Design News for Mechanical and Design Engineers

U.S. Army officers say they hope the effort will help their Advanced Combat Helmet project and will also give military doctors a better handle on the accelerations and pressures sustained by soldiers during explosions and other “concussive events.”

“We hope to get enough data to determine how much acceleration or pressure our soldiers are being exposed to,” says Lt. Col. Robert Myles, product manager for soldier survivability at Fort Belvoir. “Further down the road, we hope to learn more about the traumatic brain injuries (soldiers) may be sustaining while in theater.”

At least three sensor suppliers – BAE Systems, Med-Eng Systems and Simbex LLC – are helping the Army with the study. The suppliers are under contract to provide technology-enabled helmets that include accelerometers and pressure transducers. One such system from Simbex LLC uses a ring of piezoelectric transducers on the inside surface of the helmet. When an improvised explosive device (IED) is detonated, the shock wave from the blast excites the piezoelectric transducers and acts as a trigger to turn on a data acquisition system. The data acquisition system then collects information on the shock wave from the pressure transducer, while the accelerometers send acceleration data. Software algorithms then take the raw data and transform it into accelerations and pressures.

The Army is using multiple accelerometers and a pressure transducer in each helmet. One sensor is located outside the helmet, while the others are mounted inside the helmet, under pads that contact the soldier’s head.

“From an IED event, we can measure the accelerations from fragmentation and the pressure from the blast,” Myles says.

 The Army is employing approximately 1,200 of the sensor systems. Army representatives say military doctors hope to develop a better understanding of what soldiers are going through.

“No one really understands what causes brain injury,” says Jeff Chu, vice president of engineering for Simbex. “They believe it could be related to head accelerations or over-pressurization during a shock wave, or it could even be temperature or RF waves. It’s a very complex problem.”

In the short term, the military’s vision is also to help identify soldiers who may have traumatic brain injuries. Those soldiers might then be prevented from going back out to the field with injuries that they are unaware of.

Moreover, the Army hopes that the study will help it build better helmets.

“Without really understanding what an injury is, it’s hard for the military to build better helmets,” Chu says. “This gives them a better understanding of the injury modality and magnitude.”

		By understanding the nature of head injuries, the U.S. Army hopes to build better helmets.
		Click below for more images:
		1                2