Proof of Concept: Hit Alert Optics System

Injuries due to motor vehicle accidents have been reduced due to sensor technology. Inspired by this success story, sensor technology may be used to alert athletes of impending injury-causing forces.

Problem: Prior to 1970, therewere 1321 deaths directly associated with American football.1 Since the formation of the National CollegiateAthletic Association, the number of fatalities has decreased by approximately80%. 2 However, since 1970, an average of 67 deathshave occurred each decade as a direct result of participation in Americanfootball.1 The majority of fatalities (~81%) were reportedat the middle and high school levels of sport, which have limited access toemergent health care compared to collegiate and professional sports.1  Eachyear, approximately 7.2 million male and female high school athletes participatein sport with an estimated injury rate of 2.44 injuries per 1,000 exposures.3 Of these injuries ~30% of injuries occurred tothe head, trunk, and neck. In 2016, the most common causes of deathdirectly-related to football occurred to the head and trunk.2 Commonly, more significant injuries (paralysisor death) result from unanticipated hits leaving the athlete ill-prepared toprotect himself from injury.


During the past 15 years, accelerometers have been used to characterize the magnitude of linear (g) and rotational forces (rad/s) sustained during contact-sports (e.g. football, soccer, lacrosse, etc.). For example, concussive injuries have been recorded to occur between ~60 g and 169 g. This range of values associated with concussive injuries has resulted in a general consensus that although accelerometers are important research tools, as of 2017, they have limited clinical utility in identifying an athlete with a suspected injury such as a concussion.5 Additionally, accelerometers only detect forces associated with a hit after it has occurred. However, the use of accelerometers in a research capacity has allowed for the investigation of how male and female athletes respond to forces applied to the head and neck,6-8 to assist with equipment design9, and coaching modification.4  Though the data yielded from accelerometersmay not be able to detect a concussive event in order to alert an athletictrainer or other medical staff of a potential injury, it may be used to preventthe occurrence of concussion or other catastrophic injuries.9,10

Advanced sensor technologies have been equipped in modern motor vehiclesin inform drivers of impending collisions. The advent of motor-vehicle sensortechnology is partially responsible for the reduction of severe and moderatebrain injuries associated with motor-vehicle accidents since 2007.11 In addition to motor-vehicle sensor technology,sensors have been incorporated into everyday life via cell phones and othertechnology to facilitate communication. Sensors, coupled with Blue Tooth andglobal positioning system (GPS) technologies, have been used to track physicalactivity (e.g. FitBit™ or Garmin ™). More recently, sensors have been used withathletes during competition (e.g. Catapult™ and Zyphr™) systems which useperformance analytics to assist coaches and athletes achieve optimalperformance during practice and competition.

Building on the above advancements, the current proposal is to investigate radiofrequency identification (RFID) technology coupled with haptic feedback as a potential proximity sensor that will alert athletesof an impending hit. Haptic feedback (i.e., vibration) from the HitAlert Optics (HALO) system may allowan athlete to brace for impact via muscle contraction and body positioning to mitigatethe force induced by another athlete. The alerted athlete may also elect toevade impact by falling to the ground and/or stopping play. In order to ensurethe athlete will not experience constant vibration by the HALO system, areal-time algorithm will predict the expected linear force (g) of an athlete based on their size andspeed. If the predicted g’s exceed aset threshold, the athlete will experience a vibration on their person (e.g.helmet or shirt) allowing them to prepare for the impending collision. If successful, the HALO system may significantly reduce the number of catastrophicinjuries and death in male and female sports at all levels of play.


1.            Mueller FO, Cantu RC. AnnualSurvey of Catastrophic Football Injuries. University of North Carolina,Chapel Hill;2012.

2.            Kucera KL, Klossner D, Colgate B,Cantu B. Annual Survey of Football InjuryResearch. National Center for Catastrophic Sport Injury Research:University of North Carolina, Chapel Hill;2017.

3.            Prevention CfDCa. Sports-Related Injuries Among High SchoolAthletes, United States, 2005-2006 School Year. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5538a1.htm:Centers for Disease Control and Prevention;2006.

4.            Guskiewicz KM, Mihalik JP, ShankarV, et al. Measurement of head impacts in collegiate football players:relationship between head impact biomechanics and acute clinical outcome afterconcussion. Neurosurgery. 2007;61(6):1244-1252;discussion 1252-1243.

5.            Mihalik JP, Lynall RC, Wasserman EB,Guskiewicz KM, Marshall SW. Evaluating the "Threshold Theory": CanHead Impact Indicators Help? Med SciSports Exerc. 2017;49(2):247-253.

6.            Tierney RT, Sitler MR, Swanik CB,Swanik KA, Higgins M, Torg J. Gender differences in head-neck segment dynamicstabilization during head acceleration. MedSci Sports Exerc. 2005;37(2):272-279.

7.            Tierney RT, Higgins M, Caswell SV,et al. Sex differences in head acceleration during heading while wearing soccerheadgear. J Athl Train. 2008;43(6):578-584.

8.            Bretzin AC, Mansell JL, Tierney RT,McDevitt JK. Sex Differences in Anthropometrics and Heading Kinematics AmongDivision I Soccer Athletes. SportsHealth. 2017;9(2):168-173.

9.            Reynolds BB, Patrie J, Henry EJ, etal. Practice type effects on head impact in collegiate football. J Neurosurg. 2016;124(2):501-510.

10.          Pellman EJ, Viano DC, Withnall C,Shewchenko N, Bir CA, Halstead PD. Concussion in professional football: helmettesting to assess impact performance--part 11. Neurosurgery. 2006;58(1):78-96; discussion 78-96.

11.          Prevention CfDCa. Rates of TBI-relatedEmergency Department Visits, Hospitilizations, and Deaths - United States 2001- 2010. 2016; https://www.cdc.gov/traumaticbraininjury/data/rates.html.Accessed 11/22/2017, 2017.


Desired outcomes

The desired outcomes of the proposed collaborative study include:

Outcome 1:  To examine the effectiveness of RFID technology to determine the presence of an object within 1 m of the sensor, traveling towards the sensor at 10 m/s.

Outcome 2: To develop a collision detection algorithm using multiple RFIDs topredict impending impacts, with specificity to identify impacts that willresult in greater than 50 g of linear force and provide haptic feedback usingvibrating motor plates.

Outcome 3: To demonstrate the capability of the HALO system on the field using amock game scenario.

If successful, the outcomes of the proposed study will lead to further refinement and implementation of the HALO system which may significantly reduce catastrophic injuries in contact sport(s).