspond to the operation of the cardiac
valves and can therefore be converted into heartbeat signals. Now
that heart sound signals reflect the operation of the cardiac
valves, the heartbeat sensing unit 11 can, apart from communicating
with and working in conjunction with the pulse sensing unit 12 and
the data calculation unit 13, work alone to obtain the subject's
heart sound signals, in order for the frequency and intensity of
the heart sound and the relationship therebetween to reflect the
conditions of the cardiac valves, of the cardiac muscle function,
and of the blood flow in the heart, thereby facilitating the
determination of the presence or absence of irregular heart sound
or other cardiac abnormalities. As to the position where the
heartbeat sensing unit 11 is to be disposed, the heartbeat sensing
unit 11 in one preferred embodiment is configured to be disposed on
a subject's chest at a position corresponding to the vicinity of a
cardiac valve, such as the vicinity of an atrioventricular valve
(e.g., the mitral valve or the tricuspid valve) or the vicinity of
a semilunar valve (e.g., the aortic valve or the pulmonary valve,
which are respectively in the two arteries leaving the heart,
namely the aorta and the pulmonary artery).
[0041] As used herein, the term "pulse sensing unit 12" refers to
an assembly of components configured to obtain pulse signals in
real time. The pulse sensing unit 12 may include software as well
as hardware and be further integrated with an auxiliary component.
For example, the pulse sensing unit 12 may include a sensor for
measuring the pulse, a storage device for receiving and recording
data, a data processor, and other related components; the present
invention has no limitation in this regard. The "related
components" may be, but are not limited to, a signal amplifier, a
power supply device, a microcontroller, a communication unit, a
power unit, and a display unit. The aforesaid software may be, but
is not limited to, software for data collection or feature
extraction, software for signal amplification, and software for
data calculation and analysis. The auxiliary component may be, but
is not limited to, an adhesive patch, an electronic adhesive patch,
or an auxiliary component to render the pulse sensing unit 12 easy
to grip. In one preferred embodiment, the pulse sensing unit 12 is
a pulse wave sensor capable of converting the pulse wave signals
obtained into pulse signals. The pulse sensing unit 12 may be, but
is not limited to, a Doppler radar, a piezoelectric sensor, a
piezoresistive pressure sensor, a capacitive pressure sensor, an
acoustic wave sensor, an ultrasound sensor, a photoplethysmographic
(PPG) sensor, or other sensors capable of sensing pulse wave
signals. In addition to communicating with and working in
conjunction with the heartbeat sensing unit 11 and the data
calculation unit 13, the pulse sensing unit 12 can work alone to
obtain a subject's pulse wave signals for example, thereby
facilitating the determination of the presence or absence of an
irregular pulse or arrhythmia. As to the position where the pulse
sensing unit 12 is to be disposed, the pulse sensing unit 12 in one
preferred embodiment is configured to be disposed on a subject's
neck at a position corresponding to the carotid arteries, wherein
the position may correspond to the left or the right carotid
arteries. In a more preferred embodiment, the pulse sensing unit 12
is configured to be disposed at a pulse measuring point on the
neck. Optimally, the pulse measuring point is a point in a line
segment defined as follows. The line segment starts from a starting
point (or 0 cm position) defined as a point that is to the left or
right of, and horizontally spaced apart by 3.+-.0.3 cm from, the
peak of the thyroid cartilage (i.e., the laryngeal prominence) (or
the most prominent point of the neck that lies right below the
middle point of the lips), wherein the horizontal distance of
3.+-.0.3 cm may be, but is not limited to, 2.7 cm, 2.8 cm, 2.9 cm,
3 cm, 3.1 cm, 0.2 cm, or 3.3 cm. The line segment extends from the
starting point (or 0 cm position) for 4 cm along a direction that
extends distally at an angle of 135 degrees with respect to the
horizontal direction. For example, the pulse measuring point may be
1 cm, 2 cm, 3 cm, or up to 4 cm away from the starting point (or 0
cm position) in the direction extending distally at the angle of
135 degrees with respect to the horizontal direction. The pulse
measuring point of the invention, however, is not limited to a
point in the aforesaid line segment; the line segment defined above
is only an exemplary range that allows pulse signals to be
effectively obtained. Furthermore, to make it easier to dispose the
pulse sensing unit 12 on a subject's neck at a position
corresponding to the subject's carotid arteries (i.e., at the
carotid pulse measuring point), the pulse sensing unit 12 in one
preferred embodiment includes an adhesive patch with a thyroid
cartilage locating portion. The thyroid cartilage locating portion
may be, but is not limited to, a locating hole, a locating mark, or
other similar features with a thyroid cartilage locating function;
the invention has no limitation on the locating means to be used.
Moreover, the pulse sensing unit 12 of the invention may have other
functions than obtaining the pulse waves and pulse signals of the
carotid arteries, depending on the type of the pulse sensor
employed. For example, the pulse sensing unit 12 will be able to
obtain the blood flow sound in the neck if an acoustic wave sensor
is used, and the blood flow/pulse wave velocity in the neck if a
Doppler radar is used. The foregoing configuration is advantageous
in that the pulse sensing unit 12 can not only monitor the carotid
pulse, but also measure variation in the carotid blood flow in real
time.
[0042] As used herein, the term "data calculation unit 13" refers
to an assembly of components configured for signal processing and
computation. The data calculation unit 13 may include software as
well as hardware and be further integrated with an auxiliary
component. For example, the data calculation unit 13 may include a
storage device for receiving and recording data, a data processor,
and other related components; the present invention has no
limitation in this regard. The "related components" may be, but are
not limited to, a signal amplifier, a power supply device, a
microcontroller, a communication unit, a power unit, and a display
unit. The aforesaid software may be, but is not limited to,
software for data collection or feature extraction, software for
signal amplification, and software for data calculation and
analysis. The data calculation unit 13 is connected or coupled to,
and is configured to communicate with, the heartbeat sensing unit
11 and the pulse sensing unit 12. The data calculation unit 13 is
configured to process the signals and/or other data and parameters
obtained by the heartbeat sensing unit 11 and the pulse sensing
unit 12 in order to calculate various parameters. As an upstream
device of the sensors (i.e., the heartbeat sensing unit 11 and the
pulse sensing unit 12), the data calculation unit 13 may be
provided with an amplitude filter 131 and an analog-to-digital
converter 132 as shown in FIG. 2, in order to carry out signal
preprocessing, e.g., to convert the signals of the sensors into
digital ones to facilitate computation. In one preferred
embodiment, the data calculation unit 13 is configured to
communicate with the heartbeat sensing unit 11 and the pulse
sensing unit 12, to process signals coming from the heartbeat
sensing unit 11 and the pulse sensing unit 12, to calculate the
mean arterial pressure (MAP) using the time differences between
heartbeats and between the corresponding pulses, and to derive the
subject's systolic pressure and diastolic pressure from the mean
arterial pressure. As to the position of the data calculation unit
13, the data calculation unit 13 in one preferred embodiment is
provided in the heartbeat sensing unit 11, the pulse sensing unit
12, or a portable device. In another preferred embodiment, the data
calculation unit 13 is provided in the heartbeat sensing unit 11 or
the pulse sensing unit 12 and a portable device. In one preferred
embodiment, the data calculation unit 13 is further connected to a
communication module 14, and the communication module 14 is
configured to pair with a portable device, access the data obtained
by the data calculation unit 13, and by means of the configuration
of the portable device, output the computation result of the data
calculation unit 13 to the portable device.
[0043] As used herein, the term "communication" refers to wired or
wireless transmission-based communication. For example, the
heartbeat sensing unit 11, the pulse sensing unit 12, and the data
calculation unit 13 may be connected by wires or coupled to one
another through wireless communication modules in order to
communicate with one another. The wireless communication modules
may be, but are not limited to, Bluetooth communication modules,
WIFI communication modules, radio frequency identification (RFID)
communication modules, near-field communication (NFC) modules,
Zigbee communication modules, wireless local area network (WLAN)
communication modules, or the like; the present invention has no
limitation in this regard.
[0044] As used herein, the term "portable device" refers to an
electronic device that can be easily carried around, such as a
handheld device 200, a wearable device 300, a smart mobile device,
or the like. In one preferred embodiment, the multifunctional
measuring device 100 of the present invention is configured for use
with the handheld device 200 or the wearable device 300, in order
for the handheld device 200 or the wearable device 300 to access
and process the data measured and obtained by the multifunctional
measuring device 100.
[0045] The multifunctional measuring device 100 of the present
invention can be used to obtain a variety of physiological data,
such as carotid blood pressure, heart sound, blood flow sound,
pulse wave velocity, and the degree of carotid stenosis.
[0046] The "blood pressure" and the "pulse wave velocity" can be
obtained by the method described below.
[0047] The heart pumps blood into the aorta in a pulsing manner.
The wall of the aorta, therefore, generates pulse pressure waves,
which propagate to the downstream blood vessels at a certain
velocity along the blood vessel walls. The velocity at which such
pulse pressure waves propagate along the artery walls is referred
to as the pulse wave velocity (PWV).
[0048] The PWV is related to such factors as the biophysical
properties of the artery walls, the geometric properties of the
blood vessels involved, and the density of blood. The value of the
PWV is an early sensitive indicator of the stiffness (or
narrowness) of the arteries. The larger the value, the stiffer the
blood vessel walls (or the narrower the blood vessels). The
standard/normal PWV is 140 mm/ms.
[0049] The PWV of a carotid artery can be calculated from the pulse
wave propagation time and distance between two artery recording
positions (e.g., the position where a common carotid artery
originates from the aorta and a predetermined position of the
common carotid artery), the equation for the calculation being:
PWV = L t ( mm / ms ) , ##EQU00002##
where t is the time difference between two adjacent waveforms,
i.e., the propagation time, and L is the distance between the two
artery sensors, i.e., the propagation distance (e.g., the distance
between the aortic valve and the pulse measuring point).
[0050] An increase in the PWV of a carotid artery implies an
increase in the stiffness (or narrowness) of the carotid artery and
a decrease in the compliance of the carotid artery. Conversely, a
carotid artery with a low PWV has low stiffness and high
compliance. Age and blood pressure are the main factors that
influence the PWV, and antihypertensive therapy currently remains
the most effective method for reducing the PWV.
[0051] Calculation of the carotid PWV is based on the relationship
between pressure and the PWV. In each cardiac cycle, the
contraction of the left ventricle generates a pressure pulse that
propagates through the arteries to the very ends of those blood
vessels. The PWV of an artery is a function of the stiffness of the
artery, as can be expressed by equation (a):
PWV = ( V .rho. ) ( d P d V ) , equation ( a ) ##EQU00003##
[0052] where .rho. is the density of blood.
[0053] The stiffness of a carotid artery is associated with the
transmural pressure across the artery wall, and this pressure is a
function of the geometry of the blood vessel and the
viscoelasticity of the blood vessel wall. As the pressure acting on
an artery wall from outside the artery is typically negligible, the
stiffness and PWV of a carotid artery are a function of the artery,
and the pulses in propagation form the basis of carotid stenosis
measurement.
[0054] More specifically, correlation between the PWV and arterial
pressure forms the basis of non-invasive blood pressure
measurement. In particular, the PWV has the strongest correlation
to diastolic pressure and mean arterial pressure, as can be
expressed by equation (b):
PWV=fcn (MAP ) equation (b).
[0055] The relationship between the PWV and mean arterial pressure
can be accurately described by the following linear model equation
(c):
PWV (t )=.alpha.MAP (t )+pwv.sub.0 equation (c),
[0056] where the slope .alpha. and the constant pwv.sub.0 are
subject-specific parameters.
[0057] To trace a patient's pulse pressure and velocity, the
present invention uses the heartbeat sensing unit 11 and the pulse
sensing unit 12 to monitor a known parameter, i.e., the pulse
arrival time (PAT). Each pulse arrival time measurement is in fact
the sum of two different periods of time, namely the vascular
transit time (VTT) and the pre-ejection period (PEP). The vascular
transit time is the time for which a pressure pulse travels along
an arterial path. The pre-ejection period is the time interval
between two adjacent peaks of a composite wave, or the interval at
which the aortic valve opens, and includes electromechanical delay
and isovolumic contraction. The pulse arrival time can be expressed
by equation (d):
P A T = V T T + P E P = ( L t P W V ) + PEP , equation ( d )
##EQU00004##
[0058] where the parameter L.sub.t is the length of the path along
which a pressure pulse propagates in an artery.
[0059] Assuming the pre-ejection period is constant while
monitoring takes place, a change in the vascular transit time
directly results in a change in the pulse arrival time, and these
two parameters are associated with variation of the mean arterial
pressure. To establish the relationship between pulse arrival time
and mean arterial pressure and the linear relationship between mean
arterial pressure and PWV, it behaves as if equation (b) must be
abstracted and defined in measuring the pulse delay time at the
individual measurement pulse arrival time, as expressed by equation
(e):
P A T = ( L t P W V ) = ( L t a M A P + p w .nu. 0 ) . equation ( e
) ##EQU00005##
[0060] In one preferred embodiment, mean arterial pressure is
obtained through the following equation (I):
mean arterial pressure ( MAP ) = a ( l p t p a .times. c ) + b ,
equation ( I ) ##EQU00006##
[0061] where l.sub.p is the length of the path along which the
pulse propagates through the arteries between the aortic valve and
the pulse measuring point; t.sub.pa is the times it takes for a
pulse to reach the pulse measuring point from the aortic valve; and
a, b, and c are correction parameters. The correction parameters
are derived from a target subject database to provide necessary
adjustment to the calculation.
[0062] In another preferred embodiment, mean arterial pressure is
obtained through the following equation (II):
mean arterial pressure ( MAP ) = A ( l p t p a .times. C ) 2 + B ,
equation ( II ) ##EQU00007##
[0063] where l.sub.p is the length of the path along which the
pulse propagates through the arteries between the aortic valve and
the pulse measuring point; t.sub.pa is the times it takes for a
pulse to reach the pulse measuring point from the aortic valve; and
A, B, and C are correction parameters. The correction parameters
are derived from a target subject database to provide necessary
adjustment to the calculation.
[0064] Mean arterial pressure can be derived from the time
difference between the pulse response at the position where the
heartbeat sensing unit 11 is disposed on a subject's chest
(hereinafter also referred to as the chest position) and the pulse
response at the position where the pulse sensing unit 12 is
disposed on the subject's neck (hereinafter also referred to as the
neck position). In one preferred embodiment, the pulse arrival time
is obtained by measuring the time difference between a peak value
detected by the heartbeat sensing unit 11 and the corresponding
peak value detected by the pulse sensing unit 12. In another
preferred embodiment, the pulse arrival time is obtained by
measuring the time difference between a signal valley detected by
the heartbeat sensing unit 11 and the corresponding signal valley
detected by the pulse sensing unit 12, wherein the measurement is
triggered by the signal valleys. The present invention has no
limitation on the method by which to determine the pulse arrival
time.
[0065] Through the foregoing calculation, the pulse wave velocity
in a target arterial section (i.e., the section between the chest
position and the neck position) can be obtained, and mean arterial
pressure (MAP) can be derived from the pulse wave velocity
obtained. The severity of atherosclerosis in the target arterial
section can then be assessed by analyzing the mean arterial
pressure. The aforesaid data can also be provided to caregivers as
a way to achieve real-time monitoring.
[0066] Apart from the data calculation unit 13 of the
multifunctional measuring device 100, the afore-mentioned
calculation may be performed by a program installed in the handheld
device 200 or the wearable device 300 and be controlled by a
controller in the handheld device 200 or the wearable device 300
instead, in order to reduce the power required by the
multifunctional measuring device 100, allow the data calculation
unit 13 of the multifunctional measuring device 100 to be
miniaturized, and decrease the weight of the multifunctional
measuring device 100.
[0067] "Heart sound" refers to the various sound generated by the
heart while it is working and can be obtained by the method
described below. The sound produced by the opening and closing of
cardiac valves in a cardiac cycle has been frequently used in the
medical field. For example, the first heart sound (S1) at the
beginning of a systole is often produced by the mitral valve and
the tricuspid valve, and the second heart sound (S2) at the
beginning of a diastole, by the closing of the aortic valve. Heart
sound signals, therefore, can be converted into heartbeat signals
to shed light on the cardiac cycle. In one preferred embodiment,
the heartbeat sensing unit 11 is an acoustic wave sensor to be
disposed at the chest position, which corresponds to the vicinity
of the aortic valve, the pulmonary valve, the tricuspid valve, or
the mitral valve, and by disposing the heartbeat sensing unit 11
adjacent to a cardiac valve, the heartbeat sensing unit 11 can be
used to obtain noise/irregular sound from that cardiac valve area.
The information obtained can help diagnose valvular heart disease
such as mitral stenosis or insufficiency, tricuspid stenosis or
insufficiency, aortic stenosis or insufficiency, and pulmonary
stenosis or insufficiency.
[0068] "Carotid stenosis" can be detected by the method described
below.
[0069] As stated above, the carotid arteries on either side of the
human body can be divided into three major portions: the common
carotid artery, the external carotid artery, and the internal
carotid artery. The facial blood flow involves intercommunication
(also referred to as anatomical anastomosis) between the external
and the internal carotid arteries; that is to say, a portion of the
facial blood flow may pass through the internal carotid artery via
the aforesaid intercommunication. For example, the external carotid
artery may communicate with the internal carotid artery through the
internal maxillary artery or with the ophthalmic artery through the
facial artery. While the facial blood flow comes mainly from the
external carotid artery, the external carotid artery is also
closely related to the internal carotid artery, which supplies
blood directly to brain tissues and therefore may contribute to the
occurrence of strokes, in three ways. First, most of the
atheromatous plaque in the carotid arteries is distributed over the
junction between the external and the internal carotid arteries;
therefore, stenosis of the external carotid artery tends to have a
sustained effect on the atheromatous plaque in the adjacent
internal carotid artery or even affect the blood flow in the common
carotid artery. Second, given the anatomical anastomosis between
the internal carotid artery and the external carotid artery,
stenosis of the internal carotid artery may result in the so-called
steal phenomenon and hence reduce the blood flow in the same side
of the face. Third, as the external carotid artery accounts for 12
% of the cerebral blood flow, a reduced blood flow in the neck
caused by stenosis of the external carotid artery is associated
also with insufficient cerebral blood flow on the same side, and it
is anticipated that a reduced blood flow caused by stenosis of the
external carotid artery may have something to do with stenosis of
the internal carotid artery on the same side, too. Based on the
foregoing, the multifunctional measuring device 100 of the present
invention detects carotid stenosis by obtaining information about
the blood flow pulse waves in the neck. Conventionally, the peak
systolic velocity (PSV) of the carotid arteries is used to
determine the degree of carotid stenosis, and the PSV-based
classification of carotid stenosis is shown in TABLE 1.
TABLE-US-00001 TABLE 1 Minor Moderate Serious Severe Critical
stenosis stenosis stenosis stenosis stenosis Classification (0-29%)
(30%-49%) (50%-69%) (70%-99%) (100%) PSV <120 120-149 150-249
>250 Zero (cm/sec) velocity
[0070] To obtain the pulse wave velocity and other parameters of
the carotid arteries, the neck position, where the pulse sensing
unit 12 is disposed, corresponds to the carotid arteries. In one
preferred embodiment, the pulse sensing unit 12 is configured to be
disposed at a pulse measuring point on the neck, or more
particularly a pulse measuring point for the carotid arteries.
Optimally, the pulse measuring point is a point in a line segment
defined as follows. The line segment starts from a starting point
(or 0 cm position) defined as a point that is to the left or right
of, and horizontally spaced apart by 3.+-.0.3 cm from, the
laryngeal prominence (or the most prominent point of the neck that
lies right below the middle point of the lips), wherein the
horizontal distance of 3.+-.0.3 cm may be, but is not limited to,
2.7 cm, 2.8 cm, 2.9 cm, 3 cm, 3.1 cm, 3.2 cm, or 3.3 cm. The line
segment extends from the starting point (or 0 cm position) for 4 cm
along a direction that extends distally at an angle of 135 degrees
with respect to the horizontal direction. For example, the pulse
measuring point may be 1 cm, 2 cm, 3 cm, or up to 4 cm away from
the starting point (or 0 cm position) in the direction extending
distally at the angle of 135 degrees with respect to the horizontal
direction. The pulse measuring point of the present invention,
however, is not limited to a point in the aforesaid line segment;
the line segment defined above is only an exemplary range that
allows pulse signals to be effectively obtained. In a more
preferred embodiment, the optimal pulse measuring point of a male
subject is determined as follows. The first step is to find a
starting point that is to the left or right of, and horizontally
spaced apart by 3.+-.0.3 cm from, the laryngeal prominence (or the
most prominent point of the neck that lies right below the middle
point of the lips). The second step is to locate the optimal pulse
measuring point by finding the point that is 3 cm away from the
starting point in a direction that extends distally at an angle of
135 degrees with respect to the horizontal direction. Similarly,
the optimal pulse measuring point of a female subject is determined
by first finding a starting point that is to the left or right of,
and horizontally spaced apart by 3 cm from, the laryngeal
prominence (or the most prominent point of the neck that lies right
below the middle point of the lips), and then finding the point
that is 3 cm away from the starting point in a direction that
extends distally at an angle of 135 degrees with respect to the
horizontal direction as the optimal pulse measuring point. In one
preferred embodiment, the neck position, where the pulse sensing
unit 12 is disposed, may be any position corresponding to the left
carotid arteries or the right carotid arteries. In one preferred
embodiment, the pulse sensing unit 12 is configured to be disposed
at a position corresponding to a disease-affected or high-risk
portion of the subject's body, such as but not limited to a
position on the subject's neck that corresponds to the left or
right common carotid artery or to the outlet of the left or right
common carotid artery (i.e., the junction between the corresponding
external carotid artery and internal carotid artery, also known as
a carotid bifurcation). As the external carotid artery and the
internal carotid artery are the two branches of the common carotid
artery, the flow velocity in the common carotid artery can be
directly used to assess the possibility of atherosclerosis of the
external carotid artery and the internal carotid artery. If it is
desired to assess the condition of the external carotid artery or
the internal carotid artery alone, the position of the pulse
sensing unit 12 can be adjusted as needed. In addition to the pulse
sensing unit 12, the invention may include more sensors in order to
sense the blood flow sound waves, pulse wave velocities, pulse
waveforms, or other necessary physiological parameters in different
sections of the carotid arteries respectively, thereby obtaining a
relatively complete set of assessment data of the common and branch
carotid arteries.
I. Embodiment 1
[0071] Please refer to FIG. 3 and FIG. 4 respectively for a state
of use and an oscillogram of a multifunctional measuring device
according to the present invention.
[0072] As shown in FIG. 3, the multifunctional measuring device 100
includes a heartbeat sensing unit 11, a pulse sensing unit 12, and
a data calculation unit 13. The data calculation unit 13 is
implemented as a program installed in a handheld device 200. The
heartbeat sensing unit 11, the pulse sensing unit 12, and the data
calculation unit 13 are configured to communicate with one another
wirelessly via Bluetooth.
[0073] The heartbeat sensing unit 11 includes an acoustic wave
sensor and an adhesive patch by which the heartbeat sensing unit 11
can be adhesively attached to a subject's chest at a position
corresponding to the aortic valve in order to obtain heart sound,
heartbeat signals, etc.
[0074] The pulse sensing unit 12 includes a pressure sensor and an
adhesive patch 121 by which the pulse sensing unit 12 can be
adhesively attached to a subject's neck at a position corresponding
to the outlet of the right common carotid artery in order to obtain
carotid pulse waveforms, pulse signals, etc.
[0075] FIG. 4 shows an example of the waveforms obtained, in which
the lower waveform represents the blood flow sound waves at the
aortic valve and the upper waveform represents the blood flow pulse
waves of the right common carotid artery. The dashed line-enclosed
portions are a first-heart-sound peak (indicating the start of a
systole) obtained by the heartbeat sensing unit 11 and the
corresponding peak obtained by the pulse sensing unit 12. The time
difference between the aforesaid two peaks in a cardiac cycle is
the pulse arrival time (T.sub.PA ), and the distance between the
aortic valve and the pulse measuring point can be viewed as the
length (L.sub.p ) of the path along which the pulse propagates
through the arteries. The data calculation unit 13 can calculate
the carotid blood pressure, pulse wave velocity, etc. according to
T.sub.PA and L.sub.p.
II. Embodiment 2
[0076] Please refer to FIG. 5, FIG. 6, and FIG. 7 respectively for
a state of use of a multifunctional measuring device according to
the present invention, an audiogram for the heart sound in the
aortic valve area, and an oscillogram for the right carotid
arteries.
[0077] As shown in FIG. 5, the multifunctional measuring device 100
includes a heartbeat sensing unit 11, a pulse sensing unit 12, and
a data calculation unit 13. The data calculation unit 13 is
installed in the heartbeat sensing unit 11 and is connected to the
heartbeat sensing unit 11 by wires. The heartbeat sensing unit 11
and the data calculation unit 13 are configured to communicate with
the pulse sensing unit 12 wirelessly via Bluetooth.
[0078] The heartbeat sensing unit 11 includes an acoustic wave
sensor, a display unit 15, and an adhesive patch by which the
heartbeat sensing unit 11 can be adhesively attached to a subject's
chest at a position corresponding to the aortic valve in order to
obtain heart sound, heartbeat signals, etc. The display unit 15 is
configured to display such contents as the heart sound waveforms
and the calculation result of the data calculation unit 13. FIG. 6
shows an example of the waveforms obtained by the heartbeat sensing
unit 11.
[0079] The pulse sensing unit 12 includes an acoustic wave sensor
and an adhesive patch 121 with a thyroid cartilage locating portion
122. The thyroid cartilage locating portion 122 is a hole so that
by aligning the thyroid cartilage locating portion 122 of the
adhesive patch 121 with a subject's thyroid cartilage, the pulse
sensing unit 12 can be easily attached to the subject's neck at a
position corresponding to the left or right common carotid artery
in order to obtain carotid pulse waveforms, pulse signals, etc.
FIG. 7 shows an example of the waveforms obtained from the right
carotid arteries. One advantage of using an acoustic wave sensor as
the detector of the pulse sensing unit 12 is that, in addition to
pulse-related data, the pulse sensing unit 12 can obtain the
carotid blood flow sound to facilitate clinical diagnosis of
abnormalities (e.g., noise or irregular sound) of the carotid blood
flow.
[0080] The data calculation unit 13 can calculate the carotid blood
pressure, pulse wave velocity, etc. according to the pulse arrival
time (T.sub.PA ), which is the time difference between a
first-heart-sound peak (indicating the start of a systole) obtained
by the heartbeat sensing unit 11 and the corresponding peak
obtained by the pulse sensing unit 12 in a cardiac cycle, and the
distance between the aortic valve and the pulse measuring point,
which distance can be viewed as the length (L.sub.p) of the path
along which the pulse propagates through the arteries.
COMPARATIVE EXAMPLES 1 and 2
[0081] Comparative example 1 is a Mindray color Doppler ultrasound
diagnosis system, which uses a conventional clinical detection
technique. The right carotid arteries are manually detected in real
time, and the detection data are recorded.
[0082] Comparative example 2 is a commercially available
sphygmomanometer for use as an artery stenosis detector/pulse wave
recorder to record the blood flow sound waves in the carotid
arteries.
VALIDATION AND VERIFICATION EXAMPLE 1
[0083] Please refer to FIG. 8 and FIG. 9 respectively for the
oscillogram images and correlation analysis result of embodiment 1
and comparative example 1.
[0084] The present invention was compared with a similar product
(i.e., the conventional ultrasound diagnosis system of comparative
example 1 ) for validation and verification. In this validation and
verification example, a group of 25 subjects (including healthy
people and those who might have carotid stenosis) were examined
using comparative example 1 as well as embodiment 1. The screen
images of the two sensing devices (see FIG. 8) were analyzed to
determine the correlation between the pulse wave velocities
obtained by embodiment 1 and the peak systolic velocities recorded
by comparative example 1.
[0085] During the 30 seconds when measurements (or more
particularly, 25 measurements of the aortic pulse wave velocity
between the aortic valve and a predetermined position of the
carotid arteries) were taken simultaneously with embodiment 1 and
comparative example 1, there was a significant correlation, or a
linear relationship (see FIG. 9), between the pulse wave velocities
obtained by embodiment 1 and the peak systolic velocities obtained
by comparative example 1, the correlation coefficient R being
0.897.
[0086] Therefore, the carotid pulse wave velocities obtained
through the present invention can be used to determine the degree
of carotid stenosis, as shown in TABLE 2.
TABLE-US-00002 TABLE 2 Minor Moderate Serious Severe Critical
stenosis stenosis stenosis stenosis stenosis Classification (0-29%)
(30%-49%) (50%-69%) (70%-99%) (100%) Pulse wave <120 120-149
150-249 >250 Zero velocity velocity (cm/sec)
VALIDATION AND VERIFICATION EXAMPLE 2
[0087] Please refer to FIG. 10, FIG. 11, and FIG. 12 for the
correlation analysis results of embodiment 1 and comparative
example 2.
[0088] Three subject groups of different sizes were examined using
a commercially available sphygmomanometer (i.e., comparative
example 2 ) as well as embodiment 1. The carotid pulse waves
recorded by embodiment 1 and the carotid blood flow sound waves
recorded by comparative example 2 were analyzed, and a correlation
analysis was performed on the pulse wave velocities obtained by the
two devices.
[0089] As shown in FIG. 10, which presents the correlation analysis
result for the group consisting of five subjects, there was a
significant correlation, or a linear relationship, between the
pulse wave velocities obtained by embodiment 1 and those obtained
by comparative example 2 during the 30 seconds when measurements
were taken simultaneously with embodiment 1 and comparative example
2, the correlation coefficient R being 0.967.
[0090] As shown in FIG. 11, which presents the correlation analysis
result for the group consisting of ten subjects, there was a
significant correlation, or a linear relationship, between the
pulse wave velocities obtained by embodiment 1 and those obtained
by comparative example 2 during the 30 seconds when measurements
were taken simultaneously with embodiment 1 and comparative example
2, the correlation coefficient R being 0.968.
[0091] As shown in FIG. 12, which presents the correlation analysis
result for the group consisting of eleven subjects, there was a
significant correlation, or a linear relationship, between the
pulse wave velocities obtained by embodiment 1 and those obtained
by comparative example 2 during the 30 seconds when measurements
were taken simultaneously with embodiment 1 and comparative example
2, the correlation coefficient R being 0.950.
[0092] According to the above comparison results, the carotid pulse
wave velocities obtained through the present invention had a
significant correlation to those obtained by the commercially
available sphygmomanometer. It follows that measurements taken with
the present invention can be used to determine the degree of
carotid stenosis and calculate carotid blood pressure.
VALIDATION AND VERIFICATION EXAMPLE 3
[0093] Please refer to FIG. 13 for the carotid waveforms obtained
by disposing the pulse sensing unit 12 of the present invention at
different pulse measuring points.
[0094] In this validation and verification example, male and female
subjects were examined with embodiment 1, and the pulse measuring
point where the pulse sensing unit 12 was disposed was varied
between measurements. The various pulse measuring points to which
the pulse sensing unit 12 was adhesively attached included: point
A.sub.-0.3, which was to the right of, and horizontally spaced
apart by 2.7 cm from, a subject's laryngeal prominence; point
B.sub.0, which was to the right of, and horizontally spaced apart
by 3 cm from, a subject's laryngeal prominence; point A.sub.+0.3,
which was to the right of, and horizontally spaced apart by 3.3 cm
from, a subject's laryngeal prominence; point B.sub.1, which was 1
cm away from point B.sub.0 (or the starting point, or 0 cm
position) in a direction extending distally at an angle of 135
degrees with respect to the horizontal direction; point B.sub.2,
which was 2 cm away from point B.sub.0 in the direction extending
distally at the angle of 135 degrees with respect to the horizontal
direction; point B.sub.3, which was 3 cm away from point B.sub.0 in
the direction extending distally at the angle of 135 degrees with
respect to the horizontal direction; point B.sub.4, which was 4 cm
away from point B.sub.0 in the direction extending distally at the
angle of 135 degrees with respect to the horizontal direction; and
point B.sub.5, which was 5 cm away from point B.sub.0 in the
direction extending distally at the angle of 135 degrees with
respect to the horizontal direction.
[0095] According to the examination results, well-defined carotid
pulse wave signals were obtained from point A.sub.-0.3, point
B.sub.0, and point A.sub.+0.3 of the male subjects. While carotid
pulse wave signals were also successfully obtained from point
A.sub.-0.3, point B.sub.0, and point A.sub.+0.3 of the female
subjects, the signals from point A.sub.-0.3 and point A.sub.+0.3
were relatively weak; only the signals from point B.sub.0 were
relatively well-defined.
[0096] Moreover, regardless of the gender of the subjects, carotid
pulse wave signals were successfully obtained from point B.sub.0
(see the lower waveform in FIG. 13), point B.sub.1, point B.sub.2,
point B.sub.3 (see the upper waveform in FIG. 13), and point
B.sub.4, with point B.sub.3 producing relatively well-defined
signals and point B.sub.4 producing relatively weak signals. Pulse
wave signals were hardly obtained from point B.sub.5. The
obtainment of carotid pulse wave signals from point B.sub.4 and
point B.sub.5 may have been hindered by the neighboring cartilage
structure.
[0097] As above, the present invention provides a multifunctional
measuring device that features non-invasive detection. More
specifically, an acoustic wave sensor is adhesively attached via an
adhesive patch to a subject's body at a position adjacent to one of
the subject's cardiac valves, and a sensing unit selected as needed
from a variety of options is adhesively attached to the subject's
neck at a position adjacent to the carotid arteries. Not only can
the multifunctional measuring device detect carotid blood pressure
and pulse wave velocity, but also the measurement result can be
used to diagnose carotid stenosis and determine the cerebral blood
volume. The multifunctional measuring device of the invention is
compact in size, can be held by hand, is portable, can measure the
degree of carotid stenosis rapidly, and is suitable for use at home
as well as in hospitals (e.g., by a physician for diagnosis
purposes), nursing homes, research centers, and so on. The
multifunctional measuring device of the invention is expected to
have a strong demand in the global medical device market by those
who are of an advanced age, who have had a stroke, or who have a
high risk of cardiovascular disease.
[0098] The above is the detailed description of the present
invention. However, the above is merely the preferred embodiment of
the present invention and cannot be the limitation to the implement
scope of the present invention, which means the variation and
modification according to the present invention may still fall into
the scope of the invention.
* * * * *