The past decade has seen the release of numerous software packages aimed at enhancing anatomical education. However, there has been little research undertaken by the manufacturers of these products into the benefit or otherwise of these packages for student learning. In addition, while many of the existing software packages include interactive three-dimensional models, none of them truly offer virtual dissection i.e. the cutting through anatomical layers with a haptic (tactile) interface.
This study investigated the haptic ‘dissection’ of a three dimensional digital model of the hand and wrist in anatomy education at both undergraduate (UG) and postgraduate (PG) levels. The model was used as a teaching and revision aid both prior to and after dissection of a real cadaver. A haptic enabled version of the model, allowing for real-time cutting was compared with a non-haptic version, using instead a keyboard and mouse ‘point and click’ style interface. Both versions were tested on students of gross anatomy in relation to test results and student experience.
The model was based upon Computerised Tomography (CT) and photographic slice data from the Visible Human Project female data set. It was segmented and reconstructed using Amira® 5.2.2. From here each structure was exported as a separate STL file and imported into Geomagic Freeform® Modelling TM. Once imported into Freeform® Modelling TM, the individual structures each required varying degrees of re-modelling where detail had been lost during the segmentation process. Some smaller structures such as the nerves, veins and arteries were modelled freehand.
The final model could be dissected using FreeForm® ModellingTM, the same software in which it was created. Using FreeForm® ModellingTM as a prototype VR dissector, each anatomical structure could be selected and virtually ‘dissected’ with the PHANTOM® Desktop™ haptic tool. Three methods of interacting with the model were identified: 1) using a cutting tool to cut through the selected layer; 2) using a selection paintball to first select and then delete the layer; and 3) using planes to cut the selected structure in standard anatomical views.
The study ran over five successive years and was split into three discreet phases. Phase one compared the results of PG students across control, non-haptic and haptic groups. Phase two compared the results of UG students between control and haptic groups. Phase three compared the results of UG students across control, non-haptic and haptic groups.
Due to small group sizes and a largely non-normal distributions the results were analysed using Mann-Whitney U tests. Results for all phases indicate that use of the model, both through haptic and non-haptic interfaces produced some significantly improved test results. The non-haptic version of the model performing equal or better than those with access to the haptic version. This is likely due to cognitive load being adversely affected by the addition of the haptic device. Some students reported that the haptic device was not intuitive to use and took some time to get used to, if at all. No student used either version of the model for more than five hours, with over 40% using it for less than one hour. It is possible that with increased exposure to the haptic device students may find it easier and thus beneficial. The findings of this study indicate that when used for a short period of time only (<5 hours) the haptic device may impede rather than enhance learning.
|Date of Award||2016|
|Supervisor||Clare Lamb (Supervisor), Caroline Wilkinson (Supervisor) & Roger Soames (Supervisor)|