公开(公告)号：US3602213A

公开(公告)日：1971-08-31

申请号：US3602213D

申请日：1968-02-13

Applicant: PROTOTYPES INC

Inventor： HOWELL WILLIAM L ,  LEAF WILLIAM B

IPC: A61B5/024 ,  A61B5/026 ,  A61B5/02

CPC classification number: A61B5/0261 ,  A61B5/02416

Abstract: A method and apparatus for detecting occlusions in one of the internal carotid arteries by the differential sensing of epidermal blood flow in the supraorbital areas. A pair of photoelectric transducers that sense the relative absorption or reflection of light by the blood at the surface of the skin as an indication of blood flow are positioned over the supraorbital notches above the eyes. The blood contributions to these areas from the superficial temporal, angular and occipital arteries are eliminated by compression, leaving the internal carotids as the only suppliers. The sensor outputs are then compared, and any unbalance indicates an occlusion in one of the carotid arteries. Same may also be detected by momentarily compressing the supraorbital areas as well, and then comparing the refilling curves produced by the sensors. The location of the occlusion above or below the carotid bifurcation may be determined by removing all compression and repositioning the transducers to sense the external carotid flows.