This customer's application involves capturing ultrasound echoes from a medical imaging system, to be used in bedside monitors, defibrillators, intervascular ultrasound, ECG, etc.
The live imaging rate is 30 frames per second (fps). Each image frame depicts a full 360-degree circular section. A frame is 240 echoes, so the pulse repeat frequency (PRF) is 7200 Hz, or one echo every 140 us.
The customer anticipates signals at 50 MHz with a 50% bandwidth (the passband must extend to at least 75 MHz). The echo duration is 15 us; the signal size is roughly +/- 70 mV.
To support this application, the system would have to capture echoes from 60 consecutive triggers, ignore the next 180 triggers, then capture the next 60 triggers, etc. The customer predicts the need to construct an external interface to block the unwanted triggers. Available signals include triggers for frame-start and line-start, as well as the 8 bit line number.
The customer will be working with LabVIEW under Windows.
Data Rate Considerations:
CompuScope 8500 is an ideal solution for this customer.
The CompuScope 8500 has a bandwidth of 250 MHz, which is far more than the 75 MHz the customer needs. As such, bandwidth is not an issue.
As the maximum sample rate of the CompuScope 8500 is 500 MSPS, sampling at 250 MSPS is not a problem. In fact, the Signal to Noise Ratio at 250 MSPS will be even better.
Finally, the customer must capture 4096 points in 15 us, leaving 125 us to offload the data to the PC RAM (as the Pulse Repeat Interval is 140 us). At a data transfer rate of 100 MB/s, the customer will be able to accomplish that in approximately 40 us. Even after allowing another 20 us of overhead for non-optimized code, the customer still has 65 us left over.
The timing diagram for this application is shown below:
We encourage you to contact us and discuss your medical application in more detail with our engineering team. GaGe can provide tailored custom data acquisition hardware and software solutions to meet specific application requirements.