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Kozo Konishi

Publications and source records attributed to Kozo Konishi.

10 recordsLinked to original sources
PubMed2006

Robotic surgery setup simulation with the integration of inverse-kinematics computation and medical imaging.

At present, there are representative robot operation systems such as da Vinci and ZEUS which have realized minimally invasive surgery by the use of dexterous manipulators. In the operating room, medical staff must prepare and set up an environment in which the robot has optimal freedom of motion and its functions can be fully demonstrated for every case. The range of motion in which the robot can reach and be maneuvered is restricted by the fixed point of the trocar site. We have developed a preoperative planning system with the function of volume rendering of medical images and automatic positioning by applying an inverse-kinematics computation of surgical robot. The motion of a surgical robot can be simulated in advance with the intuitive interface and kinematics computation program running in the background of the system. If robotic surgery planning with volume rendering of DICOM images is possible, the discussion of a surgical plan can be directly made just after the diagnosis considering the patient-specific structure. This kind of setup platform would be essential for the future introduction of surgical robotics into an operating room.

Algorithms↗
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

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

Development of a camera model and calibration procedure for oblique-viewing endoscopes.

Oblique-viewing endoscopes (oblique scopes) are widely used in medical practice. They are essential for certain procedures such as laparoscopy, arthroscopy and sinus endoscopy. In an oblique scope the viewing directions are changeable by rotating the scope cylinder. Although a camera calibration method is necessary to apply augmented reality technologies to oblique endoscopic procedures, no method for oblique scope calibration has yet been developed. In the present paper, we formulate a camera model and a calibration procedure for oblique scopes. In the calibration procedure, Tsai's calibration is performed at zero rotation of the scope cylinder, then the variation of the external camera parameters corresponding to the rotation of the scope cylinder is modeled and estimated as a function of the rotation angle. Accurate estimation of the rotational axis is included in the procedure. The accuracy of this estimation was demonstrated to have a significant effect on overall calibration accuracy in the experimental evaluation, especially with large rotation angles. The projection error in the image plane was approximately two pixels. The proposed method was shown to be clinically applicable.

Algorithms↗
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↗
PubMedDate not supplied

Pulmonary embolism following laparoscopic surgery: a report of two cases.

Laparoscopic abdominal surgery is considered a low-risk procedure for postoperative complications because of reduced surgical stress and earlier mobilization. We report two patients who experienced pulmonary embolism following laparoscopic surgery; one patient underwent umbilical hernia repair and the other cholecystectomy. Although pulmonary embolism is indeed rare after laparoscopic surgery, early detection and early treatment are determinative factors for a good prognosis. Therefore, medical caregivers must remember that pulmonary embolism can be a critical complication after laparoscopic surgery and preventive measures should be employed for high-risk subjects.

Adult↗
PubMedDate not supplied

Laparoscopic splenectomy for portal hypertension.

BACKGROUND/AIMS: Laparoscopic splenectomy is now increasingly being performed. However, controversy remains regarding the effectiveness of a laparoscopic splenectomy for patients with portal hypertension. METHODOLOGY: Seventy-three patients with portal hypertension who underwent a laparoscopic splenectomy from February 1992 until October 2000 were reviewed and the effectiveness of the procedures for portal hypertension was evaluated. Forty-two patients had esophagogastric varices and twenty had a concomitant hepatocellular carcinoma. The indications for surgery were bleeding tendency due to thrombocytopenia (n = 40), difficulty in receiving treatment for hepatocellular carcinoma due to thrombocytopenia (n = 18), and sclerotherapy-resistant esophagogastric varices (n = 15). RESULTS: A laparoscopic splenectomy was successfully performed in all the patients. The rate of conversion to conventional open surgery was 9.6% (7/73). The mean operative time was 210.1 +/- 101.9 minutes, and the estimated blood loss was 374.7 +/- 352.4 mL. There were no cases of mortality, and morbidity was encountered in 11.0% of patients. The increase in the platelet count correlated significantly to the spleen weight (P < 0.001). The platelet count had been maintained at over 10 x 10(4)/mm3 for over three years. Eighteen patients with hepatocellular carcinoma successfully underwent treatment for hepatocellular carcinoma after surgery and no recurrence of esophagogastric varices was encountered. CONCLUSIONS: A laparoscopic splenectomy resulted in the successful secondary treatment of hepatocellular carcinoma and esophagogastric varices. Portal hypertension was not a contraindication. A laparoscopic approach is therefore the procedure of choice for a splenectomy in portal hypertension.

Aged↗