Malcolm White

The Design and Development of an Integrated Multi-Functional Microwave Antenna Structure for Biological Applications

A new multi-functional microwave antenna structure for use in biological applications in described. The antenna structure allows efficient propagation of Ku -band energy into biological tissue to perform in situ tissue characterization (measurement) and ablation or coagulation (treatment) of solid cancerous tumors and surrounding tissue. A calibration method that allows tissue characterization has been developed. The structure also supports a separate channel to allow material to be transported inside the structure without affecting the electromagnetic field propagation within the structure and the radiation pattern produced at the distal end. The structure is rigid and of small enough diameter to enable it to be introduced percutaneously into the human body under local anaesthesia.

New Microwave Antenna Structures for Treating Gastro-Oesophageal Reflux Disease (GERD)

The design and initial pre-clinical evaluation of microwave traveling-wave antenna structures to deliver high-frequency microwave energy with controlled depth of penetration of the electric field to produce controlled ablation around the inner wall of the oesophagus (confined to the mucosal layer) at the junction between the stomach and the oesophagus is described in this paper. The structures were fabricated using flexible microwave substrates to enable them to be attached to the outer wall of oesophageal balloons for introduction into the oesophagus. It is shown that the uniform electromagnetic field produced along the length of the structure produces controlled circumferential tissue ablation, which could be used to tighten the muscles in the lower oesophageal sphincter, where the stomach connects to the oesophagus, to reduce or eliminate regurgitation and acid exposure to the oesophagus, a condition known as gastro-oesophageal reflux disease. This paper also presents the results obtained from in-vitro tissue studies and initial in-vivo work carried out using the porcine model. This is the first study to assess the use of microwave energy to treat medical conditions associated with the oesophagus.