Abstract
Many elder persons suffer from osteoarthritis. Degeneration of the knee cartilage causes this disease. We have developed the diagnostic equipment for cartilage using an ultrasonic wave. The measurement using the proposed ultrasonic equipment is effected by operators skill and skin on cartilage. These factors leads to low reproducibility of acquisition results. Our goal is to achieve the ultrasonic diagnostic equipment with high reproducibility. In this study, we investigated three dimensional movement of the ultrasonic probe. The movement of the tip and end part of the probe was measured using two cameras. From the two photos, three dimensional position (X, Y, Z) of these parts was calculated from the theory of stereocamera. Ideal operation of probe is that the probe the end part is straightly moved and the tip part is fixed. Displacement of the tip part on X-axis, which is defined as the direction to incline the probe, were 3.44±1.82 mm (T=0 h) and 5.36±1.30 mm (T=4 h). The X-axis displacement gradually increased with cartilage degeneration. From this result, the ideal operation could not be performed, especially, in the case of deeply degenerated specimen. We had often felt that degeneration of specimen related to difficulty of measurement. This result coincided with our experience. This study suggests that some support devices to properly operate the probe is necessary.
