Case Study: Polhemus G4 in Virtual Rehabilitation

At the Union de Mutuas Rehab Unit in Valencia, Spain, some patients actually look forward to physical therapy. Thanks to BioTrak, a virtual reality rehabilitation system, repetitive physical therapy movement has now turned into a customizable, fun and challenging game for patients—and an efficient cost savings tool for the clinic. The latest electromagnetic motion tracker, G4™ by Polhemus, is the technology powering this VR system that focuses on rehabilitation.

The system, BioTrak, has a simple set up, consisting of a video display (a screen, projector or similar), a standard PC to run the software application and the Polhemus G4 electromagnetic motion tracker. The G4 system consists of the following components: the systems electronics unit, (hub), an electromagnetic source, and one or more sensors, the humeroscapular recovery application utilizes three sensors that are attached to the wrist, elbow, and scapula.

Ismael Estudillo is the CTO of Bienetec in Valencia, Spain. He describes the VR rehab game, “The application shows a virtual scenario where different colored jelly items rise from the floor. G4 allows the application to represent the patient’s feet and to transfer their movements to the virtual world. The mechanics of the application is very simple; it consists of stepping on every item with one foot, while keeping the other one still.” The initial game was created very simply to test the system—more complex versions are currently being developed.

The entire VR application has proven to be a robust system, and is currently used by therapists at different locations from 8:00 am to 8:00 pm, with few breaks in between. It provides enough interest to keep patients motivated and on schedule with their rehabilitation efforts, paving the way for cost efficiency and a speedy recovery.

Why Polhemus Electromagnetic Motion Tracking Technology?
Electromagnetic motion tracking was selected for the VR rehab application because of its affordability, ease of set-up and ability to produce repeatable results. Other technologies, such as optical systems, present line-of-sight issues, which are impractical for a typical PT clinic set-up.

Camera technology can sometimes be cost prohibitive and is known to have too many environmental limitations, such as ambient light control. Camera technology also lacks the portability that BioTrak offers.

Polhemus electromagnetic motion tracking was the perfect solution. The Polhemus G4 was chosen because of its wireless communication system, which allows for freedom of movement. Also, the set-up is simple and portable—just turn it on and start tracking. All of these factors made Polhemus motion tracking technology ideal for PT environments; the system has aided in the specific areas of balance recovery and musculoskeletal rehabilitation.

Polhemus Sensors Attached to Patient Using BioTrak Application For Musculoskeletal Application

According to Estudillo, several factors have made this virtual reality system effective for the rehabilitation application:

  • Efficiency as a clinical tool: since it has been designed by clinicians and since it is based on the motor relearning principles, this VR Rehabilitation system can be considered a powerful tool to improve balance control of patients.
  • Ease of use: BioTrak includes a friendly user interface from the point of view of both clinicians and patients.
  • Customization to patient’s needs: BioTrak can fit each patient’s impairment to provide a custom rehabilitation session to each patient.
  • Motivation: BioTrak provides enjoyable and motivating task-oriented exercises.

Dr. Felicidad Calduch, Head Physiatrist of the Rehabiliation Service, sees the benefits derived from the use of the system being twofold: “We’ve been using BioTrak during these last five years, from the development of the first prototype to its actual configuration. From a physician’s perspective, BioTrak facilitates balance rehabilitation according to the motor learning principles and accelerates the process of regaining postural stability to humeroscapular mobility. From the patient’s perspective, the process of rehabilitation becomes more enjoyable, fun and challenging without losing efficiency.”

Before BioTrak was implemented, no other virtual rehabilitation devices were being used by the clinicians at Valencia hospital. The treatment for musculoskeletal injuries was performed using traditional physical therapy. These methods were costly, tedious and time consuming, and the volume of patients was a challenge.

Cost Efficient
Dr. Felicidad Calduch has found that BioTrak has proven to be cost efficient. “The recovery of musculoskeletal injuries has a tremendous impact in terms of functional independence. The use of BioTrak has allowed us to shorten the length of stay of our hospitalized patients, since it facilitates a greater and quicker acquisition of global mobility and functionality in terms of activities of daily living. Besides, the benefit of BioTrak in terms of usability, it can be easily located in a traditional rehab unit and the set-up parameters for a complete rehab session can be easily configured. This makes BioTrak an excellent option from a cost saving perspective.”

System Versatility

Dr. Juan Gala, Medical Director of Union de Muturas and CEO of INSALUD, commented on the use of BioTrak, “From a physical therapist’s view, BioTrak represents a new and promising rehabilitation tool to deal with one of the most common and most dysfunctional deficits after several pathogies with high incidence and prevalence rates, such as musculoskeletal injuries or brain injuries. The system is versatile enough to meet each patient’s needs in terms of motor dysfunction.”

Patient Feedback is Key

Gala has seen the benefits first-hand and stated, “Other aspects of the VR system, such as “Patient Feedback,” which increases the challenge perception of the patients, and the “Results Menu” which gives an accurate and useful view of the rehab processes are clear, positive aspects of this device. In our experience, intensive treatment with BioTrak has significantly improved the balance, stamina and speed of movement of most of our patients. Moreover, most of them found their rehab sessions motivating, fun and challenging, which has even more relevance in patients with long-term rehabilitation processes.”

"BioTrak helped me a lot during my recovery after a stroke. I worked on both strength and balance and I could walk much better to the point of leaving the crutch that I usually needed. I also was able to work on the coordination of my movements.” ---Rehabilitation Patient, Neurorehabilitation Service of Hospital NISA Valencia al Mar

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About BioTrak
BioTrak is a tool based on virtual reality technology which integrates in a single platform training exercises for the rehabilitation of certain body functions that have been depleted or lost due to various pathologies. BioTrak´s technology allows the patients to interact in a virtual environment where they are challenged to fulfill simple tasks by means of their own movements. The system motivates patients in order to improve their adherence to the treatment, and serves as a very efficient tool in their process of recovery. BioTrak is a product marketed by Bienetec and devised by LabHuman. Photos Courtesy of Bienetec