Augmented reality system for digital rectal examination training and assessment

Background: Digital Rectal Examination (DRE) is a difficult examination to learn and teach because of its unsighted nature and limited cases to practice. The main challenge is students and tutors cannot see the finger when it is palpating the anal canal and prostate gland inside the patients. Objective: This project presents an Augmented Reality (AR) system to be used with benchtop models commonly available in medical schools. It enables the visualisation of the examining finger, as well as the internal organs when performing DRE. Magnetic tracking sensors are used to track the movement of the finger and a pressure sensor to monitor the applied pressure. By overlaying a virtual finger on the real finger and a virtual model on the benchtop model, students can see-through the examination and finger manoeuvres. Methods: The system was implemented in Unity, and it uses a first-generation Microsoft HoloLens, as an augmented reality device. A user study was conducted to evaluate the system with 19 participants (9 clinicians who routinely perform DRE and 10 medical students). Once finished, they were asked to answer 12 questions regarding the usefulness of the system. Results: The system shows the movement of an examining finger in real-time with a frame rate of 60 FPS on the HoloLens. It can accurately align the virtual and real models with a mean error of 3.9mm. The user study suggests that the movement of the finger is realistic; moreover, the visualisation of the finger and internal organs are useful for teaching, learning, and assessment of DRE, mainly targeting a novice group. Conclusions: The proposed AR system is designed to improve the teaching of DRE skills by providing visualisation of the finger and internal organs. The initial user study proved its applicability and usefulness