I had discounted the idea of pressure measurement for detection of PC muscle activity as it required the construction of a closed vessel possibly filled with a liquid as the volume differential would be low so the pressure differential would also be low thus making the system inherently susceptible to noise, especially of the sort being induced by the vibrator head. however i cam across [1] this which has a nice cheep pressure vessel head. All the material bio-compatibility stuff has been thought of and it has been designed to have a low volume so that nice pressures are generated. so i have bought one and i will order up a pressure transducer and with a modicum of luck it will all work and when it gets squeezed the transducer will, along with associated ancillary electronics, produce a nice output. This then gets fed to an ADC pin on the uC which will run a little algorithm that will generally reduce the strength of vibrations if it sees a pulse then slowly ramp up again. There is an inherent danger that this could lead to conditioning that will reduce PC muscle activity in response to stimulation but this can be overcome by using a second programme that will generate a pulse of vibrations only when the system sees a pressure. using both programmes should allow long periods of titillation and PC muscle exercise.

Lets just hope it works….