Adaptive Human Control Gains During Precision Grip

Eight human test subjects attempted to track a desired position trajectory with an instrumented manipulandum (MN). The test subjects used the MN with three different levels of stiffness. A transfer function was developed to represent the human application of a precision grip from the data when the test subjects initially displaced the MN so as to learn the position mapping from the MN onto the display. Another transfer function was formed from the data of the remainder of the experiments, after significant displacement of the MN occurred. Both of these transfer functions accurately modelled the system dynamics for a portion of the experiments, but neither was accurate for the duration of the experiments because the human grip dynamics changed while learning the position mapping. Thus, an adaptive system model was developed to describe the learning process of the human test subjects as they displaced the MN in order to gain knowledge of the position mapping. The adaptive system model was subsequently validated following comparison with the human test subject data. An examination of the average absolute error between the position predicted by the adaptive model and the actual experimental data yielded an overall average error of 0.34mm for all three levels of stiffness

Palpation force modulation strategies to identify hard regions in soft tissue organs

This work was supported by EPSRC MOTION grant (grant number EP/N03211X/1), National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London and Vattikuti Foundation

Canine Abdominal Palpation Training Device

Palpation is used in medical diagnostics to determine the conditions of underlying parts or organs using pressure of the hands and fingers on the body’s surface. There are no existing devices that teach abdominal palpation of small animals. This project aimed to design and create a haptic teaching device for use by veterinary students to learn canine abdominal palpation skills. The device simulates the tactile sense of a canine abdomen including palpable organs and abnormalities to teach students diagnostic skills. The team developed ten palpation devices with a soft tissue component, hard tissue component, three palpable objects, and two abnormalities in each device. Validation from the client, veterinary professionals, and mechanical testing confirmed the device met the objectives

FEELING FOR FAILURE: HAPTIC FORCE PERCEPTION OF SOFT TISSUE CONSTRAINTS IN A SIMULATED MINIMALLY INVASIVE SURGERY TASK

In minimally invasive surgery (MIS), the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue is critical for minimizing bodily trauma. Force perception in MIS is a dynamic process in which the surgeon\u27s administration of force onto tissue results in useful perceptual information which guides further haptic interaction and it is hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the perceptual relationship between applied force and material deformation rate specifies the distance remaining until structural capacity will fail, or indicates Distance-to-Break (DTB). Two experiments explored the higher-order relationship of DTB in MIS using novice and surgeon observers. Findings revealed that observers could reliably perceive DTB in simulated biological tissues, and that surgeons performed better than novices. Further, through calibration feedback training, sensitivity to DTB can be improved. Implications for optimizing training in MIS are discussed

Diagnostic Palpation in Osteopathic Medicine: A Putative Neurocognitive Model of Expertise

This thesis examines the extent to which the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Chapter 2 and Chapter 3 review, respectively, the literature on the role of analytical and non-analytical processing in osteopathic and medical clinical decision making; and the relevant research on the use of vision and haptics and the development of expertise within the context of an osteopathic clinical examination. The two studies reported in Chapter 4 examined the mental representation of knowledge and the role of analogical reasoning in osteopathic clinical decision making. The results reported there demonstrate that the development of expertise in osteopathic medicine is associated with the processes of knowledge encapsulation and script formation. The four studies reported in Chapters 5 and 6 investigate the way in which expert osteopaths use their visual and haptic systems in the diagnosis of somatic dysfunction. The results suggest that ongoing clinical practice enables osteopaths to combine visual and haptic sensory signals in a more efficient manner. Such visuo-haptic sensory integration is likely to be facilitated by top-down processing associated with visual, tactile, and kinaesthetic mental imagery. Taken together, the results of the six studies reported in this thesis indicate that the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Whereas the experts’ diagnostic judgments are heavily influenced by top-down, non-analytical processing; students rely, primarily, on bottom-up sensory processing from vision and haptics. Ongoing training and clinical practice are likely to lead to changes in the clinician’s neurocognitive architecture. This thesis proposes an original model of expertise in diagnostic palpation which has implications for osteopathic education. Students and clinicians should be encouraged to appraise the reliability of different sensory cues in the context of clinical examination, combine sensory data from different channels, and consider using both analytical and nonanalytical reasoning in their decision making. Importantly, they should develop their skills of criticality and their ability to reflect on, and analyse their practice experiences in and on action

Validation of the Haptic Cow: A simulator for training veterinary students

A virtual reality simulator, the Haptic Cow, has been developed using touch feedback technology for training veterinary students to perform bovine rectal palpation of the reproductive tract. The simulator was designed to supplement existing training and address some of the difficulties associated with teaching palpation-based skills. Students need to achieve a certain level of proficiency by graduation but this has become increasingly difficult because of problems with current training methods and a reduction in the number of opportunities to practice. A simulator- based teaching tool was developed as a potential solution. The first step involved designing a simulator on the basis of requirements established through consultation with both veterinary surgeons, as teachers, and students, as learners. Research was then undertaken to validate the simulator by following a set of established criteria described for the evaluation of new technologies used in medical education. The virtual models were assessed by experts as realistic enough representations of the same structures in the cow. An experiment to assess the effect of simulator training compared the performance of one group of students, whose training was supplemented with a simulator session, with another group of traditionally trained students. The subsequent performance for finding and identifying the uterus when examining cows for the first time, was significantly better for the simulator trained group, indicating that skills learned in the simulator environment transferred to the real task. A project was also undertaken to integrate the simulator into a curriculum, with training included as part of the farm animal course at the University of Glasgow Veterinary School. The training was well received by students, useful feedback was gathered and the simulator continues to be used as part of the course. Further developments were undertaken with the aim of creating a more versatile teaching tool and addressing some of the questions and issues raised. An automated version of the Haptic Cow was designed for students to use on their own, with computer guidance replacing the instructor's role. An evaluation found that the new version of the teaching tool was both usable and an effective way of equipping students with the skills required to find and identify the uterus. The potential to use haptic technology to investigate various aspects of performance was also explored in relation to the question of hand choice for certain palpation-based skills: differentiating between objects on the basis of softness and size. Ongoing research and development options are discussed, with the aim of building on the current work by expanding the role of haptic technology in veterinary education in the future

Life Sciences Program Tasks and Bibliography

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web pag