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Biomedical subjects

Mitsuhiro Hayashibe

Publications and source records attributed to Mitsuhiro Hayashibe.

15 recordsLinked to original sources
PubMed2006

Soft-tissue balance evaluation system for total hip arthroplasty by intraoperative contact pressure measurement at the hip joint.

We developed a system for measurement of contact pressure at the hip joint surfaces that enables checking of the artificial hip joint condition during surgery. First, we constructed the pressure sensor that forms the artificial joint. We installed eight small pressure sensors to the spherical head component, a part of the ball-socket joint. Next, we developed software for recording and visualizing the detected pressures that were recorded every 1 ms. The pressure distribution was displayed with the 3D computer graphics in real-time. The system enabled intuitive recognition of pressure direction 3-dimensions. Next, using the system, we conducted measurements during total hip arthroplasty. Although it requires some improvements in its measurement accuracy, the system allows real-time acquisition of information on the artificial hip joint in real-time. Further improvements of the calibration method should enable more accurate measurements. As a complete system, it will be a useful tool for selecting an appropriate implant that fits a patient's hip joint or for estimating the risk of complications after surgery.

Arthroplasty, Replacement, Hip↗
PubMed2006

Estimation of skeletal movement of human locomotion from body surface shapes using dynamic spatial video camera (DSVC) and 4D human model.

We have been developing a DSVC (Dynamic Spatial Video Camera) system to measure and observe human locomotion quantitatively and freely. A 4D (four-dimensional) human model with detailed skeletal structure, joint, muscle, and motor functionality has been built. The purpose of our research was to estimate skeletal movements from body surface shapes using DSVC and the 4D human model. For this purpose, we constructed a body surface model of a subject and resized the standard 4D human model to match with geometrical features of the subject's body surface model. Software that integrates the DSVC system and the 4D human model, and allows dynamic skeletal state analysis from body surface movement data was also developed. We practically applied the developed system in dynamic skeletal state analysis of a lower limb in motion and were able to visualize the motion using geometrically resized standard 4D human model.

Biomechanical Phenomena↗
PubMed2005

Surgical robot setup simulation with consistent kinematics and haptics for abdominal surgery.

Preoperative simulation and planning of surgical robot setup should accompany advanced robotic surgery if their advantages are to be further pursued. Feedback from the planning system will plays an essential role in computer-aided robotic surgery in addition to preoperative detailed geometric information from patient CT/MRI images. Surgical robot setup simulation systems for appropriate trocar site placement have been developed especially for abdominal surgery. The motion of the surgical robot can be simulated and rehearsed with kinematic constraints at the trocar site, and the inverse-kinematics of the robot. Results from simulation using clinical patient data verify the effectiveness of the proposed system.

Biomechanical Phenomena↗
PubMed2005

Development of a navigation function for an endosocopic robot surgery system.

An endoscopic robot system that we reported at MMVR11 is able to perform various surgical procedures in the stomach by using two manipulators. However, it is difficult for surgeons to recognize the 3D location and the direction of the endoscope's tip in the abdominal region during robotic surgery. In this research, we have developed a navigation function that enables image-guided surgery by superimposing the patient's abdominal organ structure onto the endoscopic image. In this paper, we describe the overview of the navigation for the robot system and the result of an animal experiment done while applying the system.

Endoscopy↗
PubMed2005

Development of a 3D visualization system for surgical field deformation with geometric pattern projection.

Intra-operative navigation in which the target position is provided to assist an intuitive understanding of the surgical field has been studied and applied in many clinical areas. Position measurement of a surgical field is usually performed with a magnetic sensor, a marker type optical position sensor. For navigation of hard tissue, the measurement of several markers dispersedly located on the surface is enough to detect the position of an object that can be assumed as a rigid body. However, for the navigation of soft tissue such as skin and liver, a sensor that can measure the deformation of the object surface time-sequentially would be essential. We have developed a 3D visualization system for surgical field deformation with geometric pattern projection. In an animal experiment, the registration of preoperative 3D organ model could be done with the time-sequentially updated surface deformation data. In the video image of surgical field, the inner structure model of organ could be superimposed successfully.

Elasticity↗
PubMed2005

Construction of a high-tech operating room for image-guided surgery using VR.

This project aimed to construct an operating room to implement high dimensional (3D, 4D) medical imaging and medical virtual reality techniques that would enable clinical tests for new surgical procedures. We designed and constructed such an operating room at Dai-san Hospital, the Jikei Univ. School of Medicine, Tokyo, Japan. The room was equipped with various facilities for image-guided, robot and tele- surgery. In this report, we describe an outline of our "high-tech operating room" and future plans.

Facility Design and Construction↗
PubMed2005

Tele-surgical simulation system for training in the use of da Vinci surgery.

Laparoscopic surgery including robotic surgery allows the surgeon to be able to conduct minimally invasive surgery. A surgeon is required to master difficult skills for this surgery to compensate for the narrow field of view, limitation of work space, and the lack of depth sensation. To counteract these drawbacks, we have been developing a training simulation system that can allow surgeons to practice and master surgical procedures. In addition, our system aims to distribute a simulation program, to provide a means of collaboration between remote hospitals, and to be able to provide a means for guidance from an expert surgeon. In this paper, we would like to show the surgery simulation for da Vinci surgery, in particular a cholecystectomy. The integral parts of this system are a soft tissue model which is created by the sphere-filled method enabling real-time deformations based on a patient's data, force feedback devices known as a PHANToM and the Internet connection. By using this system a surgeon can perform surgical maneuvers such as pushing, grasping, and detachment in real-time manipulation. Moreover, using the broadband communication, we can perform the tele-surgical simulation for training.

Computer Simulation↗
PubMed2004

[Present and future developments of the virtual surgery and tele-virtual surgery system].

One of the applications available now in the medical field is the virtual surgery system. This system allows surgeons a safe place to master surgical techniques and to plan surgical procedures before the operation. To provide the system for use in a clinical situation, a soft tissue model and a force feedback device suited for the surgery is required. In this paper, we would like to introduce our virtual surgery system, which possesses a soft tissue model that can show accurate, real-time deformation and is equipped with a force feedback device that allows the user to experience the tactile sensations. In addition, we will introduce our tele-virtual surgery simulation system for training in the procedures used in robotic surgery.

Computer Graphics↗
PubMed2003

A robotic surgery system (da Vinci) with image guided function--system architecture and cholecystectomy application.

We have developed a data fusion system for the robotics surgery system "da Vinci". The data fusion system is composed of an optical 3D location sensor and a digital video processing system. The 3D location sensor is attached to the da Vinci's laparoscope and measures its location and direction. The digital video processing system captures the laparoscope's view and superimposes 3D patient's organ models onto the captured view in real-time. We applied the system to "da Vinci" and examined this system during a cholecystectomy. In this experiment, the surgeon was able to observe the inner conditions of the organs with a stereo view.

Cholecystectomy↗
PubMed2003

Real-time 3D deformation imaging of abdominal organs in laparoscopy.

In laparoscopic surgery, surgeons encounter particular difficulties during the course of the operation. Due to the restricted view from the endoscope and the limited degree of freedom using forceps, surgeons find their movements impeded. It would be necessary to develop a support system to provide surgeons with improved laparoscopic vision. If real-time visualization of the abdominal anatomy is possible, it will be useful for accurate procedure and quantitative evaluation. In this paper, The laser-scan endoscope system acquires and visualizes the shape and texture of the area of interest in a flash of time. Results of in-vivo experiments on the liver of a pig verify the effectiveness of the proposed system.

Abdomen↗
PubMed2003

Development of Dynamic Spatial Video Camera (DSVC) for 4D observation, analysis and modeling of human body locomotion.

We have developed an imaging system for free and quantitative observation of human locomotion in a time-spatial domain by way of real time imaging. The system is equipped with 60 computer controlled video cameras to film human locomotion from all angles simultaneously. Images are installed into the main graphic workstation and translated into a 2D image matrix. Observation of the subject from optional directions is able to be performed by selecting the view point from the optimum image sequence in this image matrix. This system also possesses a function to reconstruct 4D models of the subject's moving human body by using 60 images taken from all directions at one particular time. And this system also has the capability to visualize inner structures such as the skeletal or muscular systems of the subject by compositing computer graphics reconstructed from the MRI data set. We are planning to apply this imaging system to clinical observation in the area of orthopedics, rehabilitation and sports science.

Human Body↗
PubMed2003

Development of an endoscopic robotic system with two hands for various gastric tube surgeries.

This paper presents the first report on an endoscopic robot with two manipulators which performed surgical work to resect the mucosal layer of the stomach of pigs without penetrating the body surface. We designed and developed an endoscopic surgical robot system which possesses two arm shaped manipulators for various kinds of surgery in the gastric tubes. The distal part of the manipulator functions as forceps and they are able to hold and handle soft tissues through the cooperative efforts of the right and left arms. And it is also able to incise the gastric wall by holding an electronic scalpel (brought in from the instrument channel) with the manipulator on the right side while opening the sectioning plane on the left side which was take out. With this system we succeeded in the mucosal resection of a large portion of the stomach wall of a pig during experimental surgery. It can be said that this is a new approach robotic surgery in the gastric tube with this kind of surgical robot.

Animals↗
PubMed2003

Development of a data fusion system using color information for real-time intraoperative liver surface measurement.

The goal of our study is to develop a data fusion system, which enables surgeons to easily visualize the inner structures of elastic organs during open surgery. We chose the liver as the focus of this study due to its easily deformable nature and complex vascular structures. To do so, we propose using preoperative data and supplementary intraoperative data. We captured a sequence of liver surface data for the intraoperative data by using trinocular stereo and we applied them to the preoperative 3D model's surface. Then, we modified the model to fit the intraoperative liver condition and portrayed the model's inner structures. With this method, we could establish this system.

Animals↗
PubMed2002

Intraoperative 3D shape recovery of abdominal organs for laparoscopic data fusion.

Precise measurements of geometry should accompany robotic equipments in operating rooms if their advantages are further pursued. For deforming organs including the liver, intraoperative geometric measurements play an essential role in computer surgery in addition to pre-operative geometric information from CT/MRI. The laser-scan endoscope system acquires and visualizes the shape of the area of interest in a flash of time. Results of in-vivo experiments on the liver of a pig verify the effectiveness of the proposed system. In the next stage, we aim to make a data-fusion in laparoscopy.

Animals↗