Development and clinical application of the noninvasive thrombus detection method by NIR laser

In development of an artificial heart, thrombus formation is still serious problem. However, there is no effective means to detect a thrombus. An optical measurement method is one of the best approaches which realize noninvasive thrombus detection. The purpose of this research is to develop the noninvasive thrombus detection method using NIR (Near Infra-Red) laser, and to apply the method to clinical use. By considering the optical characteristic of a thrombus and blood, we have developed the new thrombus detection system. By using this measurement system, the mockup experiment and the animal experiment were performed to detect a fake thrombus such as plastic beads (r=0.2 mm) and celite powder (0.1×0.02 mm) in the artificial heart circulatory system. The thrombus detection performance and safety of this method have been confirmed as the result of these experiments. After obtaining informed consent, the measurement examination was performed to the artificial heart (LVAS: Left Ventricular Assist System) use patient as the clinical application, and similar signals (LMES; Laser-detected Micro-Embolus Signals) corresponding to the animal experiment were detected. The proposed noninvasive thrombus detection method using NIR laser would be regarded as effective in the surveillance of the thrombus formation at the time of clinical artificial heart use.