WEARABLE BLOOD PRESSURE MONITORING SYSTEM

• US 20180078154A1
• Filed: 09/22/2016
• Published: 03/22/2018
• Est. Priority Date: 09/19/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: KNICKERBOCKER, John U., LEE, Hyung-Min, LEE, Kang-Wook
• Granted Patent: US 10,448,830 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence

Abstract

An apparatus includes one or more memories storing computer readable code and processor(s). The processor(s), in response to loading and executing the computer readable code, cause the apparatus to perform operations including receiving electrocardiogram data from an electrocardiogram sensor. The electrocardiogram data includes data from an electrocardiogram from a person. The operations also include receiving pulse wave data from one or more pulse wave pressure sensors. The pulse wave data includes data from one or more pulse waves from the person. The operations further include determining blood pressure using the electrocardiogram data or the pulse wave data from the chest and the pulse wave data from the wrist or finger, and outputting an indication of the blood pressure. Another apparatus uses pulse wave data from two pulse wave sensors (e.g., pulse wave pressure sensor(s) and/or PPG sensor(s)) and blood pressure determinations are made using these pulse wave data.

Claims

1. An apparatus, comprising:

one or more memories storing computer readable code and one or more processors, the one or more processors, in response to loading and executing the computer readable code, causing the apparatus to perform operations comprising;

receiving first pulse wave data from a first pulse wave sensor placed at a first location on a person, the first pulse wave data comprising data from one or more pulse waves from the first location of the person;

receiving second pulse wave data from a second pulse wave sensor placed at a second location on the person, the first and second locations being different locations on the person, the second pulse wave data comprising data from one or more pulse waves from the second location of the person;

determining blood pressure using at least the first and second pulse wave data; and

outputting an indication of the blood pressure.

2. The apparatus of claim 1, wherein the first pulse wave sensor comprises a pulse wave pressure sensor, the second pulse wave sensor comprises a pulse wave pressure sensor, or both the first and second pulse wave sensors comprise pulse wave pressure sensors.

3. The apparatus of claim 2, wherein at least one pulse wave pressure sensor comprises a layered structure configured, in response to pulse waves in the person, to generate electronic pulse waves in a form of a capacitance versus time.

4. The apparatus of claim 3, wherein the at least one pulse wave pressure sensor further comprises:

a sensor structure, comprising;

a first portion configured to contact a surface of skin under which arteries or veins or both are to be located;

a second portion that contacts the first portion and is configured to have a capacitance, wherein the first and second portions are configured to create a capacitance change in response to a squeezing or bending between the first portion and a fixed part of the second portion caused by a pulse pressure under the skin and in response to a return to an original state of the first portion with a release of the pulse pressure;

circuitry connected to the sensor structure and configured to measure and transmit waveforms for the sensor unit and configured to digitize the measured waveforms, wherein each waveform captures the capacitance change for its corresponding individual sensor unit.

5. The apparatus of claim 1, wherein the first pulse wave sensor comprises a photoplethysmography sensor, the second pulse wave sensor comprises a photoplethysmography sensor, or both the first and the second pulse wave sensors comprise photoplethysmography sensors.

6. The apparatus of claim 5, wherein at least one photoplethysmography sensor comprises a reflection-mode photoplethysmography sensor.

7. The apparatus of claim 1, wherein one of the first or second pulse wave sensors comprises a pulse wave pressure sensor, and another of the first or second pulse wave sensors comprises a photoplethysmography sensor.

8. The apparatus of claim 1, further comprising a hub that comprises the one or more memories and one or more processors, and wherein the one or more processors, in response to loading and executing the computer readable code, cause the hub to perform the operations.

9. The apparatus of claim 8, further comprising the first and second pulse wave sensors.

10. The apparatus of claim 9, wherein each device of a set of devices comprising the hub and the first and second pulse wave sensors comprises one of a wireless or wired network interface used to communicate between devices.

11. The apparatus of claim 9, wherein each device of the set of devices comprises one or more memories storing computer readable code and one or more processors, and each corresponding one or more processors for a device, in response to loading and executing the computer readable code, causes the corresponding device to perform operations comprising performing one or more measurements and performing communication of measurement information between a corresponding device and another device.

12. The apparatus of claim 1, wherein determining blood pressure using at least the first and second pulse wave data further comprises determining a systolic blood pressure based on pulse transit time (FIT) (SBP_PTT) using the following:

SBP_PTT=a*ln(h²/PTT²)+b,

where h is the person'"'"'s height, a and b are constants which are empirically obtained, PTT is a pulse transit time determined using the first and second pulse wave data, and ln(•

) means natural logarithm, and wherein FIT is determined as a time between a corresponding maximum inclination in pulse wave data from one of the pulse wave PPG sensor or the pulse wave pressure sensor and a corresponding maximum inclination in pulse wave data from the other of the pulse wave PPG sensor or the pulse wave pressure sensor.

13. The apparatus of claim 12, wherein the one or more processors, in response to loading and executing the computer readable code, further cause the apparatus to perform operations comprising:

outputting an indication of the systolic blood pressure based on pulse transit time (FIT) (SBP_PTT), wherein the outputting is to one or more of a display or a wireless or wired network interface.

14. The apparatus of claim 12, further comprising one or more additional pulse wave pressure sensors, and wherein the first pulse wave data from the pulse wave sensor is from at least one of the one or more additional pulse wave pressure sensors.

15. The apparatus of claim 12, wherein determining blood pressure using at least the first and second pulse wave data further comprises determining diastolic blood pressure using the following:

DBP=c*SBP_PTT+dT₂+e,

where c, d and e are constants which are empirically obtained, and T₂ is determined using certain pulse wave data from either the pulse wave pressure sensor or the pulse wave sensor and is a time interval between a peak point of a pulse wave in the certain pulse wave data and a baseline point where the pulse wave reaches to the baseline.

16. The apparatus of claim 15, wherein the one or more processors, in response to loading and executing the computer readable code, further cause the apparatus to perform operations comprising:

outputting one or more indications of one or more of the following;

the systolic blood pressure based on pulse transit time (PTT) (SBP_PTT) and the diastolic blood pressure, wherein the outputting is to one or more of a display or a wireless or wired network interface.

17. The apparatus of claim 12, wherein determining blood pressure using at least the first and second pulse wave data further comprises:

determining the systolic blood pressure using the following equation;

SBP=SBP_PTT[1+α

×

SI_DVP],

where SBP is systolic blood pressure, SBP_PTT is the systolic blood pressure based on the pulse transit time (PTT), α

is defined empirically, and SI_DVP is a stiffness index.

18. The apparatus of claim 17, wherein the one or more processors, in response to loading and executing the computer readable code, further cause the apparatus to perform operations comprising:

outputting one or more indications of one or more of the following;

the systolic blood pressure based on pulse transit time (PTT) (SBP_PTT), the diastolic blood pressure, and the systolic blood pressure, wherein the outputting is to one or more of a display or a wireless or wired network interface.

19. The apparatus of claim 17, wherein the stiffness index SI_DVP is determined using the following:

20. The apparatus of claim 19, wherein the one or more processors, in response to loading and executing the computer readable code, further cause the apparatus to perform operations comprising:

outputting one or more indications of one or more of the following;

the systolic blood pressure based on pulse transit time (PTT) (SBP_PTT), the diastolic blood pressure, the systolic blood pressure, and the stiffness index, wherein the outputting is to one or more of a display or a wireless or wired network interface.