Papers by Tomohiro Kuroda
AR instruction system to manipulate US probe in tele-echo
Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1999
Describes an instruction system to manipulate an ultrasound (US) probe in tele-echo using an augm... more Describes an instruction system to manipulate an ultrasound (US) probe in tele-echo using an augmented reality (AR) technique. In this system, an image including a patient chest and a US probe was captured at a measurement site and transferred to a diagnosis site. A medical doctor at a diagnosis site instructed the location and orientation of a US probe with
FEM-based interaction model between elastic objects for indirect palpation simulator
PubMed, 2004
Indirect palpation is required to examine lots of cases like breast cancer and prostate malignanc... more 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.
MVL: medical VR simulation library
PubMed, 2005
In the last ten years, medical VR techniques have much progress and many simulators have been dev... more 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.
An immersive communication support system for telesurgery
医療情報学連合大会論文集, Nov 23, 2000
The simulation of organ-organ interaction is indispensable for practical and advanced medical VR ... more The simulation of organ-organ interaction is indispensable for practical and advanced medical VR simulator such as open surgery and indirect palpation. This paper gives a method to represent interaction between elastic objects i.e. organs in medical VR simulation. The proposed model defines displacements of colliding elements based on temporary surface forces caused by temporary displacements, so that 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 with the proposed model. The results of experiments confirmed the method expresses organ-organ interaction in real time and produces realistic and perceivable force feedback.
Haptized Shared VR based Surgical Simulator – Applying to Vocational Experience
Simulation in Healthcare: The Journal of the Society for Simulation in Healthcare, 2006
An interaction model between multiple deformable objects for realistic haptic force feedback in surgical simulations
CARS 2002 Computer Assisted Radiology and Surgery, 2002
This paper proposes an interaction model between multiple physically-based deformable object. Thi... more This paper proposes an interaction model between multiple physically-based deformable object. This model achieves both accurate force feedback and visualization of surgical manipulations (like hold, push and move organs) while approaching the tissues of interest. Accurate force feedback improves surgical realism and enables exact simulation for diagnosis and procedural training. Interaction is represented by mutual iterative procedures of forcible displacement, calculation of deformation and reaction force. The proposed model has been applied to a simulation where a manipulating point pushes a deformable object, which is in contact with a neighboring one, and the influence of interaction on haptic force feedback has been examined.
Speculative FEM Simulation System for Invasive Surgical Operation with Haptic Interaction
Systems Modeling and Simulation
Conventional virtual reality surgical simulators are provided for non-invasive operation because ... more Conventional virtual reality surgical simulators are provided for non-invasive operation because of the calculation resource limitation of personal computer. For development of advanced simulator, simulation of invasive operation such as incision and ablation is required. Besides, for interactive haptic simulation, the rupture model should be adopted based on physics. Therefore, achievement of huge scale rupture simulation system with interactivity is
Planning and training of minimally invasive surgery by integrating soft tissue cuts with surgical views reproduction
CARS 2002 Computer Assisted Radiology and Surgery, 2002
This paper gives integrated methods that perform virtual reality based planning and training of m... more This paper gives integrated methods that perform virtual reality based planning and training of minimally invasive surgery. The authors propose an advanced framework of volumetric soft tissue cutting, which consistently combines topological changes into deformable models. Collision detection and physical constraint are provided in simulated surgery space. Time series MRI dataset are applied to a visual and haptic system with a force feedback device. The reconstructed environment enables to identify approachable region, and to discuss optimum strategy. Figures and evaluations assure that the developed methods are effective in preoperative planning as well as in learning surgeries.
Toward Visualization of Skill in VR: Adaptive Real-Time Guidance for Learning Force Exertion through the "Shaping" Strategy
Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (WHC'07), 2007
The authors aim to make principles of expert's haptic int... more The authors aim to make principles of expert's haptic interaction explicit on a virtual reality (VR) based simulator. Our approach is based on visualization of significant components of the interaction with consideration on their importance which acts as the foundation for manual skill. Delicate force exertion, which is the basis for various fine-motor skills, was chosen as an example. Expert's
Construction of Training Environment for Surgical Exclusion with a Basic Study of Multi-finger Haptic Interaction
Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (WHC'07), 2007
Virtual reality based surgical simulator allows a repetitive training without spoiling patients. ... more Virtual reality based surgical simulator allows a repetitive training without spoiling patients. Exclusion is an important surgical manipulation of pushing aside organ to make a hidden tissue visible. The authors propose an organ exclusion training simulator with multi-finger haptic interaction and stress visualization. The system equips FEM-based soft tissue deformation and exoskeletal haptic device CyberForce. Real-time simulation was achieved with a prototype system. Results of training trial suggested effectiveness of stress visualization especially in early training days. Subjective evaluation by surgeons cleared its potential. Results of a basic study showed decrease of required refresh rate in multi-finger interaction compared with single finger interaction. It suggested the system can keep realism even if calculation time is increased by multi-finger interaction
A novel approach for training of surgical procedures based on visualization and annotation of behavioural parameters in simulators
Studies in health technology and informatics, 2007
Recording performance during training sessions on simulators is becoming a new standard for asses... more Recording performance during training sessions on simulators is becoming a new standard for assessment of surgical skills and thus a significant part of training. Typical simulator-based training can be assessed using criteria that cover the whole procedure to make distinction between skill levels. Studies so far have rarely addressed the challenge of how to provide better feedback about the user's performance on a surgical simulator. Our approach for surgical training is Annotated Simulation Records (ASRs) and visualization of behavioural parameters of interaction in surgery. This paper briefly outlines a framework for building user-defined skill models and presents initial results. We demonstrate the ASR-based approach in force exertion tasks on elastic objects by utilizing a cardiovascular surgeon's recorded interaction on an aorta palpation simulator.
Organ exclusion simulation with multi-finger haptic interaction for open surgery simulator
Studies in health technology and informatics, 2007
Exclusion is a surgical manipulation of pushing aside organ in open surgery. Recently, training o... more Exclusion is a surgical manipulation of pushing aside organ in open surgery. Recently, training opportunity of surgeon is decreasing due to animal protection and patient's rights. In this study, we propose an organ exclusion training simulator with multi-finger haptic device and stress visualization. The method was applied to a medical application of exclusion which is an important manipulation to make a hidden tissue visible or to enlarge workspace. The system equips FEM-based soft tissue deformation and multi-finger haptic device. Real-time simulation was achieved with a prototype system. Experimental results of training trial suggested the effectiveness of the system and stress visualization for exclusion training. Results of subjective evaluation by surgeons were highly positive as to realism of manipulation and usefulness of the simulator.
A proposal of speculative operation on distributed system for FEM-based ablation simulator
Studies in health technology and informatics, 2007
This study aims to provide physics-based force feedback system on distributed system for simulati... more This study aims to provide physics-based force feedback system on distributed system for simulating invasive operation such as ablation. conventional PC-based VR surgical simulators with haptic interaction are hard to provide sufficient computational resources for the simulation of physics-based soft tissue fracture. For proper presentation of force feedback as real operations, physics-based simulation is inevitable. At the same time finite element method requires huge computational complexites. In this paper, the authors propose server-side speculative operation method on application layer for hiding the calculation latencies. The proposed method would achieve the response acceleration without the decomposition of conventional simulation process. The theoritical estimates of speculation parameters are mentioned.
Interactive 3D region extraction of volume data using deformable boundary object
Studies in health technology and informatics, 2005
This study aims to establish an interactive and intuitive region extraction environment for volum... more 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.
FEM-based soft tissue destruction model for ablation simulator
Studies in health technology and informatics, 2005
In surgical procedures, ablation is one of the most difficult skills to train and acquire. For th... more 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.
Study of spatial anisotropy in finger's haptic perception for advanced palpation training
Performance of Position Detection Tasks under Restriction of Finger's Movement
ABSTRACT Although many virtual reality based palpation simulators have been developed, nature of ... more ABSTRACT Although many virtual reality based palpation simulators have been developed, nature of palpation skill is not well understood. In this study, proper finger manipulation in palpation is investigated for advanced medical training. Observation of skilled physician's manipulation implied the importance of direction of finger's movement. Performance of position detection tasks under restriction of finger's movement was examined using both virtual and real environments. Virtual environment with FEM based deformation and force display was rapidly set up and an experiment was carried out. Results of the experiment showed clear difference in accuracy and completion time among restricted directions. For example, radial movement performed highest accuracy in tangential, radial, vertical and free finger movements. On the contrary, any significance was not found among the restricted directions in a real world setup consisting of a silicone- rubber model in which fingertip's motion was recorded by digital video and position was calculated by image processing techniques. Performance in combination of manipulations was also examined.
Estimation of application level speculative operation on distributed system for haptic VR simulation of invasive operation
Volume interaction framework for preoperative surgical simulation on volumetric images
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Papers by Tomohiro Kuroda