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:
Jun. 10, 1986
Filed:
Sep. 05, 1984
Yoshihiro Hayakawa, Sagamihara, JP;
Yasuhiro Nakamura, Tokyo, JP;
Ryobun Tachita, Kawasaki, JP;
Tsutomu Yano, Kawasaki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An ultrasonic wave blood flow meter comprises a probe which sends to and receives an ultrasonic wave reflected with Doppler effect from the blood flow, a detecting circuit for converting a frequency variation of the received reflected wave into a first signal whose amplitude varies with frequency and a second signal whose amplitude is kept constant, and first and second effective-value detecting circuits for obtaining d.c. components of the first and second signals. A level discrimination circuit is further provided for discriminating the level of the d.c. component detected by the second effective-value detecting circuit. First and second sensitivity-variable amplifiers are also provided for varying their sensitivities in accordance with the result of the level discrimination circuit. A dividing circuit divides the d.c. component amplified by the first sensitivity-variable amplifier by the d.c. component amplified by the second sensitivity-variable amplifier, and a voltage hold circuit holds the output of the dividing circuit in accordance with the discrimination result of the level discrimination circuit.