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:
Aug. 20, 1991
Filed:
May. 12, 1989
Joseph M Schmitt, Rockville, MD (US);
Richard L Webber, Birmingham, AL (US);
Elijah C Walker, Silver Spring, MD (US);
The United States of America, Washington, DC (US);
Abstract
A non-invasive device which determines the pulp oxygenation level of a tooth and the vitality of a tooth using multiple-wavelength optical plethysmography. A sensor is shaped to be mounted on a tooth and circuitry for processing a signal from the sensor and supplied from a photosenstive diode is used. The photosensitive diode in the sensor detects light scattered from the tooth which was emitted from red, green, and infrared LEDs. An electrocardiogram (ECG) monitor is provided so as to produce improved detection reliability by synchronous averaging using the occurrence of the R-wave of the ECG as a time marker. Using this approach, a threshold-of-detection criterion can be established based on an average computed over a period to achieve a desired signal-to-noise ratio.