Shigeru Omori

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.

Simplification of infrared illumination of stereoscopic liquid crystal TV

Stereoscopic, multi-parallax, electro-holographic and multi-planar methods are no glasses methods as real-time 3D imaging devices. These methods except stereoscopic need several parallax images or several plane images for their 3D image component. It is known there are many problems for taking and transmission of their 3D images. As for stereoscopic method using lenticular sheet limits the position of the viewers and/or is impossible to observation of the 3D image by several persons simultaneously. Conventional our method Stereoscopic Liquid Crystal TV does not have such above drawbacks but has difficulty to enlarge the size of the 3D image output screen and still remains improvement of the infrared illuminating system for the observers and the image taking system of the TV because of its characteristics of the system components. Two infrared TV cameras and two infrared lumps are necessary for the conventional method. But in this time we produced new methods necessary an infrared TV camera and an infrared lump.

Stereoscopic liquid crystal display II (practical application)

Three-dimensional displays that permit simultaneous observation by plural persons have been reported in other papers, but a 3-D endoscope is only available for stereo image and is better used in the no-glasses method. Hence conventional 3-D techniques were poor for the endoscope for medicine. We produced a new 3-D device (stereoscopic liquid crystal display) which permits simultaneous observation of a stereo pair by plural persons without glasses and we improve the device for the endoscope. We combined the 3-D endoscope and the new 3-D device. The endoscope has two CCD cameras. The cameras create a stereo pair transmitted by two NTSC signals. The system is time-parallel stereoscopic.

Mid-Infrared Robotic Laser Surgery System in Neurosurgery

There is certain limitation to do the perfect extraction of the tumors by conventional manual surgery, because the area close to the boundary between tumors and normal brain tissue is usually left in order to keep away from destruction of normal area. For the purpose to treat such the boundary area, a computer controlled robotic laser surgery system has been developed. This system is characterized by the mid-infrared laser device which can perform less invasive precise surgery with low output power (<1.0W), and the computer controlled system which can realize the ablation of designated area on brain surface within 0.5mm dislocation. For the further study, aiming to apply to use in vivo, we have developed an auto-focus system for laser irradiation. From the results of our animal study, the system enables to maintain the focal point of the laser head on brain surface to realize constant ablation in the designated area.

A feasibility study on image-based control of surgical robot using a 60-GHz wireless communication system

This paper presents an evaluation study on the feasibility of introducing wireless connection into a neurosurgical robot, which is controlled by an image-based navigation system. The wireless connection introduced into the robotic system is based on amplitude shift keying (ASK) at 60 GHz. With this wireless connection, data transmission at the bit-rate of 1 Gbps or more is possible, and here high-definition video images (1080i/1080p) can be transmitted. Such a wireless connection system is implemented in the surgical robot replaces the cable connection between the digital video camera and the controller. In this study, the wireless robotic surgical system is evaluated in terms of its accuracy of navigation using the transmitted video images. The results of a wireless connection test under a line-of-sight (LOS) environment show that navigation accuracy observed when using this wireless surgical robot is comparable to that when using a wired robotic system.

Robotic surgery in neurosurgical field

Computer-aided surgery commenced in the late 1980s when computer was clinically used for diagnosis and surgical planning. Since then the computer has been used in a surgical navigation system. In the early 1990s a robotic surgery using intelligent manipulator as surgeons new hands took place. Nowadays intraoperative diagnostic imaging as surgeons new eyes has become ubiquitous Diagnosis, surgical planning, and navigation are required to be real-timely performed intraoperatively. The time has really come to concurrently diagnose and treat, in which technology visualizing intraoperative medical information and minimally invasive surgery are fused. For that it is necessary to develop a system that real-timely updates information for decision making, and at the same time to present the timely, optimum treatment to be done according to the results of instant evaluation of ongoing treatment. To realize and support above system it is essential to combine a sensor which can precisely distinguishes a focal area from a normal tissue intraoperatively, and a manipulator which participates the treatment. In addition, the manipulator should be accurately controlled using a computer (computer-aided manipulation) according to the surgical plan made by a method aided by a computer (computer-aided design) based on intraoperatively acquired information. It is about to change quality of life to quality of treatment.

Robotic laser surgery system with volume mapping in Neurosurgery

Aiming to treat the area close to the boundary between tumors and normal brain tissue in neurosurgery, a computer controlled robotic laser surgery system with volume mapping function has been developed. In order to make sure the location of residual tumors, it is important to show the volume data of MR image to surgeon for designating the target area to be irradiated by laser on the computer monitor screen. The improved system has performed the volume data display as a 2-dimentional outline that is appeared by crossing the target surface imposing to the surface image from CCD camera. This newly system also has the function of surface shape measuring by using the auto-focus mechanism and plotting the data on the monitor screen. On our evaluation, less than 0.5 mm depth resolution can be obtained in sensing target surface by this system.

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.

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.