MAGNETIC MANIPULATION INSTRUMENTATION FOR MEDICAL PHYSICS RESEARCH

The noncontact magnetic manipulation of probe masses within the body i s an area of research that has received substantial attention from the medical physics community, especially during the past three decades. The therapeutic and diagnostic possibilities arising from such technol ogy include site-specific drug delivery within the central nervous sys tem, advancement of techniques for navigation and selective catheteriz ation of vessels within the cardiovascular and cerebrovascular systems , and the nonsurgical exploration of the alimentary and respiratory tr acts. In this review, we examine the physical principles underlying in vivo magnetic manipulation systems, and catalog the various types of instrumentation used for such purposes to date. Thereafter, we evaluat e the different methods of image-based localization used to identify t he position of the probe within the body. Finally, we appraise an emer ging technology known as nonlinear magnetic stereotaxis, a technique t hat permits minimally invasive access to difficult-to-approach parts o f the brain. We close the review with a few comments on the directions for future work within this field.