US 12,635,970 B2Granted

System for non-invasive calibration-free blood pressure (BP) measurement

AssigneesHealthcare Technology Innovation Centre, Indian Institute of Technology Madras (Iit Madras)

InventorsNabeel Pilaparambil Mashood, Jayaraj Joseph, Rahul Manoj, Raj Kiran Vangapandu, Mohanasankar Sivaprakasam

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Abstract

A system for measurement of non-invasive and calibration-free blood pressure (BP) is disclosed. The system comprises a measurement probe (302) which is in contact with a person's skin. The measurement probe (302) comprises a first array of sensors (302-1) and a second array of sensors (302-2). The first array of sensors (302-1) determines a force exerted on skin (304) and the second array of sensors (302-2) determines a compression-decompression characteristics of the arteries through skin. The force exerted on skin and the compression-decompression characteristics of the arteries are used to determine indices indicative of the material properties of the vessel. Based on the indices indicative of the material properties of the vessel, blood pressure and continuous transmural pressure waveform may be determined.

Claims14

Dependent claims

A system for generating blood pressure and continuous transmural pressure waveform in real-time, the system comprising:

a measurement probe (302) positioned in contact with skin, the measurement probe (302) comprises:
a first array of sensors comprising at least one sensor to detect a force exerted by a vessel on the skin in real-time;
a second array of sensors comprising at least one sensor to determine a compression-decompression pattern of a vessel cross-section below the skin in real-time;
a data acquisition unit (326), coupled to the measurement probe (302), to:
receive the force detected by the first array of sensors in real-time, and
receive the compression-decompression pattern determined by the second array of sensors in real-time;
a processing module (330), coupled to the data acquisition unit (326), to:
determine indices indicative of material properties including specific stiffness index (β), elastic modulus, viscoelasticity, arterial compliance, and pulse wave velocity, of the vessel based on a relationship between the force exerted on the skin and the compression-decompression pattern of the vessel below the skin in real-time;
and
generate the blood pressure and the continuous transmural pressure waveform based on the determined indices of the material properties of the vessel in real-time,
wherein the force exerted on the skin=
E
s
⁢
x
⁢
_
⁢
1
H
⁡
(
t
)
+
η
s
⁢
d
dt
⁢
(
1
H
⁡
(
t
)
)
,
wherein the compression-decompression pattern of the vessel below the skin=∝(1/D(t)) ∝1/(P(t)), and
where Es is the elastic modulus, H(t) is the compression decompression pattern, D(t) is a quasiperiodic expansion/contraction of a luminal diameter of the vessel, P(t) is a pulsative transmural pressure of the vessel acting towards a radial direction of the vessel, and ηs is a viscoelastic coefficient for vessel layers between a proximal wall of the vessel and the skin.

39 more elements

A method for generating blood pressure and continuous transmural pressure waveform in real-time, the method comprising:

detecting a force value exerted on skin above a vessel in real-time;
determining compression-decompression waveform of the vessel below the skin in real-time;
converting the detected force and the determined compression-decompression waveform to digital signals in real-time;
determining indices indicative of the material properties including specific stiffness index (β), elastic modulus, viscoelasticity, arterial compliance, and pulse wave velocity of the vessel based on a non-linear relationship between the force exerted on the skin and the compression-decompression pattern of the vessel below the skin based on the digital signal in real-time;
and
generating the blood pressure and the continuous transmural pressure waveform based on the indices of the material properties of the vessel in real-time,
wherein the force exerted on the skin=
E
s
⁢
x
⁢
_
⁢
1
H
⁡
(
t
)
+
η
s
⁢
d
dt
⁢
(
1
H
⁡
(
t
)
)
,
wherein the compression-decompression pattern of the vessel below the skin=∝(1/D(t)) ∝1/(P(t)), and
where Es is the elastic modulus, H(t) is the compression decompression pattern, D(t) is a quasiperiodic expansion/contraction of a luminal diameter of the vessel, P(t) is a pulsative transmural pressure of the vessel acting towards a radial direction of the vessel, and ηs is a viscoelastic coefficient for vessel layers between a proximal wall of the vessel and the skin.

35 more elements

A method for generating blood pressure and continuous transmural pressure waveform in real-time, the method comprising:

applying hold-down pressure by a measurement probe (302) on a skin above a vessel in real-time;
varying the hold-down pressure to multiple levels in a controlled manner in real-time;
capturing the results of the varying hold-down pressure on a geometry of the vessel and a medium surrounding the vessel in real-time;
determining indices indicative of material properties including specific stiffness index (β), elastic modulus, viscoelasticity, arterial compliance, and pulse wave velocity of the vessel based on a relationship between a force exerted on the skin and a compression-decompression pattern of the vessel below the skin in real-time;
and
generating a blood pressure and a continuous transmural pressure based on captured results in real-time,
wherein the force exerted on the skin=
E
s
⁢
x
⁢
_
⁢
1
H
⁡
(
t
)
+
η
s
⁢
d
dt
⁢
(
1
H
⁡
(
t
)
)
,
wherein the compression-decompression pattern of the vessel below the skin=∝(1/D(t)) ∝1/(P(t)), and
where Es is the elastic modulus, H(t) is the compression decompression pattern, D(t) is a quasiperiodic expansion/contraction of a luminal diameter of the vessel, P(t) is a pulsative transmural pressure of the vessel acting towards a radial direction of the vessel, and ηs is a viscoelastic coefficient for vessel layers between a proximal wall of the vessel and the skin.

35 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/019,158Filed 26 Jul 2021
Priority: IN 2020410335135 Aug 2020
Published: US 2023/0329667 A119 Oct 2023
Granted: 26 May 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

A61B 5/02007
Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow: evaluating blood…
A61B 8/04
Diagnosis using ultrasonic, sonic or infrasonic waves: measuring blood pressure
A61B 5/0053
Detecting, measuring or recording by applying mechanical forces or stimuli: by applying pressure, e.g. compression, indentation, palpation,…
A61B 5/02125
From analysis of pulse wave characteristics: of pulse wave propagation time