Burkhard Wünsche

Assessment of movement quality in robot- assisted upper limb rehabilitation after stroke: a review

Electronic supplementary materialStudies of stroke patients undergoing robot-assisted rehabilitation have revealed various kinematic parameters describing movement quality of the upper limb. However, due to the different level of stroke impairment and different assessment criteria and interventions, the evaluation of the effectiveness of rehabilitation program is undermined. This paper presents a systematic review of kinematic assessments of movement quality of the upper limb and identifies the suitable parameters describing impairments in stroke patients. A total of 41 different clinical and pilot studies on different phases of stroke recovery utilizing kinematic parameters are evaluated. Kinematic parameters describing movement accuracy are mostly reported for chronic patients with statistically significant outcomes and correlate strongly with clinical assessments. Meanwhile, parameters describing feed-forward sensorimotor control are the most frequently reported in studies on sub-acute patients with significant outcomes albeit without correlation to any clinical assessments. However, lack of measures in coordinated movement and proximal component of upper limb enunciate the difficulties to distinguish the exploitation of joint redundancies exhibited by stroke patients in completing the movement. A further study on overall measures of coordinated movement is recommended.

Evaluation of game engines for simulated surgical training

The increasing complexity and costs of surgical training and the constant development of new surgical procedures has made virtual surgical training an essential tool in medical education. Unfortunately, commercial tools are very expensive and have a small support base. Game engines offer unique advantages for the creation of highly interactive and collaborative environments. This paper examines the suitability of currently available game engines for developing applications for medical education and simulated surgical training. We formally evaluate a list of available game engines for stability, availability, the possibility of custom content creation and the interaction of multiple users via a network. Based on these criteria, three of the highest ranked engines are used for further case studies. We found that in general it is possible to easily create scenarios with custom medical models that can be cooperatively viewed and interacted with. Limitations in physical simulation capabilities make some engines unsuitable for fully interactive applications, but they can be used in combination with predefined animations. We show that overall game engines represent a good foundation for low cost virtual surgery applications and we discuss technologies which can be used to further extend their physical simulation capabilities.

Using the Kinect as a navigation sensor for mobile robotics

Localisation and mapping are the key requirements in mobile robotics to accomplish navigation. Frequently laser scanners are used, but they are expensive and only provide 2D mapping capabilities. In this paper we investigate the suitability of the Xbox Kinect optical sensor for navigation and simultaneous localisation and mapping. We present a prototype which uses the Kinect to capture 3D point cloud data of the external environment. The data is used in a 3D SLAM to create 3D models of the environment and localise the robot in the environment. By projecting the 3D point cloud into a 2D plane, we then use the Kinect sensor data for a 2D SLAM algorithm. We compare the performance of Kinect-based 2D and 3D SLAM algorithm with traditional solutions and show that the use of the Kinect sensor is viable. However, its smaller field of view and depth range and the higher processing requirements for the resulting sensor data limit its range of applications in practice.

A randomized trial of computer‐based communications using imagery and text information to alter representations of heart disease risk and motivate protective behaviour

OBJECTIVE Advances in web-based animation technologies provide new opportunities to develop graphic health communications for dissemination throughout communities. We developed imagery and text contents of brief, computer-based programmes about heart disease risk, with both imagery and text contents guided by the common-sense model (CSM) of self-regulation. The imagery depicts a three-dimensional, beating heart tailored to user-specific information. DESIGN A 2 × 2 × 4 factorial design was used to manipulate concrete imagery (imagery vs. no imagery) and conceptual information (text vs. no text) about heart disease risk in prevention-oriented programmes and assess changes in representations and behavioural motivations from baseline to 2 days, 2 weeks, and 4 weeks post-intervention. METHODS Sedentary young adults (N= 80) were randomized to view one of four programmes: imagery plus text, imagery only, text only, or control. Participants completed measures of risk representations, worry, and physical activity and healthy diet intentions and behaviours at baseline, 2 days post-intervention (except behaviours), and 2 weeks (intentions and behaviours only) and 4 weeks later. RESULTS The imagery contents increased representational beliefs and mental imagery relating to heart disease, worry, and intentions at post-intervention. Increases in sense of coherence (understanding of heart disease) and worry were sustained after 1 month. The imagery contents also increased healthy diet efforts after 2 weeks. The text contents increased beliefs about causal factors, mental images of clogged arteries, and worry at post-intervention, and increased physical activity 2 weeks later and sense of coherence 1 month later. CONCLUSION The CSM-based programmes induced short-term changes in risk representations and behaviour motivation. The combination of CSM-based text and imagery appears to be most effective in instilling risk representations that motivate protective behaviour.

Mixed reality simulation for mobile robots

Mobile robots are increasingly entering the real and complex world of humans in ways that necessitate a high degree of interaction and cooperation between human and robot. Complex simulation models, expensive hardware setup, and a highly controlled environment are often required during various stages of robot development. There is a need for robot developers to have a more flexible approach for conducting experiments and to obtain a better understanding of how robots perceive the world. Mixed Reality (MR) presents a world where real and virtual elements co-exist. By merging the real and the virtual in the creation of an MR simulation environment, more insight into the robot behaviour can be gained, e.g. internal robot information can be visualised, and cheaper and safer testing scenarios can be created by making interactions between physical and virtual objects possible. Robot developers are free to introduce virtual objects in an MR simulation environment for evaluating their systems and obtain a coherent display of visual feedback and realistic simulation results. We illustrate our ideas using an MR simulation tool constructed based on the 3D robot simulator Gazebo.

Efficient modeling and rendering of turbulent water over natural terrain

Water phenomena are some of the most visually spectacular effects found in nature. This paper presents an efficient hybrid method to model turbulent water such as fast flowing rivers and waterfalls with the intent that the model can be used as part of a larger environment or scene. The model presented uses hydrostatic theory to incorporate a 2D height field and a particle system to model respectively the main volume and spray of turbulent water. The user is able to submit any environment formed from spheres and panels making the solution very flexible and adaptable.A smooth representation of the water surface is obtained by fitting a uniform B-Spline surface to the height field. Foam, spray and other turbulent effects are represented by particles which are rendered as spheres or billboards. Our results show that the model provides a nearly realistic simulation of turbulent water and for simple scenes nearly interactive speeds are possible which compares favorably with alternative techniques. For non-interactive applications ray tracing can be used to obtain higher quality results.

Framework for Healthcare4Life : a ubiquitous patient-centric telehealth system

Health care systems in many developed countries are rapidly approaching a crisis point. The reasons are an aging population, a shrinking number of workers, health care costs increasing faster than the economy, expensive new treatment options, poor public finances, and the reducing pool of health care professionals. The problem is compounded by the fact that elderly are more often affected by chronic diseases which require ongoing, often expensive, treatment. Telehealth and telecare applications are rapidly gaining in popularity because of their promise to use existing health care resources more effectively and hence to lower costs. However, usage is limited by a design often centered around the requirements of the clinical user, healthcare provider, and the equipment vendor. Many existing systems suffer from high initial costs, cannot be extended by third parties, require extra costs to add new functionalities, and are designed to create a continuing revenue source for the vendor. Furthermore the systems are usually designed to manage diseases rather than prevent them, and do not address the social and psychological needs of the patient. In this paper we critically analyse existing consumer health informatics systems and propose a framework for overcoming the identified shortcomings. The proposed system is ubiquitous, extendable by third parties, contains social aspects, and puts the user in control. Evidence from related research suggests that the design will increase motivation and participation, encourage family and social support, and improve the recording of health parameters by reducing user resistance.

Designing a web-based telehealth system for elderly people: An interview study in New Zealand

Designing healthcare systems for the elderly is a challenging endeavour. Telehealth systems are gaining popularity among elderly users, but such applications are mostly doctor-centric and are predominantly used for managing and/or treating diseases instead of preventing them. They do little to motivate patients to change their lifestyle and proactively manage their health. To address these shortcomings, we propose a web-based telehealth system, which uses Web 2.0 technologies in order to add social support and user defined content. In this study, we determine the functional and interface requirements of the system by conducting open individual semi-structured interviews with eight elderly people of age range 60 to 87. A paper prototype and three interfaces of existing Web 2.0 health applications were used to determine the optimum user interface design of the system. A qualitative content analysis was used to evaluate the responses. Overall, the respondents were positive about the idea of using the web to manage their healthcare from home and made several suggestions such as including applications to manage their diet, physiotherapy exercises to improve their health conditions and simple network games to reduce loneliness.

Mobile games for elderly healthcare

The past decade has seen much progress of computer-based tools for health care management. At the same time, mobile devices have become ubiquitous and offer new and interesting means of interaction. In this project we investigate the use of mobile games for home based elderly care. We concentrate on rehabilitation exercises involving the arms joints and muscles, employing accelerometers to measure and give feedback to players. We discuss the design and evaluation of two such games, Bowling and Penguin Toss. A pilot study suggests that the two games are an effective means for performing range of motion exercises, but that usability depends a lot on the fluency of the interaction during the game. A purely gesture based gameplay seems to be more natural and more enjoyable for the players.

The visualization and measurement of left ventricular deformation using finite element models

Abstract Heart diseases cause considerable morbidity and the prognosis after heart failure is poor. An improved understanding of cardiac mechanics is necessary to advance the diagnosis and treatment of heart diseases. This article explains techniques for visualizing and evaluating biomedical finite element models and demonstrates their application to biomedical data sets by using, as an example, two models of a healthy and a diseased human left ventricle. The following contributions are made: we apply techniques traditionally used in solid mechanics and computational fluid dynamics to biomedical data and suggest some improvements and modifications. We obtain new insight into the mechanics of the healthy and diseased left ventricle and we facilitate, the understanding of the complex deformation of the heart muscle by novel visualizations. Finally, we also introduce in this process a toolkit designed for visualizing biomedical data sets.