Transcutaneous telemetry of cerebrospinal fluid shunt programmable-valve pressure using near-infrared (NIR) light

Abstract

An improvement for a programmable valve system of the type implanted in a patient and used to divert cerebrospinal fluid (CSF) from an intraventricular space to a terminus such as the peritoneal cavity. Such system includes means for establishing a flow path for the CSF to the terminus, which flow path includes a normally closed valve and means for adjusting the opening pressure of the valve in order to regulate the quantity of CSF diverted. The improvement enables an operator to be apprised of the actual opening pressure setting of the valve. A sensor is implantable at the patient and responds to the actual opening pressure setting, by generating an NIR telemetry signal indicative of the actual setting. This signal is transcutaneously transmitted through the skin of the patient to an external point. The telemetry signal is processed to produce observer intelligible data indicating the opening pressure setting of the valve.

1 . A system for retrieving the biometric pressure data from a programmable valve implanted in an organism comprising:
 an intracorporeal device sealed within the organism;   an extracorporeal device outside the organism;   a freespace optical data channel established between the intracorporeal device and the extracorporeal device for communication of the biometric pressure data;   a freespace electromagnetic power transmission channel established from the extracorporeal device to the intracorporeal device for transmission of power; and   a freespace mechanical power transmission channel established from the extracorporeal device to the intracorporeal device for manipulation of a position of the intracorporeal device.   
     
     
         2 . The system of  claim 1  wherein the freespace optical data channel is bidirectional. 
     
     
         3 . The system of  claim 1  wherein the freespace optical data channel is in a wavelength range between 800 nm and 1000 nm. 
     
     
         4 . The system of  claim 1  wherein the intracorporeal device is powered only upon receipt of a transmission of power from the electromagnetic power transmission channel. 
     
     
         5 . The system of  claim 4  wherein a light emitting diode on the extracorporeal device illuminates when the intracorporeal device receives power. 
     
     
         6 . The system of  claim 1  wherein the extracorporeal device includes a processor for operating on the transmitted near infrared form. 
     
     
         7 . The system of  claim 6  further comprising a memory means, in communication with the processor, for storage of a data set related to the angular position of the valve. 
     
     
         8 . The system of  claim 7  wherein the processor is further programmed to conduct signal processing on the data set. 
     
     
         9 . The system of  claim 1  wherein the extracorporeal device further comprises a coupling module, an analysis module and an external mechanical programmer. 
     
     
         10 . The system of  claim 9  wherein the coupling module further comprises:
 an optical receiver coupled to the freespace optical data channel and; 
 a power transmitter coupled to the electromagnetic power transmission channel. 
 
     
     
         11 . The system of  claim 9  wherein the external mechanical programmer further comprises:
 a driver magnet coupled to the freespace mechanical power transmission channel. 
 
     
     
         12 . The system of  claim 9  wherein the analysis module further comprises:
 an optical receiver coupled to the freespace optical data channel; 
 a decoder coupled to the optical receiver; and 
 a processor connected to the decoder programmed to interpret the biometric data. 
 
     
     
         13 . The system of  claim 9  wherein the power transmitter further includes:
 a power signal conditioner; and 
 a transformer connected to the power signal conditioner and to the power transmitter. 
 
     
     
         14 . The system of  claim 1  wherein the intracorporeal device further includes an encoding system for generating a signal related to an angular position of the valve data. 
     
     
         15 . The system of  claim 14  wherein the encoding system further comprises:
 an encoder disk; 
 an optical source adjacent to the encoder disk; 
 an optical receiver in communication with the optical source for generating an encoded signal related to the angular position of the encoder disk; and 
 an optical transmitter coupled to the freespace optical data channel adapted to transmit the encoded signal. 
 
     
     
         16 . The system of  claim 14  wherein the encoder disk further comprises:
 an optically opaque disk having an encoder pattern and a reference pattern; 
 a light source adjacent to the optically opaque disk and adapted to transmit light through the encoder pattern and the reference pattern; 
 a first reference array adjacent the encoder pattern adapted to receive light through the encoder pattern and generate an angular position signal indicative of the angular position of the encoder disk; 
 a second reference array adjacent the reference pattern adapted to receive light through the reference pattern and generate a data valid signal indicative of the validity of the angular position signal. 
 
     
     
         17 . A method of moving an implanted device in an organism comprising the steps of:
 activating the implanted device through an inductively coupled power source;   electromagnetically creating an altered position of the device; and   deriving an optical data signal from the altered position; and   transmitting it out of the organism.   
     
     
         18 . The method of  claim 17  wherein the step of activating comprises the further steps of:
 generating electromagnetic power signal by an extracorporeal device; and 
 receiving of the electromagnetic power signal by the implanted device. 
 
     
     
         19 . The method of  claim 17  wherein the step of collecting comprises the further steps of:
 generating a data signal in response to the position of a valve coupled to the implanted device; and 
 transforming the data signal into the near infrared signal. 
 
     
     
         20 . The method of  claim 17  wherein the step of electromagnetically creating further comprises:
 rotating a driver magnet above the implanted device.