Kenneth L. Carr

Radiometric sensing: an adjuvant to mammography to determine breast biopsy

Radiometric sensing, ONCOSCAN, is a noninvasive test of thermal activity in the breasts which measures microwave emissions by passive microwave radiometry. Microwave radiometric sensing will be shown to be a promising technique which, when combined with mammography, could be useful in reducing non-cancerous breast biopsies based on mammographic false positives, thereby improving the positive predictive value (PPV) of mammography. PPV is defined as the number of malignancies per number of biopsies performed. At the time of this writing, more than 90 women scheduled for open breast biopsy based on abnormal mammographic findings underwent ONCOSCAN testing prior to biopsy. These abnormal mammographic findings basically non-palpable. Various algorithms have been devised, following knowledge of biopsy outcome which separated the ONCOSCANs into those with low or high thermal activity.

Detection of extravasation of antineoplastic drugs by microwave radiometry

Microwave radiometry may be used as a non-invasive technique for subcutaneous thermal sensing. This technique was capable of demonstrating extravasation of small volumes of fluids, including the antineoplastic agent adriamycin, when these fluids were administered at room temperature in dogs. The rate of temperature drop upon extravasation was proportional to the flow rate. It is feasible that microwave radiometry may be useful as an alarm system to reduce serious complications which often accompany the extravasation of antineoplastic drugs.

Thermal Drift In Microwave Thermography

Thermal drift in microwave thermography results from prolonged contact between a microwave antenna at one temperature and a subject at a different temperature. Appropriate antenna heating can minimize thermal drift, permitting more accurate temperature measurements.

Antenna: the critical element in successful medical technology

Developments in the application of microwave technology to the solution of medical problems, particularly the detection and treatment of cancer, are discussed. In the development of cancer, microwave hyperthermia has been accepted as an adjunct procedure to radiation therapy in the treatment of superficial lesions. While not so widely reported, the use of microwave radiometry as a noninvasive passive technique for early detection of cancer appears very promising. Wider acceptance of these methods, however, awaits fundamental improvements in the ability to focus energy at depth in human tissue. Further development in the areas of antennas and antenna arrays is required if microwave technology is to provide a practical solution to the detection and treatment of cancer.<<ETX>>

Dual Mode Microwave System to Enhance Early Detection of Cancer

A dual-mode microwave system has been developed that will permit early detection of cancer. The system combines the use of the passive microwave radiometer [1]-[3] with an active transmitter. The active transmitter will provide localized heating to enhance early detection by taking advantage of the differential heating (i.e., tumor temperature with respect to surrounding tissue) associated with thermal characteristics of tumors.

Sterile docking using microwave heating

Peritonitis is the single most limiting factor for patients undergoing continuous ambulatory peritoneal dialysis (CAPD), a treatment associated with end stage renal failure (ESRD). A device which destroys microorganisms that are recognized to be the most problematic in causing peritonitis has been developed. The microwave heating technique showed efficient intraluminal disinfection of CAPD connector pairs. Moist heat has proven to be the most effective technique for disinfecting the inner lumen of commercially available medical connectors. Moist heat using microwave heating has proven to be the most effective and rapid technique. A 10/sup 6/ population reduction of various organisms which are the most prevalent and problematic in causing peritonitis was accomplished with a very short heating cycle. This process is effective due to the rapid heating of the solution contained within the connectors. Since plastic is transparent to microwave heating, the external surface of the plastic connector remains lukewarm during the process.<<ETX>>

The Effect of Antenna Match on Microwave Radiometric Thermal Patterns

Microwave thermographic profiles of the breast region of healthy female volunteers were obtained using a 4.7 GHz radiometer. Apparent temperature elevations of about 0.4°C were seen in the areolar (nipple) region compared to the other areas of the breast. At least half of this apparent areolar temperature elevation may be attributed to improved antenna match at that site. The importance of antenna match in the proper evaluation of microwave thermographic studies is emphasized.

Microwave Radiometric Thermal Patterns and Antenna Match in Healthy Female Volunteers

Microwave thermographic profiles of the breast region of female volunteers were obtained using a 4.7 GHz radiometer. Apparent temperature elevations of about 0.4°C were seen in the areolar (nipple) region compared to the other areas of the breast. At least half of this apparent areolar temperature elevation may be attributed to improved antenna match at that site. The importance of antenna match in the proper evaluation of microwave thermographic studies is emphasized.