Tele-operative Laparoscopic Surgical System

Minimally invasive surgery, specifically laparoscopic surgery, requires a shorter hospital stay compared to conventional open surgery, and thus benefits patients. Meanwhile, surgeons experience difficulties maneuvering long, thin instruments inserted through keyholes in the abdomen. Therefore, a master- slave surgical robotic system has been developed to assist in laparoscopic surgery. A tele-surgical operation between Japan and Thailand has been successfully demonstrated.

Master manipulators operated by a surgeon.
Slave manipulators.

 

Microsurgical Robotic System for Neurosurgery

A master-slave surgical robotic system capable of suturing small vessels or nerves in the brain has been developed. The robotic system includes two slave manipulators each with 7 DOFs which can be remotely operated by a surgeon using the master manipulators. Thanks to high positioning accuracy, tremor filtering and motion scaling capability, the system is able to perform the elaborate surgical operations required in neurosurgery. The robotic forceps of 3 mm diameter can be easily interchanged according to required surgical tasks. We successfully performed the anastomosis of artificial blood vessels of 0.3mm in diameter.

Master manipulators operated by a surgeon.
Slave manipulators.

 

Microsurgical Skill Assessment System

High skill levels are required in microsurgical neurosurgery as the surgeon has to anastomose vessels of 1 mm or smaller using 0.02 mm surgical sutures. We have been developing a microsurgical skill assessment system using tweezers equipped with infrared optical makers for position tracking, an inertial measurement unit for acceleration measurement, and strain gauges for force sensing. The data obtained using the system is being analyzed to extract motion elements unique to skilled surgeons for further development of skill-based control of surgical robots.

Microsurgical skill assessment system
Sensorised tweezers and experimental tasks

 

Eye Surgical Robotic Systems

Microsurgical robotic systems for eye surgery, namely vitreoretinal surgery, have been developed. One of the developed platforms (shown in the right figure) shares the same robotic platform as the neurosurgical robotic system, but it is equipped with eye surgical robotic instruments and operated with the motion scaling of 1/40. This robotic vitreoretinal surgical system showed superior operability compared to traditional manual procedures and demonstrated sufficient potential to warrant further testing in animal trials to assess clinical feasibility.

Parallel robot for vitreoretinal surgery
Master-slave robotic system for vitreoretinal surgery

 

Non-Invasive Ultrasound Theragnostic System

An ultrasound-image-guided therapeutic HIFU (High-Intensity Focused Ultrasound) system for renal diseases has been developed. The HIFU system is equipped with robotic servoing capability so as to track quasi-periodically moving renal tumors and stones. The developed system is composed of a US imaging unit, software for target detection, a robotic unit for servoing the end-effecter, HIFU irradiation control for destroying stones or tumors, and a quality assurance system for planning and maintaining HIFU irradiations.

Non-invasive ultrasound theragnostic system
US imaging probes and HIFU transducer

 

Multi-DOF Surgical Instrument with Intuitive User Interface for Pediatric Laparoscopic Surgery

Pediatric laparoscopy is difficult due to the very small working space available in the abdominal cavity of a child. Surgeons are restricted by this constraint, in addition to the problems inherent in laparoscopic surgery. Therefore, we have been developing a handheld multi-DOF surgical instrument to perform complicated surgical tasks in a small space. The diameter of the instrument is 3.5 mm and equipped with 3 DOFs facilitated by the triple-bevel-gear mechanism. In addition, an intuitive user interface has been proposed for the 3-DOF handheld forceps.

3 DOFs facilitated by the triple-bevel-gear mechanism
Intuitive interface design for the 3-DOF handheld forceps

 

Surgical Robotic System for Minimally Invasive Knee Arthroplasty

Precise positioning of the artificial knee joints onto the machined bone surfaces is crucial in knee arthroplasty, and highly-precise bone cutting needs to be performed through a small incision for minimal invasiveness. To achieve these requirements, a pre-operative planning system using CT images and an intra-operative system involving the Bone Cutting Robot has been developed. Experiments using artificial bones, swine bones, and cadaver bones have shown excellent performance by the system.

Bone Cutting Robot
Cutting of knee joint

 

Cutting Tools for Biocompatible Bone-Cutting

In arthroplasty, efficient and accurate bone-cutting needs to be achieved while maintaining a low cutting temperature. We have been developing biocompatible bone-cutting methods and dedicated cutting tools in order to simultaneously satisfy the requirements. More specifically, we have developed the control of crack propagation based on knowledge obtained by observing micro-nano phenomena in bone cutting. We have also developed a bone-cutting endmill with edges of different design; a edge with smaller radius is used for rough processing while a edge with larger radius is for finishing.

Control of crack propagation in bone cutting
Bone-cutting endmill

 

Tool Surface Functionalization Using Micro-Fabrication Technology

We have developed a new cutting tool with temperature sensing capability for continuous in-process measurement of cutting-temperature fields. A thermocouple array was mounted on the rake surface of the tool. Using this functionalized tool, we can discuss in depth the temperature influence on the workpieces. Additionally, dynamic control of the machining based on temperature can be achieved.

Thermocouple array placed on the rake surface on the cutting tool
Cutting experiment using the developed cutting tool

 

Precision Machining of Hard-Brittle Material

Tungsten alloys and engineering ceramics are very hard and fragile, and thus classified as hard-brittle materials. We have been developing precise machining methods of difficult-to-cut materials, specifically of hard-brittle materials. Inspired by innovative ideas and principles, we propose new machining methods and validate them by intensive experiments. For example, we are investigating cutting-burnishing of tungsten alloys and high-temperature cutting of ceramics.

 

Evaluation of a Regenerated Cartilage Based on its Viscoelasticity

In recent years, implantation of a regenerated cartilage has been applied to the treatment of osteoarthritis. However, an evaluation method for the implanted cartilage after the surgery has not been established. In this research, a probe-shaped diagnostic instrument has been developed to measure the viscoelasticity of the implanted cartilage so as to quantitatively evaluate the recovery status. The shape of the instrument would enable minimally invasive diagnosis, which would lead to earlier clinical applications of the developed instrument.

 

Robot assisted reposition of bone fractures

 

Precise optical measurements

 

Microrobots for medical applications