Towards a clinical implementation of a non-invasive microwave imaging system for temperature monitoring

A laboratory scale multi-illumination microwave imaging system has been successfully demonstrated for the reconstruction of biologically relevant materials and has also been shown to be sensitive to thermally induced electrical property changes. Several challenges are currently being addressed in an effort to bring the system to the clinic for use in non-invasive thermometry. These include: (1) increasing the size of the imaging region, (2) reducing image artifacts due to the presence of multiple antennas during illumination, and (3) developing a solid illumination chamber to replace the saline bath tank. The first two are intimately related. As the imaging system size is increased to clinically useful dimensions, we must inevitably reduce the lossiness of the surrounding medium which will subsequently increase the antenna-antenna interactions. This is being addressed both in terms of the design of the individual antennas and in terms of introducing compensating techniques into the numerical model. Investigating these areas will provide insight into the ultimate capability of this imaging modality. Additionally, a solid material is being developed with electrical properties close to that of saline. Working in such a lossy medium has significant advantages in terms of the antenna performance and the reduction of unwanted multi-path signals propagating into and out of the desired imaging plane. With these tasks completed, quantification of the system's ability to recover electrical property distributions and thermal profiles based on difference imaging techniques will be investigated for both phantom and in vitro experiments.