Rehabilitation Tool for Traumatic Brain Injury Patients
Erwin Yap1, David Weinberg1,Dr. Joseph Cheng2
Department of Biomedical Engineering1, Vanderbilt University, Nashville, TN, USA
Vanderbilt Medical Center2, Department of Neurosurgery, Nashville, TN, USA
Introduction:
Traumatic Brain Injury is defined as damage to the brain resulting from external mechanical forces. TBI is often caused by the rapid coup-contrecoup motion of the brain. This motion causes neurons in the brain to both stretch and contract. This causes cells to rupture, resulting in “diffuse axonal shearing”, which tends to occur in the region between the white and gray matter of the brain and causes deficiency in communications between the prefrontal cortex, parietal lobe and cerebellum (Maas, 2008).
TBI is one of the major causes of disabilities and deaths worldwide. In fact, 1.4 million people are affected annually in the US; 50,000 die; 235,000 are hospitalized; 1.1 million go through extensive rehabilitation therapy; 5.3 million Americans currently have a long-term need for TBI rehabilitation or treatment. The most common causes of TBI occur from falls (28%), car accidents (20%), assaults (11%) and struck by events (19%). All age groups are vulnerable of experiencing a TBI (CDC.gov).
The degree of TBI damage is classified between mild, moderate and severe. Executive skills are most commonly impacted in mild TBI. These skills involve a number of fundamental abilities that allow an individual to appraise a problem, formulate and initiate a plan of action. Thus, sufferers experiencesymptoms of weaken comprehension, communication problems, decreased short-term memory, attention deficit and loss of sequencing skills.In most cases, patients with mild TBI recover fully.
Patients with moderate TBI deal with weak attention span, chronic memory loss, processing sensory inputs and emotional problems. They experience loss of consciousness of between 30 minutes and 24 hours after the injury and oftentimes, they do not remember the event that caused the injury. Approximately 60% of moderate TBI patients will make a positive recovery and an estimated 25% will be left with a moderate degree of disability.
Severe TBI patientsexperience a loss of consciousness that could last days, weeks or months or even years. The greater the amount of damage, the longer the person remains in coma. Only 25 to 33% of these patients have positive outcomes and about 33% of these patients do not survive (Rao,2000).
TBI is a common injury of the recent “Global War on Terror.” The Defense Department estimates that 6 out of 10 soldiers have suffered TBI during the war. During war, most of the brain injury is caused by bullets or shrapnel hitting the head and the neck. It can also be caused by mortar or roadside blasts (Iraq War, 2008). According to Dr. Pamela Drury, neuropsychologist of the Vanderbilt VA hospital, most of the problems experienced by war veterans are navigation and sequencing. Some issues are caused by the physical aspect of the war while others obtain it due to emotional distress. According to her, whatever the cause is, it is a problem that ‘needs a solution’. In 2009, the United States Department of Defense passed a bill, which provides $300 million for TBI research and treatment.
There is currently no quick way to treat TBI. Most treatments are rehabilitation procedures that could take weeks, months or even years to complete. The goal of rehabilitation is to help the individual progress to the most independent level of functioning possible. Therapy will focus on regaining lost skills as well as learning ways to compensate for abilities that have been permanently changed because of the brain injury.Cognitive rehabilitation is a systematically applied set of medical and therapeutic services designed to improve cognitive functioning and participation in activities that may be affected by difficulties in one or more cognitive domains (Grealy, 1999). Current examples of TBI rehabilitation tools are paper manuals, making task lists, practical exercises, using a datebook or PDA as a reminder, use of visual simulation, special watches and rehabilitation classes.
At the Vanderbilt Veteran Affairs (VA) Center, they currently have a rehabilitation class utilizing the CogSMART program. The CogSMART program is created by the Center of Excellence for Stress and Mental Health of VA San Diego Healthcare system (See Appendix, page xxxix). Each class consists of approximately 5 patients with TBI talking about their problems and participating in social activities with other participants of the class. They need to attend a “class” session once a week which involves a different lesson per week. They have a workbook which contains writing assignments and questions to stimulate their brain processing skills regarding the lecture. Participants receive homework so they can continue their therapy at home.
Another important concept our design incorporates is “chunking.” The human working memory is known to be able to remember up to approximately 7 items at once, on average. Chunking is the ability to cut down on the total number of items you have to remember by grouping items together. For example, take the phone number 1-800-888-4823. There are a total of 11 numbers, but it is possible to chunk the three 8’s together, since there are all 8’s before the last four numbers. Also, the 1-800 sequence can be chunked as one item since it has already been stored in the long term memory.
Figure 2: Summary of the concept of chunking
Project objective:
The objective of our project is to create an open source 3D virtual rehabilitation tool to help improve working memory function of mild TBI patients.
Goals:
- Create a virtual rehabilitation interface accompanied by an equivalent hardware model.
- Implement a neuro-rehabilitaion evaluation tool to measure the extent of TBI injury and analyze the patient’s strengths and weaknesses by providing feedback.
- Help TBI patients regain competence in the job market by guiding them to regain executive skills.
- We want to know if there will be a difference in chunking performance for the 7-step versus the 10-step groups.
The use of virtual rehabilitation had been tested in several studies; however, no full module currently exists on the marketor the medical industry. Several studies tested the theory that virtual rehabilitation can be beneficial to learning. Two publications showed that the use of virtual rehabilitation tool on traumatic brain injury patients proved to be beneficial. According to Madeleine Grealy’s publication, “Improving Cognitive Function after Brain Injury: The Use of Exercise and Virtual Reality”, patients with cognitive difficulties were asked to steer to directions or participate in a race while in a virtual bike. Significant improvements were observed in learning, both auditory and visual, as well as the digit symbol test compared to the people not using the bike (Grealy, 1999). In another experiment, “Tasks Performance in Virtual Environments used for Cognitive Rehabilitation after Traumatic Brain Injury” by Charles Christiansen, a virtual kitchen was developed in which a meal preparation task involving multiple steps could be performed by TBI patients. The experiment was repeated twice with the same group of patients. The total score during the 2nd trial is higher which means patients improved cognitive functions after the 1st trial.
According to Dr. Pamela Drury, most soldiers coming back from the war are very young, mostly in their 20s-30s. They prefer using a computer rather than doing paper exercises. By implementing a virtual rehabilitation tool, it will help engage patients to participate in rehabilitation programs by stimulating their interests.
Methodology:
Alice Virtual Rehabilitation tool:
Alice is an educational program developed by Carnegie Mellon University that teaches students computer programming in a 3D environment. We designed ourvirtual rehabilitation toolaroundAlice, for its low resource requirements and because it is open source.
Figure 3: QFD showing the design indicators used for the creation of the Alice 3D world Rehabilitation Tool
We did not incorporate any special effects or animations because it could cause confusion and anger to the patient. We also did not incorporate any textures for structures and objects that resemble the war to prevent memories.
We created a rewards system like a “great job!” and “congratulations!” messages with a fun little spin animation at the end of the sequence tutorial to give encouragement. We utilized a flash timer (start, stop, reset functions). We created two difficulty levels: 7-step (cheeseburger) and the 10-step (table setting). No sound was used to limit distractions.
Hardware equivalent:
We created an actual prototype for both the 7-Step and 10-Step sequences that imitates the Alice virtual rehabilitation tool design. The 7-Step prototype is made with felt (velvet) materials purchased from Michaels Arts and Crafts store, which were sown together with a thread and needle.
For the 10-step prototype, we purchased plastic plates, forks, knives, napkins, cup, and small salad plastic plates from Target.
Testing:
20 healthy male college students aged 18-22 were scheduled at least a week prior to the trial date to test the prototype. They were randomly assigned to four groups as part of a 2x2 factorial design.
Figure 5: Factorial design for testing
Participants arrived on their scheduled dates, and filled out the consent forms. They are asked to complete either the 7-step or 10-step experiments depending on their groups, and they are timed as well as checked for number of accuracy and number of sequencing errors.
We prepared a consistent set-up for the experiment room. There was a chair, a table, a 4 ft2 square tablemat, and all the materials are randomly separated, then placed on the back right corner of the tablemat.
7-Step sequence
Figure 6: Cheeseburger prototype sequencing procedure
10-Step sequence
Figure 7: Table setting prototype sequencing procedures
After the pre-test, the control group explores facebook.com for two minutes while the experimental group which used our 3D Alice Virtual World demonstration of the 7-step and 10-step sequences. Aftertwo minutes, the participant completes the post-test. Same metrics are recorded for the post-test as the pre-test, including the time of completion, number of accuracy and sequence errors).
After the post-test, evaluation forms are filled out by the participant for debriefing and feedback (see appendix, page xiv).
Statistical Analysis:
We conducted a factorial ANOVA with two between subject factors (2x2 factorial design) using JMP-8 statistics software. ANOVA is a statistical tool used for continuous data, such as time (measured in seconds). Post – Pre time represents the improvement (or deterioration).We conducted a chi-squared contingency test for the accuracy and sequencing errors.
Results and Discussions:
Figure 8: Pre- and post average times with error bars
*Note error bars are of 1 standard deviation.
Significant difference in the sequence improvement was observed between the 7-Step and the 10-Step sequence groups with a p-value of0.0028 (p<.01). However, no significant difference were observed in improvement between virtual training versus no virtual training with a p-value of 0.41 (p>0.05).
Figure 9: Anova of Post-pre Total Sequence Times
There is no significant difference between the control and experimental groups for the number of sequencing errors and number of accuracy errors with a chi square p-value of 0.4843 and 0.1429 respectively. Both errors hadp>0.05.
Figure 10: Chi-squared contingency test for sequencing errors
Figure 11: Chi squared contingency test for number of accurary errors
Informal Observations:
Our design will make rehabilitation more engaging. Patients will want to use our rehabilitation tool.
Future Work:
The next step of our project is to conduct a clinical study regarding the efficacy of our design prototype. We already drafted an IRB proposal, as suggested by Dr. Cheng, to prepare for this procedure. We wish to perform clinical trials using patients with mild traumatic brain injury. The IRB proposal, once submitted, will take approximately 3 months to get approved.
We also plan on talking to Dr. David Twillie of Fort Campbell to get more insight on specific tasks that would help war veterans. We planned a teleconference with him last April 1, 2010 which he had to cancel because of unexpected circumstances.
We also plan on creating a prototype that will help patients with navigation skills because this is one of the needs of war veterans of the Iraq war according to Dr. Drury. This will be similar to a 3D maze where they have to navigate with a paper map to get to the finish line. The environment will be similar to the outside environment. We will not use any structures that will remind them of the war because this will give them flashbacks of the memories that caused them the brain damage.
For our proposed initial design, our inclusion criteria are recent war veterans ages 21-40 with mild TBI and normal vision.
After having a successful clinical trial, we plan on increasing the difficulty level of the prototype by adding more steps so that patients can progress to different levels to further their progress.
Conclusion:
In conclusion, our rehabilitation tool showed no significant improvements at sequencing skills associated with working memory function for healthy college students.
10-step process improved significantly compared to the 7-step process perhaps because of the room to improve, with extra confusion because of the three extra steps.
No significant improvement from Facebook to virtual rehab tool perhaps because the simplicity of the sequences. Perhaps both the pretest and post test trials should have been made more difficult, with greater complexity of sequences. We recommend a long term study which would involve more repetitions using the virtual rehab tool.
Economic Issues:
Market Analysis:
More than 1.4 million people are affected in the US annually; 50,000 die; 235,000 are hospitalized; 1.1 million go through extensive rehabilitation therapy. For children aged less than 15 years old, TBI results in an estimated 2,685 deaths; 37,000 hospitalizations; 435,000 emergency departments annually. 5.3 million Americans currently have long-term or lifelong need for help to perform activities of daily living as a result of TBI. Direct medical costs and indirect costs such as lost productivity totaled an estimated $60 billion in the year 2000. There is a need for TBI rehabilitation because the lives of TBI patients are being hindered, both socially and economically.
In addition, companies who hire patients with disabilities get a tax break from the government. By helping TBI patients be productive, they will be able to gain competence in the job market while companies will want to hire them due to the generous tax cut.
Competitors:
Most treatment for traumatic brain injury involves rehabilitation centers and hospitals. There are also some tools and PDAs made to help TBI patients plan their day. No current open source virtual rehabilitation tool is out on the market.
Patent Search:
We used Google patents and there were no similar patented designs.
Projected Development Cost Analysis:
Materials/Labor / Cost / ExplanationAlice 3D Software / $0 / Alice is an open source 3D tool. Anyone can download it for free.
Labor / $400 / 1 student @ $10/hr for 40 hours
Hardware equivalent (Cheeseburger) / $2 / Cost of felt ($2). Cost will vary depending on the number of patients and reusability of materials.
Hardware equivalent (Table setting) / $2 / Cost of plastic spoon ($0.50), plastic fork ($0.50), plastic knife ($0.50), plastic salad fork ($0.50), paper salad plate (negligible), paper plate (negligible), cup (negligible), napkin (negligible). Cost will vary depending on the number of patients and reusability of materials.
Instruction manual containing a consent form, rehabilitation description, and post evaluation survey. / $2 / Includes paper, printing, binding and data storage.
Total Cost / $406
Table 1: Projected Development Cost Analysis Table
*Cost will vary depending on the task assigned. The two tasks listed are the prototype tasks. If a task includes more steps and involves more delicate materials, cost will be higher. Labor cost is the majority of the budget for this project. Furthermore, this will vary depending on how quick the student completes his task.
Benefit Analysis:
This tool, if successful, can potentially help traumatic brain injury patients by lowering rehabilitation costs not only for war veterans but for patients who generally experience mild TBI. Since Alice is an open-source tool, we will be able to provide the service for free or at a low-cost. The protocol is simple and will not require the presence of trained professionals.
Cost Analysis:
Current rehabilitation treatment for war veterans are free provided by the VA if they are injured to active duty. However, one study showed that supported employment for helping TBI survivors return to work costs an average of $10,198 for the 1st year (Wehman, 1994). Our method will be more cost effective, if successful in improving the patients working memory.Also, there is a social cost associated if the patient uses datebooks, PDA, special watches or other assisted technologies.
Cost of maintenance:
There is no expected cost of maintenance. The virtual part is open-source and will always be available for free in the future. The hardware might require maintenance depending on the level of care. Each hardware prototype is not expensive and can easily be produced for less than $5.
Life Cycle:
Our product is expected to last until a much improved product replaces it.