Many patients suffering from chronic disease need treatment with continuous drug application. Without exact control of dosage and frequency, side effects may be caused affecting the quality of the patient's life. Within the Esprit program, a modular microsystem for controlled medical drug release has been developed consisting of an implantable programmable infusion pump, an external processing unit, a telemetry device and a printer. At the European IT Conference Exhibition held in Brussels last November, MICROMEDES demonstrated a prototype with closed-loop application. The next step in the project will hopefully lead to a system's test in practice.
The MICROMEDES infusion pump is divided into two separate chambers. The exterior pressure chamber contains chemically inert liquid as a drive medium whereas the interior one is functioning as the actual drug chamber taking the form of an oval-shaped bellows made of titanium. The microprocessor and the flow control system are the main components of the device. Flow control is managed by a series of silicon slices bonded together which contain pressure sensors, spiral fluid containers and microvalves. Telemetry-based communication with the external processing unit is activated through an integral antenna. Via controls on the external processing unit, the flow rate of the pump can be changed and shown on a display.
Clearly, only the use of Micro System Technology can produce the desired small size for the implants working with absorption telemetry instead of lifetime-restricting batteries and connections through the skin. The extra corporal processing unit will be worn on a belt. It is also possible to attach transponders outside the body on the skin at locations near the sensors. These sensors which measure physical parameters such as pressure and temperature have to be characterised by long-time stability and reliability. MICROMEDES aims at creating a standard interface so that any future sensor can be adapted to the closed-loop system.
The introduction of sensor controlled systems will reduce costs for the health insurance agencies and will enhance both effective treatments and strong interactions between research and industry for future products. New applications will come in reach within a short time while cooperations with several clinics in Europe will ensure the access of the end user to this novel modular microsystem.