Facial magnetomyography using an array of optically pumped magnetometers

IF 2 Q3 NEUROSCIENCES

Clinical Neurophysiology Practice Pub Date : 2025-01-01 DOI:10.1016/j.cnp.2025.03.003

Johannes von Fraunberg , Hongyu Lu , Haodi Yang , Nura Marquetand , Christoph Braun , Lukas Rüttiger , Stephan Wolpert , Marlies Knipper , Markus Siegel , Hubert Löwenheim , Justus Marquetand

{"title":"Facial magnetomyography using an array of optically pumped magnetometers","authors":"Johannes von Fraunberg , Hongyu Lu , Haodi Yang , Nura Marquetand , Christoph Braun , Lukas Rüttiger , Stephan Wolpert , Marlies Knipper , Markus Siegel , Hubert Löwenheim , Justus Marquetand","doi":"10.1016/j.cnp.2025.03.003","DOIUrl":null,"url":null,"abstract":"<div><h3>Objective</h3><div>Measuring facial muscle activity is crucial in the diagnosis of facial palsy. This study investigated whether contactless Magnetomyography (MMG) using optically pumped magnetometers (OPM) is feasible for visualizing facial muscle activity.</div></div><div><h3>Methods</h3><div>An anatomically shaped mask featuring eleven OPM was arranged on one side of the face of five healthy subjects. MMG was recorded while they performed different facial expressions. The root mean square of each OPM signal was calculated for each expression and subject and allocated to the individual face. Moreover, the maximum average muscle activity and the signal-to-noise ratio (SNR) were determined.</div></div><div><h3>Results</h3><div>The subjects’ facial muscle activity could be measured individually per facial expression. Mean RMS was 0.6pT (SD 0.4pT), resulting in a mean SNR of 2.2 (SD 1.2).</div></div><div><h3>Conclusions</h3><div>Imaging facial activity via MMG using OPM is possible, although the sensor positioning (sensor geometry and distance to the muscle) is decisive. However, the signal amplitude of the facial muscles is low and the interindividual anatomical variability renders the measurement setup challenging.</div></div><div><h3>Significance</h3><div>As the imaging of facial MMG is feasible, this study paves the way for future studies using OPM for the diagnosis, monitoring, and rehabilitation of facial muscle and facial nerve disorders.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 134-140"},"PeriodicalIF":2.0000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical Neurophysiology Practice","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2467981X25000162","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"NEUROSCIENCES","Score":null,"Total":0}

引用次数: 0

Abstract

Objective

Measuring facial muscle activity is crucial in the diagnosis of facial palsy. This study investigated whether contactless Magnetomyography (MMG) using optically pumped magnetometers (OPM) is feasible for visualizing facial muscle activity.

Methods

An anatomically shaped mask featuring eleven OPM was arranged on one side of the face of five healthy subjects. MMG was recorded while they performed different facial expressions. The root mean square of each OPM signal was calculated for each expression and subject and allocated to the individual face. Moreover, the maximum average muscle activity and the signal-to-noise ratio (SNR) were determined.

Results

The subjects’ facial muscle activity could be measured individually per facial expression. Mean RMS was 0.6pT (SD 0.4pT), resulting in a mean SNR of 2.2 (SD 1.2).

Conclusions

Imaging facial activity via MMG using OPM is possible, although the sensor positioning (sensor geometry and distance to the muscle) is decisive. However, the signal amplitude of the facial muscles is low and the interindividual anatomical variability renders the measurement setup challenging.

Significance

As the imaging of facial MMG is feasible, this study paves the way for future studies using OPM for the diagnosis, monitoring, and rehabilitation of facial muscle and facial nerve disorders.

查看原文本刊更多论文

使用光泵磁强计阵列的面部磁切面术

目的测量面肌活动对面瘫的诊断具有重要意义。本研究探讨了使用光泵磁强计（OPM）的非接触式磁强图（MMG）是否可行，以显示面部肌肉活动。方法在5名健康受试者的面部一侧放置具有11个OPM的解剖形状的面罩。当他们表现出不同的面部表情时，MMG被记录下来。对每个表情和受试者计算每个OPM信号的均方根，并将其分配给单个人脸。测定最大平均肌肉活动和信噪比（SNR）。结果受试者的面部肌肉活动可以通过每个面部表情单独测量。平均RMS为0.6pT (SD为0.4pT)，平均信噪比为2.2 （SD为1.2）。结论虽然传感器的定位（传感器的几何形状和与肌肉的距离）是决定性的，但使用OPM通过MMG成像面部活动是可能的。然而，面部肌肉的信号幅度很低，个体间的解剖差异使得测量设置具有挑战性。意义由于面部MMG的成像是可行的，本研究为未来研究利用OPM进行面部肌肉和面神经疾病的诊断、监测和康复铺平了道路。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Clinical Neurophysiology Practice NEUROSCIENCES-

CiteScore

3.90

自引率

0.00%

发文量

审稿时长

71 days

期刊介绍： Clinical Neurophysiology Practice (CNP) is a new Open Access journal that focuses on clinical practice issues in clinical neurophysiology including relevant new research, case reports or clinical series, normal values and didactic reviews. It is an official journal of the International Federation of Clinical Neurophysiology and complements Clinical Neurophysiology which focuses on innovative research in the specialty. It has a role in supporting established clinical practice, and an educational role for trainees, technicians and practitioners.