Method and apparatus for making physiological measurements

• US 4,442,844 A
• Filed: 08/28/1981
• Issued: 04/17/1984
• Est. Priority Date: 08/28/1981
• Status: Expired due to Fees

• Current Assignee: The Joseph H. Navach and Beverly Ann Navach Living Trust
• Original Assignee: Joseph H. Navach
• Inventors: Navach, Joseph H.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US06/297,513
• Time in Patent Office: 963 Days
• Field of Search: 128/633, 128/663, 128/664-665, 128/687-690
• US Class Current: 600/407
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61B 8/4227 characterised by straps, belts, cuffs or braces

Abstract

Measurements having physiological significance can be obtained by analyzing radiation which is reflected by an artery of the body. Such measurements are preferably made by immobilizing a part of the body such as the human wrist where an artery extends substantially linearly and is adjacent to and generally parallel with the surface of the skin, by then directing radiation from a radiation source or sending apparatus toward any of several specific locations along the artery at an angle such that some of the radiation will be reflected, and by next measuring the amount of reflected radiation in accordance with time through the use of a receiving or detection apparatus. These locations are specific regions or areas generally along and generally extending transverse to the artery which have been established on the basis of experience as normally being capable of reflecting back at least some radiation in an amount having physiological significance.

Claims

1. An apparatus for use in making measurements on a living body having an arteriovascular circulatory system which comprises:

a support means for engaging a part of the body adjacent to a location in the body where a length of any artery extends substantially linearly and is adjacent to and generally parallel with the surface of the skin so as to substantially immobilize said part without interfering with the circulation of blood within said artery, said support means being shaped so as to include an opening means adjacent to said length of said artery,

a radiation source means and a radiation detection means for use in making measurements by sending out radiation from said source means and by measuring radiation reaching said detection means,

holder means for holding said radiation source and detection means located in a location adjacent to said opening means, said holder means supporting said radiation source and detection means adjacent to said opening means,

positioning means for moving said holder means and said radiation source and detection means relative to said support means in a coordinate system into any of a series of locations along said length of said artery which have been established as normally being capable of transmitting at least some radiation in an amount having physiological significance from a radiation source, said positioning means being held on said said support means,

said holder means and said positioning means serving to hold both said radiation source means and radiation detection means at a specific measurement location so that as said apparatus is used at such a location some radiation from said radiation source means will traverse a part of said body and will be detected by said radiation detection means.

2. An apparatus as claimed in claim 1 wherein:

said support means comprises a gauntlet like sleeve adapted to fit closely around a portion of a limb of said body.

3. An apparatus as claimed in claim 1 wherein:

said support means comprises a gauntlet like sleeve adapted to fit closely around the forearm, the wrist and the portion of the hand adjacent to the wrist of a human body, and

said opening means comprises an opening to said gauntlet located adjacent to the portion of said sleeve adjacent to the human wrist where the radial artery is located.

4. An apparatus as claimed in claim 1 wherein:

said holder means and said positioning means hold said radiation source and detection means so that in each of said locations a signal from said source means will be directed towards an internal area within said artery and will be reflected back from said area towards said detection means.

5. An apparatus as claimed in claim 4 wherein:

said areas at said locations each corresponds to a portion of said artery located generally in a plane extending perpendicular to said artery.

6. An apparatus as claimed in claim 5 wherein:

both said radiation source and detection means have axes and both of said axes are directed substantially towards the same point on the interior of the wall of the artery in each of said locations,

said source and said detection means also being located on the opposite side of said artery from said point at an angle relative to said artery such that radiation from said source means will be reflected back to said detection means in each of said locations.

7. An apparatus as claimed in claim 6 wherein:

said radiation source means is separate from said radiation detection means, and

the axis of said source means and the axis of said detection means are located at substantially the same angle relative to a plane extending perpendicular to said artery in each of said locations,

said angle is an angle of from about 14°

to about 14.8°

.

8. An apparatus as claimed in claim 7 wherein:

said angle is an angle of from about 14.3°

to about 14.5°

.

9. An apparatus as claimed in claim 1 wherein:

said positioning means comprises an x-y table means supporting said holder means so that said holder means and said radiation source and detection means may be moved along the length of said artery to said successive locations.

10. An apparatus as claimed in claim 1 including:

grounding means for grounding the portions of said body remote from said part of said body through capacitor means.

11. An apparatus as claimed in claim 1, 2 or 4 wherein:

said areas at said locations each correspond to a portion of said artery located generally in a plane extending perpendicular to said artery,

both said radiation source and detection means have axes and both of said axes are directed substantially towards the same point on the inter-wall of the artery in each of said locations,

said source and said detection means also being located on the opposite side of said artery from said point at an angle relative to said artery such that radiation from said source means will be reflected back to said detection means in each of said locations,

said radiation source means is separate from said radiation detection means,

the axis of said source means and the axis of said detection means are located at substantially the same angle relative to a plane extending perpendicular to said artery in each of said locations,

said angle is an angle of from about 14.3°

to 14.5°

, and

said radiation source means is a means for emitting infrared radiation and said radiation detection means is a means for detecting infrared radiation so as to provide an output signal in accordance with the radiation received by it.

12. An apparatus as claimed in claim 11 including:

grounding means for grounding the limbs of said body remote from the limb of the body on which said part of said body is located through capacitor means.

15. An apparatus as claimed in claim 1 wherein:

said areas at said locations each correspond to a portion of said artery located generally in a plane extending perpendicular to said artery,

both said radiation source and detection means have axes and both of said axes are directed substantially towards the same point on the inter-wall of the artery in each of said locations,

said source and said detection means also being located on the opposite side of said artery from said point at an angle relative to said artery such that radiation from said source means will be reflected back to said detection means in each of said locations,

said radiation source means is separate from said radiation detection means,

the axis of said source means and the axis of said detection means are located at substantially the same angle relative to a plane extending perpendicular to said artery in each of said locations,

said angle is an angle from about 14.3°

to 14.5°

, and

said radiation source means is capable of emitting a series of ultrasonic bursts of radiation and said radiation detection means is capable of providing a signal varying in amplitude according to the ultrasonic signal from each of said bursts received back by it.

16. An apparatus as claimed in claim 15 including:

grounding means for grounding the limbs of said body remote from the limb of the body on which said part of said body is located through capacitor means.

13. An apparatus as claimed in 1 wherein:

said areas at said locations each correspond to a portion of said artery located generally in a plane extending perpendicular to said artery,

both said radiation source and detection means have axes and both of said axes are directed substantially towards the same point on the inter-wall of the artery in each of said locations,

said source and said detection means also being located on the opposite side of said artery from said point at an angle relative to said artery such that radiation from said source means will be reflected back to said detection means in each of said locations,

said radiation source means is separate from said radiation detection means,

the axis of said source means and the axis of said detection means are located at substantially the same angle relative to a plane extending perpendicular to said artery in each of said locations,

said angle is an angle from about 14.3°

to 14.5°

, and

said radiation source means is capable of continuously emitting ultrasonic radiation and said radiation detection means is capable of providing a continuous signal varying an amplitude in accordance with the ultrasonic radiation received by it.

14. An apparatus as claimed in claim 13 including:

grounding means for grounding the limbs of said body remote from the limb of the body on which said part of said body is located through capacitor means.

17. A process for use in making measurements on a living body having an arteriovascular circulatory system which comprises:

immobilizing part of the body in which an artery extends substantially linearly and adjacent to and substantialy parallel with the skin,

locating both a radiation source and detection means adjacent to a specific location along the length of said artery which has been established as normally being capable of reflecting at least some incident radiation in an amount having physiological significance by moving said source and detection means relative to said immobilized part of said body in a coordinate system using said immobilized part of the body as a reference, said radiation source and detection means being located in a position such that radiation from said source means will be modified as a result of contact with the body in reaching said detection means,

operating said radiation source and detection means so that radiation emitted by said source means is modified in reaching said detection means and is used to produce a signal at said detection means which is indicative of at least one physiological function.

18. A process as claimed in claim 17 wherein:

said part is on a limb of said body, and including

grounding the other limbs of said body through capacitor means while operating said radiation source and detection means.

19. A process as claimed in claims 17 or 18 wherein:

said part of said body is immobilized by encasing said part of said body in a gauntlet like sleeve adapted to fit closely around said part of said body without interfering with the pulse of said part of said body.

20. A process as claimed in claim 17 wherein:

said radiation source and said radiation detection means are separate means,

said radiation source and said detection means have axes and are located so that said axes are directed substantially toward the same point on the interior wall of said artery on the side of said artery remote from said source and detection means when said source and said detection means are operated.

21. A process as claimed in claim 20 wherein:

the axes of said source means and said detection means are located at substantially the same angle relative to a plane extending transverse to said artery at said point,

said angle is an angle of from about 14°

to about 14.8°

.

22. A process as claimed in claim 21 wherein:

said angle is an angle of from about 14.3°

to about 14.5°

.

23. A process as claimed in claim 17 wherein:

said part of said body is immobilized by encasing said part of said body in a gauntlet like sleeve adapted to fit closely around said part of said body without interfereing with the pulse of said part of said body,

said radiation source and said radiation detection means are separate means,

said radiation source and said detection means have axes and are located so that said axes are directed substantially toward the same point on the interior wall of said artery on the side of said artery remote from said source and detection means when said source and said detection means are operated,

the axes of said source means and said detection means are located at substantially the same angle relative to a plane extending transverse to said artery at said point,

said angle is an angle of from about 14.3°

to about 14.5°

,

the radiation given off by said source means and detected by said detection means is infrared radiation.

24. A process as claimed in claim 17 wherein:

said part of said body is immobilized by encasing said part of said body in a gauntlet like sleeve adapted to fit closely around said part of said body without interfering with the pulse of said part of said body,

said radiation source and said radiation detection means are separate means,

said radiation source and said detection means have axes and are located so that said axes are directed substantially toward the same point on the interior wall of said artery on the side of said artery remote from said source and detection means when said source and said detection means are operated,

the axes of said source means and said detection means are located at substantiallay the same angle relative to a plane extending transverse to said artery at said point,

said angle is an angle of from about 14.3°

to about 14.5°

,

the radiation given off by said source means and detected by said detection means is continuous ultrasonic radiation.

25. A process as claimed in claim 17 wherein:

said part of said body is immobilized by encasing said part of said body in a gauntlet like sleeve adapted to fit closely around said part of said body without interfering with the pulse of said part of said body,

said radiation source and said radiation detection means are separate means,

said radiation source and said detection means have axes and are located so that said axes are directed substantially toward the same point on the interior wall of said artery on the side of said artery remote from said source and detection means when said source and said detection means are operated,

the axes of said source means and said detection means are located at substantially the same angle relative to a plane extending transverse to said artery at said point,

said angle is an angle of from about 14.3°

to about 14.5°

,

the radiation given off by said source means and detected by said detection means is a series of bursts of ultrasonic radiation.