Method and apparatus for measuring volume fluid flow
US4807636A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1986 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Sep 9, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/8984
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system is provided for measuring volume blood flow using non-invasive ultrasonic Doppler techniques. This system includes a probe assembly including a transducer having an inner transducer element and a concentric outer transducer element. A wide beam of ultrasonic energy is transmitted using the transducer and is received by a lumen area. Reflected untrasonic energy is returned to the transducer. Both the outer and inner transducer elements of the transducer are used to generate signals representative of a wide beam and a narrow beam. These generated signals include Doppler information. The signals representative of the wide beam are processed simultaneously with signals representative of the narrow beam to produce Doppler power spectrums associated with the wide and narrow beams. Phase quadrature signals are also generated for use in determining the direction of blood flow at the insonified lumen area. An AGC circuit is utilized for controlled amplitude fluctuations in the wide beam Doppler power spectrum. The control signal is also applied to the narrow beam power spectrum to avoid the introduction of inaccuracies in the subsequent computation of the ratio of wide beam power t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.