Calibration methods and apparatus for plethysmographic measurement chambers
AssigneeLife Measurement, Inc.
InventorPhilip T. Dempster
Life of this patent
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Abstract
Methods and apparatus for calibrating volume measurement in a plethysmographic chamber are described. The present invention involves the use of a calibration volume chamber of known volume coupled to a plethysmographic measurement chamber in a plethysmographic measurement system for determining body composition, wherein a computer system calibrates the measurement system prior to conducting a volume measurement of a test subject, by measuring the chamber volume before and after opening an electronically controlled valve that connects the controlled calibration volume to the plethysmographic chamber, and comparing the measured chamber volumes based on the known reference volume.
Claims62
A method for calibrating a plethysmographic measurement system, the method comprising:
- (a) measuring the combined volume of a plethysmographic measurement chamber and a known calibration volume coupled to said chamber by an opening to obtain a baseline volume measurement;
- (b) sealing off said known volume from said chamber with an electronically controlled valve coupled to said opening;
- (c) measuring the volume of said measurement chamber sealed off from said reference volume to obtain a comparison volume measurement;
- (d) calibrating the plethysmographic measurement system based on the known calibration volume and a comparison of said baseline volume measurement and said comparison volume measurement.
A method for calibrating a plethysmographic measurement system, the method comprising:
- (a) measuring the volume of a plethysmographic measurement chamber to obtain a baseline volume measurement, wherein an opening coupling said measurement chamber to a known calibrated volume has been sealed with an electronically controlled valve;
- (b) unsealing the opening coupling said known volume to said measurement chamber with said electronically controlled valve;
- (c) measuring the combined volume of the measurement chamber and the known calibration volume coupled to said chamber by said opening to obtain a comparison volume measurement;
- (d) calibrating the plethysmographic measurement system based on the known calibration volume and a comparison of said baseline volume measurement and said comparison volume measurement.
A calibration system for calibrating a plethysmographic measurement system, the calibration system comprising:
- a computer;
- a calibration volume chamber of known volume, including an opening coupling said calibration volume chamber to a plethysmographic measurement chamber;
- an electronically controlled valve responsive to said signals from said computer, for sealing and unsealing said opening;
- wherein said computer initializes a calibration sequence prior to conducting a plethysmographic measurement of a test subject.
The calibration system of claim 42, wherein the valve actuation assembly further comprises:
- a pneumatic device wherein the action of said pneumatic device causes said valve to open or close.
A plethysmographic measurement system for conducting body composition measurements, comprising:
- a plethysmographic measurement chamber;
- measurement components, for measuring the volume of said test subject;
- a calibration volume chamber, coupled to said measurement chamber by an opening;
- an electronically controlled valve for sealing and unsealing said opening;
- a computer for operating said measurement system;
- wherein said computer initiates and runs a calibration sequence using said calibration volume and said valve, without intervention by a medical technician
Dependencies are inferred from the claim text.