Reproducibility and repeatability of measuring the electrical impedance of the pregnant human cervix-the effect of probe size and applied pressure

Jokhi, Roobin; Ghule, Vidita V; Brown, Brian; Anumba, Dilly

doi:10.1186/1475-925x-8-10

Cited by 15 publications

(24 citation statements)

References 20 publications

(33 reference statements)

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“…Both magnitude and phase at high frequencies were relatively smaller and more tightly grouped. This has also been observed by other researchers and can be explained by greater ease of penetrating cell walls with high frequency signals [19–21]. Lower frequency signals have greater difficulty penetrating cell walls and injected current tends to follow extracellular paths.…”

Section: Pilot Datasupporting

confidence: 77%

“…Collagen crosslinks present in the cervix are autofluorescent, and its emission spectra has been shown to change throughout human pregnancy [17]. Collagenous tissue also exhibits a unique impedance spectrum, and has also been studied in the pregnant cervix [18–21]. …”

Section: Introductionmentioning

confidence: 99%

“…Also, due to recent advances in LED technology, both impedance and fluorescence detection can now be performed at low cost. Unfortunately, both cervical fluorescence [17], [22–26] and impedance [20], [21] have primarily been used only as “spot checks” to predict if labor will occur within 24 hours. We hypothesize that by fusion of multiple impedance and fluorescence measurements over time for a particular patient, an earlier detection of preterm labor can be achieved.…”

Section: Introductionmentioning

confidence: 99%

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Novel device to trend impedance and fluorescence of the cervix for preterm birth detection

Etemadi

Chung

Heller

et al. 2013

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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Preterm birth is the leading cause of worldwide neonatal mortality. It follows a pathologically accelerated form of the normal processes that govern cervical softening and dilation. Softening and dilation occur due to changes in cervical collagen crosslinking, which can be measured non-invasively by changes in tissue fluorescence and impedance. We present a novel device designed specifically to take fluorescence and impedance measurements throughout pregnancy, with the end goal of fusing and trending these measurements to form an early diagnosis of preterm labor.

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Section: Pilot Datasupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Novel device to trend impedance and fluorescence of the cervix for preterm birth detection

Etemadi

Chung

Heller

et al. 2013

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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“…Electrical impedance is measured with a probe on the surface of the anterior cervical lip (Figure b) . The figure depends on the cervical hydration and collagen concentration.…”

Section: Resultsmentioning

confidence: 99%

“…The figure depends on the cervical hydration and collagen concentration. The interobserver intraclass correlation coefficients varied between 0.53 and 0.64 . One study found that a soft cervix (Bishop score ≥5) had a lower impedance than a hard cervix did , another study found that term‐pregnant women had a higher impedance than first trimester women , and a third study found that the area under the receiver operating characteristic (ROC) curve was only 0.66 for prediction of cesarean section .…”

Section: Resultsmentioning

confidence: 99%

Overview of the methods available for biomechanical testing of the uterine cervix in vivo

Hee

2014

Acta Obstet Gynecol Scand

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Value of cervical electrical impedance spectroscopy to predict spontaneous preterm delivery in asymptomatic women: the ECCLIPPx prospective cohort study

Anumba

Stern

Healey

et al. 2021

Ultrasound in Obstet & Gyne

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Objectives Preterm birth (PTB) accounts for two‐thirds of deaths of structurally normal babies and is associated with substantial lifetime healthcare costs. Prevention of PTB remains limited by the modest accuracy of prediction methods, namely transvaginal ultrasound (TVS) cervical length (CL) measurement and quantitative cervicovaginal fetal fibronectin (FFN) estimation. We report the first substantive study detailing the predictive performance of a cervical probe device based on electrical impedance spectroscopy (EIS) for PTB – the EleCtriCaL Impedance Prediction of Preterm birth by spectroscopy of the cervix (ECCLIPPx) study. We aimed to compare the accuracy of cervical EIS‐based prediction of spontaneous PTB with that of prediction using TVS‐CL and FFN in asymptomatic women in the mid‐trimester. Methods We studied asymptomatic women with a singleton pregnancy at 20–22 weeks' and 26–28 weeks' gestation. EIS was performed using a Sheffield Mark 5.0 device that makes measurements in the frequency range 76 Hz to 625 kHz using a small probe housing tetrapolar electrodes. TVS‐CL and FFN were also measured. The associations of cervical EIS, TVS‐CL and FFN with spontaneous delivery before 37 weeks and before 32 weeks were determined by multivariate linear and non‐linear logistic regression analysis. Areas under the receiver‐operating‐characteristics curves (AUC) plots of sensitivity against specificity were used to compare the predictive performance of all parameters, both in isolation and in combination. Results Of the 365 asymptomatic women studied at 20–22 weeks who were not receiving treatment, 29 had spontaneous PTB, 14 had indicated PTB and 322 had term birth. At the higher frequencies assessed, cervical EIS predicted spontaneous PTB before 37 weeks with an AUC of 0.76 (95% CI, 0.71–0.81), compared with AUCs of 0.72 (95% CI, 0.66–0.76) for TVS‐CL and 0.62 (95% CI, 0.56–0.72) for FFN. Combining all three assessments improved the prediction of spontaneous PTB before 37 weeks (AUC, 0.79 (95% CI, 0.74–0.83)) compared with TVS‐CL and FFN alone. Incorporating a history of spontaneous PTB (defined as previous mid‐trimester miscarriage or spontaneous PTB (14 to < 37 weeks)) into the cervical EIS prediction model improved the accuracy of prediction of spontaneous PTB before 37 weeks (AUC, 0.83 (95% CI, 0.78–0.87)) and before 32 weeks (AUC, 0.86 (95% CI, 0.82–0.90)). Conclusions Mid‐trimester cervical EIS assessment predicts spontaneous PTB. Larger confirmatory studies investigating its potential clinical utility and to inform effective preventive interventions are required. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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Reproducibility and repeatability of measuring the electrical impedance of the pregnant human cervix-the effect of probe size and applied pressure

Abstract: Background: The utility of cervical electrical impedance spectroscopy (EIS) as a diagnostic tool is being investigated in clinical trials. We sought to assess the reliability of two different sizes of tetrapolar probes used in measuring cervical impedance.

Cited by 15 publications

References 20 publications

Novel device to trend impedance and fluorescence of the cervix for preterm birth detection

Novel device to trend impedance and fluorescence of the cervix for preterm birth detection

Overview of the methods available for biomechanical testing of the uterine cervix in vivo

Value of cervical electrical impedance spectroscopy to predict spontaneous preterm delivery in asymptomatic women: the ECCLIPPx prospective cohort study

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