Pages: pp. 153-154
The clinical skills of medical professionals rely strongly on the sense of touch, combined with anatomical and diagnostic knowledge. Haptic exploratory procedures allow the expert to detect anomalies via gross and fine palpation, squeezing, and contour following. Haptic feedback is also key to medical interventions, for example when an anaesthetist inserts an epidural needle, a surgeon makes an incision, a dental surgeon drills into a carious lesion, or a veterinarian sutures a wound. Yet, current trends in medical technology and training methods involve less haptic feedback to clinicians and trainees. For example, minimally invasive surgery removes the direct contact between the patient and clinician that gives rise to natural haptic feedback, and furthermore introduces scaling and rotational transforms that confuse the relationship between movements of the hand and the surgical site. Similarly, it is thought that computer-based medical simulation and training systems require high-resolution and realistic haptic feedback to the trainee for significant training transfer to occur. The science and technology of haptics thus has great potential to affect the performance of medical procedures and learning of clinical skills.
This special section is about understanding the role of touch in medicine and clinical skill acquisition. We identify three major areas of haptics in medicine and clinical skill acquisition, and present papers on each of these topics in the special section:
The first two papers address human motor control and learning in medically relevant scenarios. In “Perception and Action in Teleoperated Needle Insertion,” Ilana Nisky, Assaf Pressman, Carla M. Pugh, Fernando A. Muss-Ivaldi, and Amir Karniel examined the effects of time delay on human perception and action in a virtual environment that simulates teleoperated needle insertion. They found that time delay can cause human motor behavior that is consistent with an underestimate of nonlinear tissue stiffness, even though perception of the tissue stiffness is unchanged. By changing teleoperation control parameters, the authors were able to improve human motor performance during the needle insertion task without distorting perception. In “Effect of Grip Force and Training in Unstable Dynamics on Micromanipulation Accuracy,” Eileen Lee Ming Su, Gowrishankar Ganesh, Che Fai Yeong, Chee Leong Teo, Wei Tech Ang, and Etienne Burdet stu-died whether people's micromanipulation (as in microsurgery) abilities can be improved through training in an unstable dynamic environment. Users who trained in an environment that amplified position errors through the introduction of unstable dynamics performed straight-line point-to-point movements with less error and variability than users who trained in an environment with no intro-duced dynamics. These papers not only provide inspiration for the design of medical teleoperators and trainers, but also give insight to fundamental aspects of human motor control and perception.
The next three papers are related to the design of haptic simulators for training medical procedures, and present implementations involving needle insertion. In “Constraint-Based Haptic Rendering of Multirate Compliant Mechanisms,” Igor Peterlík, Mourad Nouicer, Christian Duriez, Stéphane Cotin, and Abderrahmane Kheddar address the challenge of simulating complex interactions between medical devices and anatomical structures. Through a generic formulation using virtual mechanisms to describe both instruments and deformable soft tissue, the authors implement physically based models and solve in real time for the motions and forces resulting from interactions. The approach was applied to simulate flexible needle insertion. In “Haptic Simulator for Prostate Brachytherapy with Simulated Needle and Probe Interaction,” Orcun Goksel, Kirill Sapchuk, and Septimiu E. Salcudean present a simulator design for a specific medical procedure prostate brachytherapy. The authors use a finite-element 3D model of deformable tissue and its interaction with both a flexible needle delivering radioactive seeds and a transrectal ultrasound probe. The simulator allows both the needle and the probe to be controlled (and felt) using haptic devices, and trade-offs between accuracy and speed are discussed. In “Integrating Haptics with Augmented Reality in a Femoral Palpation and Needle Insertion Training Simulation,” Timothy Coles, Nigel John, Derek Gould, and Darwin Caldwell integrate haptics with augmented reality to create a simulator for realistic palpation and needle inser-tion into the femoral artery. The system allows both force and tactile feedback through multiple linked commercial haptic devices and a novel hydraulic device for a pulse-like effect. A face and content validation study was performed with interventional radiology experts, demonstrating high face validity of the system.
The last paper describes new technology, and its evaluation, for providing haptic feedback during a medical intervention. In “Tool Contact Acceleration Feedback for Telerobotic Surgery,” William McMahan, Jamie Gewirtz, Dorsey Standish, Paul Martin, Jacquelyn A. Kunkel, Magalie Lilavois, Alexei Wedmid, David I. Lee, and Katherine J. Kuchenbecker describe an approach that acquires tool contact acceleration signals from the patient-side manipulator of a teleoperated robot-assisted surgery system and displays corresponding vibrations to the user via sound and voice coil actuators. Experiments with the system, called VerroTouch, revealed that users appreciated the inclusion of tool contact acceleration feedback, although it did not have measurable impact on user task performance. This work represents significant progress toward a practical and compelling means to provide haptic feedback during robot-assisted surgery.
Allison M. Okamura
William S. Harwin
The papers in this special section were selected from a large number of submissions, which reflects the research community's strong interest in haptics in medicine and clinical skill acquisition. We are grateful to the numerous reviewers who provided high quality and timely reviews. Several ToH editorial board members, in particular Ed Colgate and Lynette Jones, went above and beyond the call of duty to support this special section. We would also like to express our thanks to the ToH editorial staff, Mercy Frederickson and Pilar Hawthorne, for their guidance and gentle encouragement to stay on schedule. Creating this special section was extremely rewarding due to the haptics community's enormous interest in this topic and enthusiastic involvement in the peer review process.