Abstract: A method for manufacturing hygristors includes preparing a hygroscopic gel containing a substantially greater proportion of carbon than the prior art, and milling the gel for a period of at least 24 hours to produce a smooth mixture. Substrates are dipped into the milled gel at controlled rates to coat the substrates. The coated substrates are cured under controlled temperature and humidity. Adhesion of the coating is improved by the smoother mixture resulting from the longer milling time, and by the differences in components of the mixture compared to the prior art. Long term stability and dynamic range are both increased.

Abstract: A multi-lumen catheter that contains two or more independent coaxial sensing elements which can be used for measuring and recording temperature over a wide area at the insertion site. In addition, this catheter can be used for withdrawing blood at its distal port. When a microwave probe is inserted into the proximal lumen and positioned within the catheter, it allows for accurate placement of the microwave field within the area which is temperature monitored.

Abstract: There is disclosed a surgical stereotaxic array plug of biocompatible material having an outer periphery adapted to be secured in a complementary threaded opening provided in the skull with bores traversing the plug for receiving and positioning therapeutic apparatus and fluid dispensing devices.