Haptics refers to the study of touch. When discussing haptics in medical training, a haptic task refers to a procedure where the sense of touch forms a predominate component of the sensory input required by the practitioner for success. This may be the use of a tool to inspect and manipulate internal organs, the use of direct pressure for diagnosis or to conduct a physiological change.
Haptic tasks have been traditionally hard to transfer from expert to novices due to its slow sub-conscious development through practice that leads to a qualitative understanding. Practitioners have learnt to react to subtleties haptic or visual cues that affect their in-procedure decision-making yet be unaware or unable to articulate the process. The medical field employs supervised procedures, in an apprenticeship model, to gradually expose novices to performing procedures on the patients. However, under this training regime, it has been traditionally complex to ascertain individual competency. In the recent years, simulators have been investigated as an alternative training method to deal with the issues of supervised procedures. Medical simulation training removed the risk to patients whilst providing novices a systematic approach to train haptic-centric tasks and ascertain competency in fundamental skills.
Low complexity haptic tasks such as palpation posed a significant modelling and simulation problem for resarchers. The simulation of abdominal palpation provided addition challenges due to its involvement of relatively high feedback forces and large interaction area. These challenges have not been concurrently approached in the current body of palpation simulation literature. Existing palpation simulations have been shown to have a limited effectiveness for validated training, except in specific medical fields. This was speculated to be due to reliance on virtual simulation for haptically focussed tasks.
This thesis detailed the research and development of a solution to abdominal palpation simulation. Subsequently, a functional part-task trainer was developed for validation. It was designed as a haptic device model to be incorporated within a larger realistic mock simulation scenario. At first, the thesis looked at the field of simulator driven medical training and identified a neglection haptics within the realistic mock simulations. The existing approaches and haptic technologies were investigated and it was shown that a novel approach was required to preserve the necessary equipment and psychological fidelity for haptic simulation within a mock environment. The immediate application of this technology would take place within an mannequin in mock colonoscopy simulation. It was designed to facilitate a crucial team interaction known as abdominal palpation. This procedure has no formal training methodology associated with individually or team training.
A novel approach was proposed that combined advantages of virtual simulators and physical part-task trainers to create a haptically augmented physical trainer. With the colonoscopy application in mind, the scope and design of the haptic technology was quantified by recording a range of abdominal stiffness to provide an approximate understanding of the likely haptic feedback to be experienced during a palpation interaction. Subsequently this data was modelled to provide physical relevance for the haptic simulator.
The last component of this thesis deals with the implementation, testing and validation of a novel haptic technology that was developed to fulfil the needs of a realistic mock simulation environment. This technology was implemented iteratively as a small-scale prototype that was tested and validated by gastroenterology assistants. The results indicate that although the technology is still preliminary development, the technology holds promise for the simulation of haptic feedback in abdominal palpation.