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Portable Computerized Dynamic Posturography and Balance Training System to Deliver Sensory Organization Tests in Clinic and Field Environments


RT&L FOCUS AREA(S): General Warfighting Requirements (GWR)


OBJECTIVE: Develop a portable, customizable, computerized dynamic balance and measurement system that allows programmable levels of instability to deliver accurate Sensory Organization Tests in clinic, home, or field environments.

DESCRIPTION: Traumatic brain injuries (TBI) and musculoskeletal injuries (MSKI) account for a significant proportion of limited duty days and nondeployable classification in military service members1,2. TBI and MSKI both cause short-term disability, but can have lasting consequences such as loss of strength and motor control, chronic pain, cognitive deficits, and permanent neurological damage. Postural stability is the ability to control center of mass (COM) in relation to an individual’s base of support and requires integration of an individual’s visual, vestibular, and somatosensory systems. Balance training is used to improve postural stability after injury and must target all three systems for optimal effectiveness. Currently, the most common form of balance testing and training in clinics uses a balance board or stability ball to create an unstable surface to train the somatosensory system. More recent efforts have engaged the visual system by integrating virtual reality (VR) with static force measurement platforms to assess COM motion in various VR environments. While integrated VR systems have expanded the types of visual and vestibular perturbations available, use of a static force platform means the motor control system is not challenged or perturbed in a controlled manor. Systems with dynamic platforms would be beneficial for assessment and rehabilitation from vestibular and musculoskeletal injuries.

More traditional balance testing systems incorporate programmable moving platforms capable of perturbing and measuring COM movement (e.g. computerized dynamic posturography (CDP) systems) in a systematic and measurable way. Their ability to concurrently or independently manipulate the visual, vestibular, and somatosensory systems make them an invaluable tool for delivering an objective Sensory Organization Test (SOT), which can help the clinician to determine if therapy is needed and which sensory system to focus on. Indeed, a large amount of normative and clinical SOT data exists for military personnel across various branches5. Though considered the gold standard for vestibular physical therapy assessments, the utility of current CDP systems are undermined because of their large size, high cost, and limited functionality (i.e. pre-programmed tests for evaluation only, not modifiable for targeted training), and thus are usually found only in large medical centers and specialty clinics.

The goal of this SBIR is to develop a product that maintains the strengths of traditional CDP systems, but that takes advantage of the developments in portable balance measurement devices and portable display technology (e.g. VR), thereby creating a lower cost and portable balance assessment and training system. Currently, there are no commercially available portable platforms that combine COM measurements with computerized dynamic control of platform stability; these are essential for conducting SOTs and targeted training. The development of such a platform in conjunction with VR, or similar technology, can be used to not only provide balance perturbations seen in SOTs (i.e. a sway referenced support surface) but also provide graded training that can be used during post-TBI rehabilitation or to mimic a specific dynamic environment for physical training purposes. The purpose of this SBIR is to create a portable, computerized dynamic balance and measurement system.

PHASE I: In Phase I, the performer will first define specifications for the device that must be met to deliver physical perturbations used in standard SOTs. This includes the platform’s maximum/minimum tilt angles, speed of tilt changes, speed at which data must be streamed (input and output frequencies), platform weight limits, and COM measurement accuracy. The mechanism (e.g.  springs, balls, actuators) of inducing instability at various tilt levels should be established. Although no defined standards need to be met for the following aspects of the system, specifications such as platform translation, and the number and increment of instability levels should be pre-determined by the performer.

To be effective, the device should be able to:

1) Be portable (weight, size) such that only a power source, computer, and VR headset (or similar portable display system) is required for additional setup.

2) Include a portable platform capable of controllable tilt in at least two axes (minimum ± 20⁰ in each axes). 

3) Provide controllable instability (or fluctuation) at all levels of tilt.

4) Collect and stream accurate and reliable COM and platform movement data to a computer.

5) Stream platform data to a development platform (e.g. Unity), for integration within custom gaming applications.

6) Integrate with software, capable of controlling the platform’s movement and instability levels and collecting data. 

7) Allow for easy administration of the SOT and instant test results to the clinician.

An initial proof-of-concept design will be developed to demonstrate that the product is able to meet minimum functional capability. The design will include the device’s basic architecture and components. While creating this proof-of-concept design, the performer must keep in mind the potential customer’s settings. The technology should be designed for use, at minimum, in a research or clinical setting (i.e. require minimal setup and an easy software user-interface), with potential setup capacity for in-home therapy or field-based setups. Additionally, the dynamic response of the proposed device should be mathematically outlined and numerically simulated, showing the limits and expected response of the device in terms of user mass, platform acceleration, and deflection angle. A working prototype of the physical design is preferred to demonstrate eventual full system capabilities.

Together, Phase I deliverables include:

1) Design and use specifications that the proposed device should meet.

2) CAD model and system integration diagrams of proposed device.

3) Mathematical representation and numerical simulations demonstrating ability to provide varying levels of tilt and instability in different use cases (e.g. body mass of user) including those of the SOT testing conditions.

PHASE II: In Phase II, the performer will construct and test a prototype balance training system based on requirements from the original solicitation and specifications identified in Phase I. The performer must validate the accuracy and precision of COM measurements, tilt angles, and instability levels under varying conditions (e.g. amount of platform instability, user mass, etc). As stated above, traditional CDP systems are not portable and typically require a dedicated space of ~25-30 ft2. One of the improvements of the current development is that it should only require a power source, computer, and a flat surface ~4-9 ft2. As such, the performer will demonstrate that the system is portable and can be used in a variety of settings, while providing accurate measurements. An initial FDA regulatory plan should be provided if applicable. Finally, in Phase II, the performer will also develop the software that accompanies the physical device. The software should be capable of defining and controlling tilt angles and instability levels. It should also provide real-time visualization of COM movement and platform tilt angles.

A software application should be designed to showcase the system’s ability to stream COM movement and tilt angles for integration with a virtual environment within acceptable delay times. An application should also be designed that will deliver the SOT, collect accurate COM information, and provide composite measurement results as well as individual scores for each of the SOT conditions.

Phase II deliverables include:

1. The physical working prototype balance platform capable of varying levels of tilt and instability.

2. Instruction manual for setup and usage.

3. Accompanying software that allows the user to connect a computer (wired or wirelessly) for data streaming and visualization.

4. Demonstrative software application, compatible with gaming/development platforms that support major VR devices in the current market.

5. Software infrastructure (SDK) that can be used to stream data into custom VR applications.

6. Specifications document that details limitations of the device (e.g. user weight, tilt levels, life-time, etc.).

7. Application that delivers the SOT and provides composite and individual condition scores.

PHASE III DUAL USE APPLICATIONS: The expected Phase II end-product is a well-designed, portable balance training and testing system for use in research or clinical settings that is able to deliver the SOT with the same standards of commercially available dynamic posturography systems. To move this SBIR work towards operational- and commercial-readiness, Phase III efforts should focus on validating the device’s repeatability and reliability against current devices used for SOT in targeted populations and further development for clinical use (production, delivery/setup, software, durability). This will support future commercialization efforts in both military and civilian markets. It is anticipated that DoD customers will include clinical rehabilitation settings that address TBI diagnosis and symptom treatment (vestibular dysfunction, dizziness, oculomotor system dysfunction) and clinics for MSKI injuries (chronic ankle instability, knee/ankle injury, ligament injury). Key customers may include facilities that currently own CDP systems, including large military treatment facilities (e.g. Naval Medical Center San Diego, Walter Reed National Military Medical Center), Department of Veterans Affairs hospitals (e.g. Palo Alto, Minneapolis, Seattle), and academic universities (e.g. University of Wisconsin system, University of California System, University of Pittsburgh). Additionally, a portable and lower-cost system would enable medical facilities to purchase and use more than one balance system in different clinics. It would also enable access to objective assessment and rehabilitation tools at military clinics (e.g. Twentynine Palms) and civilian outpatient clinics.  A successful device could also have implications for use in deployed settings if ruggedized. Commercial markets that could benefit from this novel product would include: private rehabilitation centers, sports training centers, and research organizations.


  1. Defense and Veterans Brain Injury Center (DVBIC). Cognitive Rehabilitation for Service Members and Veterans Following Mild to Moderate Traumatic Brain Injury.; accessed 27 JUL 20.
  2. Molloy, Joseph M., Timothy L. Pendergrass, Ian E. Lee, Michelle C. Chervak, Keith G. Hauret, and Daniel I. Rhon. "Musculoskeletal injuries and United States Army readiness Part I: overview of injuries and their strategic impact." Military medicine (2020).
  3. Filipa, Alyson, Robyn Byrnes, Mark V. Paterno, Gregory D. Myer, and Timothy E. Hewett. "Neuromuscular training improves performance on the star excursion balance test in young female athletes." Journal of orthopaedic & sports physical therapy 40, no. 9 (2010): 551-558.
  4. Zech, Astrid, Markus Hübscher, Lutz Vogt, Winfried Banzer, Frank Hänsel, and Klaus Pfeifer. "Balance training for neuromuscular control and performance enhancement: a systematic review." Journal of athletic training 45, no. 4 (2010): 392-403.
  5. Pletcher, Erin R., Valerie J. Williams, John P. Abt, Paul M. Morgan, Jeffrey J. Parr, Meleesa F. Wohleber, Mita Lovalekar, and Timothy C. Sell. "Normative data for the NeuroCom sensory organization test in US military special operations forces." Journal of athletic training 52, no. 2 (2017): 129-136.
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