Detection of pulse in oral mucosa and dental pulp by means of optical reflection method.

This paper describes a new system in which optical reflectance is used to test the pulse and vitality of oral mucosa or dental pulp. Radiation at red (660 nm) and near infra-red (850 nm) wavelengths are directed through a thin probe. The beam is directed into tissue and reflected back. Plethysmography is used to measure the pulse rate from the right forefinger. Reflected radiation is related to plethysmogram using a computer. Preliminary findings relating to the lips and gingiva in 9 healthy volunteers were promising. Preliminary tests showed that vital and nonvital pulps reflected the radiation differently. Pulpal pulse did not always correspond to plethysmogram from the right forefinger.