Katsuhiko Onishi

Osaka Electro-Communication University · Department of Computer Science

Currently, we are developing a VR exposure system for improving post-fall syndrome for elderly fallers. However, it is difficult to recognize for young people whether an elderly person is more easily to fall in a fall-prone situation. In this study, we simulated blurred vision in VR in according with the visual impairment certification criteria. We...

In recent years, the spread of VR technology has led to using VR environments composed of 3D CG models in various fields. For example, in medical and nursing care, VR is used in surgical simulations and navigation systems that utilize 3D data from CT/MRI images, etc. Because VR environments can reproduce matters that would not usually occur, simula...

In this study, 13 nurses with more than 10 years of experience as clinical nurses in the surgical field were given a simulated experience of postoperative delirium using VR, and the changes that occurred before, during, and after the experience were analyzed from three perspectives: subjective data, psychological data, and objective data. The resul...

In endoscopic surgery, it is important to search for organs, tumors and blood vessels, recognize their locations, and perform the surgery safely and quickly. Robot-assisted surgery has made it possible to perform precise operations. However, it is still difficult to perform surgery in a narrow surgical field with a narrow view. Several surgical sup...

In the field of neurosurgery, a variety of knowledge has been accumulated through a lot of surgery experiences. Due to the difficulty of expression, not all of the points that skilled neurosurgeons pay attention to during neurosurgery and the detailed precautions and procedures obtained from experience have been clearly stated and shared. Postopera...

We have developed some liver posture estimation methods for achieving a liver surgical navigation system that can support surgeons who needs to know very precise information about vessels in the liver. Those methods use 3D liver models scanned from patients and 2D images scanned by depth cameras for estimating the liver posture as accurately as pos...

In this study, we propose a system for assisting doctors with transsphenoidal surgery by understanding the positions of tumors during surgery. Transsphenoidal surgery requires examining endoscopic images to assess the situation depicted for surgery; determining the positions of tumors and organs is more difficult for transsphenoidal surgeries compa...

We have been developing a surgical support system for Robot-Assisted Laparoscopic Partial Nephrectomy (RAPN) using augmented reality (AR) technology since April 2014. In our system, three-dimensional computer graphics (3DCG) models including kidneys, arteries, veins, tumors, and urinary tracts are generated from tomographic images (DICOM) preoperat...

We aim to develop a system to evaluate pouch attachment to and removal from stoma (artificial anus). For preliminary evaluation, we devoted this study to verify if a color/depth camera can accurately capture the stoma shape. Specifically, a 3D scanner was used to take precise images of three stoma models made of human tissue-mimicking gel and with...

In this study, we used a virtual reality system, referred to as Unity, to simulate the world of the onset of postoperative delirium, as observed by patients with postoperative delirium, which cannot be realized in the real world. Here, we had the subject view the data created with Unity by connecting it to Oculus Quest 2 (head mounted display, HMD)...

Neurosurgeons accumulate a variety of empirical knowledge through surgeries. Post-operative reports, incident reports, and accident reports are effective means of recording and sharing empirical knowledge, but they are costly to analyze them, and new methods of sharing knowledge are needed. In addition, the interface using CG technology, which is u...

We are developing a surgical support system to prevent surgical accidents in liver surgery. This system consists of three subsystems. First, The Liver Position and Posture Estimation System performs Depth-Depth-Matching of real depth image and virtual depth image to estimate the position and posture of the liver during surgery. The real depth image...

Robot-assisted surgeries have enabled surgeons to perform complex procedures more precisely and easily as compared with the conventional laparoscopic surgery. These new technologies have expanded the indications of the nephron-sparing surgery to cases that are anatomically more complicated. One of the challenging cases is that of the completely end...

As we have been developing a liver surgical navigation system that uses a scanned 3D liver model of the patient, we have pointed the necessity of the efficient posture estimation from depth images to be matched with the posture of a virtual liver rendered on a computer. We have previously used the technique of calculating the sum of squared errors...

In this study, we developed an augmented-reality (AR) navigation system that can assist surgeons during transsphenoidal surgery, including identification of the tumor site. Since transsphenoidal surgery is performed by looking at an endoscopic image, thus requiring situational judgment on the image, transsphenoidal surgery poses greater challenges...

Fear of falling down is common among older people because it occurs on average in 50% of those who have fallen in the previous year. Our main aim was to investigate the reduction of FOF in elderly fallers using a virtual reality exposure therapy. To pursue this aim we developed a virtual reality exposure therapy system to clarify the following two...

Laparoscopic surgery enabled surgeons to perform more minimally invasive surgery compared with conventional open surgery. Besides, robotic surgery has become more common in many fields, thus, facilitating performance of more precise procedures. As the performance of the devices improved, surgeons aim at not only cure of the disease, but also at pre...

We are developing a liver surgical navigation system that uses a 3D liver model of the patient. As the liver contains several types of blood vessels, surgeons can sterically check the treating positions using the navigation system. For better navigation, the 3D liver model should be continuously and precisely matched with the patient’s liver state,...

In this study, our goal is to create a surgical navigation system that takes stable measurements of a surgical area using RGB/depth cameras without obstructions, such as the surgeon’s head or hands. We mounted three cutting-edge D435 Intel RealSense Depth Cameras onto a ring and photographed the surgical area from three directions. We also installe...

In this study, we developed a navigation system for transnasal endoscopic surgery based on estimations of tip positioning of laparoscopic cameras from related studies and research of orientation control methods using a 3D model display of organs during the process. In transnasal endoscopic surgery, to remove pituitary tumors, a nasoscope and surgic...

We have developed a surgical navigation system for robot-assisted laparoscopic partial nephrectomy (RALPN). In this system, a three-dimensional computer graphics (3DCG) model generated from each patient’s computed tomography image is overlaid on the endoscopic image, and we control it manually to navigate the vascular structure and tumor location i...

To prevent liver surgical accidents, we have been developing a surgery navigation system with two depth cameras with different characteristics. In this paper, we describe our developed surgical knife attachment which indicates the proximity of the blood vessels in the liver by light and sound. The method to calibrate the tip position of the knife i...

Laparoscopic surgery is becoming popular as a minimally invasive operation. It is widely used as a technique for various kinds of surgical operation. In this surgery, a surgeon uses an endoscopic camera, which is limited view volume, and forceps into the patient body. It has been needed to support system such as navigation system. Therefore, we are...

We have developed a surgery support system for robot-assisted laparoscopic partial nephrectomy. In our system, a 3D computer graphics (3DCG) model, which includes a kidney, arteries, veins, and tumors, is saved separately and overlaid on the surgeon’s viewing endoscopic camera image through the operator’s console monitor in real time. The position...

In this study, we describe about our approach for the selection technique by using user-centered region to define selection state. It is a mainly subject to realize the efficient selection gesture by user’s arm for any position on the screen. we designed selection region and pointer fixed region by using relative position of the user’s arm joints....

In this study, we propose a smart transcription algorithm for translation and/or rotation motions. This algorithm has two phases: calculating the differences between real and virtual 2D depth images, and searching the motion space defined by three translation and three rotation degrees of freedom based on the depth differences. One depth image is c...

In this paper, we propose a smart deforming and/or cutting transcription algorithm for rheology objects such as human livers. Moreover, evaluation of performance and shape precision under the proposed algorithm are experimentally verified by deforming a real clay liver and/or cutting a gel block prepared at human body temperature. First, we capture...

In this paper, we propose a graphics processing unit-based efficient surgical algorithm for operating on a human liver by a cavitron ultrasonic surgical aspirator (CUSA) scalpel in a virtual environment built with polyhedral objects in Standard Triangulation Language format. First, using z-buffers of a human liver and a CUSA scalpel in a general-pu...

We have been developing a intelligent surgical knife with LED level meter for liver surgery. When the knife approaches a part that must not be cut, it alerts by lighting LEDs gradually. Multiple markers are attached on the top of the knife to estimate the tip position during surgery. We conducted experiments to confirm the validity of operator’s na...

In recent years, the elderly population has been steadily increasing. In particular, the population is aging more rapidly in Japan than other developed countries. Surgical procedures for the elderly carry substantial risk, and there is an immediate need for measures to reduce this risk. We have been developing a support system for liver surgery by...

While watching four colors, we operate a virtual liver in order to overlap its real liver. The green pixel means that a real liver exists along the depth (Z) direction, the red pixel means that a virtual liver exists along the depth (Z) direction, the yellow pixel means that they are overlapped in the XY plane, and the blue pixel means that surface...

We proposed a depth-depth-matching algorithm as a fast motion transcription algorithm from a real liver to a virtual liver in a surgical navigation. The real is always captured by 3D depth camera, and the virtual is represented by a polyhedron with STL format via DICOM captured by MRI/CT. In our algorithm, we firstly compare a 2D depth image in a r...

In the last year, we proposed a smart transcription algorithm. In the algorithm, a real liver is always captured by 3D depth camera. As contrasted with this, its virtual liver is represented by a polyhedron with STL (Standard Triangulated Language) format (Stereo-lithography) via DICOM (Digital Imaging and Communication in Medicine) data captured b...

In this paper, we revise a previous 2D depth-depth-matching algorithm in order to copy motions fast from a real liver to a virtual liver in a surgical navigation. The real liver is always captured by 3D depth camera, and the virtual liver is represented by a polyhedron with STL format via DICOM captured by MRI/CT. In our algorithm, we firstly compa...

Virtual surgical simulator which is using computer graphics is much popular system than before. It is generally used in the medical areas, such as medical hospital or medical university. The simulator uses virtual organ models like liver, brain and so on. These models are usually based on the scanning data from patients and are used as volume model...

In this paper, we describe about our selected method by using the 3D tile menu by hand gesture motion. In the discussion of our approach,it is a mainly subject to realize the efficient selection gesture by user’s arm for any position on the screen. Therefore, we designed the selection method by using relative position of the user’s arm joints. The...

We have developed a liver surgery support system that uses two depth cameras and measures positional relationships between a surgical knife and a liver in real time. In this report, the overview of our system, the method for depth camera calibration, the estimation for knife tip positioning, and some experimental results are described.

We have been developing a laparoscopic surgical training system. To train operations under various situations, preparation of various organ model is required. For example, shape, hardness, tactile and tumor location, size of organ. In this paper, we introduce a casting process for making a soft organ model with virtual tumors at a low cost.

In recent years, the elderly population has steadily increased. In particular in Japan, the progress of the aging is proceeding at a rapid rate in comparison with other developed countries. Surgeries to elderly people carry a lot of risk, and there is a need for measures immediately. We have been developing a support system of liver surgery using I...

Dental surgical simulator could be one of the efficient tools to learning and practicing dental surgical skills. To these simulators, the visual and tactile feedback is desirable to be processed in real time. And, in the dental operation, the hand position during operations is one of the skills to learn and practice. Therefore, we develop the denta...

We describe about our dental surgical simulator which enable users to simulate dental surgical operation. Our simulator which enables the user to learn dental surgical methods through actual hand and body postures. The proposed system uses a display showing a virtual tooth model and real teeth and gums that are positioned close to the hands of the...

In this paper, we describe about a display system for dental surgical simulator. The design concept of our system is that the system allows the user to learning the dental surgical methods with the real hand and body posture. Therefore our system set a display, which shows virtual teeth model and real teeth and gums, close to user’s hand position a...

We propose a modeling system that enables users to create tree models with 3D gesture input and Interactive L-system. It generates tree models by using growth simulation based on the trunk or silhouette shapes of trees given by user gestures. The Interactive L-system is one of the growth simulation algorithm, having spatial information of tree mode...

We propose a modeling system that enables users to create tree models with 3D gesture input. It generates tree models by using growth simulation based on the trunk or silhouette shapes of trees given by user gestures. The system carefully addresses the fragile balance and tradeoff between the freedom of user interaction and the autonomy of tree gro...

We propose a real-time interactive system that enables users to generate, manipulate and edit the shape model of a tree based on growth simulation by directly indicating its global and spatial information. For this purpose, three-dimensional (3D) spatial information is introduced to the well-known L-system as an attribute of the growth simulation....

This paper describes an efficient and intuitive method of tree shape manipulation by using two hands. A user can directly manipulate the shapes of tree models by using a well-designed two-handed interface. The exact manipulation command and partial shape of the user's intended tree model is automatically embodied and selected from the user's approx...