External Controller for Dog Bladder Fullness Monitor (DBFM)

Supervisors: Tim Perkins and Prof Nick Donaldson.

Student: BEIQIONG WANG

Like humans, pet dogs also occasionally sustain Spinal Cord Injury (SCI) due to accident or disease. The resulting paralysis often results in bladder incontinence. Currently we have a number of these paralysed and incontinent dogs with bladder emptying implants, in the same style as we have used for humans for the last 30 years. However, it would be a great help to the owners of such dogs if there was an indication of the dogs’ bladder fullness, so the owners know when to take their pet out and activate the bladder emptying device. The implanted part of the DBFM is mainly a multiplexed 16 channel electro-neurogram (ENG) amplifier. The external controller, which communicates with the implant through intact skin via inductive loops, needs to be designed. It will involve:
1. A microcomputer with a display, keyboard, alarm sounder and a USB port by which it may be programmed by a PC.
2. Programme to first provide channel selection commands to the implanted amplifier. Two out of the sixteen channels must be selected.
3. On receiving response from the implant, the controller must accept serial implant data at some 400k bits per second (kbs) and store this away for further processing and or output it in analogue form to an oscilloscope. The data rate corresponds to the 2 selected channels sampled at 15kHz at 12 bits per channel, with allowance for start, stop and parity bits.
4. The controller programme must also provide for a display of channels used, neural spike rate, the bladder fullness that spike rate corresponds to and for an alarm to be sounded when the bladder is too full. It must further respond to the keyboard for channel selection etc.
5. The controller programme should only occupy a small part of processor time to allow for real time neural spike analysis to be programmed when the required data processing is known.
Initially the controller would provide the signals necessary to determine what data processing is needed. The skills needed for the project include digital and analogue circuit design and microcomputer programming.