Evaluation of an augmented reality platform for austere surgical telementoring: a randomized controlled crossover study in cricothyroidotomies

With the System for Telementoring with Augmented Reality, we want to increase the mentor and mentee sense of co-presence through an augmented reality channel that will lead to measurable improvements in the mentee’s surgical performance.

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Providing timely and adequate medical support to critically injured patients can be the difference between their life or death. Particularly in austere situations, first responders are trained to provide medical treatment in a pre-hospital fashion. However, no matter how experienced a first responder can be, the breadth of medical complications that can arise in a battlefield cannot be handled effectively by one person. Telementoring has been used as an option to provide local first responders with guidance from remote expert surgeons. Nonetheless, current telementoring platforms are not designed to provide support in austere scenarios: they are neither self-contained nor portable, and could detriment the free selection of motions of the first responders.

This manuscript introduces our System for Telementoring with Augmented Reality (STAR), a self-contained and portable platform that can be used to provide surgical telementoring in austere scenarios. We compare our system against audio-only telementoring, which represents the bare minimum support a first responder can receive during an austere scenario. Our experiment tests whether STAR could help mentees perform an emergency surgical procedure better, as assessed by experienced surgeons. We evaluate our hypothesis in a user study in which 20 US Navy corpsmen performed a practice cricothyroidotomy under each condition. The evaluation comprehended completion time and technique performance of specific cricothyroidotomy steps. The experiment was performed in an austere indoor environment that included loud background sounds (e.g. gunshots and helicopter engines), and smoke simulating low visibility due to explosions. Figure 1 showcases our study’s experimental conditions.

Figure 1

Figure 1. Participants performed one repetition of a cricothyroidotomy procedure for each telementoring condition: guidance using the STAR platform (left); and guidance using only audio communication (right).

Our telementoring platform leverages an Augmented Reality Head-Mounted Display (ARHMD) to provide the local mentee with the guidance from the remote mentor. Our system uses the ARHMD’s onboard camera to transmit a view of the operating field to the mentor. This eliminates the need of external cameras that could encumber the medics who work in austere settings. The view obtained from the ARHMD’s onboard camera is presented to the remote mentor after applying image stabilization techniques. This allows us to provide the mentors with a first-person view of the operating field that reduces jitter and sudden head motions that could led to motion sickness. After visualizing the mentee’s operating field, the mentor can create annotations representing surgical instructions using a touch interface (e.g. drawings incision lines, illustrates the placement of instruments). These annotations are sent back to the ARHMD at the mentee site, where they are projected in 3D onto the patient’s body. By integrating these features, STAR can function as a portable and self-contained austere surgical telementoring platform. Fig. 2 depicts a schematic of the STAR platform.

Figure 2

Figure 2. Schematic of the STAR platform. By integrating image stabilization routines with the ability to project mentor-authored surgical instructions onto the operating field, this portable system is designed to convey clinical expertise in austere scenarios. The participant showcased gave written informed consent to have their photo used for this image.

Our results reveal that STAR allowed participants undergoing simulated harsh field conditions to obtain higher performance and non-procedural scores while performing cricothyroidotomies, as assessed by expert evaluators. Our study hints that telementoring capabilities of ARHMD-based platforms can improve the amount of medical guidance that first responders receive from remote experts during austere situations. Overall, this study positions ARHMD-based telementoring as a promising option for providing assistance in austere scenarios in the military.

AcknowledgmentsThis work was supported by both the Office of the Assistant Secretary of Defense for Health Affairs under Award No. W81XWH-14-1-0042, and the National Science Foundation under Grant DGE-1333468. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the funders.

Edgar Rojas-Muñoz

Research Assistant, Purdue University