{ STEM with Technical Writing }

This class is by far the most challenging, but in a good way. STEM does have a large workload, but many of the projects have been a neat opportunity that most students wouldn’t get until they were in college. We’ve done smaller projects like the Build Something project that taught us how to write a technical document. We are also currently finishing up our grant proposals and starting our thesis paper. However, the biggest project we’ve been working on is the STEM individual research project that starts before the first day of school and ends February 15th, the day of the Science Fair. This has been a massive project. We have gone through all the steps of brainstorming and research, and then, for those of us who are doing an engineering project, we’ve been prototyping and many of us are entering our testing phase. There have been A LOT of ups and downs during this project, but that just makes each small win much more important. December Fair was probably one of my favorite days of STEM this year for that reason because it felt amazing to have a prototype ready to show people. This class is not easy, but at the end of it, you will have something to show for your hard work.

Orthotic hand brace to improve range of motion in patients with cerebral palsy.

Overview

People with cerebral palsy can develop contractures in their hand which cause the muscles to tighten and the hand to close in on itself. It is important to stretch these contractures out because they reduce the range of motion in the hands which can severely limit a child’s ability to learn and develop. However, stretching out the contractures can be painful, so it’s important to loosen up the muscles first. To address this problem, an orthotic has been made with two components: a robotic component and an electrical component. The robotic component helps open the hand and stretch out the contractures while the electrical component relaxes the muscles to reduce the pain of stretching the contractures out. This project is valuable to the field because no other cerebral palsy orthotic has incorporated electrical stimulation into it before, and this device is geared towards low-functioning cerebral palsy children, a demographic that doesn’t have a lot of dynamic braces available to them.

Abstract

People with spastic cerebral palsy sometimes develop contractures in the hands that cause the hand to close in on itself, reducing the range of motion (ROM). For children who use their hands to learn about the world, this is a problem. Current treatments include orthotics, which tend to be bulky and uncomfortable, and electrical stimulation which has proven effective in alleviating pain and reducing spasticity. The objective of this device is to reduce the pain caused by contractures using electrical stimulation and stretch out with contractures with the orthotic. To test the device, the angles of each participant’s fingers were measured without the device. Then, the angles of the fingers were measured with the orthotic on. The control group was measured without electrical stimulation, and the test group was measured with. Finally, the participants gave feedback for how the orthotic could be improved. The average change in finger angles was 1.88°. The control group had a 0.67° average change in angles higher compared to the test group. These results indicate that the proposed orthotic does increase ROM, and feedback from participants determined that the TENS unit did relax the muscles, however the TENS did not help improve ROM. Future testing will be done over a longer period to see the device’s effectiveness over time. Children who have cerebral palsy deal with chronic pain and are limited by their reduced ROM, but this device can increase their ROM and overall quality of life.

Keywords: cerebral palsy, contractures, range of motion, orthotic, electrical stimulation

Graphical Abstract

Graphical Abstract

Go to Research Proposal

Problem Statement

Low-functioning children with spastic cerebral palsy who develop contractures live with a lot of pain and have a decreased range of motion in their hands; therefore, they cannot explore the world around them.

Engineering Objective

The goal of this project was to build an orthotic that would help stretch out contractures and strengthen muscles, as well as include an electrical stimulation component to help relax the contractures in the hand and reduce spasticity in order to relieve pain. Combined, the two will help improve the range of motion of the hand with reduced pain.

Background Infographic

Background Infographic

image sources: https://www.dreamstime.com/illustration/brain-graphic.html, Hasudungan, 2018, https://www.benik.com/peds/wrist/w-313, and https://stiwell.medel.com/application-areas/fes-for-cerebral-palsy

Background

Procedure Infographic

Procedure Infographic

Procedure

The testing procedure was as follows. First, the angles of the participant’s fingers in their natural resting position were measured. Their entire hand up to their elbow was resting on a table, and the angles were measured using a goniometer. Then, the participants were randomly assigned to two equal groups, the first being control and the second being test. Both groups used the orthotic; however, to measure the effectiveness of the electrical component, the control group had the TENS unit turned off while the test group had it turned on. Once the glove was put on, a brief second was taken to make sure the participant was comfortable in the orthotic, and any necessary adjustments were made. If at any point the orthotic became too much for the participant (i.e. the electrical stimulation became overwhelming or caused pain), it was taken off. Next, for the test group, the TENS unit was turned on. Again, a brief second was taken to make sure the participant was comfortable to continue with the test. If they weren’t, the TENS unit was turned off. Comfort is extremely important for this device. The goal is to help people who are already in pain, not cause more harm. Once the comfort level of the participants had been established, commands were issued to the computer to turn the motors on the orthotic, starting with “thumb” and ending with “pinky”. After each command, the new resting finger angles were measured. Finally, the motors were commanded to “reset”, the TENS unit was turned off and disconnected, the glove was taken off, and the participant was given a questionnaire to give feedback on the design. The following questions were asked: How did this orthotic compare to previous devices the participant has used prior? What is one thing you liked about the device? What is one thing you wish was different about the device?

Figure #1

Figure of Average Finger Angles of Participants

Figure 1: Participant data. This graph shows the average angles for each participant’s fingers with the orthotic and without the orthotic.

Figure #2

Figure of Average Change in Finger Angles of Participants

Figure 2: Average Change in Finger Angles for Each Participant. This graph shows how the orthotic affected the hand overall. The error bars show the large standard error between the average value and actual values in the set.

Figure #3

Figure Comparing Change in Angles of Participants With and Without the Orthotic

Figure 3: TENS vs Non-TENS Average. This graph shows the average angles for each participant’s fingers with and without the TENS unit compared to the overall average change in angles.

Figure #4

Picture of a Participant Wearing the Orthotic

Figure 4: Testing Picture. This is a picture of one of the participants in the TENS unit group. It shows the testing set-up, with the hand resting on the table and the goniometer that was used to measure the angles.

Analysis

This experiment was conducted for each participant according to the methodology outlined above. The carpometacarpal (joint at the base of the thumb), metacarpophalangeal (joint at the base of the finger), proximal interphalangeal (joint in the middle of the finger), and distal interphalangeal (joint closest to the tip of the finger) joints were all measure with and without the orthotic. These angles were averaged together for each participant to create the results seen in Figure 1. Each angle without the orthotic was subtracted by each angle with the orthotic, and the results were averaged together for each participant. Those averages (referred to as the average change in finger angles) are displayed in Figure 2. Only one participant had an overall negative result from using the orthotic. There were a wide range of angle changes for each angle which led to a high standard error for each participant. This is reflected by the large standard error bars seen in Figure 2.

The overall feedback from the participant is that the motors do pull the fingers back, but the motors were also pulled forward to meet the motor, limiting its effectiveness. If the motors were more secured in place, the efficiency of the device would increase. Some participants really enjoyed the TENS unit and liked the sensation of the electrical impulses. However, it was also noted that the longer the TENS unit is on, the more uncomfortable and fatiguing it gets. A Wilcoxon signed rank test was run on the paired averages in Table 1. This test was picked because it analyzed paired data but wasn’t affected by the small dataset or presence of an outlier. A two-tailed test was run because the alternative hypothesis was that the averages with the orthotic did not equal the averages without the orthotic. This experiment was testing for a difference in angles. The test was run at a 0.05 significance level, but the p-value from this test was 0.25 which is much greater than 0.05.

Discussion

The objective was to create a hand device that would move the hand of the child wearing it to stretch out their contractures and strengthen their muscles, as well as relax the contractures in the hand and reduce spasticity to relieve pain. The target group was children with high-degree cerebral palsy, and although the participants in this test did not have contractures or spastic muscles, the data gathered shows that this device has potential. For starters, this device accomplished its primary objective. The motors were able to pull back the fingers and showed an average increase of finger angles in all but one participant. However, that participant had arthritis, which could explain the unexpected result.

The results from the TENS unit tests show that the device did not accomplish its secondary objective. While the TENS unit paired with the orthotic increased the average finger angles by 1.54°, the orthotic on its own increased the angles by 2.21°. One possible reason for this is that the TENS pads were put in the wrong place. They may need to be moved further up the arm to isolate their effect on the hand. Another possible reason is that the TENS unit is designed to help relax people with tight muscles. The participants did not have spastic muscles, so they did not need the TENS unit to relax their muscles as the device worked. It is possible that the TENS unit did more harm than good in this scenario, but there is no way to be sure until the device can be tested on children with cerebral palsy.

However, these unexpected results do not suggest that the TENS unit should be removed as part of the device. A few participants really enjoyed having the TENS unit as part of the device, and one participant particularly loved the sensation. One difficulty that arose when testing the device was with measuring the finger angles while the glove was on. The fingerless glove was not form-fitting. Between the motors and TENS unit on top of the hand and the loose-fitting glove covering 2 of the 3 joints being measured, sometimes the angles had to be measured multiple times. A couple times, the participant was asked to turn their hand over to get a better understanding of where their fingers were, which made the angles much easier to measure. In the future, the participant will be asked to turn their hand over when measuring the angles with the glove. The reason this wasn’t done at first was because there was a fear that it would mess with the results (the baseline angles were measured with the hand faced down). However, because the glove is holding the fingers in place, measuring the glove angles with the hand face up while ensure more accurate results.

The results from the Wilcoxon signed rank test showed that this test was statistically insignificant. That is likely because the difference in angle averages covered a wide range of values, ranging from -24.86 to 20.58. In future tests, this might be resolved by having a larger sample size. There simply weren’t enough participants for this round of testing, but for the next round, a larger pool would help make the test more statistically significant.

Looking at how this study compares to other research, past studies have also looked at how orthotics help children with cerebral palsy by measuring the angles in their hand (Lieber et al., 2022; Dittli et al., 2022; Yıldızgören et al, 2014). However, the study closest to the one outlined in this paper is the one done by Yıldızgören and colleagues (2014). They aimed to discover the effects of neuromuscular electrical stimulation (NMES) on the spasticity of muscles in the wrist and finger of children with cerebral palsy. The main difference is that this study is proposing a new device entirely. Up until this point, NMES has never been a component of a cerebral palsy orthotic; it has always been separate. Now though, having the two parts combined into one device could make treatment easier and electrical stimulation a more viable option for children with cerebral palsy.

Future Research

A lot of the feedback from the questionnaire was that the orthotic was very mild. This was both a good and bad thing. Many of the participants said that it was comfortable, but that it wasn’t very rigid like most splints are and that the material was too flexible. One of the biggest problems was that when the motor turned, the elastic pulled the motor more towards the finger instead of the other way around. This is because the glove chosen as the base of the orthotic was very stretchy. The orthotic should be stretchy and comfortable; however, it needs to have more firmness to it. One recommended option was weightlifting gloves, so that’ll be the next thing to investigate. The electrical component should also transition from a pre-programmed TENS unit to a custom electrical system. This will allow for targeted electrical stimulation specifically for cerebral palsy. Once those improvements are made, the device should be tested on children with cerebral palsy. This would help clear up the results of the TENS unit tests. Additionally, the “mirror glove” should be developed. In the original design, the orthotic came with a mirror glove that paired with the orthotic and allowed teachers to manipulate the orthotic while the child with cerebral palsy was wearing it. This better equipped the teachers to help the child explore and play using their hands. That is the next big addition to go along with the device.

Conclusion

The goal of the proposed orthotic was to reduce pain and stretch out contractures in the hands of children with cerebral palsy so they could explore the world around them and lead a better-quality life. The finger angles of the participants were measured, first without the orthotic, then with. The orthotic tests were broken up into two groups: one using the TENS unit, and one not. This showed whether the device had an impact on increasing the range of motion in the hand. On average, the device improved the finger angles, with the control group improving 0.67° more than the TENS group. One possibility of this unexpected result is that the participants in the test group did not have tight, spastic muscles, so the TENS unit wasn’t needed to relax anything. However, the participants in the test group enjoyed the sensation of the TENS unit, so it did have an impact on the feel of the hand. All in all, the proposed orthotic accomplished what it set out to do: it did help improve the range of motion in the hand. This device shows promise and could be used in the near future as a device to help improve the range of motion in the hands of a child with cerebral palsy, and in turn, improve their quality of life.

References

Bhardwaj, P., & Sabapathy, S. R. (2011). Assessment of the hand in cerebral palsy. Indian journal of plastic surgery : official publication of the Association of Plastic Surgeons of India, 44(2), 348–356. https://doi.org/10.4103/0970-0358.85356

Choo, Y. J., & Chang, M. C. (2021). Commonly Used Types and Recent Development of Ankle-Foot Orthosis: A Narrative Review. Healthcare, 9(8), 1046. https://doi.org/10.3390/healthcare9081046

Dittli, J., Goikoetxea-Sotelo, G., Lieber, J., Gassert, R., Meyer-Heim, A., Van Hedel, H. J. A., & Lambercy, O. (2023). A Tailorable Robotic Hand Orthosis to Support Children with Neurological Hand Impairments: a Case Study in a Child's Home. IEEE ... International Conference on Rehabilitation Robotics : [proceedings], 2023, 1–6. https://doi.org/10.1109/ICORR58425.2023.10304752

Dittli, J., Vasileiou, C., Asanovski, H., Lieber, J., Lin, J. B., Meyer-Heim, A., Van Hedel, H. J. A., Gassert, R., & Lambercy, O. (2022). Design of a compliant, stabilizing wrist mechanism for a pediatric hand exoskeleton. 2022 International Conference on Rehabilitation Robotics (ICORR), 1–6.https://doi.org/10.1109/ICORR55369.2022.9896550

Faria, B. M., Reis, L. P., & Lau, N. (2013). Cerebral Palsy EEG Signals Classification: Facial Expressions and Thoughts for Driving an Intelligent Wheelchair. Proceedings of IEEE Xplore. https://doi.org/10.1109/ICDMW.2012.89

Graham, H. K., Rosenbaum, P., Paneth, N., Dan, B., Lin, J. P., Damiano, D. L., Becher, J. G., Gaebler-Spira, D., Colver, A., Reddihough, D. S., Crompton, K. E., & Lieber, R. L. (2016). Cerebral palsy. Nature reviews. Disease primers, 2, 15082. https://doi.org/10.1038/nrdp.2015.82

Hasudungan, A. (2018). Cerebral Palsy - (DETAILED) Overview. [Video]. Youtube. https://www.youtube.com/watch?v=7fUGWKM32hE

Lieber, J., Dittli, J., Lambercy, O., Gassert, R., Meyer-Heim, A., & van Hedel, H. J. A. (2022). Clinical utility of a pediatric hand exoskeleton: identifying users, practicability, and acceptance, and recommendations for design improvement. Journal of neuroengineering and rehabilitation, 19(1), 17. https://doi.org/10.1186/s12984-022-00994-9

Nussbaum, E. L., Houghton, P., Anthony, J., Rennie, S., Shay, B. L., & Hoens, A. M. (2017). Neuromuscular Electrical Stimulation for Treatment of Muscle Impairment: Critical Review and Recommendations for Clinical Practice. Physiotherapy Canada. Physiotherapie Canada, 69(5), 1–76.https://doi.org/10.3138/ptc.2015-88

Paul, S., Nahar, A., Bhagawati, M., & Kunwar, A. J. (2022). A Review on Recent Advances of Cerebral Palsy. Oxidative medicine and cellular longevity, 2022, 2622310. https://doi.org/10.1155/2022/2622310

Shierk, A., Lake, A., & Haas, T. (2016). Review of Therapeutic Interventions for the Upper Limb Classified by Manual Ability in Children with Cerebral Palsy. Seminars in plastic surgery, 30(1), 14–23. https://doi.org/10.1055/s-0035-1571256

Yıldızgören, M. T., Nakipoğlu Yüzer, G. F., Ekiz, T., & Özgirgin, N. (2014). Effects of neuromuscular electrical stimulation on the wrist and finger flexor spasticity and hand functions in cerebral palsy. Pediatric neurology, 51(3), 360–364. https://doi.org/10.1016/j.pediatrneurol.2014.05.009

ISEF Poster

This project was a passion project of mine, and I feel like I have learned so much from the past 8 months of working on it. I ended up winning first at MSEF with this project and advancing to ISEF which was held in Los Angeles, California this year. It was an amazing experience, and I met so many incredible and intelligent people there from all over the world. I placed 4th in the Biomedical Engineering category, which is a huge accomplishment for me as someone who never dreamed of even making it to MSEF. Thank you to all of those who supported me and helped me with this project. I appreciate you so much!