Claims
- 1. An ultrasonic densitometer comprising:
a pre-inflated acoustic coupling system presenting bladder surfaces opposed along an ultrasonic propagation axis and, prior to insertion of a human heel, separated by a distance smaller than the width of a human heel; a coupling material contained within the bladder surfaces; a first ultrasonic transducer communicating with the coupling material and positioned to direct ultrasonic signals through the coupling material along the ultrasonic propagation axis; circuitry for excitation of the first ultrasonic transducer to measure propagation of ultrasonic signals; wherein the bladder surfaces are shaped to remain aligned with the propagation axis and in sliding contract with a human heel, when the human heel is inserted between the bladder surfaces across the ultrasonic propagation axis.
- 2. The ultrasonic densitometer of claim 1 wherein the bladder surfaces are substantially hemispherical.
- 3. The ultrasonic densitometer of claim 1 wherein the first and second bladder surfaces are attached to a fixed support surface and wherein the ultrasonic transducer is fixed with respect to the fixed support surface.
- 4. The ultrasonic densitometer of claim 1 including further a second ultrasonic transducer opposed to the first ultrasonic transducer having fixed separation with respect to the first ultrasonic transducer.
- 5. The ultrasonic densitometer of claim 1 further including a pump for pre-inflating the bladder system with the coupling material prior to use.
- 6. The ultrasonic densitometer of claim 1 further including a valve for releasing material from within the bladder system.
- 7. The ultrasonic densitometer of claim 1 wherein the bladders surfaces are comprised of an elastomeric membrane having a surface coating of ultrasonic coupling gel.
- 8. The ultrasonic densitometer of claim 1 including a foot support positioned beneath the opposed bladder surfaces with respect to a direction of insertion of the human heel, wherein the foot support includes at least one sensor indicating seating of a human foot against the foot support.
- 9. The ultrasonic densitometer of claim 8 wherein the sensor is a force sensor indicating a force selected from the group consisting of downward force normal to the sole of a human foot seated against the foot support and backward force parallel the sole of a human foot seated against the foot support.
- 10. The ultrasonic densitometer of claim 1 wherein the first ultrasonic transducer is selected from the group consisting of: a single ultrasonic transducer element and an array of ultrasonic transducer elements.
- 11. The ultrasonic densitometer of claim 1 including a second ultrasonic transducer opposed to the first ultrasonic transducer, wherein the second ultrasonic transducer is selected from the group consisting of: a single ultrasonic transducer element and an array of ultrasonic transducer elements.
- 12. An ultrasonic densitometer comprising:
a presence sensor providing a signal indicating the presence of a patient's foot at a measurement location; at least one bladder positioned with respect to the measurement location to present a bladder surface adjacent to a patient's foot located in the measurement location; a pump communicating with the bladder to inflate the bladder with a coupling material contained behind the bladder surface; circuitry communicating with the pump and the sensing means to produce an error condition when the pump inflates the bladder while a foot is positioned measurement location; a first ultrasonic transducer coupled to the coupling material and positioned to direct ultrasonic signals through the coupling material toward the measurement location along the ultrasonic propagation axis; circuitry for excitation of the first ultrasonic transducer for measurement of propagation of ultrasonic signals; whereby the patient's foot must be slid across the pre-inflated bladder to avoid an error condition.
- 13. The ultrasonic densitometer of claim 12 wherein the error condition is a display to the operator.
- 14. The ultrasonic densitometer of claim 12 wherein the sensing means is a force sensor communicating with a foot support to sense the pressure of the patient's foot against the foot support.
- 15. The ultrasonic densitometer of claim 12 wherein sensing means is a pressure sensor communicating with the bladder to measure excess pressure therein.
- 16. The ultrasonic densitometer of claim 12 wherein the first ultrasonic transducer is selected from the group consisting of: a single ultrasonic transducer element and an array of ultrasonic transducer elements.
- 17. The ultrasonic densitometer of claim 12 including a second ultrasonic transducer opposed to the first ultrasonic transducer, wherein the second ultrasonic transducer is selected from the group consisting of: a single ultrasonic transducer element and an array of ultrasonic transducer elements.
- 18. A method of making ultrasonic measurements of a human heel comprising the steps of:
(a) supporting a first and second bladder surface to define therebetween a distance smaller than the human heel, the first and second bladder surfaces containing a coupling material; (b) directing at least one ultrasonic transducer through the coupling material along an ultrasonic propagation axis between the first and second bladder surfaces; (c) inserting a human heel across the propagation axis between the first and second bladder surfaces causing deformation of the bladder surfaces to enlarge the cavity to accept the human heel; and (d) exciting the ultrasonic transducer to perform a measurement of the human heel.
- 19. The method claim 18 including the step of applying an ultrasonic coupling gel to the bladder surfaces prior to insertion of the foot at step (c).
- 20. The method of claim 18 including the step of pre-inflating the first and second bladder surfaces with coupling material prior to step (a).
- 21. The method of claim 20 including the step of sensing the presence of a human heel between the first and second bladder surfaces prior to pre-inflation of the bladders and when a human heel is in place in the cavity prior to pre-inflation creating an error condition.
- 22. The method of claim 20 including the step of releasing coupling material from within the first and second bladder surfaces after step (d).
- 23. An ultrasonic densitometer comprising:
a patient support; an ultrasonic transducer system including at least one ultrasonic transducer positioned with respect to the patient support to direct ultrasonic signals through a patient positioned by the patient support and to receive the ultrasonic signals after attenuation by the patient; a coupling volume positioned between the ultrasonic transducer and the patient, the coupling volume alternatively occupied by a first coupling material having a first known sound propagation property and a second coupling material having a second known sound propagation property different from the first sound propagation property; and a computer communicating with the ultrasonic transducer system to measure a first ultrasound propagation through both the patient and the first coupling material and a second ultrasonic propagation through both the patient and the second coupling material, the computer executing a stored program to compare the first and second ultrasonic propagations to produce an indication of bone quality of bone within the patient.
- 24. The ultrasonic densitometer of claim 23 wherein the coupling volume holds a first and second overlapping flexible bladder alternately filled with liquid first and second coupling materials.
- 25. The ultrasonic densitometer of claim 23 wherein the first and second coupling materials have different sound attenuations.
- 26. The ultrasonic densitometer of claim 23 wherein the first and second coupling materials have different sound propagation speeds.
- 27. An ultrasonic densitometer for measuring bone in vivo comprising:
an ultrasonic transducer system including at least one ultrasonic transducer positioned with respect to the bone to direct ultrasonic signals through the bone and to receive the ultrasonic signals after attenuation by the bone; a computer communicating with the ultrasonic transducer system to:
(i) measure a series of ultrasound signals through the bone as a function of time; (ii) fit the measured series to a predetermined asymptotic curve; and (iii) output a measurement based on the asymptotic curve.
- 28. The ultrasonic densitometer of claim 27 herein the output is based on a portion of the asymptotic curve beyond the measured series.
- 29. The ultrasonic densitometer of claim 27 wherein the transducer array system includes two transducers opposed about the bone and wherein the ultrasonic transducer system alternates the direction of propagation of ultrasound through the bone between the two transducers.
- 30. The ultrasonic densitometer of claim 27 wherein the measure of the series of ultrasound signals is a measure of a speed of ultrasonic propagation.
- 31. The ultrasonic densitometer of claim 27 wherein the measure of the series of ultrasound signals is a measure of ultrasonic attenuation.
- 32. The ultrasonic densitometer of claim 27 wherein the measure of the series of ultrasound signals is a combination of measures of speed of ultrasonic propagation and ultrasonic attenuation.
Parent Case Info
[0001] This application claims the benefit of provisional application Ser. No. 60/080,158 filed Mar. 31, 1998 and is a continuation-in-part of U.S. patent application Ser. No. 09/094,073 filed Jun. 9, 1998 which is a continuation of U.S. patent application Ser. No. 08/466,494 filed Jun. 6, 1995, which is a continuation-in-part of U.S. patent application Ser. No. 08/397,027 filed Mar. 1, 1995, now U.S. Pat. No. 5,483,965 which is a continuation of U.S. patent application Ser. No. 08/72,799 filed Jun. 4, 1993, abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 07/895,494 filed Jun. 8, 1992, now U.S. Pat. No. 5,343,863 which is a continuation-in-part of U.S. patent application Ser. No. 07/772,982 filed Oct. 7, 1991, now U.S. Pat. No. 5,119,820, which is a continuation of U.S. patent application Ser. No. 07/343,170 filed Apr. 25, 1989 now U.S. Pat. No. 5,054,490, which is a continuation-in-part of Ser. No. 07/193,295 filed May 11, 1988, now U.S. Pat. No. 4,930,511.
Provisional Applications (1)
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Number |
Date |
Country |
|
60080158 |
Mar 1998 |
US |
Divisions (2)
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Number |
Date |
Country |
Parent |
09277481 |
Mar 1999 |
US |
Child |
09746269 |
Dec 2000 |
US |
Parent |
09094073 |
Jun 1998 |
US |
Child |
09746269 |
Dec 2000 |
US |
Continuations (2)
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Number |
Date |
Country |
Parent |
08072799 |
Jun 1993 |
US |
Child |
08397027 |
Mar 1995 |
US |
Parent |
07343170 |
Apr 1989 |
US |
Child |
07772982 |
Oct 1991 |
US |
Continuation in Parts (6)
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Number |
Date |
Country |
Parent |
08795025 |
Feb 1997 |
US |
Child |
09094073 |
Jun 1998 |
US |
Parent |
08466495 |
Jun 1995 |
US |
Child |
08795025 |
Feb 1997 |
US |
Parent |
08397027 |
Mar 1995 |
US |
Child |
08466495 |
Jun 1995 |
US |
Parent |
07895494 |
Jun 1992 |
US |
Child |
08072799 |
Jun 1993 |
US |
Parent |
07772982 |
Oct 1991 |
US |
Child |
07895494 |
Jun 1992 |
US |
Parent |
07193295 |
May 1988 |
US |
Child |
07343170 |
Apr 1989 |
US |