The objective is to complete development and undertake clinical testing of a miniaturized six degrees-of-freedom (6D) spatial locator for use in acquiring multiplane medical imagery. In Phase I, we proved the feasibility of extrapolating a miniaturized locator from our pulsed DC magnetic field generation and sensing technology. We now propose entering an iterative process of clinical evaluations and hardware refinement to demonstrate further medical applicability and meet real world needs. Initially, a prototype locator will be inserted in the tip of a special transesophageal ultrasonic probe for three-dimensional imaging for laboratory testing. Major clinical testing using animals and human participants will be conducted at the University of Washington Medical Center. By capturing the rotation angles and esophageal positions of the probe, as it is translated in space, the locator facilitates 3D reconstructions of anatomical structures. Ultimately, the locator will play an important role in studying and monitoring human anatomy and bodily functions in three dimensions. In Phase II, we anticipate developing six prototype locators at our facility where Ascension currently manufactures a family of multi degrees-of-freedom measurement devices. Clinical trials at major medical centers will also be conducted for applications in cardiology, obstetrics/gynecology, and stereotaxic ultrasound localization.