ABSTRACT
Electrophysiological recording and stimulation are the gold standard for functional mapping during surgical and therapeutic interventions as well as capturing cellular activity in the intact human brain. A critical component probing human brain activity is the interface material at the electrode contact that electrochemically transduces brain signals to and from free charge carriers in the measurement system. Here, we summarize state-of-the-art electrode array systems in the context of translation for use in recording and stimulating human brain activity. We leverage parametric studies with multiple electrode materials to shed light on the varied levels of suitability to enable high signal-to-noise electrophysiological recordings as well as safe electrophysiological stimulation delivery. We discuss the effects of electrode scaling for recording and stimulation in pursuit of high spatial resolution, channel count electrode interfaces, delineating the electrode-tissue circuit components that dictate the electrode performance. Finally, we summarize recent efforts in the connectorization and packaging for high channel count electrode arrays and provide a brief account of efforts toward wireless neuronal monitoring systems.
ABSTRACT
Purpose: This research aimed to evaluate medication software for a healthcare robot. Study I compared two software versions (RoboGen and RoboGen2) for system usability, speed and accuracy of medication entry; Study II evaluated system usability and community pharmacists' views of RoboGen2. Methods: Study I had a within-subjects experimental design and recruited 40 Health Sciences students to enter different, comparable sets of prescriptions into the two systems, in randomized order, within a limit of 15 min. Screen activity was recorded to observe prescription errors. Study II had a cross-sectional observational design and recruited 20 community pharmacists using convenience sampling. Pharmacists entered three prescriptions using RoboGen2. Participants in both studies completed the System Usability Scale (SUS) following each task. Study I participants completed a questionnaire on system preference, and Study II participants a semi-structured interview. Results: Study I participants preferred Robogen2 (p < 0.001) due to its sleek and modern layout, good flow, ease of use, and intuitive design. SUS scores [t (40) = -3.40, p = 0.002] and speed of medication entry favored Robogen2 (t = 3.65, p < 0.001). No significance was found in accuracy (t = 1.12, p = 0.27). In study 2, pharmacists rated the usability of RoboGen2 below average. Themes from interviews were navigation and streamlining the system, ease of use, and integration with pharmacy software systems. Conclusion: Adding safety features and better aesthetics can improve the usability and safety of a medication prescription system. Streamlining workflow and pre-populating data can increase speed of prescription entry without compromising patient safety. However, a better approach is integration with pre-existing pharmacy systems to reduce workload while incorporating safety features built into existing dispensing systems.
ABSTRACT
There is growing evidence on the efficacy of electrical stimulation delivered via spinal neural interfaces to improve functional recovery following spinal cord injury. For such interfaces, carbon-based neural arrays are fast becoming recognized as a compelling material and platform due to biocompatibility and long-term electrochemical stability. Here, we introduce the design, fabrication, and in vivo characterization of a novel cervical epidural implant with carbon-based surface electrodes. Through finite element analysis and mechanical load tests, we demonstrated that the array could safely withstand loads applied to it during implantation and natural movement of the subject with minimal stress levels. Furthermore, the long-term in vivo performance of this neural array consisting of glassy carbon surface electrodes was investigated through acute and chronic spinal motor evoked potential recordings and electrode impedance tests in rats. We demonstrated stable stimulation performance for at least four weeks in a rat model of spinal cord injury. Lastly, we found that impedance measurements on all carbon-based spinal arrays were generally stable over time up to four weeks after implantation, with a slight increase in impedance in subsequent weeks when tested in spinally injured rats. Taken together, this study demonstrated the potential for carbon-based electrodes as a spinal neural interface to accelerate both mechanistic research and functional restoration in animal models of spinal cord injury.
