Name: Author Spotlight: Advancing Labor Management Through Electromyometrial Imaging for Understanding Uterine Contractions
Uploaded: 2023-05-26T13:40:00
Description: Watch this Scientific Journal Video about Advancing Labor Management Through Electromyometrial Imaging for Understanding Uterine Contractions at JoVE.com

We thank Deborah Frank for editing this manuscript and Jessica Chubiz for organizing the project. Funding: This work was supported by the March of Dimes Center Grant (22-FY14-486), by grants from NIH/National Institute of Child Health and Human Development (R01HD094381 to PIs Wang/Cahill; R01HD104822 to PIs Wang/Schwartz/Cahill), by grants from Burroughs Wellcome Fund Preterm Birth Initiative (NGP10119 to PI Wang), and by grants from the Bill and Melinda Gates Foundation (INV-005417, INV-035476, and INV-037302 to PI Wang).

All methods described here have been approved by the Washington University Institutional Review Board.
1. MRI-safe marker patches, electrode patches, and rulers (Figure 1)
<ol>
	<li>Print the MRI and electrode patch templates (Figure 1A) on paper.</li>
	<li>Cut clear vinyl and silicone rubber sheets (Table of Materials) into 22 (vinyl) and 44 (rubber) rectangular (120 mm x 60 mm), a...

Visualizing Uterine Contractions by EMMI for Improved Labor Management

<ol>
	<li>Hadar, E., Biron-Shental, T., Gavish, O., Raban, O., Yogev, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+between+electrical+uterine+monitor,+tocodynamometer+and+intra+uterine+pressure+catheter+for+uterine+activity+in+labor.">A comparison between electrical uterine monitor, tocodynamometer and intra uterine pressure catheter for uterine activity in labor.</a> The Journal of Maternal-Fetal &amp; Neonatal Medicine. 28 (12), 1367-1374 (2015).</li><li>Schlembach, D., Maner, W. L., Garfield, R. E., Maul, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+the+progress+of+pregnancy+and+labor+using+electromyography.">Monitoring the progress of pregnancy and labor using electromyography.</a> European Journal of Obstetrics, Gynecology, and Reproductive Biology. 144, S33-S39 (2009).</li><li>Jacod, B. C., Graatsma, E. M., Van Hagen, E., Visser, G. H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+validation+of+electrohysterography+for+uterine+activity+monitoring+during+labour.">A validation of electrohysterography for uterine activity monitoring during labour.</a> The Journal of Maternal-Fetal &amp; Neonatal Medicine. 23 (1), 17-22 (2009).</li><li>Garfield, R. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uterine+Electromyography+and+light-induced+fluorescence+in+the+management+of+term+and+preterm+labor.">Uterine Electromyography and light-induced fluorescence in the management of term and preterm labor.</a> Journal of the Society for Gynecologic Investigation. 9 (5), 265-275 (2016).</li><li>Devedeux, D., Marque, C., Mansour, S., Germain, G., Duch&#234;ne, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uterine+electromyography:+A+critical+review.">Uterine electromyography: A critical review.</a> American Journal of Obstetrics and Gynecology. 169 (6), 1636-1653 (1993).</li><li>Jain, S., Saad, A. F., Basraon, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparing+uterine+electromyography+&amp;+tocodynamometer+to+intrauterine+pressure+catheter+for+monitoring+labor.">Comparing uterine electromyography &amp; tocodynamometer to intrauterine pressure catheter for monitoring labor.</a> Journal of Woman's Reproductive Health. 1 (3), 22-30 (2016).</li><li>Lucovnik, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+uterine+electromyography+to+diagnose+term+and+preterm+labor.">Use of uterine electromyography to diagnose term and preterm labor.</a> Acta Obstetricia et Gynecologica Scandinavica. 90 (2), 150-157 (2011).</li><li>Garcia-Casado, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrohysterography+in+the+diagnosis+of+preterm+birth:+a+review.">Electrohysterography in the diagnosis of preterm birth: a review.</a> Physiological Measurement. 39 (2), 02 (2018).</li><li>Maner, W. L., Garfield, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+human+term+and+preterm+labor+using+artificial+neural+networks+on+uterine+electromyography+data.">Identification of human term and preterm labor using artificial neural networks on uterine electromyography data.</a> Annals of Biomedical Engineering. 35 (3), 465-473 (2007).</li><li>Rabotti, C., Mischi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Propagation+of+electrical+activity+in+uterine+muscle+during+pregnancy:+a+review.">Propagation of electrical activity in uterine muscle during pregnancy: a review.</a> Acta Physiologica. 213 (2), 406-416 (2015).</li><li>Cohen, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+assessment+of+uterine+contractions.">Clinical assessment of uterine contractions.</a> International Journal of Gynaecology and Obstetrics. 139 (2), 137-142 (2017).</li><li>Maner, W. L., Garfield, R. E., Maul, H., Olson, G., Saade, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predicting+term+and+preterm+delivery+with+transabdominal+uterine+electromyography.">Predicting term and preterm delivery with transabdominal uterine electromyography.</a> Obstetrics &amp; Gynecology. 101 (6), 1254-1260 (2003).</li><li>Leman, H., Marque, C., Gondry, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+the+electrohysterogram+signal+for+characterization+of+contractions+during+pregnancy.">Use of the electrohysterogram signal for characterization of contractions during pregnancy.</a> IEEE Transactions on Biomedical Engineering. 46 (10), 1222-1229 (1999).</li><li>Vasak, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uterine+electromyography+for+identification+of+first-stage+labor+arrest+in+term+nulliparous+women+with+spontaneous+onset+of+labor.">Uterine electromyography for identification of first-stage labor arrest in term nulliparous women with spontaneous onset of labor.</a> American Journal of Obstetrics and Gynecology. 209 (3), e1-e8 (2013).</li><li>Euliano, T. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+uterine+activity+during+labor:+a+comparison+of+3+methods.">Monitoring uterine activity during labor: a comparison of 3 methods.</a> American Journal of Obstetrics and Gynecology. 208 (1), e1-e6 (2013).</li><li>Garfield, R. E., Maner, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiology+and+electrical+activity+of+uterine+contractions.">Physiology and electrical activity of uterine contractions.</a> Seminars in Cell &amp; Developmental Biology. 18 (3), 289-295 (2007).</li><li>Rabotti, C., Bijloo, R., Oei, G., Mischi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vectorial+analysis+of+the+electrohysterogram+for+prediction+of+preterm+delivery:+a+preliminary+study.">Vectorial analysis of the electrohysterogram for prediction of preterm delivery: a preliminary study.</a> 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE. , 3880-3883 (2011).</li><li>Wu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+high-resolution+electromyometrial+imaging+of+uterine+contractions+in+a+translational+sheep+model.">Noninvasive high-resolution electromyometrial imaging of uterine contractions in a translational sheep model.</a> Science Translational Medicine. 11 (483), (2019).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+electromyometrial+imaging+of+uterine+contractions+in+clinical+environment.">Accuracy of electromyometrial imaging of uterine contractions in clinical environment.</a> Computers in Biology and Medicine. 116, 103543 (2020).</li><li>Cahill, A. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+electrophysiological+activation+of+the+uterus+during+human+labor+contractions.">Analysis of electrophysiological activation of the uterus during human labor contractions.</a> JAMA Network Open. 5 (6), 2214707 (2022).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+electromyometrial+imaging+of+human+uterine+maturation+during+term+labor.">Noninvasive electromyometrial imaging of human uterine maturation during term labor.</a> Nature Communications. 14 (1), 1198 (2023).</li><li>Kok, R. D., de Vries, M. M., Heerschap, A., vanden Berg, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Absence+of+harmful+effects+of+magnetic+resonance+exposure+at+1.5+T+in+utero+during+the+third+trimester+of+pregnancy:+A+follow-up+study.">Absence of harmful effects of magnetic resonance exposure at 1.5 T in utero during the third trimester of pregnancy: A follow-up study.</a> Magnetic Resonance Imaging. 22 (6), 851-854 (2004).</li><li>Choi, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+case+series+of+15+women+inadvertently+exposed+to+magnetic+resonance+imaging+in+the+first+trimester+of+pregnancy.">A case series of 15 women inadvertently exposed to magnetic resonance imaging in the first trimester of pregnancy.</a> Journal of Obstetrics and Gynaecology. 35 (8), 871-872 (2015).</li><li>Ray, J. G., Vermeulen, M. J., Bharatha, A., Montanera, W. J., Park, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+between+MRI+exposure+during+pregnancy+and+fetal+and+childhood+outcomes.">Association between MRI exposure during pregnancy and fetal and childhood outcomes.</a> JAMA. 316 (9), 952-961 (2016).</li><li>Benedetti, M. G., Agostini, V., Knaflitz, M., Bonato, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+EMG+in+clinical+and+sports+medicine.">Applications of EMG in clinical and sports medicine.</a> Intech Open. , 117-130 (2012).</li><li>Lange, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Velocity+and+directionality+of+the+electrohysterographic+signal+propagation.">Velocity and directionality of the electrohysterographic signal propagation.</a> PloS One. 9 (1), e86775 (2014).</li><li>Planes, J. G., Morucci, J. P., Grandjean, H., Favretto, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=External+recording+and+processing+of+fast+electrical+activity+of+the+uterus+in+human+parturition.">External recording and processing of fast electrical activity of the uterus in human parturition.</a> Medical &amp; Biological Engineering &amp; Computing. 22 (6), 585-591 (1984).</li><li>Mikkelsen, E., Johansen, P., Fuglsang-Frederiksen, A., Uldbjerg, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrohysterography+of+labor+contractions:+propagation+velocity+and+direction.">Electrohysterography of labor contractions: propagation velocity and direction.</a> Acta Obstetricia et Gynecologica Scandinavica. 92 (9), 1070-1078 (2013).</li><li>Young, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+uterine+pacemaker+of+labor.">The uterine pacemaker of labor.</a> Best Practice &amp; Research. Clinical Obstetrics &amp; Gynaecology. 52, 68-87 (2018).</li><li>Goldenberg, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+management+of+preterm+labor.">The management of preterm labor.</a> Obstetrics and Gynecology. 100 (5), 1020-1037 (2002).</li><li>Rubens, C. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevention+of+preterm+birth:+harnessing+science+to+address+the+global+epidemic.">Prevention of preterm birth: harnessing science to address the global epidemic.</a> Science Translational Medicine. 6 (262), 5 (2014).</li><li>Shi, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Screen-printed+soft+capacitive+sensors+for+spatial+mapping+of+both+positive+and+negative+pressures.">Screen-printed soft capacitive sensors for spatial mapping of both positive and negative pressures.</a> Advanced Functional Materials. 29 (23), 1809116 (2019).</li><li>Lo, L. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+inkjet-printed+PEDOT:PSS-based+stretchable+conductor+for+wearable+health+monitoring+device+applications.">An inkjet-printed PEDOT:PSS-based stretchable conductor for wearable health monitoring device applications.</a> ACS Applied Materials and Interfaces. 13 (18), 21693-21702 (2021).</li><li>Lo, L. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretchable+sponge+electrodes+for+long-term+and+motion-artifact-tolerant+recording+of+high-quality+electrophysiologic+signals.">Stretchable sponge electrodes for long-term and motion-artifact-tolerant recording of high-quality electrophysiologic signals.</a> ACS Nano. 16 (8), 11792-11801 (2022).</li></ol>

Electromyography has indicated that the frequency and amplitude of uterine electrical signals alter during the gestational period2,16,25. Several studies have explored the uterine propagation patterns of uterine contractions in patients in active labor10,17,26,27,28. ...

Clinically, uterine contractions are measured either by using an intrauterine pressure catheter or by performing tocodynamometry1. In the research setting, uterine contractions can be measured by electromyography (EMG), in which electrodes are placed on the abdominal surface to measure the bioelectrical signals generated by the myometrium2,3,4,5,6,7. One can use the magnitude, frequency, and propagation features of electrical bursts8,9,10,11,12&#160;derived from EMG to predict the onset of labor in the preterm. However, in conventional EMG, the electrical activity of uterine contractions is measured from only a tiny region of the abdominal surface with a limited number of electrodes (two13 and four7,14,15,16 at the center of the abdominal surface, and 6417 at the lower abdominal surface). Furthermore, conventional EMG is limited in its ability to study the mechanisms of labor, as it reflects only the averaged electrical activities from the entire uterus and cannot detect the specific electrical initiation and activation patterns on the uterine surface during contractions.
A recent development called electromyometrial imaging (EMMI) has been introduced to overcome the shortcomings of conventional EMG. EMMI enables noninvasive imaging of the entire myometrium&#39;s electrical activation sequence during uterine contractions18,19,20,21. To acquire the body-uterus geometry, EMMI uses T1-weighted magnetic resonance imaging (MRI)22,23,24, which has been widely used for pregnant women during their second and third trimesters. Next, up to 192 pin-type electrodes placed on the body surface are used to collect electrical recordings from the myometrium. Finally, the EMMI data processing pipeline is performed to combine the body-uterus geometry with the electrical data to reconstruct and image electrical activities on the uterine surface21. EMMI can accurately locate the initiation of uterine contractions and image propagation patterns during uterine contractions in three dimensions. This article aims to present the EMMI procedures and demonstrate the representative results obtained from pregnant women.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>16 G Vinyl 54&#34; Clear</td>
			<td>Jo-Ann Stores</td>
			<td>1532449</td>
			<td></td>
		</tr>
		<tr>
			<td>3 T Siemens Prisma</td>
			<td>Siemens</td>
			<td>N/A</td>
			<td>MRI scanner</td>
		</tr>
		<tr>
			<td>3M double coated medical tape &#8211; transparent</td>
			<td>MBK tape solutions</td>
			<td>1522</td>
			<td>Width - 0.5&#34;</td>
		</tr>
		<tr>
			<td>Active electrode holders with X -ring</td>
			<td>Biosemi</td>
			<td>N/A</td>
			<td>17 mm</td>
		</tr>
		<tr>
			<td>Amira</td>
			<td>Thermo Fisher Scientific</td>
			<td>N/A</td>
			<td>&#160;Data analysis software</td>
		</tr>
		<tr>
			<td>Bella storage solution 28 Quart clear underbed storage tote</td>
			<td>Mernards</td>
			<td>&#160;6455002</td>
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			<td>Extreme-temperature silicone rubber translucent</td>
			<td>McMaster-Carr</td>
			<td>86465K71</td>
			<td>Thickness 1.32&#8221;</td>
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			<td>Gorilla super glue gel</td>
			<td>Amazon</td>
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			<td>LifeTime carbide punch and die set, 9 Pc.</td>
			<td>Harbor Freight</td>
			<td>95547</td>
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			<td>McKesson medical supply company</td>
			<td>Q55172</td>
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			<td>Pin-type active electrodes</td>
			<td>Biosemi</td>
			<td>Pin-type</td>
			<td></td>
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			<td>REDUX electrolyte gel</td>
			<td>Amazon</td>
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			<td>Soft cloth measuring tape</td>
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			<td>any brand can be used</td>
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			<td>Sterilite layer handle box</td>
			<td>Walmart</td>
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			<td>Vida scanner</td>
			<td>Siemens</td>
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			<td>MRI scanner</td>
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			<td>Nature made</td>
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electromyometrial imaging of uterine contractions in pregnant women

During normal pregnancy, the uterine smooth muscle, the myometrium, begins to have weak, uncoordinated contractions at late gestation to help the cervix remodel. In labor, the myometrium has strong, coordinated contractions to deliver the fetus. Various methods have been developed to monitor uterine contraction patterns to predict labor onset. However, the current techniques have limited spatial coverage and specificity. We developed electromyometrial imaging (EMMI) to noninvasively map uterine electrical activity onto the three-dimensional uterine surface during contractions. The first step in EMMI is to use T1-weighted magnetic resonance imaging to acquire the subject-specific body-uterus geometry. Next, up to 192 pin-type electrodes placed on the body surface are used to collect electrical recordings from the myometrium. Finally, the EMMI data processing pipeline is performed to combine the body-uterus geometry with body surface electrical data to reconstruct and image uterine electrical activities on the uterine surface. EMMI can safely and noninvasively image, identify, and measure early activation regions and propagation patterns across the entire uterus in three dimensions.

Author Spotlight: Advancing Labor Management Through Electromyometrial Imaging for Understanding Uterine Contractions 

Electromyometrial Imaging of Uterine Contractions in Pregnant Women

Our research aims to develop a non-invasive imaging technology termed electromyometrial imaging to generate real-time, 3D images of uterine contractions in humans. Our work will create a deeper understanding of the mechanism of uterine contractions during human labor. We aim to answer major questions in human labor management and the prediction of preterm birth and the labor arrest.The correlation pattern of the EMMI-derived uterine activation index, maximal activation ratio, and cervical dilation differed between nulliparous and multiparous groups, suggesting myometrial memory may contribute to faster labor progression in multiparous patients than in nulliparous patients. EMMI-derived activation curves have a sigmoid evolution nature, potentially reflecting the bioelectrical stimulation response dynamics during contractions. With the non-invasive electromyometrial imaging system, we are ready to visualize human labor, uterine contractions, to answer some fundamental questions about human labor, such as where the contraction start, how they propagate, and where they stop.Electromyometrial imaging can also provide multiple novel measures to reflect human labor progression. We plan to make EMMI portable and low-cost for extensive research by substituting MRI with ultrasound and a costly wired electrode system with disposable wireless electrode patches. This will expedite our work on creating a normal term atlas of EMMI.This atlas will serve as a reference point for studying different disease conditions by defining normal labor contractions.

Representative MRI-safe patches and electrode patches are shown in Figure 1B,C, created from the template shown in Figure 1A. The bioelectricity mapping hardware is shown in Figure 1C, with the connections of each component marked in detail. Figure 2 shows the entire EMMI procedure, including an MRI scan of the subject wearing MRI patches (Figure 2A), 3D op...

Watch this Scientific Journal Video about Advancing Labor Management Through Electromyometrial Imaging for Understanding Uterine Contractions at JoVE.com

We present a protocol for conducting electromyometrial imaging (EMMI), including the following procedures: multiple electromyography electrode sensor recordings from the body surface, magnetic resonance imaging, and uterine electrical signal reconstruction.

During normal pregnancy, the uterine smooth muscle, the myometrium, begins to have weak, uncoordinated contractions at late gestation to help the cervix ...

electromyometrial-imaging-of-uterine-contractions-in-pregnant-women

Research

JoVE Journal

Bioengineering

Applying MRI-Safe Marker Patches, Electrode Patches, and Rulers for Electromyometrial Imaging 

To begin print the MRI and electrode patch templates on paper. Cut 22 rectangular and four square patches from the clear vinyl sheet. Similarly, cut 44 rectangular and eight square patches from the silicone rubber sheet, and from the color silicone rubber sheet.To make MRI safe marker patches overlay a template with a clear vinyl patch, and glue MRI safe markers to the vinyl patch at the centers of the circles, which represent the electrode holder cavities on the template. Make electrode patches by labeling the circle locations on the silicone rubber patches. And punch holes at those locations using a punch set with a diameter of eight millimeters.Also punch the holes in the transparent material. Align the circumference of the punch toll with the circumference of the electrode holder cavity, and attach electrode holders over each hole with double-sided adhesive collars. Install the X-ring into the cavity on top of the electrode holder.Cover the holder with the color-coded silicone sheet and insert the pin type active electrode through the X-ring into the holder. Apply three strips of medical grade, double-sided tape to the electrode patch between the rows of electrodes along the long edge of the patch. Cut six measuring tapes at their 30 centimeter marks and retain the top section from zero to 30 centimeters.To make a horizontal ruler glue the zero centimeter edges of two measuring tapes to a long piece of vinyl strip with a gap in the width of the tape. Apply double-sided adhesive tape to each ruler.

Conducting MRI Scan, Bioelectricity Mapping, and 3D Optical Scan for Electromyometrial Imaging

Place a horizontal ruler at the patient's iliac crest level with the center crossing over the vertical ruler. Peel the liner off the double-sided tape on the patches. Place additional patches to the left and right of the first two patches so that the patches are bilaterally symmetric.Raise the head of the exam bed to around 40 degrees and guide the patient to lie down in Fowler's position. Place a vertical ruler along the midline of the abdomen with the three-centimeter mark near the fundus region, determined by manual palpation. Apply a horizontal ruler so that its center is at the six-centimeter mark of the vertical ruler and extends to the left and right lateral along the natural curvature of the abdomen.Place two square patches below the sixth and seventh patches on the right abdominal surface. Take photos and notes of the patch layout to record the positions of the rulers relative to each other and the patient's umbilicus. After the MRI scan is complete, remove the MRI patches and rulers from the patient and clean the abdomen and back with baby wipes.Remove the double-sided tape from the patches, disinfect the patches with germicidal disposable wipes, and apply new double-sided tape for the next experiment. Fill the conductive gel to a curved-tip irrigation syringe. To prepare the patches for the bioelectrical mapping and 3D optical scan.Add the gel into the electrode holder cavities on each electrode batch using the syringe and remove the liners of the double-sided tape. After applying the electrode patches, connect the power and data cords of the 3D optical scanner and open the 3D scanning software. Hold the handheld optical scanner upright with the flashing cameras facing the patient.Press the Start button on the scanner to start the scanning, and press the Start button again to record the scanning. Move the scanner around the patient to take 3D optical scans capturing the electrode locations. Press the Stop button on the scanner to finish the 3D scanning.After taking photos and notes of the patch layout, note the positions of the rulers relative to each other and the patient's navel. Place the fore grounding electrodes on the patient in the positions shown on the screen. After connecting the components of the bioelectricity mapping hardware, open the software ActiView on the laptop.Check the electrode offset mode in ActiView. Click Start File and then Pause to save the bioelectricity signal data streams in real time. After a 900-second recording, click Pause File followed by Stop to finish the recording and to store the multielectrode measurement in a binary data file.After the last recording, turn off the analog to digital, or A-D box, and disconnect the electrode patches, grounding electrodes, optical fiber, and USB cable. Remove the electrode patches and grounding electrodes from the patient and clean the patient's abdomen and lower back with a towel or baby wipes. This figure represents six successive uterine surface potential maps, 0.2 seconds apart in anterior, left, posterior, and right views.The respective time of each uterine potential is labeled in the electrogram, which is from the sites indicated with asterisks in the surface potential maps. A region of high positive potential starts at the site marked with an asterisk, enlarges, and finally diminishes. These electromyometrial imaging-generated potential maps alow investigators to visualize the dynamic progression of uterine contractions in three dimensions.