Closed Loop Pacing Control Research
Development of research apparatus to conduct animal studies for new blood Flow-Sensor.
Client Concept: In order to discover new ways of doing research for an impedance sensor (a way to measure the flow of blood through the heart), the client wanted to develop a new computer system that would act as a pacemaker, but would have the flexibility of adjusting the control of the heart rate as their experiments were in progress. They had chosen a hardware platform (DSpace) and a high-level programming interface (Matlab).
Challenge: To customize and create a new graphical functionality in Matlab that would work with the DSpace hardware, and ultimately take real-time information from their impedance sensor and control the pacemaker. Additionally, a graphical user interface was needed for use in configuring and controlling the system while experiments were underway.
Since the experiments were to be done on live animals, both under anesthesia and awake on a treadmill, a high degree of reliability and control had to be maintained while allowing easy and quick reconfiguration of the computer system. The client also wanted a way of "replaying" the raw data collected during animal experiments back through the computer system with different ideas implemented for the system configuration. This would allow maximizing use of the data collected without having rerun the experiments.
SterlingTech Solution:
By connecting the DSpace hardware to their custom hardware, our team wrote software to setup and collect data from the sensor. We then implemented a pacemaker that could be configured as the client desired, in real-time, during the experiments. In addition we created custom Matlab blocks with their new experimental algorithms programmed inside, done in a way that could be configured at runtime. With the system at this level of readiness, we began dog studies; first with anesthetized animals, then as the custom algorithms matured, with live dogs on treadmills.
While the studies were ongoing, we began work on a "replay" program. This program used an off-the-shelf data capture program the client was already using to open existing data files, ran the data back through the DSpace system, and captured the new output data. This approach minimized the amount of custom software to be developed in order to meet their needs, and allowed reuse of the same system used in clinical studies to produce new data. Therefore, there was no chance of inconsistency from using a different system with possible slight differences.
SterlingTech met the client's goals by:
- Using their new sensor with their selection of hardware (DSpace)
- Providing a flexible (graphical) way of setting up the system and configuring it at runtime
- Providing a way of reusing valuable data from the studies with new algorithms to be as humane as possible in their use of animals
- Conferring with the client on possible new algorithms for utilizing their sensor, and implementing those algorithms
- Having the system ready for multiple studies over time of engagement
- Supporting their effort to produce data for a patent application which was issued
Underlying Technology: included C and C++ for Windows/PC; C and Assembly for the TI DSP (TMS320C6X)