Patent ID: 8057422

Claim:
A programmable valve system of the type which is implanted in a medical patient and used to divert a quantity cerebrospinal fluid (CSF) from an intraventricular space of the patient to a terminus cavity; said system including means for establishing a flow path for the CSF to the terminus cavity, which flow path includes a normally closed valve and means for adjusting a pressure setting of the normally closed valve in order to regulate the quantity of CSF diverted; an improvement enabling an observer to be apprised of the pressure setting, comprising: (a) a transmitting means, implantable in the medical patient, responsive to the pressure setting, for generating a (near infrared) NIR telemetry signal and indicative of the pressure setting, for transcutaneous transmission through the skin of the medical patient to an external point; and (b) a receiving means positionable externally of the medical patient, for receiving the NIR telemetry signal at the external point and for producing therefrom observer intelligible data indicating the pressure setting; wherein the transmitting means comprises: a NIR emitter emitting a NIR light beam; a mirror reflecting a first portion of the NIR light beam as a reflected light beam and transmitting a second portion of the NIR light beam as a transcutaneous light beam carrying the telemetry signal; an optical encoder positioned on the normally closed valve to encode the pressure setting into the reflected light beam as an encoded light beam; a first photodetector detecting the encoded light beam; and, an electronic circuit, connected to the photodetector, modulating the NIR emitter at an output frequency in proportion to the pressure setting as detected from the encoded light beam; wherein the receiving means comprises: a display device; and, a second photodetector detecting the transcutaneous light beam; a frequency detector, connected to the second photo detector, detecting the output frequency; a microprocessor, connected to the frequency detector, for determining the pressure setting based on the output frequency.