System and method for monitoring pressure, flow and constriction parameters of plumbing and blood vessels

• US 6,237,398 B1
• Filed: 09/29/1998
• Issued: 05/29/2001
• Est. Priority Date: 12/30/1997
• Status: Expired due to Term

• Current Assignee: Remon Medical Technologies Ltd. (Boston Scientific Corporation)
• Original Assignee: Remon Medical Technologies Ltd. (Boston Scientific Corporation)
• Inventors: Tsaliah, Yosef, Porat, Yariv, Doron, Eyal
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/161,658
• Time in Patent Office: 973 Days
• Field of Search: 73/54.06, 73/54.07, 73/54.09, 73/54.14, 73/597, 73/861.23, 73/861.25, 73/861.26, 73/861.27, 73/861.28, 73/861.18, 137/2, 137/3, 137/92, 600/16, 600/17
• US Class Current: 73/54.09
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/02158 provided with two or more sensor elements
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/413 Monitoring transplanted tissue or organ, e.g. for possible rejection reactions after a transplant
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: G01F 1/36 the pressure or differential pressure being created by the use of flow constriction
• CPC Class Codes: G01F 1/72 Devices for measuring pulsing fluid flows
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H10N 30/302 Sensors

Abstract

The present invention provides a system and method of quantifying flow, detecting a location of an obstruction and quantifying a degree of the obstruction in a pipe characterized in pulsatile flow. The method includes the steps of (a) attaching at least two spaced pressure sensors onto inner walls of the pipe; (b) using the at least two spaced pressure sensors for recording pressure records associated with each of the at least two pressure sensors within the pipe; and (c) using the pressure records for quantifying the pulsatile flow in the pipe, for detecting the location of the obstruction in the pipe and for quantifying the degree of the obstruction in the pipe.

Claims

1. A system for quantifying pulsatile flow in a pipe, the system comprising:

(a) at least two pressure sensors;

(b) a mechanism for attaching said at least two pressure sensors onto inner walls of the pipe in a spaced configuration;

(c) a processing module for receiving pressure records from each of said at least two pressure sensors and for quantifying the pulsatile flow in the pipe; and

(d) a non-invasively activatable acoustic transducer element for communicating data from within the pipe to a receptive acoustic transducer outside thereof.

2. The system of claim 1, wherein said non-invasively activatable acoustic transducer element includes:

(i) a cell member having a cavity;

(ii) a substantially flexible piezoelectric layer attached to said cell member, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof at its resonance frequency upon impinging of an external acoustic wave; and

(iii) a first electrode attached to said external surface and a second electrode attached to said internal surface.

3. The system of claim 1, wherein said mechanism for attaching said at least two pressure sensors onto said inner walls of the pipe in said spaced configuration is a platform which serves for holding said at least two pressure sensors and is itself insertable into the pipe.

4. The system of claim 1, wherein the pipe is selected from the group consisting of a portion of a plumbing installation and a blood vessel.

5. The system of claim 3, wherein said platform is a stent insertable into a blood vessel.

6. A system for detecting a location of an obstruction in a pipe characterized in pulsatile flow, the system comprising:

(a) at least two pressure sensors;

(b) a mechanism for attaching said at least two pressure sensors onto inner walls of the pipe in a spaced configuration;

(c) a processing module for receiving pressure records from each of said at least two pressure sensors and for detecting the location of the obstruction in the pipe; and

(d) a non-invasively activatable acoustic transducer element for communicating data from within the pipe to a receptive acoustic transducer outside thereof.

7. The system of claim 6, wherein said non-invasively activatable acoustic transducer element includes:

(i) a cell member having a cavity;

a substantially flexible piezoelectric layer attached to said cell member, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof at its resonance frequency upon impinging of an external acoustic wave; and

(iii) a first electrode attached to said external surface and a second electrode attached to said internal surface.

8. The system of claim 6, wherein said mechanism for attaching said at least two pressure sensors onto said inner walls of the pipe in said spaced configuration is a platform which serves for holding said at least two pressure sensors and is itself insertable into the pipe.

9. The system of claim 6, wherein the pipe is selected from the group consisting of a portion of a plumbing installation and a blood vessel.

10. The system of claim 8, wherein said platform is a stent insertable into a blood vessel.

11. A system for quantifying a degree of an obstruction in a pipe characterized in pulsatile flow, the system comprising:

(a) at least two pressure sensors;

(b) a mechanism for attaching said at least two pressure sensors onto inner walls of the pipe in a spaced configuration;

(c) a processing module for receiving pressure records from each of said at least two pressure sensors and for quantifying the degree of the obstruction in the pipe; and

(d) a non-invasively activatable acoustic transducer element for communicating data from within the pipe to a receptive acoustic transducer outside thereof.

12. The system of claim 11, wherein said non-invasively activatable acoustic transducer element includes:

(i) a cell member having a cavity;

(ii) a substantially flexible piezoelectric layer attached to said cell member, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof at its resonance frequency upon impinging of an external acoustic wave; and

(iii) a first electrode attached to said external surface and a second electrode attached to said internal surface.

13. The system of claim 11, wherein said mechanism for attaching said at least two pressure sensors onto said inner walls of the pipe in said spaced configuration is a platform which serves for holding said at least two pressure sensors and is itself insertable into the pipe.

14. The system of claim 11, wherein the pipe is selected from the group consisting of a portion of a plumbing installation and a blood vessel.

15. The system of claim 13, wherein said platform is a stent insertable into a blood vessel.

16. A system for quantifying flow, detecting a location of an obstruction and quantifying a degree of the obstruction in a pipe characterized in pulsatile flow, the system comprising:

(a) at least two pressure sensors;

(b) a mechanism for attaching said at least two pressure sensors onto inner walls of the pipe in a spaced configuration;

(c) a processing module for receiving pressure records from each of said at least two pressure sensors and for quantifying the pulsatile flow in the pipe, for detecting the location of the obstruction in the pipe and for quantifying the degree of the obstruction in the pipe; and

(d) a non-invasively activatable acoustic transducer element for communicating data from within the pipe to a receptive acoustic transducer outside thereof.

17. The system of claim 16, wherein said non-invasivly activatable acoustic transducer element includes:

(i) a cell member having a cavity;

(ii) a substantially flexible piezoelectric layer attached to said cell member, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof at its resonance frequency upon impinging of an external acoustic wave; and

(iii) a first electrode attached to said external surface and a second electrode attached to said internal surface.

18. The system of claim 16, wherein said mechanism for attaching said at least two pressure sensors onto said inner walls of the pipe in said spaced configuration is a platform which serves for holding said at least two pressure sensors and is itself insertable into the pipe.

19. The system of claim 16, wherein the pipe is selected from the group consisting of a portion of a plumbing installation and a blood vessel.

20. The system of claim 18, wherein said platform is a stent insertable into a blood vessel.

21. A system for quantifying flow in a pipe characterized in pulsatile flow, the system comprising:

(a) at least two pressure sensors;

(b) a mechanism for attaching said at least two pressure sensors onto inner walls of the pipe in a spaced configuration;

(c) a processing module for receiving instantaneous pressure records from said at least two pressure sensors and for calculating an acoustic wave propagation velocity from said instantaneous pressure records to thereby determine at least one of pressure gradient, flow velocity and acoustic impedance across said at least two pressure sensors thus quantifying the pulsatile flow in the pipe.

22. The system of claim 21, wherein said pressure gradient, flow velocity and acoustic impedance across said at least two pressure sensors determined by said processing module is used by said processing module to detect a location of an obstruction in the pipe relative to said at least two pressure sensors.

23. The system of claim 22, wherein said pressure gradient, flow velocity and acoustic impedance across said at least two pressure sensors determined by said processing module is used by said processing module to quantify a degree of said obstruction.

24. The system of claim 21, wherein said mechanism for attaching said at least two pressure sensors onto said inner walls of the pipe in said spaced configuration is a platform which serves for holding said at least two pressure sensors and is itself insertable into the pipe.

25. The system of claim 21, wherein the pipe is selected from the group consisting of a portion of a plumbing installation and a blood vessel.

26. The system of claim 21, wherein said platform is a stent insertable into a blood vessel.

27. The system of claim 21, further comprising:

(d) a non-invasively activatable acoustic transducer element for communicating data from within the pipe to a receptive acoustic transducer outside thereof.

28. The system of claim 27, wherein said non-invasivly activatable acoustic transducer element includes:

(i) a cell member having a cavity;

(ii) a substantially flexible piezoelectric layer attached to said cell member, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof at its resonance frequency upon impinging of an external acoustic wave; and

(iii) a first electrode attached to said external surface and a second electrode attached to said internal surface.