Name: Applying MRI-Safe Marker Patches, Electrode Patches, and Rulers for Electromyometrial Imaging
Uploaded: 2023-05-26T13:40:00
Description: Watch this Scientific Journal Video about Applying MRI-Safe Marker Patches, Electrode Patches, and Rulers for Electromyometrial Imaging at JoVE.com

applying mri-safe marker patches, electrode patches, and rulers for electromyometrial imaging 

Visualizing Uterine Contractions by EMMI for Improved Labor Management

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.

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.

Watch this Scientific Journal Video about Applying MRI-Safe Marker Patches, Electrode Patches, and Rulers for Electromyometrial Imaging at JoVE.com

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.

Research

JoVE Journal

Bioengineering

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