Improving User Performance in Rehabilitation Exercises

• Author / Creator

  Ocampo, Renz J R

• Disabling events such as stroke affect millions of people worldwide, causing a need for efficient and functional rehabilitation therapies in order for patients to regain motor function for reintegration back into their normal lives. Rehabilitation regimes often involve performing exercises that mimic the movements done in activities of daily living. These are sometimes complemented with serious games controlled through a robotic user interface to increase the motivation of the patients, further increasing the likelihood of success of the therapy. However, alongside physical disability, some patients (e.g., stroke patients) develop cognitive deficiencies that affect their ability to think, plan, and carry out tasks. In such cases, serious games, which are commonly displayed on a 2D monitor to the patient, may be too hard for patients due to the spatial disconnect between the visual coordinate frame (screen frame) and the hand coordinate frame (robotic user interface frame). Patients will have to do mental transformations to align their hand movements with their movements on-screen. The colocation of visual and motor frames for rehabilitation in commercial devices is still in its infancy, and while there are research regarding the use of visual-motor colocation in rehabilitation, its effectiveness has not yet been explored. This thesis presents a study of the effectiveness of visual-motor colocation in rehabilitation exercises by integrating augmented reality in serious games to achieve the above-mentioned colocation. A technique called projection mapping is utilized to project digitally constructed objects onto the real-world environment. Physical interaction with these objects is handled through a haptic user interface. The system is comprised of a projector, a game engine to create the virtual environment, a haptic user interface to interact and receive force feedback on the virtual objects, and a depth sensor to implement head tracking in 3D scenarios.The system design and the investigations in this study consist of two stages: first implementing visual-haptic colocation in a 2D spatial augmented-reality display in Chapter 3, and then further extending the work into a 3D environment in Chapter 4. The 2D case involves a task where reaching motions are performed using a 2D planar haptic robot. For the 3D case, three tasks are presented, each requiring a combination of spatial accuracy, awareness, and manipulation. Disability-induced cognitive deficiency is simulated on able-bodied participants by putting them under a cognitive load while performing the tasks. Each of the tasks in the 2D and 3D cases are compared to their non-colocated counterpart (tasks displayed on a 2D screen placed in front of the user) in terms of several user performance indicators. Results show a significant increase in user performance when visual and motor frames are colocated for both 2D and 3D cases. Furthermore, one of the tasks in 3D showed that visual-motor colocation can alleviate the negative effects of cognitive loading.Finally, after the validation of the effectiveness of AR in robot-assisted therapy, we combine AR with a heavy-duty robot in Chapter 5 and explore the use of this robot-AR system in occupational rehabilitation and functional capacity evaluations. The biomechanics of the user's arm while performing the task with the robot-AR system is compared with their arm biomechanics for an equivalent real-world task. An analysis for similarity of the arm biomechanics is carried out to determine if using the robot-AR system can produce the same upper-limb movements as in conventional rehabilitation practices.By increasing the user performance, which consequently increases the likelihood of success in performing the exercise, this work of bridging the spatial disparity between two frames can potentially improve the efficiency of current rehabilitation practices that use serious games for therapy. It has been shown that users who are set up to succeed more are more likely engaged in rehabilitation. It becomes a positive feedback loop where as the patient's performance improves with practice, this improvement allows the patient to do even more. While not all patients achieve this positive feedback structure, we hope to make it easier for patients to reach this ``threshold."

• Subjects / Keywords

  • Functional Capacity Evaluation
  • Augmented Reality
  • Serious Games
  • Robotics
  • Rehabilitation
  • Virtual Reality

• Graduation date

  Spring 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-rfcx-q989

• License

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