Quasi-static pipeline in electroconvulsive therapy computational modeling
Year: 2023
Type: article
Abstract: BACKGROUND: Computational models of current flow during Electroconvulsive Therapy (ECT) rely on the quasi-static assumption, yet tissue impedance during ECT may be frequency specific and change adaptively to local electric field intensity. OBJECTIVES: We systematically consider the application of the quasi-static pipeline to ECT under conditions where 1) static impedance is measured before ECT and 2) during ECT when dynamic impedance is measured. We propose an update to ECT modeling accounting for frequency-dependent impedance. METHODS: The frequency content on an ECT device output is analyzed. The ECT electrode-body impedance under low-current conditions is measured with an impedance analyzer. A framework for ECT modeling under quasi-static conditions based on a single device-specific frequency (e.g., 1 kHz) is proposed. RESULTS: Impedance using ECT electrodes under low-current is frequency dependent and subject specific, and can be approximated at >100 Hz with a subject-specific lumped parameter circuit model but at <100 Hz increased non-linearly. The ECT device uses a 2 μA 800 Hz test signal and reports a static impedance that approximate 1 kHz impedance. Combined with prior evidence suggesting that conductivity does not vary significantly across ECT output frequencies at high-currents (800-900 mA), we update the adaptive pipeline for ECT modeling centered at 1 kHz frequency. Based on individual MRI and adaptive skin properties, models match static impedance (at 2 μA) and dynamic impedance (at 900 mA) of four ECT subjects. CONCLUSIONS: By considering ECT modeling at a single representative frequency, ECT adaptive and non-adaptive modeling can be rationalized under a quasi-static pipeline.
Source: Brain stimulation
Authors: Gozde Unal, Cynthia Poon, Mohamad FallahRad, Myesha Thahsin, Miklos Argyelan, Marom Bikson
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,830
Awards: kHz frequency Spinal Cord Stimulation: Novel Temperature-Based Mechanisms of Action, "Bridges to the Baccalaureate Research Training Program at LaGuardia Community College", Non-Invasive Vagal Nerve Stimulation in Patients with Opioid Use Disorders, The coupled vascular hypothesis for transcranial direct current stimulation (tDCS), G8478103073, G-RISE: Graduate Research Initiative for Student Advancement at The City College of New York, Non-Invasive Vagal Nerve Stimulation in Patients with Opioid Use Disorders
OpenAlex ID: W4327560062