Search

Interventional Radiology procedures (e.g., angioplasty, embolization, stent graft placement) provide minimally invasive therapy to treat a wide range of conditions. These procedures involve the use of flexible tipped guidewires to advance diagnostic or therapeutic catheters into a patient’s vascular or visceral anatomy. This paper presents a real-time physically based hybrid modeling approach to simulating guidewire insertions. The long, slender body of the guidewire shaft is simulated using nonlinear elastic Cosserat rods, and the shorter flexible tip composed of a straight, curved, or angled design is modeled using a more efficient generalized bending model. Therefore, the proposed approach efficiently computes intrinsic dynamic behaviors of guidewire interactions within vascular structures. The efficacy of the proposed method is demonstrated using detailed numerical simulations inside 3-D blood vessel structures derived from preprocedural volumetric data. A validation study compares positions of four physical guidewires deployed within a vascular phantom, with the co-ordinates of the corresponding simulated guidewires within a virtual model of the phantom. An optimization algorithm is also implemented to further improve the accuracy of the simulation. The presented simulation model is suitable for interactive virtual reality-based training and for treatment planning. [ABSTRACT FROM PUBLISHER]

Guidewire and catheter manipulation is a core skill in endovascular interventional radiology. It is usually acquired in an apprenticeship on patients, but this training is expensive and risky. Simulation offers an efficient alternative for core skills training, though the instrument complex behaviour requires accurate replication. This paper reviews the mass-spring model used to simulate seven guidewires and three catheters, and the matching with their real world counterparts by tuning our model's bending coefficient, which allows replication of the instrument flexibility. This coefficient was matched through computed tomography imaging of a vascular phantom in which each instrument was inserted and manipulated. With an average distance of 2.27mm (standard deviation: 1.54) between real and virtual instruments, our representation showed realistic behaviour. [ABSTRACT FROM AUTHOR]

Training in interventional radiology is slowly shifting towards simulation which allows the repetition of many interventions without putting the patient at risk. Accurate segmentation of anatomical structures is a prerequisite of realistic surgical simulation. Therefore, our aim is to develop a generic approach to provide fast and precise segmentation of various virtual anatomies covering a wide range of pathology, directly from patient CT/MRA images. This paper presents a segmentation framework including two segmentation methods: region model based level set segmentation and hierarchical segmentation. We compare them to an open source application ITK-SNAP which provides similar approaches. The subjective human influence such as inconsistent inter-observer errors and aliasing artifacts etc. are analysed. The proposed segmentation techniques have been successfully applied to create a database of various anatomies with different pathologies, which is used in computer-based simulation for interventional radiology training. [ABSTRACT FROM AUTHOR]

This paper reports on a low cost system for training ultrasound imaging techniques. The need for such training is particularly acute in developing countries where typically ultrasound scanners remain idle due to the lack of experienced sonographers. The system described below is aimed at a PC platform but uses interface components from the Nintendo Wii games console. The training software is being designed to support a variety of patient case studies, and also supports remote tutoring over the internet. [ABSTRACT FROM AUTHOR]

During a standard procedure of liver biopsy, the motion due to respiration may be difficult to handle. The patient is often requested to hold his breath or to breathe shallowly. Ideally, this physiological behaviour should be taken into account in a virtual reality biopsy simulator. This paper presents a framework that accurately simulates respiratory motion, allowing for the fine tuning of relevant parameters in order to produce a patient-specific breathing pattern that can then be incorporated into a simulation with real-rime haptic interaction. This work has been done as part of the CRaIVE collaboration [1], which aims to build interventional radiology simulators. [ABSTRACT FROM AUTHOR]

Interventional radiology training and assessment would benefit greatly from the introduction of simulation. Assessment methods should facilitate the highest standards of training and therefore must be chosen on the basis of evidence of impact on learning. A study of assessment in a training model shows the need for specialty specific metrics which were derived from a task analysis of interventional procedures. [ABSTRACT FROM AUTHOR]

To adequately simulate the forces generated during interventional radiological (IR) procedures, non intrusive in‐vivo methods must be used. Using finger tip mounted, non intrusive capacitance force sensor pads (PPS, Los Angeles, California) we have been able to measure the forces involved in interventional radiology without a change in procedure technique. Data acquired during the process of calibration of the capacitance pads in conjunction with extensive in‐vitro needle puncture force measurement using a commercially available tensile tester (Nene Industries, UK) are presented here. [ABSTRACT FROM AUTHOR]

A SensAble Omni force feedback device has been modified to increase the face validity of a needle insertion simulation. The new end effector uses a real needle hub and shortened needle shaft in place of the Omni's pre-fitted pen shaped end effector. This modification facilitates correct procedural training through the simulation of co-located visual and haptic cues in an augmented reality approach to simulation. The development of the new end effector is described and a pictorial guide to its manufacture and the fitting process is provided. Initial results from face validation studies bode well for the fidelity of this low cost device. [ABSTRACT FROM AUTHOR]

We present an integrated system for training ultrasound guided needle puncture. Our aim is to provide a cost effective and validated training tool that uses actual patient data to enable interventional radiology trainees to learn how to carry out image-guided needle puncture. The input data required is a computed tomography scan of the patient that is used to create the patient specific models. Force measurements have been made on real tissue and the resulting data is incorporated into the simulator. Respiration and soft tissue deformations are also carried out to further improve the fidelity of the simulator. [ABSTRACT FROM AUTHOR]

The article presents obituaries for several physicians including psychiatrist Murray Archibald Jackson, general practitioner Robert Andrew Fay and general practitioner Wilfred Ernest Chapman.

A SensAble Omni force feedback device has been modified to increase the face validity of a needle insertion simulation. The new end effector uses a real needle hub and shortened needle shaft in place of the Omni's pre-fitted pen shaped end effector. This modification facilitates correct procedural training through the simulation of co-located visual and haptic cues in an augmented reality approach to simulation. The development of the new end effector is described and a pictorial guide to its manufacture and the fitting process is provided. Initial results from face validation studies bode well for the fidelity of this low cost device.

This paper reports on a low cost system for training ultrasound imaging techniques. The need for such training is particularly acute in developing countries where typically ultrasound scanners remain idle due to the lack of experienced sonographers. The system described below is aimed at a PC platform but uses interface components from the Nintendo Wii games console. The training software is being designed to support a variety of patient case studies, and also supports remote tutoring over the internet.

We present an integrated system for training ultrasound guided needle puncture. Our aim is to provide a cost effective and validated training tool that uses actual patient data to enable interventional radiology trainees to learn how to carry out image-guided needle puncture. The input data required is a computed tomography scan of the patient that is used to create the patient specific models. Force measurements have been made on real tissue and the resulting data is incorporated into the simulator. Respiration and soft tissue deformations are also carried out to further improve the fidelity of the simulator.