Fetal heart monitoring
US8579820B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 2009 |
| Grant date | Nov 12, 2013 |
| Priority date | — |
| Expiry date | Apr 20, 2030 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B8/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A transmit amplifier (12) drives an ultrasound transducer (11) to emit a pulse, and a receive amplifier (13) amplifies the echo signal detected by the transducer. The receive amplifier's gate opens a fixed delay after the end of the transmit pulse, and a demodulator (14) multiplies the received signal by the local oscillator signal. A low-pass filter removes the sum of the frequencies and passes the difference of the frequencies (the received signal's Doppler frequency) to be digitized by an ADC. ADC readings are made for each of several range bins in intervals during the receive gate-open interval. One or two of the Doppler audio signals will contain the signal from the fetal heart. When a periodic signal is found, its rate is tested to see if it lies within or outside the typical range of a fetal heart.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.