ABSTRACT
A wireless power transfer and communication system based on near-field inductive coupling has been designed and implemented. The feasibility of using such a system to remotely control drug release from an implantable drug delivery system is addressed. The architecture of the wireless system is described and the signal attenuation over distance in both water and phosphate buffered saline is studied. Additionally, the health risk due to exposure to radio frequency (RF) radiation is examined using a biological model. The experimental results demonstrate that the system can trigger the release of drug within 5 s, and that such short exposure to RF radiation does not produce any significant (Subject(s)
Drug Delivery Systems/instrumentation
, Electric Power Supplies
, Eye/drug effects
, Ophthalmic Solutions/administration & dosage
, Prostheses and Implants
, Signal Processing, Computer-Assisted/instrumentation
, Telemetry/instrumentation
, Drug Implants/administration & dosage
, Equipment Design
, Equipment Failure Analysis
, Humans
ABSTRACT
The development of an implantable system designed to deliver drug doses in a controlled manner over an extended time period is reported. Key performance parameters are the physical size, the power consumption and also the ability to perform wireless communications to enable the system to be externally controlled and interrogated. The system has been designed to facilitate wireless power transfer, which is very important for miniaturisation as it removes the need for a battery.
Subject(s)
Drug Therapy, Computer-Assisted/instrumentation , Electric Power Supplies , Infusion Pumps, Implantable , Microfluidic Analytical Techniques/instrumentation , Telemedicine/instrumentation , Telemetry/instrumentation , Drug Therapy, Computer-Assisted/methods , Equipment Design , Equipment Failure Analysis , Microfluidic Analytical Techniques/methods , Miniaturization , Telemedicine/methods , Telemetry/methodsABSTRACT
An analogue CMOS VLSI neural processing chip has been designed and fabricated. The device employs "pulse-stream" neural state signalling and is capable of computing some 360 million synaptic connections per second. In addition to basic characterisation results, the performance of the chip in solving "real-world" problems is also demonstrated. The experience gained from the development of this device has resulted in the design of a second "pulse-stream" chip with improved performance and features. It is anticipated that this second device will be integrated into a standard bus-based system and find early application in robotic control.
Subject(s)
Neural Networks, Computer , Computers, Analog , Image Processing, Computer-Assisted , Neurons , Semiconductors , SynapsesABSTRACT
Results from working analog VLSI implementations of two different pulse stream neural network forms are reported. The circuits are rendered relatively invariant to processing variations, and the problem of cascadability of synapses to form large systems is addressed. A strategy for interchip communication of large numbers of neural states has been implemented in silicon and results are presented. The circuits demonstrated confront many of the issues that blight massively parallel analog systems, and offer solutions.
