Haptic forces and gamification on epidural anesthesia skill gain

Epidural anesthesia is a blind medical procedure, where the needle insertion is a critical step. Its correct placement and location is related to the tactile perception and the loss of resistance (LOR) of tissues inside the epidural lumbar region, in order to avoid the puncture of the dura-mater membrane. Skill development and maintenance occurs through continuous practice. The main objective of this work is the development of a virtual simulator to enhance the training on the epidural anesthesia, in order to reduce the high failure rate currently reported on these medical procedures. This simulator integrates the development of the following 3 new models: (1) a force-displacement model to cover the progression of resistance forces generated by tissues along the needle insertion, based on real experiment data; (2) a force-needle model, to calculate the axial forces produced by needle deflection upon insertion, based on experiment data; and (3) a tissue model to design the thickness for each tissue on the simulator, from patient height, weight and age, based on average body measurements. The developed models added more realism when compared to previous works. The force-displacement model considers stiffness, friction and cutting forces for each tissue on epidural region, and includes a representation of needle insertion stages before and after the puncture in the behavior of each tissue. Other force models did not consider force modifiers for needle deflection before. The simulator environment implements the integration of a haptic device to control the needle movement, manipulated by the user. These devices enable to reproduce the resistance generated by the developed models providing physical feedback to user movements, to emulate sensations and reactions from the bypassed tissues (skin, fat, spinal ligaments, epidural space and dura-mater), as if those actions were executed in a real patient. The haptic device used presents six degrees of freedom (DOF), allowing translations and rotations on three axes (x, y, and z). The simulator interface was improved by incorporation of points and achievements as gamification elements to enhance the user interaction. These elements may contribute for maintenance of the trainee activity along the procedure practices, and to motivate and stimulate the student learning and skill improvement. No work have employed gamification elements on the interface of epidural simulators before.