Continuous wave transmission/reception type ultrasonic imaging device and ultrasonic probe
US6261232A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2000 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Mar 30, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/8906
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A high frequency continuous wave capable of achieving sufficient lateral resolution is produced by a wave transmitting device (20) to constitute a transmitted ultrasonic wave. A frequency of the continuous wave is alternated in a rectangular wave manner by a frequency modulator (15) so as to be frequency-modulated. An alternating time period of the frequency modulation is set to such time two times longer than such delay time which is defined from a time instant when a signal voltage is applied to a piezoelectric transducer element (1) up to another time instant when an ultrasonic wave originated from the piezoelectric transducer is reflected from a focal point 5 and then is reached to the piezoelectric transducer element. In a delay circuit (35), a delay equal to the delay time is applied to the transmitted ultrasonic wave so as to be used as a reference signal. A mixture signal produced by mixing the transmitted ultrasonic wave with the received ultrasonic wave is lock-in-detected (55), so that a reflection signal reflected from the checking object is selectively detected. As a result of increasing a total wave number of transmitted/received waves per unit time, since the continu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.