The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 2014
Filed:
Apr. 11, 2007
John Crowe, University Park, GB;
Mark Grubb, University Park, GB;
Barrie Hayes-gill, University Park, GB;
Nicholas Miles, University Park, GB;
John Crowe, University Park, GB;
Mark Grubb, University Park, GB;
Barrie Hayes-Gill, University Park, GB;
Nicholas Miles, University Park, GB;
The University of Nottingham, , GB;
Abstract
A photoplethysmograph device includes a light source for illuminating a target object. A modulator drives the light source such that the output intensity varies as a function of a modulation signal at a modulation frequency. A detector receives light from the target object and generates an electrical output as a function of the intensity of received light. A demodulator with a local oscillator receives the detector output and produces a demodulated output, insensitive to any phase difference between the modulation signal and the oscillator, indicative of blood volume as a function of time and/or blood composition. A number of demodulators may be provided to derive signals from multiple light sources of different wavelengths, or from an array of detectors. The plethysmograph may operate in a transmission mode or a reflectance mode. When in a reflectance mode, the device may use the green part of the optical spectrum and may use polarizing filters.