With spinal procedures potentially causing irreversible injury to patients, and an adverse affect rate of up to 30 percent - from spinal headaches to cardiac arrest, neurological impact and even death ("Incidents of Post-Lumbar Puncture Headaches", The Collaborative Neurology Book; Rodgers A, et al. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ December 16, 2000;321:1493-7) - they present a compelling case for the role of computer-based simulators to train physicians on procedures that require a delicate sense of touch.
The trials are the culmination of a two-year project, Medical Competency Assessment Procedure (MedCAP), funded by the Europea Union's Leonardo da Vinci technology incubator agency. If successful, MedCAP's creators envision future teaching and testing applications in other specialties.
"Placing a fine needle very close to the spinal cord requires the operator to feel very small changes in resistance as the needle tip passes through each anatomical structure. Traditionally this has been learned by practising on patients under supervision. Clearly that is not ideal. Furthermore, in today's clinical setting, medical trainees have fewer opportunities to practise", stated Professor George Shorten, director of the anaesthesiology department at Cork University Hospital. "We can't assume that practitioners can perform high-risk procedures just because they have been licensed for a certain number of years, or because they answered questions correctly on an exam. Touch-enabled computer simulators allow a variety of clinical cases to be presented, and provide objective and quantifiable metrics which together describe physician competence. These learning opportunities pose zero risk to patients while physicians demonstrate competency."
Led by the Cork University Hospital, the MedCAP team developed a virtual reality computer-based simulator with which anaesthetists hold a SensAble haptic device - like a high-precision Nintendo Wii - as 3D computer screens direct them to perform a lumbar puncture procedure. The haptic device literally pushes back on the user's hand so they feel surface tension as the spinal needle meets the skin; a "pop" as it punctures the skin; and the different viscosities of tissue, ligaments, cerebrospinal fluid and dura mater, the tough outer layer of the meninges surrounding the spinal cord. Should trainees puncture too far and enter the other meninges or the spinal cord itself - or puncture only into the skin - they feel different sensations and receive immediate alarms and on-screen error messages.
In the clinical trials, groups of skilled anaesthetists and residents-in-training must perform a lumbar puncture on six virtual patients who present at different ages and complications, and answer a battery of clinical care questions. The simulator is blind to the user's experience level, merely recording and scoring them on nearly 200 competencies and calculating a score that suggests the user is either a knowledgeable practitioner, or a trainee. Users receive detailed feedback on their performance, so that they can practise any areas of weakness until they achieve competency. Once clinical trials are completed this fall, results are expected to show that the practising anaesthetists score better than residents-in-training - suggesting the simulator is a valid competency assessment tool.
"It's not enough to train specialists with the traditional 'do one, see one, teach one' approach to learning by apprenticeship on patients", stated Erik Lovquist, researcher at the University of Limerick's Interactive Design Center, who was technical lead of the collaboratively developed haptically enabled simulator. "The MedCAP-system offers the potential to assess competence of those performing other high stakes medical procedures in a valid and reliable way."
The MedCAP partnership includes the Interaction Design Centre, University of Limerick, Ireland and the University Graz, Austria as well as the clinical centres in Cork and Pecs. Its approach is based on the competence-based knowledge space theory, developed by Dietrich Albert and the team at the University of Graz.
"With today's haptic devices and toolkits it's possible to create computer-based systems that mimic and quantify even the most subconscious aspects of human touch", stated Dr. David Chen, chief technology officer of SensAble Technologies. "The MedCAP project showcases the invaluable role that haptically-enabled simulators can play in medical certification, beyond its already-demonstrated role in training - and the sophistication that SensAble's haptics technology allows."
Founded in 1993, SensAble Technologies is a developer of 3D touch-enabled (force feedback) solutions and technology that allow users to not only see and hear an on-screen computer application, but to actually "feel" it. With 41 patents granted and over 7000 systems installed worldwide, SensAble Technologies' haptic technology is being used in applications ranging from designing toys and footwear, to surgical simulation and stroke rehabilitation, to dental restorations, as well as a range of research and robotic applications. The company markets its own 3D modelling solutions as well as its haptic devices and developer toolkits to medical, dental, design, and manufacturing companies; educational and research institutions; and OEMs. SensAble products are available through direct and reseller channels worldwide. More company news is available in the VMW September 2009 article SensAble customer, Ohio Supercomputer Center, wins National Award for haptically-enabled surgical simulation teaching tool.