A novel redundant motion control mechanism in accordance with medical diagnostic and therapeutic task functions for a NIUTS

The authors have developed a non-invasive ultrasound theragnostic system (NIUTS) with a focal lesion servo (FLS) function based on stereo ultrasound imaging in order to compensate for movement while irradiating high-intensity focused ultrasound (HIFU) onto a focal lesion. In the present paper, we propose a redundant motion control mechanism of the HIFU focus, for therapeutics, that is independent of the ultrasound probes for diagnostics. Using the proposed redundant motion control mechanism, an arbitrary designated position in the focal lesion can be treated without altering the viewpoint of the ultrasound probes. The proposed mechanism enables (i) noise factors, which deteriorate the image quality (IQ) for FLS, to be reduced, thereby enhancing the FLS performance, and (ii) enables the destruction of a focal lesion (kidney stone) with a preoperatively designated locus that is moving due to respiration/heartbeat.