This study examines the ability to selectively activate different nerve fibers in a finger by using different sinusoidal stimulation frequencies. Specifically, the stimulation of A-beta, A-delta, and C-fibers is looked into, and responses from each of three different stimuli (5 Hz, 250 Hz, and 2000 Hz) are compared. Action potential (AP) responses from the different nerve fibers are simulated. Activation thresholds are determined for each fiber type. The resulting firing frequencies are compared with thresholds found in the literature to determine the stimulating signal amplitude at which sensations begin to be perceived for each stimulation frequency. Results indicate that while selective stimulation of C-fibers and A-beta fibers appears to be possible with 5 Hz and 2000 Hz, respectively, selective stimulation of A-delta fibers may not be possible due to them requiring a higher stimulating signal amplitude to cause the nerve to reach the physiological threshold than A-beta fibers for 250 Hz. Thus, selective stimulation of the three types of nerve fibers may not be possible for all three examined frequencies.

Carpal tunnel syndrome (CTS) diagnosis could be improved by selectively activating the different types of nerve fibers traversing the carpal tunnel. The objective of this study is to assess the potential of an anodal blocking technique using tripolar surface electrodes for achieving selective fiber activation and evaluating the severity of CTS. Simulations were performed using McNeal's model to determine the stimulating and blocking thresholds for different diameter/conduction velocity groups of nerve fibers. At 9.36 mA stimulus amplitude all nerve fibers from 9 mum to 20 mum were activated. When the current amplitude was increased further, large nerve fibers started getting blocked while small nerve fibers remained active. By gradually increasing the current amplitude small nerve fibers can be selectively activated without the activation of large fibers. The severity of CTS generally progresses from large to small nerve fibers, hence by comparing normal values of amplitude and peak latency of different nerve fiber diameter groups to the CTS affected median nerve recordings of the patient, severity of this syndrome could be detected.

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While the use of antibiotics for secondary infections in COVID-19 has been described in scientific literature and guidelines have been issued for their appropriate use, the importance of listening to patients in a systematic manner has often been overlooked. To highlight this issue, we spoke with patients about their experiences with antibiotics as treatment for COVID-19 and their understanding of antimicrobial resistance (AMR). We found that there is a general lack of awareness of the risks of AMR, and even when patients are knowledgeable, fear of COVID-19 and pressure from healthcare providers often override considerations for appropriate use. We present case examples of three patients’ experiences and provide recommendations for health systems, healthcare providers, and patients or caregivers on actions they can each take to reduce the risk of AMR during and beyond the COVID-19 pandemic. We also share ways that the patient community can be empowered to provide their voices to decision-making on both COVID-19 treatment protocols and prescriptions of antibiotics.