Non invasive blood analyte sensor

Claim 1

A device for non-invasive measurement of concentration of a specific analyte in arterial blood flowing in a patient's body part, which device comprises a first portion having a surface profile adapted to be held against said body part, a low-cost, self-focused, white light source of near infrared radiation mounted in a second portion associated with said first portion such that a wide band of white light optical radiation illuminates the body part and near infrared radiation is transmitted through or reflected from said body part to provide an absorption spectrum of said arterial blood, a third portion containing detection means located to receive radiation transmitted through or reflected from said body part, which detection means comprises a radiation collector to which is attached a bundle of optical fibers, each of which fibers has a distal end connected to one of at least two filters, including a first filter selective for a first radiation signal having a first wavelength identifiable with the specific analyte and a second filter selective for a second radiation signal having a second wavelength corresponding to a reference signal, said first and second signals being obtained from a pulsatile component of the absorption spectrum only, and a detector adapted to receive and process said first and second signals to provide a ratio representative of the desired concentration.

Claim 2

A device for non-invasive measurement of concentration of a specific analyte in arterial blood flowing in a patient's body part, which device comprises a first portion having a surface profile adapted to be held against said body part, a low-cost, self-focused, white light source of near infrared radiation mounted in a second portion associated with said first portion such that a wide band of white light optical radiation illuminates the body part and near infrared radiation is transmitted through or reflected from said body part to provide an absorption spectrum of said arterial blood, a third portion containing detection means located to receive radiation transmitted through or reflected from said body part, which detection means comprises a radiation collector to which is attached a bundle of optical fibers, each of which fibers has a distal end connected to one of at least two filters, including a first filter selective for a first radiation signal having a first wavelength identifiable with the specific analyte and a second filter selective for a second radiation signal having a second wavelength corresponding to a reference signal, said first and second signals being obtained from a pulsatile component of the absorption spectrum only, and a detector adapted to receive and process said first and second signals to provide a ratio representative of the desired concentration.

Claim 7

A method for measuring the concentration of a specific analyte in arterial blood flowing in a patient's body part, which comprises placing said body part against a device comprising a low-cost, self-focused, white light source of near infrared radiation and detection means comprising a radiation collector to which is attached a bundle of optical fibers, each of which fibers has a distal end connected to one of at least two filters and a detector, irradiating said body part with a wide band of white light optical radiation from said source to obtain a near infrared absorption spectrum of a pulsatile component of the arterial blood, filtering out of the pulsatile component of said spectrum a first wavelength signal identifiable with the specific analyte and a second wavelength signal corresponding to a reference signal and using the detector to process said first wavelength and second wavelength signals and provide a ratio representative of the concentration of the analyte.

Claim 8

A method for measuring the concentration of a specific analyte in arterial blood flowing in a patient's body part, which comprises placing said body part against a device comprising a low-cost, self-focused, white light source of near infrared radiation and detection means comprising a radiation collector to which is attached a bundle of optical fibers, each of which fibers has a distal end connected to one of at least two filters and a detector, irradiating said body part with a wide band of white light optical radiation from said source to obtain a near infrared absorption spectrum of a pulsatile component of the arterial blood, filtering out of the pulsatile component of said spectrum a first wavelength signal identifiable with the specific analyte and a second wavelength signal corresponding to a reference signal and using the detector to process said first wavelength and second wavelength signals and provide a ratio representative of the concentration of the analyte.