Abstract
LAY SUMMARY
Clothes that remotely monitor the wearer’s heart rate, breathing rate, and other vital signs are becoming more available and reliable. The information obtained from these clothes could help military forces create more realistic and stressful training scenarios to better prepare soldiers for combat. It could also provide valuable information to medical personnel about wounded soldiers to help save lives. This study confirmed this type of garment was reliable and functional, and obtained accurate data when used in a military field training exercise by a reserve medical unit of the Canadian Armed Forces.
The use of garments with embedded health sensors to monitor vital signs is an emerging area of civilian and military performance optimization and remote health care delivery. This technology may enable military forces to optimize training to generate certain levels of physiologic stress within soldiers, thus better preparing them for combat. Additionally, in combat environments, these garments may allow for medical providers to monitor wounded soldiers and provide direction to medical personnel in the field or better prepare them to receive casualties at medical facilities. This study assessed the performance and reliability of the Hexoskin garment in a two-day military field exercise by a Canadian Forces Health Services Group reserve unit. It determined the garment was fully functional, did not impact soldier performance, and reliably measured physiologic data for the duration of the exercise. Future research may assess the reliability of these garments in more extreme environmental conditions or in wounded personnel.
L’utilisation de vêtements munis de capteurs de santé intégrés pour surveiller les signes vitaux est un secteur émer-gent visant à optimiser la performance civile et militaire et à fournir des soins à distance. Cette technologie pourrait permettre aux forces militaires d’optimiser leur entraînement de manière à produire certains niveaux de stress physiologique chez les soldat(e)s et, ainsi, à mieux les préparer au combat. De plus, dans des environnements de combat, ces vêtements pourraient permettre aux dispensateurs de soins d’évaluer les soldat(e)s blessé(e)s et de donner des recommandations au personnel médical sur le terrain ou de mieux les préparer à recevoir des blessé(e)s aux établissements de santé. Dans la présente étude, les chercheurs ont évalué la performance et la fiabilité du vêtement Hexoskin lors d’un exercice militaire de deux jours sur le terrain, mené par une unité de réserve du Groupe des Services de santé des Forces canadiennes. L’étude a établi que le vêtement était pleinement fonctionnel, qu’il ne nuisait pas à la performance des soldat(e)s et qu’il mesurait les données physiologiques avec fiabilité pendant la durée de l’exercice. Des futures recherches pourraient évaluer la fiabilité de ces vêtements dans des conditions environnementales extrêmes ou auprès de membres du personnel blessés.
Embedded health sensors in clothing have seen increased use by high-performance athletes and astronauts over the past decade. There has been research in the use of embedded sensors for remote monitoring during training and in combat environments with different military organizations around the world.1–6 The ability to obtain precise, real-time, and continuous monitoring of vital signs creates the potential to optimize soldiers for the battlefield through physiologically stressful training in different environments. Additionally, it may enable medical providers to administer a higher level of medical care and advice to forward personnel when soldiers are wounded.
For this study, a Hexoskin7 smart garment that included sensors for continuous cardiac, respiratory, and activity monitoring was worn by a member of the Canadian Armed Forces (CAF) 12 (Vancouver) Field Ambulance during Exercise Trained Medic 2021, the final military training exercise of the 2020–21 training year. Continuous data collection for 30 hours was achieved. During the final mass casualty simulation, the device’s Bluetooth connectivity was tested on cell phones while in the field for real-time point-of-care monitoring. Data were then downloaded and analyzed using the computer-based Hexoskin Connected Health Platform.
This study is the first documented use of this technology in a CAF reserve health services unit.
With current COVID-19 pandemic constraints requiring significant personal protective equipment, the use of such garments may make ground and aeromedical transport safer for clinicians by using remote monitoring that allows for minimized patient contact. Furthermore, monitoring soldiers’ vital signs remotely could determine the level of physiologic stress they experience during training to ensure adequate stress levels are reached. Additionally, in the case of a wounded soldier wearing these garments, clinical information obtained may allow for earlier recognition of casualty decompensation and continuous assessment of patients while en route to higher levels of care. In theory, this could permit more timely and efficient medical interventions.
The adaptation of civilian-developed technology to military environments offers the opportunity to utilize new technologies for military applications with less financial impact than developing those technologies in-house. Remote-monitoring garments offer many potential applications within both training and operational military environments for performance optimization and remote medical care. With the current pandemic, the use of remote medical vital signs monitoring is of even more importance as it enables the collection of vital patient information without placing medical providers in close contact with personnel.
A large body of current published literature exists regarding the specific Hexoskin platform, with over 100 scientific publications in print. Applications vary from use in acrobatic acts, overground walking activities, monitoring of elite cyclists, and validation of the biometric technology in chronic obstructive pulmonary disease patients. In addition to the Hexoskin platform, several other off-the-shelf embedded platforms are being tested, and others are in development, including by military forces. While there is research on measuring physiologic parameter environments, such as space flight missions, no current published literature exists on the use of remote monitoring for casualties following injury.
The incorporation of wearable technologies has been discussed within the context of the Internet of Battlefield Things (IoBT) concept. As information technology matures, the modern battlefield is becoming increasingly network-centric, with militaries relying on the integration of complex networks to gather and share data to gain an advantage over adversaries and accomplish objectives.8 Compact wearable devices have inspired research on the feasibility of allowing individual soldiers to act as sensors themselves to feed data to the larger IoBT network — a data capture capability that was, until recently, only relegated to larger military platforms such as ships, vehicles, and aircra?. Such integration down to the granular level of the individual soldier has the potential to confer a tactical advantage during combat engagement and improve soldier survivability.9,10 By incorporating connected soldiers into the IoBT data network, command and control can be further improved by allowing access to real-time data on the physiologic condition of troops and instantaneously disseminating mission-critical information in a highly dynamic and unpredictable environment.
With respect to soldiers’ health and safety, existing literature explores the applications of wearable devices in detecting impending soldier failure due to excessive stress and casualty detection, triage, and early clinical management immediately following a battlefield injury.11 Research in this area has the potential to predict the likelihood of soldiers reaching stress limits and suffering degraded performance in addition to optimizing casualty triage for treatment and evacuation using limited resources. The pairing of biometric devices with environmental sensors can also be useful in quantifying long-term health risks because of occupational or deployment-related duty.12 The collection of continuous biometric data from multiple devices and sources has allowed space for the research of artificial intelligence and computer algorithms in analyzing and processing raw data to paint an accurate picture of a subject’s physiologic condition and inform medical providers.13 As the portability of devices and the feasibility of integrating individual soldiers into the IoBT continues to improve, careful examination of safe electromagnetic field (EMF) exposure levels emitted from wearable devices has garnered increased interest and relevance.14
During Exercise Trained Medic 2021, a section commander (183-cm, 79-kg, 32-year-old male) leading medical assistants/technicians participated in scenario-based training that assessed tactical medicine and Individual Battle Task Standards competencies. The final exercise was conducted over two nights and three days in moderate weather conditions in British Columbia, Canada, in March 2021. The highest temperature was 10 °C and the low was 4 °C. Scenarios had participants conduct point reconnaissance, execute section attacks, repel enemy attacks, and respond to a mass casualty incident. Reacting to simulated enemy fire, securing an objective, and providing tactical field care to friendly and hostile casualties were also emphasized. Members placed in a leadership capacity practised their ability to maintain command and control and coordinate at the tactical level with nearby forces.
For the duration of the exercise, the Hexoskin garment was reported to be comfortable to wear and did not pose an impediment to the execution of skills performed in a field training environment. The thin and lightweight upper-body garment was worn over bare skin in conjunction with a cotton T-shirt, military fatigue top, rain jacket, and a tactical load-bearing vest with a full load of blank ammunition. Of note, the soldier was not wearing body armour or ballistic plates. During activities that included running, crouching, crawling, and li?ing equipment, as well as simulated casualties, the Hexoskin did not restrict breathing or limit range of motion, nor did it interfere with the handling of small arms. Constructed using polyester and elastane fabrics, the Hexoskin’s properties allowed it to be comfortably worn at all times in this pilot study, regardless of level of exertion, body heat, or perspiration generated by its user. The recording device and cable were secured in a zippered pocket located on the right lower thorax and were slim enough to remain unnoticed by the user in various stances and positions. A proper fit negated the need for readjustment or repositioning of fabric or sensors. None of the components produced any pressure points, and the Hexoskin garment was free of any wear following completion of training.
As illustrated in Figures 1–4, data capture was robust and was consistently captured throughout the time the garment was in use. The version used during the weekend exercise collected continuous cardiac, pulmonary, and sleep data. Continuous one-lead electrocardiograph, along with continuous respiratory ventilation with chest and abdominal respiratory inductance plethysmography sensors, reports minute ventilation and respiratory rates.7 A more fulsome version of embedded sensor clothing (AstroSkin) includes temperature monitoring, blood pressure, and oxygen saturation, which would greatly increase utility to health care providers.
This study demonstrates that the Hexoskin garment with embedded health sensors captured reliable, continuous data in a soldier performing a variety of physical tasks, in a variety of weather conditions, in a combat training environment over the course of 30 hours. The garment did not impact the soldier’s ability to perform duties, nor did it cause any discomfort or complications. The garment withstood the conditions to which it was exposed with no apparent failure or breakdown.
The feasibility of using a Hexoskin-type garment in a true combat setting could be further assessed by having participants wear the garment for extended periods while wearing full fighting order typically found on soldiers in a combat environment (e.g., with the addition of body armour with ballistic plates and a full load of live ammunition). More investigation is required to determine whether the additional layers and kit would impact the comfort and performance of the Hexoskin in providing continuous data collection of soldiers carrying out duties under austere conditions in a variety of environmental conditions. The impact of sand and grit, in addition to the continuous friction exerted from the weight of gear, could impact the performance of a Hexoskin-style garment worn for long periods and could spur the development of smart clothing that can withstand the conditions commonly experienced by soldiers in a true battlefield setting. For example, does wearing body armour lead to the development of pressure points and abrasions in the user? Is the garment robust enough to withstand wear and capture accurate data if the user is heavily soiled or immersed in water? Would this garment perform adequately in arctic or desert conditions?
Figure 1. Hexoskin dashboard - breathing rate (Data Visualisation Platform by Carré Technologies Inc. [Hexoskin])
Figure 2. Hexoskin dashboard - heart rate (Data Visualisation Platform by Carré Technologies Inc. [Hexoskin])
Further questions regarding data transmission security, risk of hacking, and compromise of operational and medical security also arise when using embedded sensors. As the adoption of the IoBT concept gains increasing military relevance around the world, the issue of cybersecurity and exploitation of intelligent networks becomes more pressing. Wearable biometric devices offer tremendous advantages in improving soldier performance and survivability; however, it also presents an additional electronic warfare node susceptible to attack by opposing forces.15 Any device that emits wireless signals has the potential to be detected and intercepted by hostile forces, regardless of whether my.hexoskin.com © 2019 Carré Technologies, Inc. transmitted signals are cryptographically concealed. Troops emitting electromagnetic radiation can have their positions triangulated by well-resourced and tech nologically savvy opposing forces, leaving them vulnerable to kinetic attack. Biometric data that are intercepted and deciphered would be of tremendous value for any enemy force wishing to gather insight on the morale, health, and combat readiness of a given unit deployed in an area of operations. Any transmitting biomonitoring equipment that is adopted must be fielded with electronic warfare countermeasures and protocols in place to mitigate possible exploitation by enemy signals intelligence capabilities.16
Figure 3. Hexoskin dashboard - continuous electrocardiogram (Data Visualisation Platform by Carré Technologies Inc. [Hexoskin])
Figure 4. Hexoskin dashboard - activity (Data Visualisation Platform by Carré Technologies Inc. [Hexoskin])
Ethical considerations for this type of technology also need to be addressed. Having soldiers submit to continuous biometric monitoring is intrusive and presents a my.hexoskin.com © 2019 Carré Technologies, Inc. considerable breach of an individual’s privacy. Will militaries expect to collect biometric data of their troops at all times, even when forces are not actively engaged in completing mission-essential tasks? Can this technology be abused for untoward purposes? For example, is there a risk of abuse by the chain of command in utilizing bio-monitoring data to penalize subordinates if data profiles are incongruent with levels of exertion a particular task is expected to elicit? Perhaps these concerns can be mitigated if these data are given the same level of security and treatment as traditional patient electronic health record documentation and are only collected and interpreted by members of military health services.
Other avenues of research include studying the use of this garment in injured soldiers who require advanced medical care or medevac. Could the information obtained from these garments enable clinicians to provide medical advice to medical technicians in the field or better prepare them to receive casualties for whom vital signs are being continuously monitored?
This was the first research trial of Hexoskin embedded health sensors in a CAF reserve field ambulance environment. Further research is required to assess the utility of real-time clinical vital signs monitoring in providing care under fire, prolonged field care, and care during transport and infectious disease monitoring situations.
| 1. | U.S. Army DEVCOM Army Research Laboratory Public Affairs. Uniforms with programmable fiber could transmit data and more [Internet]. Arlington County, VA: United States Army. 2021 Jun 14 [cited 2021 Aug 7]. Available from: https://www.army.mil/article/247472/uniforms_with_programmable_fiber_could_transmit_data_and_more. Google Scholar |
| 2. | Gondalia A, Dixit D, Parashar S, et al. IoT-based healthcare monitoring system for war soldiers using machine learning. Procedia Comput Sci. 2018;133:1005–13. https://doi.org/10.1016/j.procs.2018.07.075. Google Scholar |
| 3. | Kurhe PS, Agrawal SS. Real time tracking and health monitoring system of remote soldier using ARM 7. Int J Eng Trends Technol. 2013;4(3):311–15. Google Scholar |
| 4. | Nikam S, Patil S, Powar P, et al. GPS based soldier tracking and health indication system. Int J Adv Res Elec Electron Instr Eng [Internet]. 2013 [cited 2022 Jan 20];2(3):1082–8. Available from: https://www.ijareeie.com/upload/march/17_GPS%20BASED%20SOLDIER.pdf. Google Scholar |
| 5. | Wararkar P, Mahajan S, Mahajan A, et al. Soldier tracking and health monitoring system. Int J Comput Sci Appl [Internet]. 2013 [cited 2022 Jan 20];3(1): 37–42. Available from: http://www.iraj.in/journal/journal_file/journal_pdf/4-137-143192772737-42.pdf. Google Scholar |
| 6. | Govindaraj A, Banu DS. GPS based soldier tracking and health indication system with environmental analysis. Int J Enhanc Res Sci Technol Eng. 2013;2(12):46–52. Google Scholar |
| 7. | Carre Technologies Inc. (Hexoskin). Key metrics delivered by Hexoskin [Internet]. Montreal (QC): Carre Technologies Inc. (Hexoskin); [cited 2021 Aug 7]. Available from: https://www.hexoskin.com/pages/key-metrics. Google Scholar |
| 8. | Kott A, Swami A, West BJ. The Internet of Battle Things. Computer (Long Beach, CA). 2016;49(12):70–5. https://doi.org/10.1109/mc.2016.355. Google Scholar |
| 9. | Shi H, Zhao H, Liu Y, et al. Systematic analysis of a military wearable device based on a multi-level fusion framework: research directions. Sensors (Basel). 2019;19(12):2651. https://doi.org/10.3390/s19122651. Medline:31212742 Google Scholar |
| 10. | Gaikwad NB, Ugale H, Keskar A, et al. The Internet-of-Battlefield-Things (IoBT)-based enemy localization using soldiers’ location and gunshot direction. IEEE Internet Things J. 2020;7(12):11725–34. https://doi.org/10.1109/jiot.2020.2999542. Google Scholar |
| 11. | Friedl KE. Military applications of soldier physiological monitoring. J Sci Med Sport. 2018;21(11):1147–53. https://doi.org/10.1016/j.jsams.2018.06.004. Medline:29960798 Google Scholar |
| 12. | Misra V, Lee B, Manickam P, et al. Ultra-low power sensing platform for personal health and personal environmental monitoring. 2015 IEEE International Electron Devices Meeting (IEDM); 2015 Dec 7-9; Washington, DC. p. 13.1.1–4. https://doi.org/10.1109/IEDM.2015.7409687. Google Scholar |
| 13. | Fortino G, Ghasemzadeh H, Gravina R, et al. Advances in multi-sensor fusion for body sensor networks: algorithms, architectures, and applications. Inf Fusion. 2019;45:150–2. https://doi.org/10.1016/j.inffus.2018.01.012. Google Scholar |
| 14. | Nasim I, Kim S. Human EMF exposure in wearable networks for Internet of Battlefield Things. MILCOM 2019 — 2019 IEEE Military Communications Conference (MILCOM); 2019 Nov 12–14; Norfolk, VA. https://doi.org/10.1109/MILCOM47813.2019.9020889. Google Scholar |
| 15. | Zhu L, Majumdar S, Ekenna C. An invisible warfare with the Internet of Battlefield Things: a literature review. Hum Behav Emerg Technol. 2021;3(2):255–60. https://doi.org/10.1002/hbe2.231. Google Scholar |
| 16. | O’Donoughue NA. Emitter detection and geolocation for electronic warfare. Boston: Artech House; 2020. Google Scholar |
Carre Technologies Inc. (Hexoskin) supplied the embedded health sensor clothing free of charge for use in the study.
Conceptualization: P Dhillon
Methodology: P Dhillon and E Juneau
Formal Analysis: P Dhillon
Investigation: P Dhillon and K Tam
Data Curation: K Tam Writing — Original Dra?: K Tam and E Juneau
Writing — Review & Editing: K Tam and E Juneau
Project Administration: P Dhillon, K Tam, and E Juneau
