Biomechanical Analysis Systems
VILA: Vest Integrated Load Assist
Navy helicopter pilots have increasingly complained of fatigue and chronic lower back pain linked to the repeated use of torso-mounted Personal Survival Equipment (PSE). A survey showed that 88.1% of 648 Navy H-60 helicopter pilots experienced back or neck pain during or immediately after flights, leading to less availability of pilots, reduced operational readiness, shortened careers, and increased medical costs. Several factors contribute to this, including PSE weight, poor posture, seating ergonomics, aircraft vibration, and total flight hours, but the PSE’s weight is considered a significant contributor to the issue. Therefore, the Navy seeks technologies to reduce the effective weight of PSE by over 70%. The immediate aim is to decrease the frequency and severity of fatigue and back pain among naval aviators and ultimately to protect aviators’ musculoskeletal health, increase mission endurance, and reduce lower back injuries. The Navy anticipates that its H-60 helicopter will serve as the testbed for flight demonstration of the system, but the technology is expected to be applicable to other rotary-wing and fixed-wing aircraft seating systems.
VILA (Vest Integrated Load Assist) is a low-profile, carry-on exoskeleton (a,b) with fully-prototyped passive and battery powered variants for mission flexibility (c). Each replaces the rear seat cushion of a MH-60S (d) and is equipped with quick-release magnetic connectors for rapid don/doff and emergency egress. VILA requires no modifications to the seat or airframe, passing the weight of heavy flight vests and PSE to the seat to reduce spinal loading and fatigue while passively following pilot upper body motions during operational tasks (e).
ExoJETS
Combat parachute jumping is a high-risk activity, with significant potential for injuries that require time and resources to resolve, slowing the unit down, and increasing their risk of being attacked. The Army seeks the development of an exoskeleton system that mitigates Parachute Landing Fall (PLF) forces experienced by Warfighters with the goal of reducing injuries. These PLF injuries are closely correlated with touch points, where the body of the subject impacts the ground, which include feet, calf, thigh, rear, and back. While exoskeletons have been used successfully to absorb energy associated with high joint torques, a detailed analysis shows that any system that increases overall weight without compensating for added impact in ALL touch points has a greater likelihood of actually INCREASING injury probability and severity than no system at all. Therefore, short of creating a full-body exoskeleton, which is not feasible for this application, the key challenge in the design of a PLF-injury-mitigating exoskeleton is to reduce impact force below what would be present with no exoskeleton.
FTL’s ExoJETS is an enabling technology for injury mitigation and data logging during a parachute landing. ExoJETS works by reducing the landing velocity just before touchdown. ExoJETS is a compact system that includes environmental sensing for control and IMUs for biomechanics logging. It is also compatible with existing assistive exoskeleton systems for rapid landing zone departure and assisting loaded movement to the aircraft. ExoJET’s body-worn sensors collect real-time data on the biomechanics of para-jumping to provide unit training insight to both Warfighters and Military Units and potentially inform proper or dangerous landing techniques.
ExoJETS mitigates risk of injury by reducing descent velocity moments before touchdown (A). Musculoskeletal simulations of a thrust-decelerated descent (B) used to design the system indicate that descent velocities can be reduced up to 40% (C) with resulting muscle strain less than walking. ExoJETS accomplishes this through lightweight cold gas thrusters (D) that pass load to the feet with Dephy Gen 2 Boots (E & F). A lightweight passive exoskeletal device braces the leg (G). Additionally, an integrated IMU-based biomechanics capture system automatically logs data during the PLF (G), and biometric software enables immediate review of landing kinematics and dynamics with soldier specific data, allowing direct comparison between decelerated and non-decelerated PLFs, and PLFs by non-experts utilizing various control approaches implemented through a PC interface. The system is compatible with Dephy’s ExoBoot actuator (H), which can be quickly swapped out for load carriage to the plane pre-jump, and rapidly exiting the landing zone post-jump.
SPARO
Sponsored by the Defense Health Agency, FTL’s SPARO (Sensorized Prosthetic Alignment Read-Out) provides clinicians and researchers a tool that enables quantitative measurements of prosthetic alignment and the effects it has on the rest of the body’s motions and dynamics through whole body gait and movement analysis.
Cutting-edge wearable motion capture technology provides immediate feedback to the prosthetist through a custom software interface, providing load transfer and kinematics data between the residual limb and external environment, along with whole body modeling. These objective measurements enable data-driven adjustments that will not only arrive at the best results but will get there faster than traditional methods by using machine learning in concert with SPARO’s proprietary alignment guide in a virtual 3D environment.
This new ability to precisely align prosthetic components also enables apples to apples comparisons of different prosthetic limbs, across specific patient populations. Further, full body biomechanics analysis can be performed using SPARO’s inexpensive precision motion capture technology. SPARO is the cutting edge of prosthetic limb adjustment technology.
SoundFit
SoundFit is a patented ultrasonic tool that monitors and records relative motion between a prosthesis socket and the bone within a remaining limb after amputation. Accurate and quantitative measurement of relative bone-to-prosthesis location during prescribed exercises such as walking for lower limb, or lateral arm raises for an upper limb, enables custom, comfortable fitment and high performance mechanical energy transfer, filling the knowledge gap that currently exists when trying to assess the performance of a socket interface.
There is a clear industry need for determining acceptable ranges for socket performance metrics values. These metrics may include sagittal/frontal range of motion and peak velocity during an activity, which correlate with interface stiffness and damping. These performance metrics, derived with FTL’s SoundFit, allow analysis of industry-wide statistical trends for direct application by prosthetics clinicians.
FTL’s SoundFit serves as a guide during the fitment process, allowing comparison of a socket’s performance to trends seen in the community of subjects having similar impairments, physiology and mobility. Driving the socket fitment with data rather than subjectivity will help to enhance a patient’s interaction with the world via a prosthesis, and ultimately will improve the patient’s quality of life.
For more information, please check out FTL’s brochure about the next generation of SoundFit, titled FoCUS! FoCUS is currently deployed in test labs across the country.
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