Kazutaka Toyoda

A surgical robot with vision field control for single port endoscopic surgery.

Robotic end‐effectors for single port endoscopic surgery (SPS) require a manual change of vision field that slows surgery and increases the degrees of freedom (DOFs) of the manipulator.

Development of a robotic system with six-degrees-of-freedom robotic tool manipulators for single-port surgery.

Current robotic systems have limitations for single‐port surgery (SPS) because the instruments are large, the arms collide and the field of vision requires manual readjustment. We have developed an SPS robotic system that manipulates the vision field.

Development of a tool manipulator driven by a flexible shaft for Single Port Endoscopic Surgery

Recently, a robotics system was developed to assist in Single Port Endoscopic Surgery (SPS). However, the existing system required a manual operation of vision and viewpoint, hindering the surgical task. We proposed a surgical endoscopic robot for SPS with dynamic vision control, the endoscopic view being manipulated by a master controller. The prototype robot consists of a manipulator for vision control, and dual tool tissue manipulators (gripping: 5DOF, cautery: 3DOF) can be attached at the tip of sheath manipulator. In particular, this paper focuses on the details of the mechanism and control scheme of the tool manipulator. The experimental results show that our manipulator exhibits a response with a precision of less than 0.15 [mm] and a time delay of less than 31 [ms], when the input frequency was 1.0[Hz].

Comparison of transtibial and transportal techniques in drilling femoral tunnels during anterior cruciate ligament reconstruction using 3D-CAD models

Purpose The purpose of this study was to assess the differences in bone tunnel apertures between the trans-accessory medial portal (trans-AMP) technique and the transtibial (TT) technique in double-bundle anterior cruciate ligament reconstruction. The extent of ovalization and the frequency of overlap of the two tunnel apertures were compared. Methods The simulation of femoral tunnel drilling with the TT and the trans-AMP techniques was performed using three-dimensional computer aided design models from two volunteers. The incidence angle of drilling against the intercondylar wall, the femoral tunnel position, the ovalization, and the overlap were analyzed. The aperture and location of the tunnels were also examined in real anterior cruciate ligament reconstruction cases (n=36). Results The surgical simulation showed that a lower drill incident angle induced by the TT technique made the apertures of two tunnels more ovalized, located anteromedial tunnels in a shallower position to prevent posterior wall blow out, and led to a higher frequency of tunnel overlap. The trans-AMP group had tunnel places within the footprint and had less ovalization and overlap. The results of analysis for tunnels in the clinical cases were consistent with results from the surgical simulation. Conclusion In the TT technique, the shallow anteromedial tunnel location and more ovalized tunnel aperture can lead to a higher frequency of tunnel overlap. Compared with the TT technique, the trans-AMP technique was more useful in preparing femoral tunnels anatomically and avoiding tunnel ovalization and overlapping in double-bundle anterior cruciate ligament reconstruction.

The concept and feasibility of EXPRT: Intelligent armrest using robotics technology

BACKGROUND Continuous precise motions are required in microneurosurgery to provide high-quality surgical results. Stabilizing the surgeons arm and reducing fatigue during surgery are expected to improve the precision of microsurgical procedures. We have developed an intelligent armrest, EXPERT, that follows the surgeons hand and fixes at an adequate position automatically using robotics technology. OBJECTIVE To understand the feasibility of EXPERT by using the system in laboratory experiments and clinical situations. METHODS EXPERT has an arm holder and acts as a passive controlled robot with 5 degrees of freedom. The system has 3 modes: transfer, arm-holding, and arm-free mode, which are selected automatically. In the transfer mode, the arm holder follows the surgeons arm. In the arm-holding mode, EXPERT supports the surgeons arm weight by fixing the arm holder. The surgeon can move his/her arm away from the arm holder in the arm-free mode. The surgeon can change the position of armrest while looking through the microscope and can continue the microsurgical procedure while holding surgical instruments. Since 2010, EXPERT has been applied in 13 surgeries. RESULTS The EXPERT system decreased surgeon fatigue and reduced difficulty in performing surgical procedures. The EXPERT system markedly reduced surgeon hand tremor. There were no complications related to the use of this system. CONCLUSION EXPERT is a useful tool for holding the surgeons arm comfortably and following the surgeons arm automatically.

Intercondylar Roof Impingement After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension

Background: Although an anatomically placed graft in anterior cruciate ligament (ACL) reconstruction is reported to have a low risk of roof impingement, which may cause deterioration of the graft or an extension deficit, the incidence of roof impingement by these grafts has not been evaluated in hyperextensible knees. Purpose: To evaluate the incidence of roof impingement by the native ACL in hyperextensible knees and to examine the risk of roof impingement by anatomic placement of the ACL graft in hyperextensible knees. Study Design: Controlled laboratory study. Methods: Twelve patients were selected for a hyperextensible knee group (group A), defined as having hyperextension of the knee of greater than 10°. Twelve patients were recruited to a normal extension knee group (group B) with normal extension of the knee of less than 5° of hyperextension. Magnetic resonance imaging (MRI) scans of the knee positioned in 30° of flexion and full extension were acquired from all patients. The shape of the native ACL at full extension was compared between the groups. A 3-dimensional (3D) bone model was created from the acquired 2D MRI scans. A virtual anatomic double-bundle ACL reconstruction in each patient and a virtual anatomic single-bundle reconstruction in the patients in group A were performed using the 3D MRI bone models. The volume of the overlap between the graft and roof was calculated to evaluate graft impingement in each instance. Results: The MRI scans showed posterior bowing of the native ACL in the group A knees. The simulated double-bundle ACL reconstruction showed that the overlapped volume was significantly greater in patients in group A than in patients in group B (P < .05). However, the overlap of the simulated single-bundle ACL reconstruction was significantly less than for the double-bundle ACL reconstruction (P < .05). Conclusion: To reduce the risk of roof impingement by the graft, single-bundle ACL reconstruction with the graft placed at the center of the footprint might be the better method for patients with a hyperextensible knee than an anatomic double-bundle ACL reconstruction. Clinical Relevance: It is recommended that surgeons cautiously consider roof impingement after anatomic double-bundle ACL reconstruction in patients with a hyperextensible knee.

Telesurgery of Microscopic Micromanipulator System "NeuRobot" in Neurosurgery: Interhospital Preliminary Study.

Object Robotic surgery can be applied as a novel technology. Our master-slave microscopic-micromanipulator system (NeuRobot), which has a rigid endoscope and three robot-arms, has been developed to perform neurosurgical procedures, and employed successfully in some clinical cases. Although the master and slave parts of NeuRobot are directly connected by wire, it is possible to separate each part and to apply it to telesurgery with some modifications. To evaluate feasibility of NeuRobot in telesurgery, some basic experiments were performed. Methods The quality of telemedicine network system between Shinshu University and one of the affiliated hospitals, which was completely separated from other public network systems, was investigated. The communication delay was calculated from the transmitting and the receiving records in the computers set in each hospital. The relationship between the change in communication delay from the master part to the slave part of NeuRobot (0, 100, 300, 500 and 700 ms) respectively and feasibility of NeuRobot was investigated. The task performance time in each time changing group was compared. Feasibility of NeuRobot in telesurgical usage was evaluated. The master part and the slave part of NeuRobot placed in each hospital were connected through private network system. Interhospitally connected NeuRobot was compared with directly connected one in terms of task performance time. Results Less than 1 ms was required for corresponding the data in a steady transmitting state. Within 2 seconds after connection, relative time delay (maximum 40 ms) and packet loss were sometimes observed. The mean task performance time was significantly longer in over 500 ms delayed group compared with directly connected NeuRobot. There was no significant difference in the task performance time between directly connected NeuRobot and interhospitally connected NeuRobot. Conclusion Our results proved that telesurgical usage of NeuRobot was feasible. Telesurgical usage of telecontrolled manipulator system is recommended for application in a private network system in order to reduce technical and ethical problems. Some technical innovations will bring breakthrough to the telemedicine field.

Development of a smart surgical robot with bended forceps for infant congenital esophageal atresia surgery

Minimally invasive surgery (MIS) is commonly used in pediatric operations. This method greatly benefits patients because of the reduced surgical trauma. To perform such surgery smoothly, doctors must be highly skilled. To reduce operating difficulties, a great deal of research on surgical systems have been carried out. However, in some cases, smaller workspaces limit the application of MIS. For example, the workspace of infant congenital esophageal atresia (ICEA) surgery is only around 30×30×30 mm. Until now, most ICEA surgeries have been manually performed with traditional instruments. This paper presents a smart surgical robot (SSR) for ICEA surgery. The robot is composed of two slave arms, each consisting of a positioning manipulator and a surgical tool manipulator. The positioning manipulator uses a selective compliance assembly robot arm (SCARA) and a screw-pair mechanism to achieve translational movement in 3D space, and the surgical tool manipulator uses a “double screw drive + universal joint” structure to allow an omni directional bending motion. During surgery, the surgeon first creates the workspace manually to explore the target esophagus. The SSR system is then applied to perform operation. The configuration of the SSR means it can perform tissue manipulation under endoscopic view in a small workspace. Experimental results show that the endoscopic view permits the SSR system to be operated intuitively and accurately in the target workspace.

In vivo experiments of a surgical robot with vision field control for single port endoscopic surgery

Recently, robotics systems are focused to assist in Single Port Endoscopic Surgery (SPS). However, the existing system required a manual operation of vision and viewpoint, hindering the surgical task. We proposed a surgical endoscopic robot for SPS with dynamic vision control, the endoscopic view being manipulated by a master controller. The prototype robot consists of a manipulator for vision control, and dual tool tissue manipulators (gripping: 5DOFs, cautery: 3DOFs) can be attached at the tip of sheath manipulator. In particular, this paper focuses on an in vivo experiment. We showed that vision control in the stomach and a cautery task by a cautery tool could be effectively achieved.

Dexterous master-slave surgical robot for minimally invasive surgery - Intuitive interface and interchangeable surgical instruments

Effect of the needle tip shape on fall of force after puncture in epidural anesthesia K. Naemura Æ H. Saito School of Bionics, Tokyo University of Technology, Tokyo, Japan Unisis Corporation, Tokyo, Japan