DAQ Application: Ultrasonic Imaging | GaGe

Medical Application Case Study - Data Acquisition Imaging / Ultrasound

Medical Applications

Ultrasonic Imaging

Customer Case

The customer is digitizing signals returned from an ultrasonic transducer used in the study of cardiac phenomena.

At the moment, a 5 MHz transducer is being used, but the customer wants to upgrade to a 10 MHz transducer in the near future. This transducer will give him better spacial resolution.

The customer needs one channel of very fast (100 MSPS), preferably 12-bit A/D conversion which is controlled by an external trigger signal. Bandwidth of the analog front-end of the A/D card or system must be very flat up to 15 or 20 MHz.

The application is to capture 128 acquisitions with a trigger repeat frequency of 10 KHz, i.e. 100 us between triggers, without missing any triggers.

For each trigger, 8192 points need to be captured at 100 MSPS sample rate. Once the acquisition is complete, the customer wants to bring this data into his LabVIEW, which already exists. His program displays each of the 128 records, captured one by one, and then saves them to disk for later analysis.

Finally, the customer wants to do as little programming as possible.

GaGe Case Solution

For the 5 MHz transducer, the customer has been using the Tektronix model 720 digitizer with a GPIB card. He is able to sample at 50 MSPS with on-board memory of 1 Megabyte and get just enough data for his application. This memory cannot be extended because the manufacturer has discontinued the product line and does not provide a memory upgrade, even to existing customers.

The 1 MB memory limit means that if the customer changes the sample rate to 100 MSPS (to better digitize the 10 MHz transducer signal), he will not be left with enough memory to store all the data he wants.

Therefore, this methodology is unacceptable if state of the art transducers are to be used.

The solution for this customer is to use a CompuScope 8012A - 4M high speed A/D board along with the LabVIEW for Windows driver from GaGe.

The CompuScope 8012 will be set up in Multiple Record mode, which allows data from successive triggers to be stacked in the on-board memory without any software intervention, i.e. under hardware control. This will guarantee that no triggers are missed.

With 4 Megasamples of available memory, the customer can store up to 512 successive acquisitions of 8192 points each with a guarantee of no missed triggers. This is more than enough for this and any future applications.

Once the on-board memory buffer is filled up, the acquisition will stop and the PC will be allowed access to the data. The customer's LabVIEW program can then access the data and display it on the screen or save it to disk. This will work close to 10 times faster because the customer does not have to transfer data over GPIB (GaGe's transfer rate is 10 to 15 times faster than GPIB).

All this can be done by including GaGe's powerful LabVIEW driver into the customer's existing program (VI). The VI diagram (LabVIEW's equivalent to source code), which shows how to use CompuScope 8012 in Multiple Record Mode, is supplied with the drivers.

GaGe Case Recommended Products

Medical Application Request

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.