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:
Sep. 11, 1990
Filed:
Dec. 27, 1989
Applicant:
Inventors:
Hisashi Nishiyama, Tokyo, JP;
Kageyoshi Katakura, Tokyo, JP;
Shizuo Ishikawa, Kanagawa, JP;
Toshio Ogawa, Tokyo, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A61B / ;
U.S. Cl.
CPC ...
12866109 ; 7386125 ;
Abstract
A pulse doppler apparatus transmits a ultrasonic sound wave at transmission intervals T and T+Ts alternately and iteratively, detects the phase difference attributable to the doppler shift in the reflected sound wave signal at the interval T and the phase difference in the reflected signal at the interval T+Ts sequentially, detects the difference between both phase differences, and transforms the difference into a doppler frequency. The apparatus includes an MTI filter which exerts the same filtering characteristics on the reflected sound signals at both intervals T and T+Ts.