Measuring bioimpedance in the human uterine cervix: Towards early detection of preterm labor

Yen Shi Gillian Hoe, Edith D. Gurewitsch, Ashkon Shaahinfar, Elbert S. Hu, Somponnat Sampattavanich, Melanie Ruffner, Kenny H.S. Ching, Robert H. Allen

Research output: Contribution to journalConference article

4 Scopus citations


We have created a bioimpedance probe designed to detect subtle changes in human cervical tissue composition in vivo, and thereby detect the onset of cervical remodeling in a non-invasive manner sooner than existing clinical methods allow. Our cervical bioimpedance measurement device, which can be used during a routine pelvic examination, is composed of a contoured probe with disposable tip and, within the probe's handle, a bioimpedance sensor equipped with an integrated chip capable of generating sinusoidal voltage of varying frequencies. A constant force spring assures consistent measurements through a range of contact forces applied. An activation switch allows the operator to control the application of current. The sensor can be synchronized with a computer data storage and analysis system, which interfaces with the device. With the probe placed in contact with a collagen gels of varying concentration, the relationship between measured bioimpedance and collagen concentration is verified to be positive exponential (R 2 = 0.94) and repeatability in saline solution showed that measurements varied by less than ±10% over 20 trials. Finally, a variety of user-applied forces showed that impedance values plateau when forces exceed 1N.

Original languageEnglish (US)
Pages (from-to)2368-2372
Number of pages5
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume26 IV
Publication statusPublished - Dec 1 2004
Externally publishedYes
EventConference Proceedings - 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2004 - San Francisco, CA, United States
Duration: Sep 1 2004Sep 5 2004



  • Bioimpedance
  • Cervical ripeness
  • Cervical tissue composition
  • Human uterine cervix
  • Impedance measurement
  • Linear tetrapolar electrodes
  • Non-invasive tissue analysis
  • Pregnancy
  • Preterm labor
  • Probe
  • Tetrapolar

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

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