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US 2001/0020128 A1Published application
Ultrasonic densitometer with pre-inflated fluid coupling membranes
AssigneeLunar Corporation
InventorsRichard F. Morris, Steven Morris, David R. Strait
Life of this patent
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Abstract
A contained water ultrasonic densitometer employs pre-inflated bladders holding coupling fluid about ultrasonic transducers. The bladders in a relaxed state define a cavity smaller than the human heel so that when the heel is inserted, the bladders conform to the heel in a wiping action removing entrapped air.
Claims32
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 more elements
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.
4 more elements
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.
2 more elements
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.
2 more elements
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.
3 more elements
Dependencies are inferred from the claim text.