Probe devices particularly useful for non-invasive detection of medical conditions

• US 6,488,633 B1
• Filed: 02/08/2000
• Issued: 12/03/2002
• Est. Priority Date: 07/14/1999
• Status: Expired due to Term

• Current Assignee: Itamar Medical Ltd. (Asahi Kasei Corporation)
• Original Assignee: Itamar Medical Ltd. (Asahi Kasei Corporation)
• Inventors: Schnall, Robert P.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): CARTER, RYAN CHRISTOPHER
• Application Number:
  US09/499,354
• Time in Patent Office: 1,029 Days
• Field of Search: 600/481, 600/485-488, 600/490, 600/499-500
• US Class Current: 600/481
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/1073 Measuring volume, e.g. of limbs
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

A device for application to a body part of a patient to determine the physiological condition of the patient. The device includes a housing, in the form of a hollow socket closed at its distal end and open at its proximal end, for receiving the body part, a pressurizing device for applying a pressure field around the body part when received in the housing, and a sensor for sensing changes in the body part related to changes in pulsatile blood volume therein. The housing includes at least three contiguous but separate sections including a distal end section at its distal tip, a proximal end section at its opposite end, and at least one middle section between the end sections. The pressurizing device applies a pressure field to the portions of the body part received within at least the distal end section and the middle section of the housing. The distal end section is configured to apply pressure to all of the distal portion of the body part including its distal most tip. The sensor is configured to sense pulsatile volume changes in at least one segment distal to the proximal-most segment.

Claims

1. A device for application to a body part of a patient to determine the physiological condition of the patient, comprising:

a housing for receiving the body part;

pressurizing means for applying a pressure field around the body part when received in said housing;

and a sensor for sensing changes in said body part related to changes in blood volume therein, wherein

said housing includes at least three contiguous but separate sections including a distal end section at a distal end of said housing, a proximal end section at a proximal end of said housing, and at least one middle section between said distal and proximal end sections,

and wherein said pressurizing means applies a pressure field to portions of the body part received within at least said distal end section and said middle section of the housing,

and said sensor senses changes in the portion of said body part received within said middle section of the housing.

2. The device according to claim 1, wherein said pressurizing means also applies a pressure field to said proximal end section.

3. The device according to claim 2, wherein said pressurizing means comprises:

a deformable membrane within said housing defining end fluid chambers with said distal and proximal end sections, and a middle fluid chamber with said middle housing section;

and a fluid pressure source for applying a fluid pressure to all of said chambers.

4. The device according to claim 3, wherein said deformable membrane comprises resilient elastomeric material.

5. The device according to claim 3, wherein said distal and proximal middle section is longer than said housing end sections.

6. The device according to claim 3, wherein said housing is configured to receive a digit of the patient;

said distal end section being closed and enclosing one or more chambers, for receiving a distal end of the digit;

said proximal end section being open and enclosing one or more additional chambers, at the proximal end of the housing and connected thereto by said middle section.

7. The device according to claim 6, wherein said sensor also senses changes in the distal end of the digit received in said distal end of the housing.

8. The device according to claim 6, wherein said housing comprises at least three contiguous parts secured together, including:

a thimble-shaped cap at the closed distal end of the housing;

an annular collar at the proximal end of the housing; and

an intermediate sleeve secured between the thimble-shaped cap and the annular collar.

9. The device according to claim 8, wherein said parts of the housing are secured together by a first annular ring which secures said thimble-shaped cap to said intermediate sleeve, and a second annular ring which secures said intermediate sleeve to said annular collar.

10. The device according to claim 9 wherein, on said first annular ring, is mounted a U-shaped bar pressing said membrane means against the inner surface of said thimble-shaped cap to divide the chamber therein into two sub-chambers to be located on opposite sides of a distal tip of the digit when inserted into said housing, and to more firmly retain the digit therein.

11. The device according to claim 9, wherein said deformable membrane includes at least three separate membranes, comprising:

a distal membrane having an open end secured by said first annular ring to said thimble-shaped cap to define one end chamber in said cap;

an annular intermediate membrane having open opposite ends secured to said intermediate sleeve by said first and second annular rings to define a middle chamber in the intermediate sleeve;

and a further annular membrane having one end secured to said annular collar by said second annular ring, and the opposite end secured to said annular collar by a third annular ring to define another end chamber within said annular collar.

12. The device according to claim 3, wherein said membrane means consists of a single membrane of tubular shape closed at one end and open at an opposite end, said device further including a plurality of spaced internal annular rings for clamping spaced annular portions of said membrane to an inner surface of said housing to define said fluid chambers.

13. The device according to claim 12, wherein the inner surface of said tubular housing, and outer surfaces of said spaced internal annular rings, are formed with mating rib and recess formations enabling the rings to be snap-fitted within said housing, and to press the annular portions of the tubular membrane against the inner surface of the housing to define said chambers.

14. The device according to claim 13, wherein said mating rib and recess formations comprises annular ribs formed on the inner surface of said housing, and annular recesses formed on the outer surfaces of said rings.

15. The device according to claim 12, wherein said housing comprises one part of tubular shape closed at said distal end and open at said proximal end.

16. The device according to claim 12, wherein, on one of the internal annular rings at the distal end of the housing is mounted a U-shaped bar pressing said membrane means against a thimble-shaped cap to divide a first chamber therein into two sub-chambers to be located on opposite sides of a distal tip of a patient'"'"'s digit when inserted into said housing, and to more firmly retain the patient'"'"'s digit therein.

17. The device according to claim 6, wherein said closed distal end of the housing, and the end fluid chamber therein, are of substantially shorter length than the other housing sections and the fluid chambers therein.

18. The device according to claim 6, wherein said end fluid chamber in the closed distal end section of the housing includes an abutment element having a concave surface for receiving the distal tip of the patient'"'"'s digit.

19. The device according to claim 18, wherein said abutment element is located such that, when engaged by the distal tip of the patient'"'"'s digit, most of said end fluid chamber is located forwardly of the distal tip of the patient'"'"'s finger.

20. The device according to claim 6, wherein said end chamber in the closed distal end section of the housing is fluidly coupled to the fluid chamber in the open proximal end section of the housing.

21. The device according to claim 6, wherein said distal end section of the housing is an open cylinder and is closed by the end fluid chamber therein mounted within and closing one end of the cylinder.

22. The device according to claim 21, wherein said end fluid chamber closing the open end of the cylinder includes a rigid element mounted within one end of the cylinder and enclosed by the membrane defining said end fluid chamber.

23. The device according to claim 22, wherein said rigid element is formed with holes therethrough permitting free flow of fluid within said end chamber with respect to both sides of the rigid element.

24. The device according to claim 23, wherein said rigid element is formed with a concave surface for receiving the distal tip of the patient'"'"'s finger.

25. The device according to claim 21, wherein said end fluid chamber closing the end of said open cylinder is open to the atmosphere at a front thereof to provide relatively constant pressure over a wide range of volume changes in accordance with the Laplace effect.

26. The device according to claim 1, wherein said pressurizing means applies a static pressure field of sufficient magnitude such that a heartward-most compartment of said pressure field acts as a venous tourniquet to prevent venous pooling, and retrograde venous blood flow or shockwave propagation into the more distal end of the body part.

27. The device according to claim 1, wherein said proximal end section includes a sponge cushion.

28. The device according to claim 1, wherein said sensor includes an optical sensor at an underside of said middle housing section, and another optical sensor at an upper side of said proximal end section.

29. The device according to claim 1, wherein said housing sections further include air vents between said sections venting an interior of the housing to atmosphere.

30. The device according to claim 1, wherein said housing sections are of a total length to cover two phalanges of a patient'"'"'s finger.

31. The device according to claim 1, wherein said housing sections are of a total length of approximately 50 mm.