Use of gallium arsenide in medical applications

Microwave technology can be used to solve many medical problems where conventional technology has proven inadequate. This is particularly true for applications involving the generation of heat and the measurement and monitoring of temperature. Through cost-effective fabrication techniques based upon MMIC technology, this microwave technology has now become affordable. Several applications illustrating the significance of MMIC technology will be discussed. MMS´s IV Injection-Site Monitor, for example, is based on passive microwave radiometric monitoring of subcutaneous tissue temperature. This technique is based upon the assumption that an unwanted accumulation of liquid (i.e., an extravasation into the tissue surrounding the infusion site) will result in a temperature differential. An extravasation is defined as the unwanted occurrence of infiltration of fluid during IV infusion beyond the vein or artery into the surrounding tissue. Extravasations of IV fluids in children can have serious consequences when gross extravasations occur. Skin necrosis can occur, which may require treatment with skin grafting. These advanced sequelae are less frequent in the adult population, but in newborns and young children they are much more prevalent and can be catastrophic. Neonates and infants are unable to communicate pain and are more prone to tissue necrosis. To address this application, the sensitive radiometer must be small and lightweight to meet the requirements of the pediatric (including neonatal) patient population.