2025 Volume 63 Issue 1 Pages 9-15
In ultrasonography, the reproducibility of imaging is poor because ultrasound images change depending on factors such as the contact force or contact angle with the imaging target. This study developed a measurement module for the contact force on an imaging target for an ultrasound probe. The contact force measurement module consists of a set of probe-side parts, a set of hand-side parts, four 6-axis force sensors, and an inertial sensor. The two sets of the probe-side and hand-side parts are connected only by the 6-axis force sensors so that the reaction force of the contact force from the measurement object can be applied only to the sensors. In addition, the gravity effect of the probe mass depending on the probe angle can be compensated for by measuring the attitude of the module using the inertial sensor. In this study, a prototype contact force measurement module was fabricated. The contact force measurement characteristics of the prototype were evaluated by varying the angle of the probe. In the experiment, the contact force was measured by operating an ultrasound probe with the module to contact the target surface vertically as well as by a load cell placed under the target surface. The values measured by the module were compared to those measured by the load cell at the －30, 0, 15, and 30° angles. The values measured by the module increased linearly with an increase in the values measured by the load cell under all conditions. The slope of the approximate line between the value measured by the load cell and that measured by the module was 0.98 and the R2 value was 0.9999 at an angle of 0°. The slopes and R2 values of －30, 15, and 30°were comparable with those of 0°. This result suggests that the proposed module can be applied to the contact force measurement in ultrasonography without depending on the angle of the ultrasound probe to the horizontal plane.
