Development of a Smartphone-Based mHealth Platform for Telerehabilitation

Telerehabilitation is becoming increasingly valuable as a method for expanding medical services. The smartphone-based mHealth platform (SMPT) has been developed to provide high-quality remote rehabilitation through a smartphone and inertial measurement units. The SMPT uses smartphone as a main platform with connection to medical backend server to provide telerehabilitation. Patients would be referred to therapists to receive a tutorial of exercise technique prior to conducting their home exercise. Once patients begin their home exercises, they can report any problems instantly through the SMPT. The medical staff can adjust the exercise program according to patient feedback and the data collected by the SMPT. After completing the exercise program, patients visit their clinician for re-evaluation. A Service User Technology Acceptability Questionnaire from both medical professional and public perspective revealed a high level of agreement on enhanced care, increased accessibility, and satisfaction and a moderate level of agreement on the use of this platform as a substitute for traditional rehabilitation. Concerns about privacy and discomfort were low in the medical professional and public groups. Concerns about care personnel were also significantly different between the two groups. The SMPT is a promising system for providing telerehabilitation as an adjunct to traditional rehabilitation, which may result in improved outcomes compared with those achieved when using traditional rehabilitation alone.

I. INTRODUCTION 30 T ELEMEDICINE can be defined as the adoption of 31 telecommunication technologies to provide medical infor-32 mation and services [1]. The focus on telemedicine is increas- 33 ing because of the possibilities it offers for expanding the 34 coverage of medical services. Telerehabilitation is an extension 35 of telemedicine that involves delivering rehabilitation services 36 remotely for certain medical conditions [2]. With the spread 37 of COVID-19 worldwide, the importance of this technology 38 has increased [3]. The traditional rehabilitation service is 39 an outpatient treatment provided by certified therapists in 40 the clinic. This treatment has several inherent limitations, 41 including the length of time of the clinical visit, long periods of 42 waiting between sessions, a lack of therapists, low accessibility 43 for people with disabilities, and the lack of continuity in the 44 rehabilitation after the patient returns home [4], [5]. Through 45 the remote delivery of telerehabilitation, these limitations can 46 be mostly overcome, and several studies have achieved positive 47 results when using telerehabilitation to treat different diseases 48 that limit patient physical function [6], [7], [8], [9], [10]. Con-49 sequently, telerehabilitation is being increasingly considered 50 a valuable tool by medical providers and the wider society. 51 The estimated global market size for this technology has been 52 reported to be over $160 billion, and this market is expanding 53 exponentially [9]. 54 We developed a smartphone-based mHealth platform 55 (SMPT) utilizing inertial measurement units (IMUs) to provide 56 telerehabilitation acted as an adjunct to traditional rehabili-57 tation. The aim of the SMPT is to extend the high-quality 58 rehabilitation from hospital to home setting. Telerehabilitation 59 can be delivered through several methods, including computer-60 based [ [21]. 62 Computer-based and set-top-box-based systems allow patients 63 to access rehabilitation at home. Furthermore, these systems 64 can meet patients' needs by providing different exercise pro-65 grams with visual or audio instructions. However, computer-66 based and set-top-box-based telerehabilitation systems require 67 additional equipment [20], [21], which is neither easily avail-68 able nor portable. Although telecommunications applications, 69 such as Skype and Teams, provide the other solution for 70 telerehabilitation, the patients in need of rehabilitation are 71 mainly the elderly, who exhibit a low likelihood of using the 72  The proposed SMPT for telerehabilitation consists of a 138 smartphone, two IMUs, a digital television (DTV), and a 139 server, as illustrated in Fig. 1. When a user wishes to perform 140 a rehabilitation exercise, they first use the smartphone applica-141 tion (app) to connect to the IMUs through a Bluetooth interface 142 and to the DTV through a high-definition multimedia interface 143 or Wi-Fi. After the smartphone has successfully connected to 144 the server in a hospital through Wi-Fi or a 4G or 5G network, 145 the telerehabilitation program can be initiated. Besides the 146 IMU device, other medical devices with Bluetooth interface 147 could also be connected, for example, the sphygmomanometer. 148 The senior physician who has higher authority in the medical 149 center would be the system manager to help maintain the 150 accounts of the system. The system is available to other 151 users, patients using the same system, but each patient will 152 have their own account. The patient can only access to their 153 personal information on the system. Therefore, there is no 154 ethical consideration of the system.

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The software architecture of SMPT is presented in Fig. 2    is implemented using ReactJS technology and runs in a 198 browser environment. The backend software for engineers is 199 maintained and managed by engineering-related personnel. 200 The system's backend data are interfaced in the application 201 programming interface (API) mode, and the backend API 202 server is implemented using.NET Core technology and the 203 following technical solutions: (1) Entity Framework as the 204 data capture layer; (2) Identity Framework for controlling the 205 authority mechanism; (3) the IIS application pool and database 206 connection pool for optimizing resource utilization; and (4) the 207 Microsoft SQL Server as the database engine.

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A key program executed in the backend server is the 209 backend software for medical personnel, which is presented 210 and operated on a Web interface. A general description of the 211 backend software for medical personnel is presented in the 212 following text. 213 1) Case Management: The primary function of case man-214 agement is to manage the user's personal data, including 215 case list queries, new cases, case modification, password 216 modification, and a detailed page view for a single case. 217 2) Personnel Management: Personnel management involves 218 adding and modifying information on back-office personnel 219 (medical personnel). When adding personnel, the ID (account) 220 number, password, name, personnel role, and administrator 221 authority must be entered. Passwords can also be reset.      The exercise database was designed by certified therapists 304 in Taiwan on the basis of their experience and the existing 305 literature [35], [36], [37]. The SMPT is unique and has a 306 high level of expandability. New therapeutic exercise protocols 307 can be easily added through the medical personnel backend 308 server. The main protocols in the current system include 309 stretching exercises, range-of-motion exercises, and endurance 310 and strength training. To develop an exercise program, the 311 medical personnel must enter relevant information, including 312 the number of repetitions and sets for each exercise, the 313 resting time between each set, the duration and time limit 314 of each exercise, and the target angle interval measured by 315 the IMUs. The therapist can add several exercises to generate 316 an exercise task, and each exercise task can be added to a 317 rehabilitation module. For example, in the case of adhesive 318 capsulitis, a stretch-based exercise to increase the range of 319 motion in the shoulder joint, which is a key exercise for this 320 disorder, can be included in a muscle strengthening program. 321 The therapist can select pre-existing shoulder range-of-motion 322 and muscle strength exercises and combine them to create an 323 adhesive capsulitis rehabilitation module. Fig. 4 illustrates the 324 relationship among exercises, exercise tasks, and rehabilitation 325 modules. A new exercise task can be modified from the exist-326 ing exercise task template or created using several exercises. 327 All exercise programs, tasks, and rehabilitation modules can be 328 shared with other medical personnel and modified, as required, 329 in the backend server, thereby allowing the clinical practitioner 330 to develop appropriate rehabilitation modules promptly. In the developed SMPT for telerehabilitation, the software 334 is divided into a medical backend server and a smartphone 335 app for patients. To better accommodate to the clinical setting, 336 several combine discussion meetings including the engineers 337 and medical professions were held to discuss the exercise in 338   angle should be held for, and the target angle of the exercise.

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The system interface for observing the detailed parameters of 376 an exercise is displayed in Fig. 7. By selecting the target angle 377 and hold time, stretching and stability exercises can be tailored 378 effectively.

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Moreover, medical personnel can view the task performance 380 in the backend server to evaluate the quality of movement and 381 decide whether to progress to the next stage of rehabilitation. 382 The backend server would generate the report of the complete 383 rate of the exercise. Take shoulder exercise as an example, 384 the target angle of shoulder flexion is 120 degrees, and the 385 actual angle performed by the patient would be shown in 386 the post exercise report to justify the complete rate of the 387 patient. On the other hand, the number of the task being done 388 could be seen from the backend server allowing the medical 389 personnel to evaluate the compliance of the patient. The 390 patient's feedback can also be viewed through the platform, 391 thereby providing further input for subjective measurements 392 such as rate of perceived exertion or pain scale, if required. The 393 system interface for medical personnel operation is depicted in 394 Fig. 8. An artificial intelligence module can be added to the 395 designed system in the future to improve how the collected 396 data are used and to assist a clinician in creating effective 397 therapeutic exercise protocols.

B. System Implementation for Patients 399
Patients can download the app to their smartphone and 400 begin exercises by their own at home after completing training 401 sessions with a therapist. The SMPT is not designed for a 402 single musculoskeletal disorder but is an evolving exercise 403 database that can provide specific exercise protocols for dif-404 ferent diseases. Therefore, switching to a new platform or 405 app for different musculoskeletal problems is unnecessary. 406 Moreover, our system can connect to other Bluetooth sensors 407 apart from the IMUs, which can provide additional information 408 to the patient. For example, the system can be combined with 409 the sphygmomanometer with Bluetooth interface, which can 410 provide the blood pressure and heart rate of the patient to 411 the system. Medical personnel provide the patient with an 412 account and a password, and the designed system also supports 413 log in through a QR code. After the first log in, the patient 414 is logged in automatically. The smartphone operating screen 415 is illustrated in Fig. 9. The welcome screen contains four 416 windows: "My Tasks," "Practice Mode," "My Reward," and 417 "My Devices." By clicking "My Tasks," the patient enters 418 the exercise window and begins the rehabilitation session. 419 Clicking on "Practice Mode" enables the patient to practice 420 different exercises from the database with the permission 421 of medical personnel; clicking on "My Reward" allows the 422 patient to view their rewards for completing exercises; and 423 clicking on "My Devices" enables the patient to check the 424 connection to the IMUs. Under the "My Tasks" option, the 425 patient can initiate their personalized therapeutic exercise 426 program according to the schedule designed by a medical 427 professional. Although a training session prior to commencing 428 the home exercise program is provided in the hospital, a short 429 video tutorial is provided at the beginning of each exercise 430 to ensure that the patient performs the exercise accurately. 431 Captions are provided in Mandarin and English because the 432 patient's primary caregiver may not be a native Mandarin 433 speaker (Fig. 10).  Step 5: press OK to finish). as shown in Fig. 11. After completing the training ses-438 sions, the patient can send feedback through a question-439 naire, which can be observed in the medical backend server. 440 Fig. 9. Four windows on the SMPT welcome screen: "My Tasks," "Practice Mode," "My Reward," and "My Devices."   11. Exercise window. Information includes the angles measured by the IMUs, the hold time, the remaining sets, and the number of repetitions. A video demonstration is also provided to ensure that the patient performs the exercise correctly.
Patient feedback helps to modify exercises, if required, in real 441 time.

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The patient's motivation and compliance are key to treat-443 ment outcomes [39]. Studies have revealed that adding playful 444 elements to rehabilitation protocols is an effective method for 445 enhancing these two aspects [40], [41]. After the completion 446 of every training session, the patient receives a pet as a reward. 447 Taking the idea from the famous comics, Pokémon, as more 448 sessions being completed, the patient will either receives a 449 new pet or the the existed pet will undergo an evolution and 450 grow up. The patients could access to their pets through the 451 "My Reward" window on the welcome screen. The additional 452 enjoyment and sense of achievement provided by the system 453 may deepen the engagement and participation of patients. According to Hajesmaeel-Gohari et al., the Telehealth 456 Usability Questionnaire, Telemedicine Satisfaction Question-457 naire, and Service User Technology Acceptability Question-458 naire (SUTAQ) are the leading questionnaires for assessing 459 the feasibility and satisfaction of telerehabilitation [42], [43], 460 [44]. After reviewing these questionnaires, the SUTAQ was 461 considered the most suitable for evaluating our platform [45]. 462 A new questionnaire based on the SUTAQ was designed in 463 this study, with different versions being designed for the public 464 and medical professionals. Similar to the original SUTAQ, the 465 questionnaire designed in this study contains six subscales: 466  Table II presents a comparison of relevant studies on the fol-508 lowing indicators: platform used, sensor used, target disease, 509 monitored body parts, portability, cost, real-time monitoring, 510 reward system, automatic synchronization, device extensibil-511 ity, and software extensibility. Only the system proposed by 512 Bermejo-Gil et al. requires no sensors. However, although 513 this system can provide guidance on the exercises, it cannot 514 monitor patient movements. Moreover, most of the systems in 515 the compared studies were developed for a specific disease. 516 Only the SMPT can be used for multiple musculoskele-517 tal diseases. With regard to monitored body parts, all the 518 smartphone-based platforms can track a patient's whole-body 519 movements, whereas the other systems can only track the 520 movement of specific body parts. The data in Table II indicate 521 that systems comprising smartphones and wearable devices 522 are more portable than are the other systems and can be 523 used without environmental limitations. Regarding system 524 applications, only the SMPT can simultaneously provide the 525 functions of real-time monitoring, a reward system, the auto-526 matic synchronization of exercises, and device and software 527 extensibility. Moreover, the cost of the SMPT is relatively low. 528 All the examined indicators suggest that the SMPT is superior 529 to other similar systems.

530
The results obtained using the SUTAQ indicated that the 531 public and medical professionals viewed the SMPT posi-532 tively. A high level of agreement was identified between the 533 aforementioned groups in terms of increasing the accessibility 534 of rehabilitation, enhancing the quality of rehabilitation, and 535 satisfaction for this platform. Although the obtained scores 536 did not support the SMPT being used as a substitute for 537 traditional rehabilitation, its current design is intended to offer 538 additional high-quality rehabilitation outside the hospital and 539 not intended to replace current forms of treatment. Moreover, 540 with regard to the privacy and discomfort and care personnel 541 concerns subscales, a significant difference was identified 542 between the scores of the public and medical professionals. 543 In general, the medical professionals appeared to exhibit more 544 conservative attitudes toward the SMPT than did the public.

545
Recommendations and feedback obtained using the ques-546 tionnaire suggested that invasion of the professional privacy of 547 medical personnel, interference in current practice, uncertainty 548 over the effectiveness of the platform, uncertainty over patient 549 ability to perform the exercises correctly, and inability to 550 access patient conditions before the exercises (e.g., vital signs) 551 were the main concerns of the medical personnel with the 552 SMPT. To address these concerns, a comprehensive train-553 ing program can be conducted for medical professionals to 554 familiarize them with the designed platform. The goal of the 555 SMPT is not to replace medical professionals but to provide 556  In this study, an SMPT with a medical backend server 589 and smartphone app was developed and clinically evaluated.

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The SMPT contains an evolving therapeutic exercise database 591 designed by medical professionals that comprises exercises 592 suited to patients' conditions as well as validated and com-593 mercially available IMUs for monitoring the exercise quality. 594 physical therapists can use the SMPT to create new exercises, 595 individual tasks, and rehabilitation modules quickly for dif-596 ferent rehabilitation treatments. Once an exercise program has 597 been designed, the SMPT can be used immediately, and the 598 patient can view the program content on their smartphone. The 599 patient's smartphone is immediately updated if the physical 600 therapist makes any adjustments to the exercises. An instant 601 report system allows medical personnel to modify the cus-602 tomized rehabilitation tasks, monitor patient progression, and 603 receive patient feedback in real time. The reward system may 604 potentially maximize compliance by increasing motivation. 605 In the future, artificial intelligence can be incorporated into 606 the designed system for analyzing the collected data to assist 607 medical personnel in designing suitable personalized exercise 608 plans. We believe that using the SMPT as a treatment adjunct 609 to traditional rehabilitation would result in superior outcomes 610 to those achieved when using traditional rehabilitation alone. 611 and P. Remagnino, "A distributed gamified system based on automatic 638 assessment of physical exercises to promote remote physical rehabilita-639 tion," IEEE Access, vol. 8, pp. 91424-91434, 2020.