Asko Ristolainen

Low cost anatomically realistic renal biopsy phantoms for interventional radiology trainees

This paper describes manufacturing of economically affordable renal biopsy phantoms for radiology residents and practicing radiologists. We reconstructed a realistic 3-dimensional patient-specific kidney model from CT data, manufactured an organ mould and casted the kidney phantoms. Using gelatin gel materials with calibrated parameters allowed making phantoms with realistic mechanical, ultrasound and CT properties including various pathologies. The organ phantoms with cysts included were further casted into gelatin gel medium. They were validated by radiology residents in biopsy training and compared against self-made phantoms traditionally used in the curriculum of interventional radiology. The realism, durability, price and suitability for training were evaluated. The results showed that our phantoms are more realistic and easier to use than the traditional ones. Our proposed technology allows creating a low-cost (50

A bio-mimetic design and control of a fish-like robot using compliant structures

/kg) alternative to the pricy commercial training phantoms available today.

Development of a Cognitive Robotic System for Simple Surgical Tasks

This paper presents a bio-mimetic approach to the design and control of a fish-like robot with compliant parts. One of the key contributions of this work is the use of continuous structures instead of discrete assemblies. In this framework, the motion of the robot is accomplished by copying the kinematics of a biological fish swimming in a sub-carangiform mode. The flexible part referred to as the tail is modeled as a cantilever beam with non-uniform cross-section actuated by a time varying moment. The geometrical and inertial properties of the tail are known. The method of assumed mode is used to derive the equations of motion of the tail; a relationship between the applied torque and the lateral line deflections is calculated. The expression of the torque mimicking the midline kinematics of a biological fish is then computed. A prototype implementing the proposed approach is built. Experiments are performed on a given tail in air and in water. The calculated and experimental midline deflections are then compared.

Economically affordable anatomical kidney phantom with calyxes for puncture and drainage training in interventional urology and radiology

The introduction of robotic surgery within the operating rooms has significantly improved the quality of many surgical procedures. Recently, the research on medical robotic systems focused on increasing the level of autonomy in order to give them the possibility to carry out simple surgical actions autonomously. This paper reports on the development of technologies for introducing automation within the surgical workflow. The results have been obtained during the ongoing FP7 European funded project Intelligent Surgical Robotics (I-SUR). The main goal of the project is to demonstrate that autonomous robotic surgical systems can carry out simple surgical tasks effectively and without major intervention by surgeons. To fulfil this goal, we have developed innovative solutions (both in terms of technologies and algorithms) for the following aspects: fabrication of soft organ models starting from CT images, surgical planning and execution of movement of robot arms in contact with a deformable environment, designing a surgical interface minimizing the cognitive load of the surgeon supervising the actions, intra-operative sensing and reasoning to detect normal transitions and unexpected events. All these technologies have been integrated using a component-based software architecture to control a novel robot designed to perform the surgical actions under study. In this work we provide an overview of our system and report on preliminary results of the automatic execution of needle insertion for the cryoablation of kidney tumours.

Hydromast: A Bioinspired Flow Sensor with Accelerometers

Background Trends in interventional radiology and urology training are orientated towards reducing costs and increasing efficiency. In order to comply with the trends, we propose training on inexpensive patient-specific kidney phantoms. Purpose To develop a new kidney phantom for puncture and drainage training in interventional urology and radiology, and to evaluate their anatomical correctness and suitability for training compared to the traditional way of training on home-made phantoms. Material and Methods A case study for validation of kidney phantoms was conducted with nine radiology students divided into two groups: one trained on standard home-made training phantom (n = 4) and the other on our kidney phantoms (n = 5). Another test phantom was used to evaluate the effectiveness of the training of the two groups. The tests were video recorded and analyzed. Duration of the procedure was used as the primary indicator of procedure’s quality. Comparison tests were also conducted with professional radiologists. Anatomical correctness of the kidney phantom was evaluated by comparing the post mortem kidney scans with reconstructed models from CT scans. Subjective feedback was also collected from the participants. Wider use of kidney phantoms was analyzed. Results The average volumetric difference between post mortem kidney scans and reconstructed CT kidney models was 4.70 ± 3.25%. All five students practicing on the kidney phantom improved their performance and the results were almost equal to the results of the professional radiologist while in the other group two students out of four trained on standard home-made training phantoms failed to improve their performance. However, the small number of test subjects prevents us from drawing general conclusions about the efficiency of the new practice. The kidney phantoms were found usable also for nephrostomy catheter placement training under fluoroscopy. Conclusion The feedback from radiologists showed that the anatomically correct features of the phantom is an added value for the training and has a potential to increase the quality of minimally invasive procedures in general.

Development of high fidelity liver and kidney phantom organs for use with robotic surgical systems

Fish have developed advanced hydrodynamic sensing capabilities using neuromasts, a series of collocated inertial sensors distributed over their body. We have developed the hydromast, an upscaled version of this sensing modality in order to facilitate near bed sensing for aquatic systems. Here we introduce the concept behind this bioinspired flow sensing device as well as the first results from laboratory investigations.