Measurement of body fat using ultrasound methods and devices

• US 5,941,825 A
• Filed: 10/21/1996
• Issued: 08/24/1999
• Est. Priority Date: 10/21/1996
• Status: Expired due to Fees

• Current Assignee: Philipp Lang
• Original Assignee: Philipp Lang
• Inventors: Grampp, Stephan, Lang, Philipp, Mendlein, John D.
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US08/731,821
• Time in Patent Office: 1,037 Days
• Field of Search: 600/437, 600/442, 600/443, 600/449, 600/587
• US Class Current: 600/449
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/4272 involving the acoustic interface between the transducer and the tissue

Abstract

The present invention provides for a method of measuring layer thickness in an object comprising 1) transmitting at least a first and a second ultrasound pulse from at least a first and second position, 2) measuring at least one reflective distance from the first pulse and at least one reflective distance from the second pulse, wherein the reflective distance is from the object'"'"'s external surface (or probe) to a reflective interface of at least one layer, 3) selecting the reflective distance having the shortest reflective distance to indicate the distance between the external surface (or probe surface) and the reflective interface of at least one layer, wherein the selecting of the shortest reflective distance reduces ultrasound transmission parallax of the first and second pulses relative to a plane in the object. Other ultrasound methods and devices are disclosed for measuring layer thickness in patients or subjects in need thereof, particularly subjects in need of fat or muscle measurement.

Claims

1. A method of measuring body fat, comprising:

transmitting into a body at least a first and a second ultrasound pulse from at least a first and second position,

measuring at least one reflective distance from said first pulse and at least one reflective distance from said second pulse, wherein said at least one reflective distance is from the skin to

     1) a fat/muscle or

     2) a fat/fascia interface, and

selecting said at least one reflective distance having the shortest distance to indicate the distance between the inner and outer border of subcutaneous fat tissue,

wherein said selecting of said at least one reflective distance corrects for an ultrasound transmission parallax of said first and second pulses relative to a plane in said subcutaneous fat tissue.

2. The method of claim 1, wherein at least one of said pulses is transmitted substantially perpendicular to said plane.

3. The method of claim 1, wherein said transmitting step includes transmitting said first pulse with a first transmission angle with respect to said plane and transmitting said second pulse with a second transmission angle with respect to said plane, wherein there is a predetermined divergent angle between said first and second pulse or a convergent angle between said first and second pulse,

said measuring further comprises detecting said first pulse and second pulse with an ultrasound detector at said first and second transmission angles, and

wherein said predetermined divergent angle or said predetermined convergent angle improves the measurement of a shortest reflective distance compared to the measurement of a shortest reflective distance in the absence of said predetermined divergent or convergent angle.

4. The method of claim 3, wherein said body is a human body.

5. The method of claim 3, further comprising using a computational unit that corrects for non-orthogonal probe alignment with said tissue, wherein said computational unit permits computational determination of a shortest reflective distance.

6. The method of claim 3, wherein said transmitting step comprises transmitting at said predetermined divergent angle between a first position and second position and said first pulse has a centered first axis of transmission and said second pulse has a centered second axis of transmission, wherein said first and second axis do not converge.

7. The method of claim 1, wherein said transmitting step includes transmitting said first and second pulses from a first ultrasound generator and said first generator has at least a first and a second position, said first and second position are mechanically connected and guiding said generator from said first position to said second position with a mechanical connection.

8. The method of claim 7, further comprising using said mechanical connection with a mechanical motor to oscillate said generator at least once from said first to said second position.

9. The method of claim 8, wherein said mechanical motor provides a frame time from about 10 to 500 ms.

10. The method of claim 7, further comprising using said mechanical motor comprised of at least a first and second magnet to move said first ultrasound generator on a track, and said first ultrasound generator further comprises a magnetic source or material that magnetically communicates with said at least one first or second magnet to change said transmission angle.

11. The method of claim 1, wherein said transmitting of said first pulse is from a first ultrasound generator and said transmitting of said second pulse is from a second ultrasound generator and said first and second ultrasound generators are permanently fixed in a first and a second position.

12. The method of claim 11, wherein said transmitting from said first and second ultrasound generators is with different transmission frequencies.

13. The method of claim 12, wherein said first and second ultrasound generators are both adapted to generate B-scans.

14. The method of claim 12, wherein said first and second pulses have a set frequency between about 0.5 and 5 MHz.

15. The method of claim 14, wherein said transmitting step comprises transmitting said first and second pulses at a first and a second transmission angle, respectively, with about a 10 degree difference in said first and second transmission angles.

16. The method of claim 15, wherein said first and second pulses have a set frequency between about 1 and 3 MHz.

17. The method of claim 11, wherein said first ultrasound generator is adapted to generate an A-scan.

18. The method of claim 11, wherein said transmitting step comprises transmitting with said first ultrasound generator at two or more frequencies between about 0.5 and 5 MHz and transmitting with said second ultrasound generator at two or more frequencies between about 0.5 and 5 MHz.

19. A compact ultrasound system for interrogating an object, comprising:

at least a first and a second ultrasound source that are adapted to be in contact with an object,

said first ultrasound source provides a first pulse with a first transmission angle with respect to a physical plane of said object and said second ultrasound source provides a second pulse with a second transmission angle with respect to said physical plane,

said first ultrasound source has a first detector that receives an alpha ultrasound signal and said second ultrasound source has a second detector that receives a beta ultrasound signal, and a computational unit that computes a shortest reflective distance within said object using signals from said first transmission angle and said second transmission angle.

20. The ultrasound system of claim 19, wherein said system is in a handheld housing.

21. The ultrasound system of claim 20, wherein said first and second ultrasound sources are at least one linear array of ultrasound crystals that are adapted to be sequentially timed.

22. The ultrasound system of claim 19, wherein said object comprises human fat and said shortest reflective distance is in a tissue with 1) a skin/fat interface and 2) a fat/muscle or fat/fascia interface.

23. The ultrasound system of claim 19, wherein said second ultrasound source transmits said beta ultrasound signal.

24. The ultrasound system of claim 19, wherein said first and second ultrasound source are from a first ultrasound generator and said first ultrasound generator has at least a first and a second position, said first and second position are mechanically connected and said first ultrasound generator is guided from said first position to said second position with a mechanical connection.

25. The ultrasound system of claim 24, wherein said mechanical connection uses a mechanical motor to oscillate said first ultrasound generator at least once from said first to said second position and said mechanical motor is at least a first and second magnet to move said first ultrasound generator on a track, and said first ultrasound generator further comprises a magnetic source or material that magnetically communicates with said first or second magnet to change a transmission angle.

26. The ultrasound system of claim 19, wherein said first ultrasound source is a first ultrasound generator and said second ultrasound source is a second ultrasound generator and said first and second ultrasound generators are permanently fixed in a first and a second position.

27. The ultrasound system of claim 26, wherein said first and second ultrasound sources have different transmission frequencies and are also ultrasound detectors.

28. The ultrasound system of claim 27, wherein said first and second sources have a divergent angle of about 10 to 20 degrees.

29. The ultrasound system of claim 19, wherein said first and second sources have a convergent angle of about 5 to 25 degrees.

30. The ultrasound system of claim 19, wherein said first source and said second source comprise at least one linear array of ultrasound crystals and said linear array transmits ultrasound signals in response to a trigger pulse that fires each crystal in said linear array.

31. A computer program embodied on a computer readable medium and comprising instructions for calculating tissue layer based on shortest reflective distance measurement of tissue thickness from ultrasound measurements in a body.

32. The computer program embodied on a computer readable medium of claim 31, wherein said computer readable medium is a chip.

33. The computer program embodied on a computer readable medium of claim 31, wherein said computer readable medium includes instructions for transmitting signals from an ultrasound probe at different transmission angles to determine a shortest reflective distance.

34. A compact ultrasound system, comprising:

at least a first ultrasound source adapted to transmit an ultrasound pulse at different transmission angles to a plane of a human,

at least a first ultrasound detector,

a computational unit for processing signals recorded at different transmission angles from said at least a first ultrasound detector and calculating or generating the shortest reflective distance using said signals for determining the presence of a fat layer.

35. The ultrasound system of claim 34, wherein said at least first ultrasound detector comprises at least two ultrasound transducers positioned at two different angles.

36. The ultrasound system of claim 34, wherein said computational unit comprises a program that permits the calculation of a fat layer thickness.

37. The ultrasound system of claim 34, wherein said first ultrasound source transmits an ultrasound pulse with an acoustic mirror to generate at least one additional axis of transmission.

38. The ultrasound system of claim 34, wherein said at least a first ultrasound source and detector form an ultrasound probe and said ultrasound probe and computational unit are encased in a housing and said housing is handheld.

39. The ultrasound system of claim 38, wherein said ultrasound probe is adapted for A-scan.