Eisuke Aoki

A novel robotic laser ablation system for precision neurosurgery with intraoperative 5-ALA-Induced PpIX fluorescence detection

We developed a combined system of tumor detection by 5-ALA-induced PpIX fluorescence and precise ablation by micro laser for the first time, with an automatic focusing and robotic scanning mechanism for the brain surface. 5-ALA accumulates on tumors to be metabolized to become PpIX that is a fluorescent. Intra-operative detection of 5-ALA induced PpIX fluorescence provides useful information for tumor detection. The wavelength of the micro laser is 2.8 microm close to the absorption band of water. This laser is effective only on the surface of brain tissue, enabling precise ablation at the boundary between tumor and normal tissue identified by intra-operative 5-ALA induced fluorescence. Combination tests of the fluorescence measurement and the laser ablation were performed, and it was possible to extract the area with fluorescence appropriately from the measurement data, and the micro laser with automatically scanning selectively ablated the extracted area.

Modular Design of Master-Slave Surgical Robotic System with Reliable Real-Time Control Performance

This paper describes a master-slave surgical robotic system with software modular system design, which integrates various independently developed surgical devices. When we add new functions to the developed modular system, there is no need for time-consuming redesign of the entire system. However, we cannot evaluate the computational system load exactly because the system configuration changes according to the components included. A master-slave system should be a stable and reliable control system with high sampling frequency to enable human visual feedback control. Moreover, it requires consistent master-slave operation on the integrated component. To maintain reliable real-time performance and consistent operation, even with changes in system configuration, we introduced a software system consisting of; A position registration system to realize consistent operation on the integrated component, modular asynchronous system to avoid performance changes caused by the introduction of various subsystems and a management system to arbitrate inconsistencies between systems. An optical tracking system is used to integrate position and motion information of the subsystems to simplify setup in an operating theater. We evaluated the feasibility of the modular master-slave system by integrating independently developed components into the system. The results of the evaluation experiments showed that we could control all the subsystems consistently as an entire master-slave surgical system on an integrated coordinate system with stable real-time response

DEVELOPMENT OF MASTER-SLAVE ROBOTIC SYSTEM FOR LAPAROSCOPIC SURGERY

ABSTRACT Laparoscopic surgery is widely performed as a less traumatic minimally invasive surgery. It, however, requires experiences and skills for surgeons. For realizing high quality and preciseness of surgical operation, we developed a new compact slave robot in a master-slave system. It consisted of manipulator positioning arm, forceps manipulator, and bending forceps. We integrated them into a slave robot with seven DOFs. In vivo experiment was conducted to evaluate the basic motion and the feasibility.

Robotic System for Less Invasive Abdominal Surgery

We developed a master-slave robot system assisting minimally invasive abdominal surgery. It realized a large working space and compact mechanism. The slave robot consisted of three modules; manipulator-positioning arm, forceps manipulator, bending forceps with 2 DOFs. Manipulator-positioning arm had 6 DOF. Each DOF was passive and had only pneumatic-drive braking mechanism. The system was designed so that three manipulators are operated cooperatively. Thus, the three positioning arms were mounted at the suspending device. We integrated the sophisticated forceps such as bending forceps, bipolar electric cautery, and semiconductor laser forceps, which can create the next generation of surgery. We also developed a novel wide angle-view laparoscope using two wedge prisms. It was compact and safe because it did not require moving or bending to move the view. The robot is controlled by a surgeon using a master manipulator system developed by Mitsuishi et al. Each DOF had enough working range and satisfactory performance in experiments simulating clinical environment.

Development of a Compact Automatic Focusing System for a Neurosurgical Laser Instrument

In neurosurgery such as the treatment of glioma, it is important to remove the tumor precisely and accurately, which can be achieved with a micro laser with a wavelength of 2.8 µm. It is necessary, however, to maintain a constant distance from the brain surface. We developed an automatic focusing system for the micro laser ablation system. This system is using a triangulation method with a guide laser and a small CCD camera. The guide laser spot was attenuated and penetrates the biomedical tissue according to its scattering and absorption features. Therefore, each measurement parameter such as the luminance threshold in the image processing was necessary to be appropriately controlled. In this research, we proposed the focusing method to appropriately control the luminance threshold. We confirmed that this method works effectively on biomedical tissue. In the future, we will carry out a combination test with the micro laser system and achieve a precise operation system for brain tumors.

System Design for Implementing Distributed Modular Architecture to Reliable Surgical Robotic System

A method that resolves the two competing requirements for a surgical robotic system (reliability and scalability) is discussed, along with its preliminary implementation in a master-slave system. The proposed method enables an architecture that can be scaled without impairing the performance of the surgical robotic system. Our method uses an optimized architecture consisting of two components: a common object request broker architecture (CORBA) and a master-slave system that typically operates using two-way communication links between a client and a remote server (the dedicated system architecture). In this new architecture, the surgical robotic system can maintain a reliable performance and can integrate with various systems in a transparent manner, regardless of the hardware, operating system, or programming language. Our method was evaluated by recording all the available surgical information, and shows a reliable scalability for a surgical robotic system requiring real-time operation, regardless of the condition of the components of a CORBA-based system.

Development of an automatic focusing system for a precise laser ablation system in neurosurgery

Abstract In treatment of diseases such as encephaloma using neurosurgery, it is very important to remove the tumor accurately at the boundary between the tumor and normal tissue. This is to prevent the recurrence of cancer. To achieve this precise removal of the tumor, we have proposed a new treatment method using 5 Aminolevulinic Acid (5-ALA) and a microlaser with a wavelength of 2.8 μm. In this method, the tumor is labeled by 5-ALA induced fluoresced and is cauterized by the microlaser. Since the ablation by microlaser depends on the displacement from the focal point, it is necessary to keep the distance between the laser probe and the target the focal length. In this research, we have developed the automatic focusing mechanism using two guide lasers and a CCD camera. We have performed focusing accuracy evaluation experiment and irradiation experiment using in porcine pig. Experimental results showed that the focusing accuracy was within 0.5 mm and possibility of clinical application was demonstrated.