Medical sensor with amplitude independent output
AssigneeMallinckrodt Inc.
InventorsAdnan I. Merchant, Michael Bernstein
Life of this patent
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Abstract
The present invention provides a medical sensor for detecting a blood characteristic. The sensor includes a transducer for producing an analog signal related to the blood characteristic. The analog signal is converted into a transmission signal which is in amplitude-independent form for transmission to a remote analyzer. In one embodiment, a current-to-frequency converter converts a signal from a pulse oximeter sensor into a frequency signal which can be transmitted over a transmission line to a remote pulse oximeter.
Claims7
A medical diagnostic apparatus for detecting a blood characteristic, comprising:
- a radiation emitter for directing radiation into a patient, the radiation having an intensity, the intensity of at least one wavelength component of said radiation being modified by interaction with blood having said blood characteristic to produce a modified intensity radiation signal;
- a photodetector mounted to receive said modified intensity radiation signal;
- a converter connected to said photodetector, said converter generating a converted signal in response to the detected intensity of said modified intensity radiation signal, said converted signal having said detected intensity encoded in one of a frequency and a digital component of said converted signal, eliminating the encoding of said intensity signal as an electrical signal level;
- and
- an output, coupled to said converter, for transmitting said converted signal to a remote signal processing unit.
A method for detecting a blood characteristic, comprising:
- directing radiation into a patient, the radiation having an intensity, the intensity of at least one wavelength component of said radiation being modified by interaction with blood having said blood characteristic to produce a modified intensity radiation signal;
- receiving said modified intensity radiation signal;
- generating a converted signal in response to the detected intensity of said modified intensity radiation signal, said converted signal having said detected intensity encoded in one of a frequency and a digital component of said converted signal, eliminating the encoding of said intensity signal as an electrical signal level;
- and
- transmitting said converted signal to a remote signal processing unit.
A medical diagnostic system for detecting a blood characteristic, comprising:
- a radiation emitter for directing radiation into a patient, the radiation having an intensity, the intensity of at least one wavelength component of said radiation being modified by interaction with blood having said blood characteristic to produce a modified intensity radiation signal;
- a photodetector mounted to receive said modified intensity radiation signal;
- a converter connected to said photodetector, said converter generating a converted signal in response to the detected intensity of said modified intensity radiation signal, said converted signal having said detected intensity encoded in one of a frequency and a digital component of said converted signal, and eliminating the encoding of said intensity signal as an electrical signal level;
- and
- an analyzer system electromagnetically coupled to said converter for receiving and processing said converted signal to determine said blood characteristic.
Dependencies are inferred from the claim text.