Soft-Tipped, Compliance Controllable Sensor for Measuring Forces During Minimally Invasive Surgery

Force sensing is key to understanding interactions during surgery. It allows surgeons to monitor tissue health and locate inclusions during palpation. Force sensors commonly interact using hard tips, which increase tissue damage. Other force sensors use soft tips to interact, measuring force through methods such as visual surface tracking 1, 2, magnet position tracking 3, 4, and meniscus tracking 5. However, these sensors have outer diameters larger than 12 mm, preventing them from fitting through commonly available trocars used in minimally invasive surgery. The compliance of three of these sensors could be pneumatically adjusted allowing the range and sensitivity of the sensors to be controlled 2, 4, 5. No soft-tipped sensors with outer diameters below 12 mm have demonstrated the ability to measure force with an adjustable range. In this paper, we present a soft-tipped compliance controllable sensor with an outer diameter of 11.6 mm. We investigate the ability of this sensor to adjust its force sensing range and sensitivity, and to measure the magnitude and angles of forces.