Usability and Reliability of a New Physical Therapy Tool
Condition: Healthy Normals
Study type: Observational

Summary: 
      Rehabilitation exercise conducted at home following injury improves clinical and functional
      outcomes. Optimum compliance with prescribed exercise regimens requires regular patient
      instruction, performance assessment, monitoring and general encouragement from healthcare
      staff. Exercise at home though convenient for patients is not conducive for provision of the
      professional support needed to maximize prescribed regimen effectiveness.

      Software in development by Reflexion Health Inc. along with the Naval Medical Center San
      Diego (NMCSD) is being designed to facilitate remote staff-patient interaction during at-home
      rehabilitative exercise sessions. Microsoft Kinect® will serve as the hardware platform for
      the designed software package tentatively called, "Reflexion." Kinect® contains a
      marker-less/controller-less motion tracking camera. The final Reflexion software will rely on
      a "Rehabilitation Measurement Tool (RMT)" to detect cardinal plane skeletal joint movement
      and its velocity utilizing the embedded Kinect® camera while also providing patient visual
      feedback via an avatar on a television screen.

      In this observational minimal risk study, RMT/Kinect® functional reliability and usability
      will be assessed. Twenty healthy subjects will physically set-up and turn-on the
      hardware/software system; receive exercise directions from the RMT; then conduct a series of
      knee exercises similar to those prescribed after anterior cruciate ligament (ACL) repair.

      An initial limited data set, obtained by Reflexion Health, provided validity and reliability
      measures. Eighteen degrees of absolute difference was detected between manual goniometry and
      Kinect® measurements in relevant planes of movement utilized during prescribed ACL exercise.
      Good relative agreement between RMT and goniometry scores was obtained (ICC = 0.89). A
      correctable systematic bias toward underestimation by the RMT will allow for future more
      accurate estimations of joint positioning improving face validity.

      RMT functional reliability and general usability will be expressed in this study utilizing
      descriptive statistics and scaled questionnaires. Hardware component malfunction (Kinect®
      camera, laptop, PC, or LCD television/monitor) as well as RMT internally logged software
      errors and failure will tallied and measured to ascertain RMT reliability.

      User-RMT interaction quality will be evaluated with video recordings of each set-up and
      exercise session. Specifically, usability measures will include: need for additional
      assistance setting-up or operating the RMT; number of attempts required by the subject to
      interact with a specific feature: time spent on specific elements during the session.
      Participant feedback will be elicited post-session using two scaled questionnaires: System
      Usability Scale (SUS)and Reflexion Usability Scale (RUS). Findings from the study will guide
      software modifications needed prior to implementation of future clinical studies within the
      NMCSD population.
    

Detailed description: 
      1. General Approach:

           We plan on using an observational study design to assess the reliability and usability
           of the RMT by healthy volunteers as they participate in a simulated session of knee
           physical therapy as presented by the RMT. Each session will be supervised by research
           staff and recorded for later review and assessment of areas of concern for reliability
           and usability.

        2. Methods:

           The study will use 20 (n=20) healthy volunteers. These subjects will be actively
           recruited from Naval Medical Center San Diego and Orthopedic by research staff. We will
           also use an informational flyer placed in the NMCSD Physical Therapy and Orthopedic
           outpatient clinic waiting room. No medical records will be used to identify subjects for
           recruitment. Subjects will be approached by research staff and will be asked about
           participation and will undergo standard practices regarding meeting, inclusion and
           exclusion criteria and clinical trial consent by trained research staff. Those who
           consent to participate will be taken to an area that houses the RMT hardware and
           software. Subjects will then undergo a brief 5 minute tutorial on the setup, power-on,
           and navigation of the hardware and gesture controlled software.

           After the orientation session each subject will be presented the RMT hardware and asked
           to connect the hardware components via provided cables and subsequently power on the
           system and application as well as position themselves correctly in front of the camera.
           Next, they will be instructed to follow the on screen prompts to enter their subject ID
           and pertinent login information and navigate the system using gestures. Following the
           setup process they will then proceed to engage in four exercises sequentially presented
           by the RMT software. Approximately 5 repetitions of each exercise will be recorded and
           evaluated by the RMT after which the subject will be asked to follow the onscreen
           prompts to review a summary of their activity as presented by the RMT and exit the
           application. After their interaction with the RMT they will be asked to complete a
           System Usability Scale questionnaire as well as a Reflexion Usability Scale
           questionnaire.

           We anticipate the total time required by each subject will be approximately 45 minutes.
           Research staff will be available to provide any assistance as requested by the subjects
           in their interaction with the RMT. Additionally, staff will also intervene while
           consented subjects perform the exercises if they detect any signs of impending injury or
           harm. Subjects will be allowed to terminate their involvement at any time and for any
           reason.

           Review of the research staff notes during the subject interaction with the RMT, SUS and
           RUS results, and videotape of the interaction between the subject and RMT will be
           corroborated post-hoc.

             1. Sample Size

                We estimate the sample size of this study to be approximately 20 subjects. Since no
                direct comparison is being made to a control cohort, no inferential statistical
                analysis will be performed. This means that there is no meaningful way to
                appropriately power the study via sample size adjustments. Our choice of 20
                subjects, therefore, was based on balancing the logistics required to test this
                platform with collecting sufficient data to understand the usability of then
                system.

             2. Randomization

                N/A

             3. Blinding

                N/A

             4. Initial Orientation Session

           Subjects will be given a brief video tutorial on how to connect the Kinect camera to the
           television and laptop, power on the RMT and Kinect camera, and operate the RMT hardware
           and software by research staff; any questions will be answered at that time regarding
           RMT operation. Then, subjects will be evaluated by a licensed, currently practicing
           physical therapist and shown the four exercises they will perform in the session. The
           therapist will work with each of the patients until they achieve a satisfactory
           performance in each of the exercises, as assessed by the therapist.

        3. Components

             -  Hardware:

                  -  Kinect Camera

                  -  LCD Television

                  -  Laptop PC

             -  Software:

                  -  Windows 7 Operating System

                  -  Rehabilitation Measurement Tool Software Application

        4. Statistical Analysis:

      The primary goal of this research is to understand the usability and reliability of the
      system. Since the present application is relatively novel, there are no standard mthods to
      'success' or 'failure' of the system. Therefore, we do not intend to perform any inferential
      statistical analyses. Rather, we will generate descriptive statistics to be used in a
      post-hoc fashion to determine system reliability, and usability for future applications to
      sick patients undergoing physical therapy for post-ACL reconstruction surgery. Descriptive
      statistics provide better insight into the data allowing a more informed assessment of
      potential risks of the system. Understanding the distributional nature of the data (e.g.,
      normal symmetric, normal skewed, bimodal, etc.) and the variability of the data scores can
      better identify overall safety risks as well as help to specify individuals that could
      potentially incur a greater safety risk, should one exist.
    

Intervention name(s): Rehabilitation Measurement Tool
Intervention type(s): Device
Intervention description(s): The Rehabilitation Measurement Tool represents a telerehabilitation tool for physical therapy.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Healthy males and femailes, ages 18-35
      
Keywords: rehabilitation; physical therapy; telemedicine