This customer is building a system to be used as a test station for examining human tissue for disease. Diseased organs differ from healthy organs in ways that can be measured via the echoes of ultrasound transmissions which are passed through the tissues. The customer's system will build a 3D image of the tissue under examination.
In order to obtain a clear ultrasound image of the object being studied, the successive data captures have to be aligned to eliminate a distorted image. Jitter which would result from an asynchronous triggering is not acceptable.
The other major concern is the time delay between the emission of the ultrasound pulse and the gathering of the reflected signals. This factor is dependent on the distance between the emitter and the object under study. The size of the test chamber also affects the signal time delay. This means delay times vary between a few microseconds and 300 microseconds.
The current system is making use of a 7 to 8 MHz emitter, therefore the data acquisition card must have a sampling rate in the range of 40 to 50 MSPS. There has to be allowance for higher frequency transmitters which are now being developed. Also, the system has to have the flexibility of a secondary input channel which will be used to determine the phase shift of the signal. The actual number of samples taken is determined by the application. A single point may be enough, or 200 to 300 microseconds of data (approximately 15 Ksamples) may have to be collected.
The system will incorporate a motor controller which steps the transmitter to take images of the subject in a three-dimensional grid. These images are captured and stacked in the PC Host memory and from the total data, the imaged object is displayed on the PC monitor.
The customer will use CompuScope 8012A/PCI for this application, along with a special Sync Card Modification provided by GaGe.
This additional circuit card will synchronize the triggering of the ultrasound transmitter and the "Delay Control Unit" supplied by the customer. The "Sync Card" will receive the clock signal from the CompuScope 8012A/PCI in order to synchronize the Trigger Out signals with the sample rate clock. The sample rate clock is the timing used by the customer's Delay Control Unit to time the signal sent to the CompuScope 8012A/PCI external trigger, thus ensuring the synchronization and alignment of the samples.
By selecting the CompuScope 8012A for PCI bus, the customer has allowed for future improvements in transmitters. The 100 MSPS sampling rate of the card allows transmitter frequencies up to 25 MHz.
The system can be completely integrated with the motor control card which is run by LabVIEW, since the CompuScope 8012A/PCI supports LabVIEW for Windows.
The maximum PRF (Pulse Repeat Frequency) is obtained since the CompuScope 8012A/PCI is using the PCI bus to achieve data transfer rates of 50 MSPS (100 Mbytes/sec).
The optional External Clock Upgrade has given this system another dimension of flexibility allowing for future synchronization with auxiliary equipment.
Since this system will require two free ISA slots and one free PCI slot, GaGe also recommends the GaGePC/PCI 686 for a turnkey system.
A representation of the system solution is illustrated 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.