Validation of a surgical drill with a haptic interface in spine surgery.

Real haptics is a technology that reproduces the sense of force and touch by transmitting contact information with real objects by converting human movements and the feel of the objects into data. In recent years, real haptics technology has been installed in several surgical devices. A custom-made surgical drill was used to drill into the posterior lamina to verify the time required for penetration detection and the distance the drill advanced after penetration. A surgeon operated with the drill and the same aspects were measured and verified. All experiments were performed on female miniature pigs at 9 months of age with a mean body weight of 23.6 kg (range 9-10 months and 22.5-25.8 kg, n = 12). There were statistically significant differences in the average reaction time and the distance travelled after penetration between a handheld drill and the drill with the penetration detection function (p < 0.001). The reaction time to detect penetration and the distance after penetration were both significantly improved when compared with those of the handheld surgical drill without the penetration detection function, with mean differences of 0.049 ± 0.019 s [95% CI 0.012, 0.086 s] and 2.511 ± 0.537 mm [95% CI 1.505, 3.516 mm]. In this study, we successfully conducted a performance evaluation test of a custom-made haptic interface surgical drill. A prototype high-speed drill with a haptic interface accurately detected the penetration of the porcine posterior lamina.

A study on safe forceps grip force for the intestinal tract using haptic technology.

PURPOSE: The present study used haptic technology to determine the safe forceps grip force for preventing organ damage when handling the intestinal tract. MATERIAL AND METHODS: The small intestines of ten male beagle dogs (weighing 9.5-10 kg) were grasped with the entire forceps for one minute; the small intestines were then pulled out of the forceps and evaluated for damage. The force at which the shaft inside the forceps was pulled to close the tip of the forceps was defined as the grip force. Small intestine damage was classified into macroscopic (serosal defects, hemorrhage, hematomas, grip marks) and microscopic (damage layer to the mucosa, submucosa/muscularis mucosa, inner orbicularis muscle, external longitudinal muscle, serosa/subserosa). Grip marks and damage layer to the serosa/subserosa have been considered as acceptable safety margins when grasping the small intestines of beagle dogs. RESULTS: The macroscopic findings showed that the maximum grip force that produced a 0% incidence of hemorrhage and hematoma was 15 N. At the microscopic level, the maximum grip force that produced a 0% incidence of external longitudinal muscle injury was 15 N, respectively. CONCLUSIONS: A grip force of 15 N does not damage the small intestines of beagle dogs.

3D-Printed Micro-Tweezers with a Compliant Mechanism Designed Using Topology Optimization.

The development of handling technology for microscopic biological samples such as cells and spheroids has been required for the advancement of regenerative medicine and tissue engineering. In this study, we developed micro-tweezers with a compliant mechanism to manipulate organoids. The proposed method combines high-resolution microstereolithography that uses a blue laser and topology optimization for shape optimization of micro-tweezers. An actuation system was constructed using a linear motor stage with a force control system to operate the micro-tweezers. The deformation of the topology-optimized micro-tweezers was examined analytically and experimentally. The results verified that the displacement of the tweezer tip was proportional to the applied load; furthermore, the displacement was sufficient to grasp biological samples with an approximate diameter of several hundred micrometers. We experimentally demonstrated the manipulation of an organoid with a diameter of approximately 360 µm using the proposed micro-tweezers. Thus, combining microstereolithography and topology optimization to fabricate micro-tweezers can be potentially used in modifying tools capable of handling various biological samples.

[Development of real-world haptic technology].

This paper introduces the principle of real-world haptic and its technology applied to high-grade surgery and/or welfare areas. The existing technology has depended on force sensors, which leads to a trade-off issue between stability and performance. The implementation and realization of a better system has been an unsolved problem for a long time. The authors invented a novel technology that works without force sensors. Modal decomposition and acceleration-based bilateral control(ABC method)are its key concepts. This idea has been actualized with three dof robotic forceps. Several experimental results found by the application of haptic forceps mounted on a 6 dof industrial robot are shown.

Newly developed haptic forceps enables sensitive, real-time measurements of organ elasticity.

Currently available master-slave manipulators cannot recognize the elasticity of organs or tissues. The aim of this study was to examine whether a newly developed haptic forceps using a linear motor could measure the elasticity of living organs using an animal model. We measured the elasticity values and the disruption limit values of rat organs using the new haptic forceps. The elasticity of the materials was calculated using the formula "power / position", with N/m as the unit. We successfully and reproducibly measured the changes in the elasticity values of various materials in real time. We were also able to perceive tactile changes transmitted through the forceps. The changes in gastrointestinal contraction were synchronized with the visually observed changes, and these changes were monitored and measured as elasticity values in real time using the forceps. The damage limits were also successfully measured. In conclusion, the new haptic forceps enabled highly sensitive, real-time measurements of elasticity in living rat organs. The use of this forceps enables the disruption limit values of organs to be measured, and the device could be useful for setting safety limits when grasping organs during endoscopic surgery.