Method and device for the non-invasive measurement of pressure

• US 4,987,898 A
• Filed: 01/17/1989
• Issued: 01/29/1991
• Est. Priority Date: 01/17/1989
• Status: Expired due to Fees

• Current Assignee: Noninvasive Medical Incorporated
• Original Assignee: Noninvasive Medical Incorporated
• Inventors: Sones, William
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/297,308
• Time in Patent Office: 742 Days
• Field of Search: 128/645, 128/646, 128/652, 128/675, 128/676, 128/748, 73/715, 73/723, 73/725-727, 73/751, 73/753
• US Class Current: 600/398
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers
• CPC Class Codes: A61B 5/03 Detecting, measuring or recording fluid pressure within the body other than blood pressure, e.g. cerebral pressure; Measuring pressure in body tissues or organs A61B5/205 takes precedence

Abstract

An improved, non-invasive pressure sensing method and device is provided which allows for the measurement of pressure in a vessel having flexible walls or otherwise provided with an external elastic membrane. The disclosed method and device provides for the application of a coplanar array of pressure sensors or transducers against the elastic vessel wall, the internal pressure of the vessel being measured at a point at which at least three of the transducers, arranged in a triangular configuration, measure the same pressure.

Claims

1. A method of non-invasive detection of pressure within a vessel having an elastic wall portion, comprising the steps of:

(a) placing a coplanar triangular array of three pressure transducers into contact with the elastic wall portion;

(b) monitoring the pressure detected by said transducers;

(c) advancing said array against said elastic wall portion until the pressure sensed by three monitored transducers is equal; and

(d) generating a first signal indicating the pressure measured by said transducers when the pressure sensed by said three monitoring transducers is equal.

2. The method of claim 1 further comprising the step of zeroing said pressure transducers prior to said advancing step.

3. The method of claim 1 further comprising the steps of monitoring the pressure of a fourth transducer centrally located within a triangle whose vertices are defined by said three monitored transducers and generating a second signal indicating the pressure within the vessel measured by said fourth transducer.

4. The method of claim 1 further comprising the step of further monitoring said pressure detected by said coplanar sensor array following said generating step and adjusting the position of said pressure sensor array against the elastic wall to maintain said equality of pressure signals.

5. The method of claim 1 further comprising the step of affixing said coplanar array to the elastic wall portion.

6. A device for non-invasive measurement of pressure within a vessel having an elastic wall portion, comprising:

(a) three pressure transducers arranged in a coplanar triangular array;

(b) means for bringing said array into contact with the elastic wall portion;

(c) output means for generating a pressure signal corresponding to the pressure measured by each said pressure transducer;

(d) comparison means whereby the signals transmitted from the three pressure transducers are compared;

(e) a signal generating means whereby an indication of signal equality from said three pressure transducers can be displayed or transmitted;

(f) display means for indicating the pressure measured by said transducers.

7. The device of claim 6, further comprising fixture means for carrying said coplanar array in a predetermined position relative to the vessel.

8. A device for non-invasive measurement of pressure within a vessel having an elastic wall, comprising:

(a) three pressure transducers arranged in a coplanar triangular array;

(b) a fourth pressure transducer disposed within said triangular coplanar array;

(c) means for bringing said array into contact with the elastic wall portion;

(d) output means for generating a pressure signal corresponding to the pressure measured by each of four said pressure transducers;

(e) comparison means for determining a condition of equality of said pressure signals from said four pressure transducers;

(f) signal generating means for indicating the pressure measured by said transducers when the pressure sensed by said four of said monitoring transducers is equal; and

(g) display means for indicating the pressure measured by the said fourth pressure transducer.

9. The apparatus of claim 8 further comprising signal generating means for generating an equality signal in response to said determination of equality of said pressure

10. The apparatus of claim 8 wherein said coplanar array is carried on a planar surface.

11. The apparatus according to claim 10 wherein said pressure transducers are arranged at the vertices of a triangle on said planar surface.

12. The apparatus of claim 10 further comprising a probe carrying said coplanar array.

13. The apparatus of claim 10 further comprising means for adjusting the position of said planar surface in response to said comparison means to maintain said condition of equality of said pressure signals.

14. The apparatus of claim 8 further comprising means for monitoring said pressure signals from said coplanar transducer array.

15. The apparatus of claim 8 further comprising recording means for recording the pressure within the vessel as indicated by said pressure signals.

16. The apparatus of claim 8 further comprising a fourth transducer disposed centrally to a triangle whose vertices are defined by said three pressure transducers.

17. A device for non-invasively measuring pressure within a vessel having an elastic wall portion, comprising:

a rigid flat plate;

three pressure transducers, disposed in a triangular array carried on and coplanar with the surface of said plate;

means for advancing said array against the surface of said elastic wall portion in a controlled manner;

output means for generating a pressure signal corresponding to the pressure measured by each said pressure transducer;

comparison means whereby the signals transmitted from said three pressure transducers are compared;

control means for repositioning said coplanar array to maintain said condition of equality of said pressure signals;

means responsive to said control means for repositioning said coplanar array;

means for displaying and recording the value of any said pressure signal; and

fixture means for carrying said plate, including housing means for holding said plate in a predetermined position relative to the vessel.