Biomedical subjects

Tomohiro Kuroda

Publications and source records attributed to Tomohiro Kuroda.

9 recordsLinked to original sources

PubMed2005

Interaction model between elastic objects for haptic feedback considering collisions of soft tissue.

The simulation of organ-organ interaction is indispensable for practical and advanced medical VR simulator such as open surgery and indirect palpation. This paper describes a method to represent real-time interaction between elastic objects for accurate force feedback in medical VR simulation. The proposed model defines boundary deformation of colliding elements based on temporary surface forces calculated by temporary deformation. The model produces accurate deformation and force feedback considering collisions of objects as well as prevents unrealistic overlap of objects. A prototype simulator of rectal palpation is constructed on general desktop PC with a haptic device, PHANToM. The system allows users to feel different stiffness of a rear elastic object located behind another elastic object. The results of experiments confirmed the method expresses organ-organ interaction in real-time and produces realistic and perceivable force feedback.

Computer Simulation↗

PubMed2005

Electronic clinical path system based on semistructured data model using personal digital assistant for onsite access.

Clinical Paths (Paths) have been introduced by different hospitals for patient care management. An Electronic Clinical Path (ECP) with onsite access provision seems to improve the efficiency of medical staffs because they can share vast medical information about patients at a time and also can reuse accumulated data easily, which is impossible with paper-based Path. Data model is the basis for implementing ECP. However, there is no established model for ECP. The purpose of this study is to introduce a model for ECP and implement an ECP with onsite access system. We introduced a Semistructured Data Model (SSDM) for ECP, and implemented a Web application system based on this model using Personal Digital Assistant (PDA) as inputting device. Our system functioned as expected with wireless LAN, and users handled the data on bedside using PDA. By introducing SSDM, we showed the correspondence between schema of Paths and implementation of ECP.

Access to Information↗

PubMed2005

Improving precise positioning of surgical robotic instruments by a three-side-view presentation system on telesurgery.

For faultless collaboration among the surgeon, surgical staffs, and surgical robots in telesurgery, communication must include environmental information of the remote operating room, such as behavior of robots and staffs, vital information of a patient, named supporting information, in addition to view of surgical field. "Surgical Cockpit System, " which is a telesurgery support system that has been developed by the authors, is mainly focused on supporting information exchange between remote sites. Live video presentation is important technology for Surgical Cockpit System. Visualization method to give precise location/posture of surgical instruments is indispensable for accurate control and faultless operation. In this paper, the authors propose three-side-view presentation method for precise location/posture control of surgical instruments in telesurgery. The experimental results show that the proposed method improved accurate positioning of a telemanipulator.

Humans↗

PubMed2005

FEM-based soft tissue destruction model for ablation simulator.

In surgical procedures, ablation is one of the most difficult skills to train and acquire. For the risk of ablation failure, ablation training environments are desired. This paper proposes FEM-based deformation and destruction soft tissue model for ablation training simulator. The proposed model employs shearing stress hypothesis. The result of simulation experiments shows that the model can express different destruction progression by manipulation.

Catheter Ablation↗

PubMed2005

MVL: medical VR simulation library.

In the last ten years, medical VR techniques have much progress and many simulators have been developed for education, planning, rehearsal and so on. On the other hand, developing a simulator takes much more labor and cost. In this paper, we propose MVL: Medical Virtual reality simulation Library, which supports simulation of several significant medical manipulations considering multiple organ interaction. The result of developing simulators using MVL confirmed validity about variety and developing cost.

Computer Simulation↗

PubMed2005

Interactive 3D region extraction of volume data using deformable boundary object.

This study aims to establish an interactive and intuitive region extraction environment for volume data. A volume clipping method using deformable boundary object is proposed to support 3D region extraction task. Slice-based volume rendering of boundary elements enables to visualize clipped results in real time. Geometrical transformation and physics-based deformation support intuitive modification of 3D region of interest. Some extraction tasks are tested using CT data set on the developed system. All tests confirmed real-time visualization of clipped results is effective for interactive 3D region extraction in volume visualization and virtual object modeling.

Elasticity↗

PubMed2004

FEM-based interaction model between elastic objects for indirect palpation simulator.

Indirect palpation is required to examine lots of cases like breast cancer and prostate malignance. This paper proposes interaction model between elastic objects to simulate indirect palpation. The interaction is simulated by displacement of colliding elements based on normal stress derived from temporary displacement. The physics-based approach represents the difference of physical properties such as stiffness of colliding objects. Deformation and haptic reproduction is possible to be carried out in real time with two organ models consisting of roughly 200 nodal points. As an example, we developed a rectal palpation simulator based on the proposed method. The experiment using rectal palpation simulator confirmed that the method enables a user to perceive difference of stiffness of prostate model located behind rectum model indirectly.

Computer Simulation↗

PubMed2004

Physics-based preoperative approach planning using hybrid virtual bodies.

This paper proposes a hybrid model mixing geometry and volume data to improve representation of virtual bodies. This model applies object-oriented data models and rendering techniques to virtual organs, and enables both interactive VR simulation and detailed volume visualization of tissue of interest (e.g. coronary). Also, a physics-based framework interactively simulates estimated surgical fields which are used in preoperative discussion. Based on the proposed methods, a VR-based strategic planning system is developed. The system does not need high cost manual segmentation of patient dataset and efficiently supports planning of surgical approaches in cardiovascular surgery.

Humans↗

PubMed2004

Practical haptic navigation with clickable 3D region input interface for supporting master-slave type robotic surgery.

Conventional display in robotic surgery such as flat displays or stereoscopic displays decreases obtainable information around target tissue. For supporting manipulation and performing safe surgery, this paper proposes a haptic navigation method, which enables surgeons to avoid collision with untouchable regions around target tissue by producing force feedback through a master manipulator. This paper also developed an input interface for assignment of 3D untouchable regions through 2D device. Simulator based experiment clears effectiveness of the proposed haptic navigation for improving safety of robotic surgery.

Humans↗