Force-detecting gripper and force feedback system for neurosurgery applications

Purpose For the application of less invasive robotic neurosurgery to the resection of deep-seated tumors, a prototype system of a force-detecting gripper with a flexible micromanipulator and force feedback to the operating unit will be developed. Methods Gripping force applied on the gripper is detected by strain gauges attached to the gripper clip. The signal is transmitted to the amplifier by wires running through the inner tube of the manipulator. Proportional force is applied on the finger lever of the operating unit by the surgeon using a bilateral control program. A pulling force experienced by the gripper is also detected at the gripper clip. The signal for the pulling force is transmitted in a manner identical to that mentioned previously, and the proportional torque is applied on the touching roller of the finger lever of the operating unit. The surgeon can feel the gripping force as the resistance of the operating force of the finger and can feel the pulling force as the friction at the finger surface. Results A basic operation test showed that both the gripping force and pulling force were clearly detected in the gripping of soft material and that the operator could feel the gripping force and pulling force at the finger lever of the operating unit. Conclusions A prototype of the force feedback in the microgripping manipulator system has been developed. The system will be useful for removing deep-seated brain tumors in future master-slave-type robotic neurosurgery. © 2013 CARS

Silicone retractor with embedded force-sensing function for attachment to surgical suction pipes

A silicone retractor that can be attached to suction pipes was developed in order to enhance the usability [1]. The measurement of the retracting force is desired in order to avoid damage to brain tissue due to an unexpected large force. This paper presents a force-sensing embedded silicone retractor that can be attached to suction pipes. The developed silicone retractor can provide three functions at the same time: suction, retracting, and retracting force measurement. The force-sensing system is based on a visualization mechanism that displays the force as a colored pole motion. The surgeon can then roughly estimate the retracting force. With a fiberscope, the retracting force can be measured with a resolution of 0.05-0.3 N. The retractor is made of silicone and has the advantages of disposability, low cost, and easy sterilization/disinfection. The system was validated through finite element method analysis and experiments. © 2015 IEEE.IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2015; BEXCOBusan; South Korea; 7 July 2015 through 11 July 2015; Category numberCFP15775-ART; Code 11713

Three-axis force visualizing system for fiberscopes utilizing highly elastic fabric

This paper presents a novel force sensing system for fiberscopes. The key features of the system are its low cost, high resolution, small size, and ability to measure three-dimensional force. A previous study described a novel force sensing system that could be attached to a very thin fiberscope, based on a force visualization mechanism utilizing panty stocking fabric - a highly elastic material. However, this system measures force in only one direction. In this paper, the system is extended to measure forces in any of three directions. The system is targeted for application to neurosurgical examinations. It may also be useful for other medical and non-medical examinations that involve the use of fiberscopes. © 2014 IEEE.2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2014; Besancon; France; 8 July 2014 through 11 July 2014; Category numberCFP14775-ART; Code 10711

Haptic threshold for pulling force feedback on surgeon\u27s fingertip in medical robotic systems

The human fingertip has very high density of the receptor to accept sense of touch stimulation. The corresponding somatic sensory area in a brain is very large, and considered to be a specialized part for palpation. A lot of haptic display system then have been developed with the investigation of human haptic perception. However, the researches about the human perception for pulling force at grasping, namely static frictional force are limited. This paper investigated it, aiming at a future development of pulling and grasping force feedback system for neurosurgical robotic systems. For the purpose, this paper explored the possibility of displaying pulling force to an index finger during grasping. The absolute and difference thresholds for pulling sense were the targets. The results showed that grasping disturbs the pulling sense, and the sides of index fingertip can be used to display pulling sense, relatively large force, namely scaled force feedback is required for the perception. The results provide an important insight at a hardware and controller design of force feedback systems. © 2016 IEEE.42nd Conference of the Industrial Electronics Society, IECON 2016; Palazzo dei CongressiFlorence; Italy; 24 October 2016 through 27 October 2016; Category numberCFP16IEC-ART; Code 12554

Incompressible Liquid Based Force Sensible Silicone Retractor Attachable to Surgical Suction Instruments

This paper presents a silicone retractor, which is a continuation and extension of a previously developed system that had the same three functions as the old version: 1) retracting, 2) suction, and 3) force sensing. These features make the retractor a safe choice for use in neurosurgery. Suction is achieved by attaching the retractor to a suction pipe. The retractor has a deformation area filled with an incompressible liquid that is displaced in proportion to the extent of deformation; fiberscopes or human eyes detecting the displacement get a visual representation of the force. The new design improves on the old one in three ways—miniaturization, made possible by the incompressible-liquid-based mechanism, and measurement of force distribution by distribution of the areas deformed by force. The system was validated by conducting experiments

Identification of Danger State for Grasping Delicate Tofu with Fingertips Containing Viscoelastic Fluid

In this study, we experimentally investigated the process leading to fracture in tofu grasping by deformable fingertips filled with a fluid. In our previous papers [1, 2], we developed deformable fingertips using a rubber bag filled with a viscoelastic fluid, and presented a strategy for delicate tofu grasping without any advance knowledge about fracture. However, the predication point was close to fracture, and the prediction was then still a gamble. In order to realize fracture prediction at an earlier stage, we examined the process leading to fracture when pushing tofu by the deformable fingertips. The stiffness of the fingertips can be controlled with the pressure of the fluid inside the fingertips. The pushing force and fluid pressure were examined for different levels of stiffness of the fingertips. The main findings and contributions are as follows. 1) The convergence of the ratio of the contact force to fluid pressure gives an indication of dent occurrence. This convergence could be seen when fingertip rubber bag was not filled (low stiffness). 2) It was easier for a dent to occur when the fingertip rubber bag was not filled than when it was filled (high stiffness). 3) Changes in the rate of increase of the fluid pressure as the tofu was pushed were repeatedly observed. We defined this as a phase change and present a method for detecting such changes. The phase change points were detected by comparing the fitting accuracies of different approximation models. 4) The last and second to the last phase changes before fracture were detected by detecting the first phase change (after the convergence of the rate of the contact force to fluid pressure if the fingertip bag was not completely filled). The detected points can be regarded as alert points indicating a fracture risk that is not close to the fracture point. © 2015 IEEE.IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2015; Congress Center Hamburg (CCH)Messeplatz 1Hamburg; Germany; 28 September 2015 through 2 October 2015; Category numberCFP15IRO-ART; Code 11788

Finger-attachment device for the feedback of gripping and pulling force in a manipulating system for brain tumor resection

Purpose: Development and evaluation of an effective attachment device for a bilateral brain tumor resection robotic surgery system based on the sensory performance of the human index finger in order to precisely detect gripping- and pulling-force feedback. Methods: First, a basic test was conducted to investigate the performance of the human index finger in the gripping- and pulling-force feedback system. Based on the test result, a new finger-attachment device was designed and constructed. Then, discrimination tests were conducted to assess the pulling force and the feedback on the hardness of the gripped material. Results: The results of the basic test show the application of pulling force on the side surface of the finger has an advantage to distinguish the pulling force when the gripping force is applied on the finger-touching surface. Based on this result, a finger-attachment device that applies a gripping force on the finger surface and pulling force on the side surface of the finger was developed. By conducting a discrimination test to assess the hardness of the gripped material, an operator can distinguish whether the gripped material is harder or softer than a normal brain tissue. This will help in confirming whether the gripped material is a tumor. By conducting a discrimination test to assess the pulling force, an operator can distinguish the pulling-force resistance when attempting to pull off the soft material. Pulling-force feedback may help avoid the breaking of blood pipes when they are trapped in the gripper or attached to the gripped tissue. Conclusion: The finger-attachment device that was developed for detecting gripping- and pulling-force feedback may play an important role in the development of future neurosurgery robotic systems for precise and safe resection of brain tumors. © 2017 CARSEmbargo Period 12 month

Stiffness Measurement System Using Endoscopes with a Visualization Method

A novel stiffness-sensing system was developed that works by attaching the proposed sensing part to endoscopes or cameras. The system provides a method to investigate the stiffness of tissues or objects in deep areas that can only be observed with endoscopes in order to detect abnormalities. The system is an extension of our previous force sensing system that utilized a force visualization mechanism. The force is visualized at the sensing part, and can be measured as visual information via endoscopes or cameras. The sensing part also has a limiting structure used as a threshold for the applied force. By measuring the force at the limitation, the stiffness can be measured. The limitation point is detected by the brightness changes of the captured images. The developed sensing part has the advantages of having no electronic components, being disposable, simple, easy to sterilize, MRI-compatible, and low-cost. Image processing methods for realizing the mechanism are also proposed. The system was experimentally validated. © 2001-2012 IEEE