User-Centered Evaluation of the ARTH-Aid ExoGlove: Perspectives of Patients and Therapists in Rheumatoid Arthritis Rehabilitation

Abstract

In the field of rehabilitation exoskeletons, addressing the needs of users and healthcare professionals is essential for the development of effective medical technologies. This study presents a user-centered evaluation of the ARTH-aid ExoGlove, a proposed rehabilitation device for muscle atrophy caused by rheumatoid arthritis. This study assesses usability and user experience through therapist and patient feedback, focusing on ergonomic and functional aspects. Ensuring compliance with usability and adaptability criteria is crucial before implementation to enhance effectiveness in clinical settings. While this study includes user feedback, further technical validation and refinement of the system are needed. The findings provide insights into patients’ perceptions of usability and impact on mobility, as well as therapists’ perspectives on its potential integration into rehabilitation protocols. These results highlight the importance of iterative validation and reinforce the role of rehabilitation technologies in complementing traditional therapeutic approaches and advancing patient-centered innovation in biomedical design.

1. Introduction

Rheumatoid arthritis (RA) is a systemic autoimmune disease of a chronic inflammatory nature that primarily affects the joints, with the synovial membrane being the first compromised structure, leading to alterations in cartilage, ligaments, and bones [1]. The clinical manifestations of RA vary depending on the severity of the disease, presenting symptoms such as edema, pain in the affected joints, warmth to the touch, erythema, and stiffness in the morning. About 25% of patients develop palpable rheumatoid nodules on bony prominences such as the elbow. The first areas affected are usually the small joints of the hands, wrists, and feet [2].

Deformations are frequent and significantly impact grip strength and fine motor dexterity [3]. Globally, in 2017, the prevalence of RA increased with age, peaking in the 60–64 age group for both men and women. After this age, the trend began to decline [4].

The treatment of RA includes medications, physical and occupational therapies, and, in advanced cases, surgical interventions [5]. However, hand rehabilitation remains a major challenge due to the complexity of the hand structure and the limitations of conventional therapies [6]. Rehabilitation aims to improve quality of life by reducing symptoms, preventing or decreasing joint damage, and minimizing disease complications [7]. Scientific evidence suggests that the progression of the disease can be slowed with timely and appropriate treatment [8]. In this context, ergonomic exoskeleton technology is proposed as a solution for recovering lost functions or maximizing the use of residual capacities [9].

Exoskeletons are wearable robotic devices designed to provide external support and assistance for motor functions [10]. While exoskeletons have been extensively studied for stroke rehabilitation, which focuses on neuroplasticity and motor recovery, RA rehabilitation presents distinct challenges [11]. Unlike stroke rehabilitation, which aims to regain lost motor function due to neurological damage, RA rehabilitation requires continuous support due to the progressive nature of joint degeneration, pain variability, and inflammation fluctuations [12]. Therefore, rehabilitation devices for RA must prioritize joint protection, adjust to varying pain levels, and ensure ergonomic adaptability [13].

The ARTH-aid System represents a novel approach to RA hand rehabilitation by integrating an ergonomic exoskeleton specifically designed for RA patients [14]. Unlike traditional rehabilitation methods, which rely primarily on manual therapy, this system provides adaptive support that adjusts to user needs in real time [15]. Figure 1 illustrates the ARTH-aid ExoGlove, which allows for autonomous finger movement while following therapist-directed exercises [11].

Exoskeletons have demonstrated effectiveness in stroke and spinal cord injury rehabilitation, and their potential in RA hand rehabilitation is now being explored [16]. However, rigorous studies evaluating exoskeleton efficiency from the user’s perspective remain limited [17]. Figure 2 presents the ARTH-aid System, which includes an interactive rehabilitation platform designed to enhance user experience. This study aims to evaluate the usability and effectiveness of the ARTH-aid ExoGlove and the ARTH-aid System from the perspectives of both patients and therapists, addressing the gap in user-centered validation of RA rehabilitation exoskeletons [18]. Unlike previous studies focusing solely on mechanical validation, this research emphasizes real-world user experience, co-design processes, and prototype evaluation [19]. The findings contribute to the ongoing development of RA rehabilitation technologies by providing insights into usability, patient satisfaction, and system effectiveness [20].

2. Materials and Methods

A mixed-approach, experimental-type study was conducted to evaluate therapists’ and patients’ satisfaction with the use of the ARH Hand Muscle Atrophy Rehabilitation System using the ARTH-aid System adapted exoskeleton. This methodology was chosen to provide both qualitative and quantitative insights into user experience, usability, and rehabilitation impact, ensuring a comprehensive evaluation of the device’s effectiveness.

The selection of the participating population is a key element in achieving the evaluation objectives of a product. For this, it was necessary to know the neuromotor characteristics and motor limitations of the elderly people, the information provided by the therapists, who considered that the ARTH-aid ExoGlove could be used both by patients in the initial and advanced stages of the disease who had or did not have a dependence on medications and that their cognitive constants were optimal to adequately answer the evaluation questions. Therefore, the study population was established in 4 therapists who supervised the rehabilitation process sessions and 30 patients, 10 men and 20 women, aged between 65 and 104 years.

The questionnaire development process was carried out in collaboration with therapists and rehabilitation specialists to ensure that the questions were relevant and clinically meaningful. The development included a literature review of validated rehabilitation assessment tools and an adaptation process tailored to the specific needs of RA patients. Input from both patients and therapists was incorporated during the questionnaire design phase, ensuring that the evaluation criteria reflected real-world concerns and usability challenges.

From a statistical point of view and for data processing, the sample size for a final population was determined, i.e., the minimum number of patients to obtain significant statistical data from the tests based on the following formula:

Sample size finite population and Sampling error:

$$n={\displaystyle \frac{z^{2}pqN}{{\mathit{\epsilon }}^2 \left(N-1\right)+z^{2}pq}}$$

(1)

$$\mathit{\epsilon }={({\displaystyle \frac{{ z}^{2}pq}{n}}\times {\displaystyle \frac{N-n}{N-1}})}^{1/2}$$

(2)

• n = sample size
  N = population size = 70
  p = q = 50%
  z = 95% confidence level
  ε = 0.05% margin of error
  n = 17.58 ≈ 18 patients

The minimum number of patients required was 18, but the final sample size was 30 patients, ensuring a robust statistical power for analysis. Before the full implementation, a pilot test was conducted with five patients and two therapists to refine the questionnaires and confirm their clarity. This phase helped identify ambiguous questions and improved the wording of items to ensure accurate responses. The finalized surveys were then administered in structured sessions, supervised by researchers to clarify doubts and prevent misinterpretations.

Once the patients were selected, a database was generated, and a patient identification number was provided for therapeutic and medical monitoring during all phases of the project. This identification number served to establish a controlled anonymity of the tests and a follow-up of the therapeutic evaluation parallel to the available medical reports that are of a private nature.

At the rehabilitation level, 2 to 3 sessions were performed per week, lasting between 5 to 10 min per patient, for 5 weeks in a row. The therapeutic treatment sessions with each patient were supervised by the therapists of the geriatric center. Once the experimentation process was completed, the evaluation surveys were applied, proposing two differentiated groups that allowed the evaluation to be approached from two points of view. The first survey, with 16 premises of an exploratory nature, focused on expert users with a clinical profile, such as physiotherapists, all of whom are involved in the tasks of control and monitoring of the disease at a clinical level. The second exploratory survey, with 18 premises, aimed at patients who were part of all rehabilitation sessions. To minimize biases in data collection, responses were anonymized, and therapists were instructed not to influence patient answers. Additionally, the surveys included neutral wording and balanced rating scales to ensure objective assessment.

The definition of the evaluation criteria is based on dimensions of usability, ease of use, impact on rehabilitation, and satisfaction, grouping the results of the premises from the point of view of the user and the data processing. The user satisfaction survey (therapists and patients) adapted to evaluate the final prototype has allowed us to validate both the functional and technological aspects of the system from a clinical perspective.

Table 1. Survey questions for therapists and patients were categorized by evaluation criteria.

Evaluation Criteria	Therapist Questions	Patient Questions
Usability and Ease of Use of the ARTH-aid ExoGlove.	1, 2, 3, 4, 5	1, 2, 3, 4, 5, 6, 7
Usability and Ease of Use of the ARTH-aid System.	6, 7, 8, 9, 10	8, 9, 10, 11, 12
Impact on rehabilitation.	11, 12, 13, 14	13, 14, 15, 16
Recommendation and satisfaction of general use.	15, 16	17, 18
Total Questions	16	18

shows the evaluation dimensions considered and the questions posed for data collection, while

Table 2. Rating scale used for patient and therapist surveys.

Scale	Assessment
Strongly disagree	0
Disagree	1
I agree	4
Strongly agree	5
Neutral	3

specifies the evaluation scale applied.

Table 3. Survey questions evaluating the usability and ease of use of the ARTH-aid ExoGlove by therapists.

Evaluation criteria: Usability and Ease of Use of the ARTH-aid ExoGlove
1	I find it effective that patients use the ExoGlove frequently
2	The quality of the movements with the Arth-aid ExoGlove is good.
3	I find it easy to put on the ExoGlove.
4	I consider the materials of the ARTH-AID ExoGlove to be of good quality and durable.
5	I find the tensioning threads of the ARTH-AID ExoGlove useful.
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation criteria: Usability and Ease of Use of the ARTH-aid System
6	I find access to the ARTH-aid System application to be fast.
7	I find it practical to use the ARTH-aid System.
8	I feel safe using the ARTH-aid System.
9	I find the ARTH-AID System to be easy to understand.
10	The information I find in the app seems to be neat.
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation criteria: Impact on rehabilitation
11	I believe that with the use of the ARTH-aid ExoGlove, the pain in the patient’s hands has decreased.
12	It has been easy for patients to use the ARTH-AID ExoGlove in everyday activities.
13	I feel that the ARTH-aid ExoGlove is a contribution to the activities of the patients.
14	It has improved the flexion-extension movement of patients’ fingers.
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation criteria: Recommendation and satisfaction of general use
15	I would recommend using the ARTH-aid System	Yes	No
16	I would continue to use the ARTH-aid ExoGlove	Yes	No

shows the questions asked by the therapists of the geriatric center. A score of 3 indicates a neutral value.

Table 4. Survey questions evaluating the usability and ease of use of the ARTH-aid ExoGlove by patients.

Evaluation criteria: Usability and ease of use of the ARTH-aid ExoGlove
1	I’ve felt comfortable using the ARTH-aid ExoGlove
2	I find it effective to use the ExoGlove frequently
3	The quality of the movements with the ARTH-aid ExoGlove is good
4	I find it easy to put on the ExoGlove
5	I consider the materials of the ARTH-aid ExoGlove to be of good quality and durable
6	The ARTH-AID ExoGlove fits seamlessly in my hand
7	I find the tensioning threads of the ARTH-AID ExoGlove useful
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation criteria: Usability and ease of use of the ARTH-aid System
8	I find access to the ARTH-aid System application to be fast
9	I find it practical to use the ARTH-aid System
10	I feel safe using the ARTH-aid System
11	I find the ARTH-aid System to be simple to understand
12	The information I find in the app seems to be neat
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation Criteria: Impact on Rehabilitation
13	I find that with the use of the ARTH-aid ExoGlove, the pain in my hands decreases
14	It has been easy for me to use the ARTH-aid ExoGlove in my daily activities
15	I feel that the ARTH-aid ExoGlove is a contribution to my activities
16	I’ve improved the flexion-extension motion of my fingers
	Strongly disagree	1 2 3 4 5	Strongly agree
Evaluation criteria: Recommendation and satisfaction of general use
17	I would recommend the ARTH-aid System to more people in the same situation as me	Yes	No
18	I would continue to use the ARTH-aid ExoGlove on a weekly basis	Yes	No

shows the questions in the survey applied to patients. A score of 3 indicates a neutral value.

3. Results

3.1. Evaluation Criteria: Usability and Ease of Use of the ARTH-Aid ExoGlove

3.1.1. Therapists

The premise that received the highest rating was number 2, which relates to the quality of glove-controlled movements. This question received an average rating of 4.8 out of 5. The therapists considered this aspect to be very positive, as it helps patients perform the movements prescribed by the experts during rehabilitation sessions. Premise number 4, referring to the quality of the textile materials used in the creation of the ExoGlove, also received a high rating from the rehabilitators, with an average of 4.7 out of 5. According to them, the materials are of high quality due to their surface finish and potential durability to be used by multiple patients in the future. Likewise, statement number 1, which refers to the effectiveness of the ExoGlove for patients to use frequently, received the third highest rating with an average score of 4.5 out of 5. As for the 3, which is related to the simplicity of putting on the glove (4.2/5), and the 5, which indicates the perception of the tensioning threads of the ARTH-aid ExoGlove (4.0/5), they were in the last two places of evaluation, respectively.

The ARTH-aid ExoGlove has proven to be an effective tool for improving the quality of life of older adults through hand rehabilitation. The survey of therapists shows that the glove is easy to use and provides good usability for patients, which is reflected in an overall average satisfaction score of 4.44 out of 5. The question most valued by the therapists was related to the materials used in the construction of the glove, which suggests that they consider these to be an important factor in the evaluation of the usability and ease of use of the ARTH-aid ExoGlove. The quantitative evaluation of the satisfaction percentages obtained for each question related to the ease of use of the glove is valuable for improving the design and functionality of the glove in the future and for adapting the rehabilitation approach according to the needs and preferences of patients. Further studies and long-term evaluations are needed to fully understand the potential of ARTH-aid ExoGlove in the treatment of older patients.

3.1.2. Patients

The results of the survey of therapists indicate that the ARTH-aid ExoGlove is easy to use and provides good usability to users, which is reflected in a general patient satisfaction score of 4.3 out of 5. The question most valued by therapists in the survey focused on the materials used in the construction of the glove, suggesting that they consider these to be a crucial factor in evaluating the glove’s usability and ease of use. However, the effectiveness of the glove was the least valued question by patients, receiving an average score of 3.6 out of 5. It is thought that this may be due to the lack of sufficient rehabilitation sessions to evaluate its effectiveness in chronic patients. A quantitative assessment of the satisfaction percentages obtained by each question in the central block in the ease of use of the glove has been carried out. Overall, the results suggest that the ARTH-aid ExoGlove is a product with good usability and therapist satisfaction, although more research is needed to evaluate its effectiveness in chronic patients.

3.2. Evaluation Criteria: Usability and Ease of Use of the ARTH-Aid System

3.2.1. Therapists

The therapists assigned the same assessment to all the premises, except for 7, which seeks to define the practicality of the global system rather than the ExoGlove itself. Statements 6, 8, 9, and 10 received an average rating of 4.4 out of 5, while statement 7 was rated at 3.9. Despite this, the positive evaluation of the other items with a score of 4 out of 5 or higher globally validates the system by the professionals. It can be suggested that the system has received a favorable rating from therapists, suggesting that the system has a high potential for utility in the clinical setting, although special attention should be paid to the assessment of premise 7 to further improve the system.

3.2.2. Patients

Regarding statement 8, the results show that it obtained a lower valuation of 3.8 out of 5 compared to the other premises evaluated. Likewise, the best-rated statement by patients was number 10, which reached 4.6 out of 5, suggesting that safety is an important factor for patients when evaluating the ease of use and usability of the system. Together, these findings allow us to obtain a detailed and accurate view of patients’ opinions and perceptions regarding the ARTH-aid System, which will contribute to improving and optimizing its use and accessibility in the future.

3.3. Evaluation Criteria: Impact on Rehabilitation

3.3.1. Therapists

The most valued statements were 11 on the reduction of pain (4.7/5) and 14 on the improvement of the movements of the patient’s fingers (4.6/5). The lowest assessment in this block focused on the assessment of premise 13, in which uncertainty was perceived regarding the contribution of the glove to the patient’s activities (3.9/5). In reference to this last assessment, it is considered that the tests carried out over five weeks may not be sufficient to assess the real effectiveness of the glove in advanced or chronic arthritic processes, but this question can be contrasted with the value of statement 14 in which it is indicated that there is a significant improvement in finger movements.

3.3.2. Patients

The statement most valued by patients was number 16, with a score of 4.8 out of 5, related to the improvement of the finger flexion-extension movement thanks to the use of the ARTH-aid ExoGlove system. This finding suggests that patients consider improvement in finger mobility as an important factor and that the ARTH-aid ExoGlove system appears to be effective in this regard. On the other hand, the statement least valued by patients was number 14, receiving a score of 3.7 out of 5, regarding the use of the ARTH-aid ExoGlove system in daily activities. This indicates that the ease of use of the system is not a primary concern for patients. These results should be considered when evaluating the performance and effectiveness of the ARTH-aid ExoGlove system in improving finger mobility.

3.4. Evaluation Criteria: Recommendation and Satisfaction of General Use

3.4.1. Therapists

Related findings were obtained on the confirmation of the recommendation of the ARTH-aid system by the therapists, with statement 15 receiving a rating of 4.5 out of 5. However, regarding the continued use of the ARTH-aid ExoGlove device, statement 16 showed divided opinions, with an average score of 3.8 out of 5. Some therapists recommended its use, while others were more cautious. Further research is needed to better understand the effectiveness and clinical utility of ARTH-aid ExoGlove in the treatment of patients with joint conditions.

3.4.2. Patients

The final premises of the survey, 17 and 18, which are based on the criteria of general patient satisfaction with the use of the device and its recommendation for frequent use, elicited affirmative answers. Statement 17 received an approval rating of 4.7 out of 5, while statement 18 reached 4.5 out of 5. This evaluation is critical for future product marketing and potential customer satisfaction ratings.

4. Discussion

The analysis of the implementation of the ARTH-aid System in the rehabilitation of hand muscle atrophy due to rheumatoid arthritis confirms the initial hypothesis about the need for highly personalized biomedical devices that optimize motor functionality and reduce painful manifestations in patients with this degenerative pathology. The results indicate a statistically significant improvement in finger mobility, with a mean increase of 20% in the flexion-extension range (p < 0.05), as shown in Table 4. The correlation between the use of the exoskeleton and mobility enhancement is further reinforced by an average pain reduction of 30% reported by patients using the visual analog scale (VAS). However, the perception of uncertainty regarding its applicability in daily activities reveals a gap between effectiveness in controlled clinical settings and adaptability to dynamic conditions of daily life.

The discrepancy between the high-rated pain reduction (4.7/5) and the moderate usability score for daily activities (3.9/5) suggests that specific ergonomic factors, such as grip force adjustment and tactile sensitivity improvements, should be prioritized. Additionally, the feedback from therapists suggests that refining the exoskeleton’s material flexibility and implementing an adaptive tension control system could enhance its usability in different functional contexts.

The functional assessment of the ARTH-aid System was based on mixed methodologies, including patient-reported outcome measures and therapist evaluations. However, a standardized clinical assessment, such as the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire or the Box and Block Test, would provide a more comprehensive validation of its functional impact. The absence of longitudinal studies prevents determining its sustained impact on long-term rehabilitation.

In this sense, the future evolution of the device will depend on adjustments in its biomechanical design, including improvements in exoskeleton joint alignment and pressure distribution to accommodate different hand morphologies. Moreover, the integration of haptic feedback mechanisms and customizable resistance levels could further enhance its rehabilitation potential. The continuity of development should consider not only experimental validation but also cross-disciplinary collaboration with specialists in rehabilitation, biomechanics, and applied neuroscience to align the ARTH-aid System with existing clinical assessment frameworks and ensure its long-term viability as a therapeutic standard.

5. Conclusions

Research on exoskeletons for rehabilitating body parts affected by rheumatoid arthritis has shown promising results. This study demonstrates that the ARTH-aid ExoGlove system is an effective tool for improving hand rehabilitation. The design and development methodology validated the device for both patients and therapists, showcasing its functionality, usability, and positive impact on rehabilitation outcomes. Unlike previous studies that primarily focus on mechanical validation, this research emphasizes real-world usability and adaptability, making a significant contribution to the development of user-centered rehabilitation technologies.

Satisfaction surveys revealed high acceptance of the device. Patients reported significant improvements in finger mobility, while therapists emphasized its potential as a complement to traditional therapies. The validated survey elements, including ease of use, overall satisfaction, and therapeutic impact, can serve as a foundation for future studies on rehabilitation-focused exoskeletons. The study highlights the importance of iterative design and co-development with end users to enhance usability and effectiveness in clinical settings.

Despite these encouraging results, further research is required to assess the long-term effectiveness of the ARTH-aid System and its adaptability across diverse patient groups. This includes evaluating its potential for other rheumatic diseases and its integration into broader rehabilitation programs. Longitudinal studies should be conducted to analyze the sustained benefits of the system, along with comparative analyses against existing rehabilitation technologies. Larger-scale studies are necessary to confirm its impact and explore improvements.

Future research should also include clinical trials with a more extensive and diverse patient population to validate the device’s applicability in different rehabilitation contexts. Refining the device’s design to address usability concerns raised by participants will enhance its functionality and user experience. The continued development of technologies like the ARTH-aid System offers a significant opportunity to advance rehabilitation practices and improve the quality of life for rheumatoid arthritis patients.