title: Electromagnetic interference in intraoperative monitoring of motor evoked potentials and a wireless solution.
abstract: Intraoperative neurophysiological monitoring (IONM) is utilized to minimize neurological morbidity during spine surgery. Transcranial motor evoked potentials (TcMEPs) are principal IONM signals in which the motor cortex of the subject is stimulated with electrical pulses and the evoked potentials are recorded from the muscles of interest. Currently available monitoring systems require the connection of 40-60 lengthy lead wires to the patient. These wires contribute to a crowded and cluttered surgical environment, and limit the maneuverability of the surgical team. In this work, it was demonstrated that the cumbersome wired system is vulnerable to electromagnetic interference (EMI) produced by operating room (OR) equipment. It was hypothesized that eliminating the lengthy recording wires can remove the EMI induced in the IONM signals. Hence, a wireless system to acquire TcMEPs was developed and validated through bench-top and animal experiments. Side-by-side TcMEPs acquisition from the wired and wireless systems in animal experiments under controlled conditions (absence of EMI from OR equipment) showed comparable magnitudes and waveforms, thus demonstrating the fidelity in the signal acquisition of the wireless solution. The robustness of the wireless system to minimize EMI was compared with a wired-system under identical conditions. Unlike the wired-system, the wireless system was not influenced by the electromagnetic waves from the C-Arm X-ray machine and temperature management system in the OR.
authors.affiliation: Department of Electrical and Computer Engineering, New York Institute of Technology, Harry Schure Hall, Room #226B, Northern Blvd., Old Westbury, New York 11568-8000, USA. Electronic address: afarajid@nyit.edu.
authors.forename: Aydin
authors.initials: A
authors.lastname: Farajidavar
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Dallas, Texas, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Seifert
authors.affiliation: Neurology Department, Texas Scottish Rite Hospital for Children, Dallas, Texas, USA; Neurology and Neurotherapeutics Department, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA.
authors.forename: Mauricio R
authors.initials: MR
authors.lastname: Delgado
authors.affiliation: Neurology Department, Texas Scottish Rite Hospital for Children, Dallas, Texas, USA; Neurology and Neurotherapeutics Department, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Sparagana
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Dallas, Texas, USA.
authors.forename: Mario I
authors.initials: MI
authors.lastname: Romero-Ortega
authors.affiliation: Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas, USA.
authors.forename: J-C
authors.initials: JC
authors.lastname: Chiao
mesh_terms: D000818:Animals; D016477:Artifacts; D055590:Electromagnetic Phenomena; D019054:Evoked Potentials, Motor; D005260:Female; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D009873:Operating Rooms; D051381:Rats; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D059015:Wireless Technology
keywords: Electromagnetic interference; Intraoperative monitoring; Wireless medical devices