Methodology for Designing Hardware for Measuring Parameters of a Digital Signal

In the production of various devices, various problems can arise, leading to the appearance of defects, both explicit and latent. This may be due to both poor quality materials and imperfect technology. To identify defects, devices are tested. If the device uses a digital signal transmission at high frequencies, it is usually considered sufficient to check the functioning of the individual components using technological programs. But at high transmission frequencies, or due to defects, the digital signal is distorted, and in devices where there is no error control, violations of the signal integrity during transmission can lead to failures and failures. Moreover, under normal conditions, the signal can meet the requirements, and in difficult conditions, go beyond the permissible limits. If an individual instance of a device can be susceptible to such failures, this can be identified in more detail by examining the signals flowing through its circuits. The most obvious way requires an oscilloscope, on the screen of which a person looks at the parameters of such a signal, time and amplitude characteristics. This is a very slow operation, so optimization might be the next step. For example, the use of flying probes, or probes with commutation, recording and automatic comparison of oscillograms with the exemplary one. In any case, these tests require equipment operating at frequencies much higher than the circuit itself, which means that at high baud rates, such equipment starts to be expensive.

A Generic Sequential Stimulation Adapter for Reducing Muscle Fatigue during Functional Electrical Stimulation

Background: Clinical applications of conventional functional electrical stimulation (FES) administered via a single electrode are limited by rapid onset neuromuscular fatigue. “Sequential” (SEQ) stimulation, involving the rotation of pulses between multiple active electrodes, has been shown to reduce fatigue compared to conventional FES. However, there has been limited adoption of SEQ in research and clinical settings. Methods: The SEQ adapter is a small, battery-powered device that transforms the output of any commercially available electrical stimulator into SEQ stimulation. We examined the output of the adaptor across a range of clinically relevant stimulation pulse parameters to verify the signal integrity preservation ability of the SEQ adapter. Pulse frequency, amplitude, and duration were varied across discrete states between 4 and 200 Hz, 10 and100 mA, and 50 and 2000 μs, respectively. Results: A total of 420 trials were conducted, with 80 stimulation pulses per trial. The SEQ adapter demonstrated excellent preservation of signal integrity, matching the pulse characteristics of the originating stimulator within 1% error. The SEQ adapter operates as expected at pulse frequencies up to 160 Hz, failing at a frequency of 200 Hz. Conclusion: The SEQ adapter represents an effective and low-cost solution to increase the utilization of SEQ in existing rehabilitation paradigms.