## 3 Results
### Control Strategy Based on EMG Signals  
The wearable device relies on actuators controlling an EMG controller (EMG Sensor Controller) that captures the muscle signal from the forearm to identify the user's intention in performing a certain action. The EMG module consists of a signal processing unit and three gel surface electrodes that are positioned in the muscle area of interest (Flexor Digitorum Superficialis--FDS) of the forearm. Before positioning the surface electrodes, the skin was cleaned with medical alcohol to ensure that there were no layers of fat or impurities that would prevent or alter the quality of the captured signal. The EMG module provides an analog output signal of between 0 V and 9 V and has a supply voltage of between 3.5 V and 9 V--DC. The module is based on an integrated H124 SG. To visualize the analog output signal from the EMG module captured from the FDS muscle of the  
Figure 8: Flexing motion actuation of phalanges using PneuNets actuators.  
Figure 9: The component parts of the glove with soft actuators.  
forearm, a digital oscilloscope (DS1054, Rigol, Beijing, China) was used, which is shown in Figure 10 below. Experimental data were taken from the right hand of a healthy subject in a sitting position performing repeated finger flexion and extension exercises.  
EMG signals were captured with a sampling frequency of 100 Hz, and the amplitude of the signal at the time of contraction (corresponding to the realization of the flexion movement) varied considerably in contrast to the baseline amplitude, which showed a much lower amplitude. Based on the variation of this signal at the time of FDS muscle contraction, the control strategy of the wearable device can be constructed by EMG control. The device control strategy based on control using EMG is one of relatively low complexity but has provided satisfactory results in rehabilitation phases. The strategy for control powering the actuators is based on closed-loop control, which is shown in Figure 11a, where the main components of the system are also pictured. The black arrows represent the electrical signal, and the green arrows serve as the compressed air supplying the actuators.  
In order to better highlight the control logic via EMG signals, a flowchart has been created, shown in Figure 11b, highlighting the conditions that must be met to achieve the flex motion. The three conditions necessary to be able to supply air to the actuators and achieve the finger flexion movement are related to the amplitude value of the captured EMG signal (A) exceeding the set threshold (B). This threshold is chosen in advance based on initial assessments of the patient's condition. The second condition is that the pressure sensor (P.S.) has a nominal value of 0 MPa and the flex sensor (F.S.) has a nominal value of 0\({}^{\circ}\). For example, if the patient intends to grip an object, the electrical signal of the muscles is continuously monitored, and when the signal amplitude exceeds a certain amplitude value (particularly pre-set in advance for each patient), the electro valve opens, supplying the five actuators that drive the fingers in flexion movement with pre-selected power. The pressure supply to the actuators is switched off when the flex sensor value reaches approximately 120\({}^{\circ}\). When reaching this value, the actuators will be held in position for two seconds by  
Figure 11: (**a**) Scheme of the closed-loop control system, (**b**) flow chart for control based on EMG signal capture of a wearable device for rehabilitation/assistance.  
Figure 10: EMG signal captured from the FDS muscle area of the forearm.  
switching the solenoid valve to the intermediate position. After two seconds, the solenoid valve will open and depressurize the actuators. If controlled depressurization is desired, the solenoid valve will switch between the intermediate and open positions. When the amplitude value of the EMG sensor exceeds that value again, the above steps are repeated.