Solid hydrogel coupling for ultrasound imaging and therapy

The present invention employs hydrogels as acoustic couplings for clinical applications of ultrasound imaging and therapy, but is particularly applicable to high intensity focused ultrasound (HIFU) based therapy. While other materials can be used, it has been determined that polyacrylamide is sufficiently robust and transmissive to withstand the high temperatures encountered in HIFU therapy. One embodiment of a hydrogel coupling (16) is configured in shape and size (length) to ensure that a focal region (14) of an ultrasound transducer (10a) is disposed proximate the target area when the distal tip (18) of the transducer (10a) is in contact with tissue. These couplings (16) can be shaped to correspond to the beam focus characteristics of specific transducers (10a). Water can be applied to hydrate the tip of the hydrogel coupling during use, and medication absorbed into the hydrogel material can be applied to the tissue in contact with the distal surface of the hydrogel.