A Design of Self-Assisted Patient Control Technique for Early Rehabilitation Interventions to Prevent the Reduced elbow Joint ROM of COVID-19 Patients

1.   Introduction

The novel coronavirus SARS-CoV-2 outbreak, named COVID-19, has posed new challenges for the health care system globally amid its highly infectious and quick respiratory mode of transmission. Based on evolving evidence, people who are at the highest risk of COVID-19 infection mandatory for self-quarantine, hospitalization, or ICU admission mostly are those who are elderly, having at least one comorbidity. Moreover, it has been evidenced that the bedridden period for young people led to greater devastating impacts on functional capacity as compared to 40 years older ^[1,2,3]. The epidemiological studies have revealed that the risks of musculoskeletal system complications are more prevalent in pre-frail ICU admitted critical COVID-19 patients ^[1].

The estimated stay length in the hospital and ICU of 20 days and 3 weeks, respectively, impose adverse effects on various body systems of the patients ^[1,2,3]. The adverse outcomes of bed rest for 4-6 weeks, either in the hospital set up or home-bound quarantine, include muscle wasting, decrease in the rate of force generation capacity of skeletal muscles up to 6% - 40%, variations in the muscle contractile protein (actin and myosin) turnover, reduction in joint flexibility especially the elbow and muscle weakness, which limit the activities of daily living (ADLs), declined muscle viability, lack of muscular weight-bearing, modification in the homeostatic balance of muscular proteins, augmented breakdown of muscle protein, and deterioration in the muscle mitochondria function ^[4,5,6].

This situation emphasizes the compulsion and benefits of early musculoskeletal strength intervention and has been evidenced of better and early recovery, along with positive effects on psycho-social and physical factors ^[7,8,9]. To combat against the joint and muscle strength deterioration in COVID-19 patients, an early intervention including controlled muscle mobilization and strengthening exercises are recommended, which demonstrated the effective results as well ^[10,11]. These exercises include ambulation, cycle ergometer, pre-gait exercises, resistance exercise regimen, ADL training, and active mobilisation (convenient bed stretches, sitting, and standing by bedside) ^[12,13].

All the interventions mentioned above mainly require Physiotherapists and nursing staff to access the patients and are expected to have direct interaction with them (e.g., workout and rehabilitation), and therefore measures to inhibit transmission of COVID-19 are crucial ^[14]. Therefore, a need arises for a self-driven Physiotherapy device for early musculoskeletal exercise for ICU-bound patients who are either unconscious or frail with restricted joint motions, as well as patients hospitalised in isolation wards or quarantine centres and require joint mobility with minimum physiotherapists and nursing staff interaction. The patient and physiotherapist proportions are often compromised with fewer therapist access, and critical problems include a higher risk of COVID-19 virus transmission ^[15]. Self-Assisted physiotherapy (SAPT-COVID-19) offers an alternative solution for addressing physiotherapist demand in hospitals and preventing close contact with COVID-19 patients and allows them to access their mobility in the hospital or quarantine without the need of any physiotherapist.

The principal purpose of SAPT-COVID-19 is to encourage physical therapy in COVID-19 patients with those who are immobile and admitted explicitly in ICU. These patients can experience recovery sooner with the aid of this physiotherapy device with minimal intervention of physiotherapists to prevent infection and propagate the virus. The key objective is to avoid muscle weakening and strength deterioration in the elbow, resulting in extended ICU stay and postpone returning to regular daily activities. This is especially critical for older adults who also have chronic joint diseases, such as osteoarthritis, which hinders joint strength and motion difficulties. This exercise system configuration includes the recovery of the full elbow range-of-motion (ROM).

A. Materials and Methods

To determine the feasibility and accuracy of SAPT-COVID-19, eight healthy volunteers who agreed to participate in this study were selected to form four different age groups. The volunteers were divided into two equal groups, 4 volunteers in each group with age range as follows, adult (50 ± 5), young adult (20 ± 5), adolescent (15 ± 5), childhood (8 ± 2). Among the 8 volunteers in both groups, the adult gender is male, and the remainder is female. The volunteers have different upper limbs proportion to ensure that age and height do not impact the efficiency of physiotherapy device. The volunteers were explained about the study, and informed verbal consent was taken. Studies on COVID-19 patients could not be performed, as it is evident that these patients were either under quarantine, hospitals or ICU and inaccessible due to pandemic. Therefore, the volunteers selected were representatives of the educational profession, teachers, and students, who worked or studied at home during the lock-down period (approx. 5 months) in Saudi Arabia, Eastern Province. It was assumed that their mobility levels should have compromised, as they were home-bound due to the COVID-19 pandemic

Two protocols were used to determine the ability of patients to perform the exercise: acute care and the SAPT-COVID-19 device protocol. The first protocol depends on the physician’s assessment of the patient condition to determine cognitive abilities for acute care patients; a Richmond Agitation Sedation Scale (RASS) ^[15,16]. The second protocol relies on the continuous measurement of the angle of flexion and proposes appropriate therapy following the Mayo Elbow Performance Index system (MEPI), which has been applied in this study for the home-bound volunteers ^[17]

II.   Hardware Description

The SAPT-COVID-19 device consists of six key elements. A servo motor (DS5160SSG) with an exoskeleton, Arduino Mega 2560, NIMH DC 8.4v battery, Single Pole Double Throw (SPDT switch), pulse monitor, and LCD screen 2.4-inch. An 8.4v NIMH DC battery powers the servo motor. The TFT LCD is a touchscreen that detects and displays the text using control and LCD data pins. The pulse sensor continually transmits the heart rate signal to Arduino. Eventually, SPDT switch mechanism is used for switching on/off operation, as shown in Figure 1 (I).

The prototype incorporates TFT LCD touch screens that improve the interface. The user can start the system by inserting maximum and minimum heart rates (HR) and repetition time. The LCD was programmed to receive input from the user by entering the values through the touch keypad. The screen displays these inputs and informs the user about starting the operation. The instruction” to determine your level, flex your elbow” appears on the screen, and the patient then flexes the elbow to an appropriate level. The active exercise begins when the instruction “flex your elbow” appears on the screen continuously until repetitions are over. The completed level 1 exercise is shown in Figure 6. In this procedure, the minimum and maximum heart rate were set at 55 BPM and 110 BPM, and level “1” of 10 seconds with 5 repetitions, well before the exercise completes, as shown in Figure 1 (II) (A to L). The SAPTCOVID-19 device also indicates the appropriate alert in the case of a breach in the conditions, i.e., turn off the switch or heart rate exceeds the defined limits. The alert operation was checked explicitly by shifting the switching condition to “off” and measured the heart rate below and above the defined limits.

The SAPT-COVID-19 device was developed to provide a manual (active) and automated (passive) flexion for COVID-19 patients, specifically ICU-bound, hospitalized, and self-quarantined. The automated flexion was for severe vulnerabilities. The automated displacement works under the framework for angular orientation and a closed-loop mechanism of the servomotor. It was performed by having a fixed setpoint based on the following condition: 50 degrees for level 1, 100 degrees for level 2, and 125 degrees for level 3, then modified its position corresponding to the feedback from the servomotor potentiometer. The controller supplies the output power to the DC motor. The crucial role of the device was to establish a single session with active (or passive) flexions, information from the patient, and user feedback. Moreover, the exercise session can only continue if the ON/OFF switch is turned on and the patient’s heart rate is stable and secure.

The basic operation of the device is illustrated in the flow chart, as shown in Figure 2. The critical variables in the flow chart are Maximum heart rate limit (Max HR), Minimum heart rate limit (Min HR), Elbow flexion repetition (reps), the time duration between various Repetitions (RepTime), Maximum flexion angle (Max angle), Patient-level (level), automatic flexion angle (Motor setpoint) and the number of completed repetitions (count).

Once the exercise session starts, user input is requested through a touch screen. The user’s input sets three parameters: minimum heart rate, maximum heart rate, and repetition time. The first step requiring the participation of patients is the assignment of their levels. The specific angle of the patient is determined before starting the exercise session. The patient is asked to flex once within 30 seconds, and the maximum angle is determined. The level is allocated based on the MEPI framework. Consequently, the number of repetitions and the servomotor setpoint is established from the level. The patient will be informed of the level, and the session will begin. The workout session requires manual flexion at each repetition, and each procedure measures the maximum angle. The maximum angle refers to the patient’s elbow’s range-of-motion (ROM). When the patient elbow angle becomes too low (<15°), the mode changes to automated flexion, and the servomotor executes this in one round, and the count is incremented. The patient will be provided flexion reminders and repeat this procedure before all repetitions have been done and the session is finished. The length of the session is determined by multiplying [repeat time] x [sets number]. Monitoring of the heart rate and the switching condition recurs during the workout. If the switch is off or the heart rate is over defined thresholds, an alarm message would be shown on the TFT screen. This monitoring is achieved by the “check condition” which is a predefined process in the flowchart.

Figure 1:Figure 1: SAPT-COVID-19 components connection with Aurdino (I).SAPT-COVID-19 level 1 exercise display on the horizontal TFT LCD touch screen (II)

Figure 2:Figure 2: Flowchart illustrates the basic working principle of SAPT-COVID-19

III.   Results and Discussion

The volunteers were demonstrated SAPT-COVID-19 device operations, how to apply it to the upper limb, and choose the different options in the system. The volunteers initiated the program by a switch on the button and then, entering the maximum and minimum heart rate levels and the repetition time via the touchpad. The screen shows those inputs and informs the volunteers to start the operation. When the instructions, “determine your level” and “flex your elbow,” appear on the screen, the volunteers shall flex the elbow to a level appropriate for them.

To evaluate the level assessment efficacy for active session, 4 volunteers (2 from each group) were chosen, and their levels were determined. The device is assigned with three levels based on the Mayo Elbow Performance Index (MEPI) as follows: level 1 0-50°, level 2 50-100°, and level 3 above 100°. This level evaluation is especially relevant for COVID-19 patients whose rates of frailty index can vary with different levels of joint motions.

The Volunteers are proposed to perform a manual exercise (active) to evaluate the correct angles using the SAPT-COVID-19 device. For the level 1 assessment, all the 4 volunteers were required to flex below 50 °, 50°-100° for level 2, and above 100° for level 3. The data of level 3 was recorded after the statements “your level is 3” and “your session of 10 flexion starts now” were displayed on the screen. The same procedure was applied for level 1 with 5 flexions and level 2 with 8 flexions. A total of 12 plots illustrates the full range of motion for each volunteer, four subplots for each level, as shown in Figure 3 (A, B and C). The curve rises with upper limb flexion and descends with extension. It can be observed that all the volunteers had angles below 50°, 50°-100°, and above 100°, and the maximum angles achieved by the volunteers for each level are demonstrated in Figure 4 (A, B, and C). The device has successfully determined not just the levels of all volunteers, but also discriminated against the minor variations in their angles. For instance, the maximum angles at level 1 were 46°, 49°, 47°, 48° for volunteers 1, 2, 3 and 4 respectively. Level 2 and Level 3 have the consistent observation with a maximum angle of 99°, 99°, 99°, 97°, and 127°, 130°, 127°, 130°, as shown in Figure 4 (A, B, and C), respectively. These values are very close to each other, which is hard to detect using a conventional tool, such as goniometer, with the naked eyes.

To evaluate the level assessment efficacy for automatic (passive) session of the SAPT-COVID-19 device, the volunteer’s elbows remained at zero angles (laying position) for all flexions in levels 1, 2, and 3. Initially, device is leveled at zero, so the motor rotates to the angle of the setpoint value to allow the flexion, and it heads down to zero before deactivating. The repetition count is incremented by 1. The device evaluates the angle reached after 30 seconds of appearance of the statement, “flex your elbow”. The servomotor controller shifted to an automatic mode where the servomotor flexes the limb to the desired angle. The device was able to lift the arm correctly up to 50° for level 1, 100° for level 2, and 125° for level 3, as shown in 5 (A, B, and C). Each plot includes 4 subplots representing volunteers. The total number of flexions in automatic (passive) mode is identical as programmed to the manual (active) mode, level 1 with 5 flexions, level 2 with 8 flexions, and level 3 with 10 flexions, as shown in Figure 5 (A, B, and C).

To study the maximum elbow (ROM) and to assess the efficacy of the device in the prevention of ROM decline among the adult, young adult, adolescent, and childhood, a total of eight volunteers participated. While all eight volunteers were healthy and active, they were asked to perform the device manual programmed exercise. The volunteers of group 1 performed level 3 exercise for six consecutive days with 10 flexions, and the remaining 4 volunteers of group 2 performed similar exercise sessions for 14 consecutive days simultaneously. The period was specified for 6 and 14 days, depending on minimum and median time from the onset of COVID-19 symptoms till mortality.

The first study was undertaken to observe the improvement in elbow ROM with 4 volunteers of group 1 for 6 consecutive days, as shown in Figure 6 (A, B, C and D). The maximum ROM of group1 volunteers after 10 flexion session of day 1 was observed as 121°, 121°, 122°, and 124°, respectively as shown in Figure 6 (A, B, C and D). Following 10 flexion sessions over the remaining five days, it was observed that with every passing day, the elbow ROM of all volunteers strengthened gradually and consistently. Throughout the session, the angle of the 10 flexion was either higher or maintained and indicated that with each repeated motion, the ROM appeared to improve. The volunteer 1 had a steady increase in ROM from day1 to day 6 by 4°, as shown in Figure 6 (A). Both volunteers 2 and 3 had a relative increase in angles by 5° each, as shown in Figure 6 (B and C). Meanwhile, volunteer 4 maintained an angle of 126° in days 3 and 4, then increased by 3° in day 6, as shown in Figure 6 (D). Nevertheless, each volunteer displayed different ROM improvement patterns, which could be attributed to their age and gender. After completion of 6 consecutive days sessions with 10 flexions of group 1 volunteers using the device, the recorded ROM elbow of an adult, young adult, adolescent, and childhood, were observed as 124°, 126°, 127°, and 129°, respectively.

The second study was undertaken to observe the improvement in elbow ROM by 4 volunteers of group 2 who completed the same exercise sessions but for 14 days in a row and following the same instructions as group 1, by manual programmed device. The results taken after 14 days of exercise correspond to 6 days of exercise, as shown in Figure 7 (A, B, C, and D). The maximum elbow ROM of group 2 volunteers after 10 flexion session of day 1 was observed as 121°, 121°, 122°, and 124°, respectively as shown in Figure 7 (A, B, C, and D). The group 2 volunteers strengthened their elbow ROM by 10°, 8°, 11°, 11°, 10° respectively after 14 consecutive days of exercise sessions. In the first 4 days, their maximum angles were 123°, 125°, 120°, and 127° and next 4 days; it increased to 126°, 128°, 123°, and 129°. Finally, the highest elbow ROM achieved at day-14 of an adult, young adult, adolescent, and childhood was observed as 130°, 131°, 129°, and 135° respectively, as shown in Figure 7 (A, B, C and D). However, ROM had been either maintained or improved throughout the exercise session; consequently, all the volunteers ROM steadily improved between days 1 and 14. These findings suggested that the device is an efficient tool for strengthening the ROM by considerably improving the elbow joints and prevent ROM degradation

IV.   Conlusion

The SAPT-COVID-19 is a self-driven device that emphasizes its efficacy by alternating manual and automated modes. It yielded significant results for the maintenance and progression of elbow ROM with the repeated application for the home-bound volunteers. The use of accurate load-bearing servomotor makes it applicable for patients who are frail and critically ill and have hand movements roughly up to 15°. It is reliable for level classification and precise angle detection. These findings provide evidence that the device may be used effectively to improve full elbow range-of-motion (ROM) in several groups of COVID-19 patients, from self-quarantine through ICU admission.

Figure 3:Figure 3: SAPT-COVID-19 manual angular movement of volunteers arm, (A) Level 1 4-volunteers (I, II, III, and IV), (B) Level 2 4-volunteers (I, II, III, and IV) and (C) Level 3 4-volunteers (I, II, III, and IV)

Figure 4:Figure 4: SAPT-COVID-19 maximum angle of (A) Level 1(B) Level 2 and (C) Level 3

Figure 5:Figure 5: SAPT-COVID-19 Automatic angular movement of volunteers arm, (A) Level 1 4-volunteers (I, II, III and IV), (B) Level 2 4-volunteers (I, II, III and IV) and (C) Level 3 4-volunteers (I, II, III and IV)

Figure 6:Figure 6: SAPT-COVID-19 manual programmed exercise for 6 consecutive days following 10 flexions (A) adult (B) young adult (C) adolescent, and (D) childhood

Figure 7:Figure 7: SAPT-COVID-19 Manual Exercise for 14 Consecutive Days Following 10 Flexions (A) Adult (B) Young Adult (C) Adolescent, and (D) Childhood.