Embedded device for flow monitoring

• US 9,883,836 B2
• Filed: 02/08/2016
• Issued: 02/06/2018
• Est. Priority Date: 02/08/2016
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cahan, Amos, Deligianni, Hariklia, Hsueh, Pei-Yun S., van Kessel, Theodore G.
• Primary Examiner(s): Chen, Tse
• Assistant Examiner(s): IP, JASON M
• Application Number:
  US15/018,218
• Publication Number:
  US 20170224279A1
• Time in Patent Office: 729 Days
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6862 Stents
• CPC Class Codes: A61B 7/045 Detection of Korotkoff sounds A61B5/0225 takes precedence; measuring blood pressure A61B5/021
• CPC Class Codes: A61B 8/02 Measuring pulse or heart rate
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/065 to determine blood output from the heart in general A61B5/029
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/42 Details of probe positioning or probe attachment to the patient
• CPC Class Codes: A61B 8/4444 related to the probe
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/24 : Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
• CPC Class Codes: A61F 2/2403 : with pivoting rigid closure members check valves with hinged closure members in general F16K15/03
• CPC Class Codes: A61F 2/82 : Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00

Abstract

A system and method for monitoring a health status of a subject. The system comprises: a medical device implantable in the subject and having a passage or compartment through which blood flows through; a sensor device embedded at or near a surface of said passage within said medical device for generating signals suitable for measuring a Doppler shift effect occurring within said passage; and a control device coupled to said sensor device for measuring a liquid blood flow rate within said passage based on sensor generated signals outputs. The embedded sensor device comprises a first piezo-electric element configured to generate an acoustic excitation signal and a second piezo-electric element configured to receive said acoustic excitation signal. The second piezo-electric element emits a signal responsive to said acoustic excitation signal. Control device in real time compares a generated output signal with the input excitation signal to determine a Doppler frequency shift measurement.

Claims

1. A system for monitoring a health status of a subject comprising:

a prosthetic cardiac valve implantable in the subject'"'"'s heart and having an annulus body defining a compartment through which blood flows through upon an opening of cardiac valve leaves;

a first piezo-electric element embedded within said annulus body at or near a surface of said annulus body for generating acoustic excitation signals that traverse a liquid blood medium within said compartment, and one or more second piezo-electric elements embedded within said annulus body and configured to receive said acoustic excitation signal and responsively generating an output signal for measuring a Doppler shift effect occurring within said compartment;

a signal generator for applying a stimulus signal to said first piezo-electric element for generating an acoustic excitation signal;

a multichannel amplifier configured for receiving a signal output from the one or more second piezo-electric elements in response to receiving said acoustic excitation signal, and comparing, in real time, a generated output signal with the excitation signal to output a Doppler frequency shift measurement signal; and

an A/D converter for receiving a frequency shift measurement output signal from said amplifier and converting said frequency shift measurement output signal to a corresponding digital signal,

a microphone sensor embedded on an outer surface of the implanted prosthetic cardiac valve for real-time capturing of sound of blood flowing through said cardiac valve leaves opening and generating corresponding data signals of said captured sounds;

a processor element coupled to said multichannel amplifier for receiving said corresponding digital signal for use in real time measuring the liquid blood flow rate across said compartment, and monitoring a cardiac output and a function of the prosthetic cardiac valve based on said received digital signal, said processor element further configured to identify a laminar blood flow versus a turbulent blood flow based on said captured sounds, and correlate said generated data signals received from said embedded microphone sensor with the corresponding digital signal to identify a change in said cardiac output.

2. The system of claim 1, further comprising:

a communications transceiver for transmitting signals to and receiving signals from a device external to said subject, said external device comprising a mobile phone, a smartphone, a laptop, a computer device configured for operator-independent, continuous monitoring of blood flow rate and/or measurement of cardiac output.

3. The system of claim 2, wherein said processor element is further configured to:

determine, in real-time, whether a change in monitored liquid blood flow velocity is a result of a change in the cross-sectional area of the compartment or a change in the blood flow rate.

4. The system of claim 3, wherein said processor element is configured to analyze received embedded piezo-electric sensor data, said processor element is further configured to:

correlate data signals received from one or more other sensor devices with received sensor generated output signals, said correlating used for determining whether a detected change in blood flow rate results from a change in the cross-sectional area of the compartment or the change in cardiac output.

5. The system of claim 4, wherein said other sensor devices providing data signals for correlation comprise one or more of:

a pressure sensor device, a pulse monitor device, an accelerometer device for sensing dilatation and recoil of a blood vessel associated with a heartbeat, or an EKG (electrocardiogram) signal.

6. The system of claim 3, wherein said communications transceiver transmit signals to said mobile phone, smartphone, laptop, or computer device configured to analyze received embedded piezo-electric sensor data, and further configured to correlate data signals received from one or more other sensor devices for determining whether a detected change in blood flow rate results from a change in the cross-sectional area of the compartment or the change in cardiac output.

7. The system of claim 2, further comprising an ultracapacitor for harvesting energy generated in the body of the user, said ultracapacitor providing energy for operating said embedded piezo-electric elements sensor and communication tranceiver, said ultracapacitor harvesting energy converted from one of:

fluid flow vibration, heat, or sound produced from local tissue in the subject.

17. The system of claim 3, wherein a change in a cross-sectional area of the compartment is a function of a cardiac valve leaves position throughout a human heart cycle, said processor element monitoring said liquid blood flow velocity for all stages of the heart cycle.

8. A method for monitoring a health status of a subject comprising:

applying, using a signal generator, a stimulus signal to a first piezo-electric element embedded within an annulus body of a prosthetic cardiac valve at or near a surface of said annulus body, the prosthetic cardiac valve implanted in the subject'"'"'s heart, the annulus body defining a compartment through which blood flows through upon an opening of cardiac valve leaves, said first embedded piezo-electric element configured to generate acoustic excitation signals that traverse a liquid blood medium within said compartment, said prosthetic cardiac valve having one or more second piezo-electric elements embedded at or near a surface of said annulus body and configured to receive said acoustic excitation signals;

generating acoustic excitation signals, by said embedded first piezo-electric element, said acoustic excitation signals traversing a liquid blood medium within said compartment for receipt at said second piezo-electric element embedded within the annulus body, said second piezo-electric element responsively generating an output signal for measuring a Doppler shift effect occurring within said compartment;

receiving, at a multichannel amplifier, a signal output from the one or more second piezo-electric elements in response to receiving said acoustic excitation signal,

comparing, in real time, a generated output signal with the excitation signal to output a Doppler frequency shift measurement signal;

receiving, at an A/D converter element, the frequency shift measurement output signal from said amplifier and converting said frequency shift measurement output signal to a corresponding digital signal,

real-time capturing, using a microphone sensor embedded on an outer surface of the implanted prosthetic cardiac valve of sound of blood flowing through said cardiac valve leaves opening and generating corresponding data signals of said captured sounds;

communicating said corresponding digital signal to a processor element; and

determining at said processor element, a real time liquid blood flow rate measure within said compartment based on said received corresponding digital signal for use in real time monitoring a cardiac output and a function of the prosthetic cardiac valve, and

using said processor element to identify a laminar blood flow versus a turbulent blood flow based on said captured sounds, and correlate said generated data signals received from said embedded microphone sensor with the corresponding digital signal to identify a change in said cardiac output.

9. The method of claim 8, further comprising:

transmitting, via a communications transceiver, signals representing said determined liquid blood flow rate measure to a processor device external to said subject, said external processor device comprising a mobile phone, a smartphone, a laptop, or a computer device configured for operator-independent, continuous monitoring of blood flow rate and/or measurement of cardiac output.

10. The method of claim 9, further comprising:

determining, in real time, at said processor element, whether a change in monitored liquid blood flow velocity is a result of a change in the cross-sectional area of the compartment or a change in the blood flow rate.

11. The method of claim 10, wherein said processor element is configured to analyze received embedded piezo-electric sensor data, said method further comprising:

correlating data signals received from one or more other sensor devices with received sensor generated output signals at said processor device, said correlating used for determining whether a detected change in blood flow rate results from a change in the cross-sectional area of the compartment or a change in cardiac output.

12. The method of claim 11, wherein said other sensor devices providing data signals for correlation comprise one or more of:

a pressure sensor device, a pulse monitor device, an accelerometer device for sensing dilatation and recoil of a blood vessel associated with a heartbeat, or an EKG (electrocardiogram) signal.

18. The method of claim 10, wherein a change in a cross-sectional area of the compartment is a function of a cardiac valve leaves position throughout a human heart cycle, said processor element monitoring said liquid blood flow velocity for all stages of the heart cycle.

20. The method of claim 9, further comprising:

using an ultracapacitor to harvest energy generated in the body of the user, said ultracapacitor harvesting energy converted from one of;

fluid flow vibration, heat, or sound produced from local tissue in the subject, and said ultracapacitor providing energy for operating said embedded piezo-electric elements sensor and communication tranceiver.

13. A computer program product comprising:

a computer readable storage device, tangibly embodying a program of instructions executable by a computing device for monitoring a health status of a subject, said subject having a prosthetic cardiac valve implanted in the subject having an annulus body defining a compartment through which blood flows through upon an opening of cardiac valve leaves, said prosthetic cardiac valve having a first piezo-electric element embedded within said annulus body at or near a surface of said annulus body and configured to generate acoustic excitation signals that traverse a liquid blood medium within said compartment and having one or more second piezo-electric elements embedded within the annulus body at or near a surface of said annulus body within said prosthetic cardiac valve and configured to receive said acoustic excitation signals, said program of instructions configuring a processor element to;

apply, using a signal generator, a stimulus signal to the embedded first piezo-electric element for generating an acoustic excitation signal;

receive, at a multichannel amplifier, a signal output from the one or more second piezo-electric elements in response to receiving said acoustic excitation signal,

compare, in real time, a generated output signal with the excitation signal to output a Doppler frequency shift measurement signal;

receive, at an A/D converter element, the frequency shift measurement output signal from said amplifier and converting said frequency shift measurement output signal to a corresponding digital signal,

receive said corresponding digital signal at said processor element; and

capture, in real-time, using a microphone sensor embedded on an outer surface of the implanted prosthetic cardiac valve, a sound of blood flowing through said cardiac valve leaves opening and generate corresponding data signals of said captured sounds;

determine at said processor element, a real time liquid blood flow rate measure within said compartment based on said received corresponding digital signal for use in real time monitoring a cardiac output and a function of the prosthetic cardiac valve, and

identify, at said processor element, a laminar blood flow versus a turbulent blood flow based on said captured sounds, and correlate said generated data signals received from said embedded microphone sensor with the corresponding digital signal to identify a change in said cardiac output.

14. The computer program product of claim 13, said program of instructions configuring said computing device to initiate a communications transceiver to:

transmit signals representing said determined liquid blood flow rate measure to a device external to said subject, said external device comprising a mobile phone, a smartphone, a laptop, a computer device configured for operator-independent, continuous monitoring of blood flow rate and/or measurement of said cardiac output.

15. The computer program product of claim 14, wherein said program of instructions further configure the processor element to:

determine, in real time, whether a change in monitored liquid blood flow velocity is a result of a change in the cross-sectional area of the compartment or a change in the blood flow rate.

16. The computer program product of claim 15, wherein said program of instructions further configure the processor element to:

analyze received embedded piezo-electric sensor data; and

correlate data signals received from one or more other sensor devices with received sensor generated output signals at said processor device, said correlating used for determining whether a detected change in blood flow rate results from a change in the cross-sectional area of the compartment or a change in said cardiac output.

19. The computer program product of claim 15, wherein a change in a cross-sectional area of the compartment is a function of a cardiac valve leaves position throughout a human heart cycle, said processor element monitoring said liquid blood flow velocity for all stages of the heart cycle.