Method and apparatus for measuring arterial and venous blood flow in body appendages

• US 5,692,520 A
• Filed: 05/08/1996
• Issued: 12/02/1997
• Est. Priority Date: 11/08/1994
• Status: Expired due to Fees

• Current Assignee: Laborie Medical Technologies Inc.
• Original Assignee: Laborie Medical Technologies Inc.
• Inventors: Lavoisier, Pierre
• Primary Examiner(s): Bahr, Jennifer
• Assistant Examiner(s): YARNELL, BRYAN KEITH
• Application Number:
  US08/646,639
• Time in Patent Office: 573 Days
• Field of Search: 128/633, 128/664-7, 128/668, 128/670, 128/672, 128/677, 128/678, 128/687, 128/688, 128/691, 128/694, 128/748, 128/774
• US Class Current: 600/587
• CPC Class Codes: A61B 5/02422 within occluders
• CPC Class Codes: A61B 5/4393 Sexual arousal or erectile dysfunction evaluation, e.g. tumescence evaluation

Abstract

The present invention is directed to a non-invasive method and apparatus for measuring arterial and venous blood flow in body appendages. The present invention is also directed to a non-invasive method and apparatus for measuring penile tumescence as a function of arterial and venous blood flow in the penis and penile rigidity as a function of suprasystolic intra-cavernosal pressure. These measurements are performed to make a diagnosis in the field of erectile dysfunctions. Since every normal adult male experiences erections during rapid eye movement sleep, the measurements are preferably made during the patient'"'"'s sleep, but can also be performed when the patient is awake for diagnosis and treatment.

Claims

1. A method for measuring penile rigidity comprising the steps of:

providing an apparatus for measuring arterial and venous blood flow and tissue pressure in body appendages, the apparatus comprising;

a cuff comprising a flexible, non elastic band, one face of which is covered with at least one plastic container capable of being filled with a fluid,

means to position, close and firmly hold said band around a body appendage of the patient with said container on the inside of the cuff against said appendage,

a pressure transducer in direct communication with the fluid inside said container to measure the pressure of said fluid, and

electronic means to modify the sensitivity of the pressure transducer and to amplify and/or display signals generated by said transducer,

the improvement comprising said cuff wherein said band has two longitudinally parallel containers covering one face of said band, wherein a first container is capable of being filled with a non compressible liquid and a second container is capable of being filled with a gas and said pressure transducer is in direct communication with the liquid in said first container wherein said pressure in said second container is maintained at a constant level,

wrapping said cuff around the penis of a patient while said penis is non erect with said filled containers and said photoplethysmography probe in direct contact with said penis,

closing said cuff to rigidly hold said filled containers and photoplethysmography probe against said penis,

measuring the pressure of the fluid within said first container as said penis becomes erect,

emitting, during said pressure measurement, a light beam from said photoplethysmography probe and measuring a reflected light beam with said probe, and

amplifying, recording and displaying data from said measurements.

2. The method of claim 1 wherein said light beam emitted by said photoplethysmography probe is directed toward said penis.

3. The method of claim 1 further comprising the steps of:

recording a pulse signal with said photoplethysmography probe while said penis is non erect and during penile tumescence, for measured pressures inferior to a preset pressure value,

recording a signal from said pressure transducer above said preset pressure value, and

obtaining a curve of the pulse signal recording and the pressure transducer signal and evaluation of the pulse from a surface area under each curve,

whereby a curve representative of changes in arterial blood flow during penile tumescence is obtained.

4. The method of claim 3 further comprising the steps of:

recording a signal from said pressure transducer for pressures inferior to said preset pressure value,

obtaining a curve of said pressure signal, and

applying fluid mechanics laws to calculate from said curve and said curve of changes in arterial blood flow, changes in venous blood flow,

whereby a curve representative of changes in venous blood flow is obtained.

5. A method for measuring nocturnal penile tumescence and intra-cavernosal pressure while a patient is sleeping and diagnosing erectile dysfunction comprising the steps of:

providing an apparatus for measuring arterial and venous blood flow and tissue pressure in body appendages, the apparatus comprising;

a cuff comprising a flexible, non elastic band, one face of which is covered with at least one plastic container capable of being filled with a fluid,

means to position, close and firmly hold said band around a body appendage of the patient with said container on the inside of the cuff against said appendage,

a pressure transducer in direct communication with the fluid inside said container to measure the pressure of said fluid, and

electronic means to modify the sensitivity of the pressure transducer and to amplify and/or display signals generated by said transducer,

the improvement comprising said cuff wherein said band has two longitudinally parallel containers covering one face of said band, wherein a first container is capable of being filled with a non compressible liquid and a second container is capable of being filled with a gas and said pressure transducer is in direct communication with the liquid in said first container wherein said pressure in said second container is maintained at a constant level,

wrapping said cuff around the penis of a patient while said penis is non erect with said filled containers and said photoplethysmography probe in direct contact with said penis,

closing said cuff to rigidly hold said filled containers and photoplethysmography probe against said penis,

measuring the pressure of the fluid within said first container as said penis becomes erect,

emitting, during said pressure measurement, a light beam from said photoplethysmography probe and measuring a reflected light beam with said probe,

amplifying, recording and displaying data from said measurements,

obtaining and plotting curves from said data,

for each tumescence period, identifying a period of pressure plateau corresponding to a vascular phase and identifying pressure peaks corresponding to muscular phases,

evaluating surface areas of said plateau and of said peaks and transferring the results to an X-Y graph wherein the plateau surface area is plotted on the X-axis and the surface area of the peaks is plotted on the Y-axis, and

plotting a curve with time on the X-axis and the plateau pressure and maximum peak pressures on the Y-axis,

whereby said curve provides a means to analyze and classify a patient'"'"'s erectile dysfunction.

6. In an apparatus for measuring arterial and venous blood flow and tissue pressure in body appendages, the apparatus comprising:

a cuff comprising a flexible, non elastic band, one face of which is covered with at least one plastic container capable of being filled with a fluid,

means to position, close and firmly hold said band around a body appendage of the patient with said container on the inside of the cuff against said appendage,

a pressure transducer in direct communication with the fluid inside said container to measure the pressure of said fluid, and

electronic means to modify the sensitivity of the pressure transducer and to amplify and/or display signals generated by said transducer,

the improvement comprising said cuff wherein said band has two longitudinally parallel containers covering one face of said band, wherein a first container is capable of being filled with a non compressible liquid and a second container is capable of being filled with a gas and said pressure transducer is in direct communication with the liquid in said first container.

7. The apparatus of claim 6 further comprising a photoplethysmograph in combination with said cuff wherein a probe of said photoplethysmograph is attached to said second container.

8. The apparatus of claim 7 wherein said probe of said photoplethysmograph is attached to said second container so that a light beam emitted by said probe is directed toward said appendage.

9. The apparatus of claim 7 wherein said second container is transparent.

10. The apparatus of claim 7 wherein pressure in said second container is maintained at a constant level.

11. The apparatus of claim 7 wherein said electronic means comprises a computer.

12. The apparatus of claim 7 wherein said electronic means comprises a portable recording unit capable of recording and subsequently downloading data corresponding to signals generated by said pressure transducer and said photoplethysmograph.

13. The apparatus of claim 6 wherein said electronic means comprises a computer.

14. The apparatus of claim 6 wherein said electronic means comprises a portable recording unit capable of recording, storing and subsequently downloading data corresponding to said signals.

15. The apparatus of claim 6 further comprising means to measure changes in penile circumference.