Objective Sensor-based Feedback Improves Performance of Skill in Applying Junctional Hemorrhage Control Devices

Bauchwitz, B.1, Kwan, C.2, Niehaus, J.1, Pugh, C.2, and Weyhrauch, P.1

Presented at the Military Health System Research Symposium (MHSRS), Kissimmee FL (August 2017)


Junctional and inguinal bleeding from battlefield injuries is a significant and challenging problem. Inventors have developed new devices, such as the SAM® Junctional Tourniquet (SJT) to address these injuries. While several new tourniquets have been developed, validated, and approved for use, training that teaches and refreshes skills related to these technologies has been only partially addressed. Such training is vital because these skills are critical but infrequently used. To address these needs, we developed a training system that is designed to provide objective assessment and real-time feedback during the application of junctional tourniquets, called Tourniquet Master Training (TMT). TMT includes instructional materials and a sensor-based live-training system on a manikin, which has been described previously (Kwan et al. 2016, Weyhrauch et al. 2014). This study evaluated the training effectiveness of TMT in a population of EMS professionals.


We recruited 46 EMS professionals to participate in this study. Prior to training, all participants recorded their demographics and rated their confidence in applying junctional tourniquets. Participants reviewed instructional material teaching how to apply the SJT to stop inguinal hemorrhage, and were randomly assigned to either a “feedback” or “no feedback” group. Participants then performed five manikin simulation training trials in which they attempted to treat an inguinal hemorrhage using the SJT, either with or without TMT feedback, depending on their group assignment. All participants then completed two assessment trials without feedback, and were assessed on the location of the tourniquet, amount of pressure applied, time to complete the simulation, and correctness and order of the application steps. After the session, participants rated their confidence in applying junctional tourniquets and responded to a series of open-ended survey questions about their experience.


All participants reported an increase in confidence at applying junctional tourniquets, with a greater increase for participants who received TMT real-time feedback. Participants in both conditions rated the training experience positively, and most participants who received feedback stated that it was beneficial. Participants who received the feedback completed their tourniquet applications more quickly and applied a more correct amount of pressure. All participants had equally low error rates for performing steps correctly and in the correct order. Sensor data was insufficient to determine whether the location was more correct for participants with feedback, and subjective video analysis did not reveal any obvious differences. More experienced participants performed worse on most metrics, but still improved when given feedback.


Our results indicate that training with TMT feedback can improve the ability to apply junctional tourniquets such as the SJT. An interesting result is that the data shows expert users perform worse on TMT metrics initially but improve over time with TMT feedback. One possibility is that existing training processes are negatively impacting the training of these skills. Further work is suggested to determine whether and why current training practices result in a deficit, and whether future training systems can incorporate those lessons to improve training results.

1 Charles River Analytics
2 University of Wisconsin-Madison

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