Closed loop framework for nerve electrical stimulation and eCAP anodal blocking
Gespeichert in:
| Titel: | Closed loop framework for nerve electrical stimulation and eCAP anodal blocking |
|---|---|
| Autoren: | Crespo Aranda, Alejandro |
| Weitere Verfasser: | Romero Lafuente, Sergio, Schnepel, Philipp |
| Quelle: | UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) |
| Verlagsinformationen: | Universitat Politècnica de Catalunya, 2025. |
| Publikationsjahr: | 2025 |
| Schlagwörter: | Electrophysiology, Neuroestimulació, Nerves, Peripheral, Nervis perifèrics, Neural stimulation, Electrofisiologia, Àrees temàtiques de la UPC::Enginyeria biomèdica |
| Beschreibung: | This thesis explores the generation and selective blocking of electrically evoked compound action potentials (eCAPs) in the giant nerve fibres of the earthworm (Lumbricus terrestris), establishing a foundational framework for a closed-loop control system for adaptive peripheral nerve stimulation (PNS). The primary objective of this research was to develop a closed-loop selective PNS system capable of dynamically adjusting both stimulation and blocking parameters in real time, guided by neurophysiological feedback. Secondary aims included the experimental characterization of eCAP generation and anodal block in a simplified animal model, identification of key parameters influencing activation and blocking thresholds, and the implementation and preliminary evaluation of closed-loop stimulation protocols using earthworms. The experimental approach involved determining activation thresholds in the earthworm’s giant fibres under cathodal stimulation with both sinusoidal and custom-constructed waveforms, and under anodal stimulation with a step function. Fatigue analyses were conducted to evaluate the stability of neural responses over time, while dual-site recordings were employed to assess bidirectional eCAP propagation. Anodal block phenomena were examined across a range of stimulation amplitudes, and a prototype closed-loop system was implemented using a Python-based Bayesian optimization algorithm. The results show distinct activation thresholds for medial and lateral giant fibres. Fatigue testing demonstrated minimal changes in eCAP amplitude and latency over 15 minutes, indicating stable neural responsiveness. Dual-site recordings verified consistent bidirectional signal propagation. Parameter sweeps revealed well-defined temporal “anodal-block windows” during which anodal pulses selectively suppressed signals propagating in the posterior direction, without affecting those traveling anteriorly. This work confirms the reliable generation and direction-specific blocking of eCAPs in the giant fibres of Lumbricus terrestris using both sinusoidal and custom waveforms. It provides a detailed characterization of anodal block dynamics with high temporal resolution and demonstrates the feasibility of real-time, feedback-driven stimulation adjustment. These findings contribute to the understanding of selective PNS mechanisms and lay essential groundwork for future development of adaptive neuromodulation strategies in more complex biological systems and clinical settings. Incoming |
| Publikationsart: | Master thesis |
| Dateibeschreibung: | application/pdf |
| Sprache: | English |
| Zugangs-URL: | https://hdl.handle.net/2117/442170 |
| Dokumentencode: | edsair.dedup.wf.002..e822f8b6d7723e1beb17bb15536ed844 |
| Datenbank: | OpenAIRE |
Nájsť tento článok vo Web of Science | Abstract: | This thesis explores the generation and selective blocking of electrically evoked compound action potentials (eCAPs) in the giant nerve fibres of the earthworm (Lumbricus terrestris), establishing a foundational framework for a closed-loop control system for adaptive peripheral nerve stimulation (PNS). The primary objective of this research was to develop a closed-loop selective PNS system capable of dynamically adjusting both stimulation and blocking parameters in real time, guided by neurophysiological feedback. Secondary aims included the experimental characterization of eCAP generation and anodal block in a simplified animal model, identification of key parameters influencing activation and blocking thresholds, and the implementation and preliminary evaluation of closed-loop stimulation protocols using earthworms. The experimental approach involved determining activation thresholds in the earthworm’s giant fibres under cathodal stimulation with both sinusoidal and custom-constructed waveforms, and under anodal stimulation with a step function. Fatigue analyses were conducted to evaluate the stability of neural responses over time, while dual-site recordings were employed to assess bidirectional eCAP propagation. Anodal block phenomena were examined across a range of stimulation amplitudes, and a prototype closed-loop system was implemented using a Python-based Bayesian optimization algorithm. The results show distinct activation thresholds for medial and lateral giant fibres. Fatigue testing demonstrated minimal changes in eCAP amplitude and latency over 15 minutes, indicating stable neural responsiveness. Dual-site recordings verified consistent bidirectional signal propagation. Parameter sweeps revealed well-defined temporal “anodal-block windows” during which anodal pulses selectively suppressed signals propagating in the posterior direction, without affecting those traveling anteriorly. This work confirms the reliable generation and direction-specific blocking of eCAPs in the giant fibres of Lumbricus terrestris using both sinusoidal and custom waveforms. It provides a detailed characterization of anodal block dynamics with high temporal resolution and demonstrates the feasibility of real-time, feedback-driven stimulation adjustment. These findings contribute to the understanding of selective PNS mechanisms and lay essential groundwork for future development of adaptive neuromodulation strategies in more complex biological systems and clinical settings.<br />Incoming |
|---|