Research on Biomedical Engineering
Research on Biomedical Engineering
Original article

Preliminary results of cervical impedance measurements

Thiago Kira de Souza Saito, Rafael Augusto Pedriali, Cinthia Mara Gabella, Maurício Chaves Junior, Elvio João Leonardo


Introduction: In this work, we report the development and initial tests of a measuring system that is used to measure the cervical electrical impedance with the purpose of assessing cervical ripening. The objective is to offer a system that provides real-time information about the cervical electrical impedance and, indirectly, of the cervical ripening with the aim of preventing premature birth.

Methods: Probes were developed and initial tests were performed. The probes used had electrodes that are far apart, with the assumption that in such cases deeper layers of the cervical tissue are measured.

Results: Preliminary measurements were performed in a single session on a non-gravid uterus, using as excitation signal a sinusoidal wave with frequency varying from 3 kHz to 100 kHz. Results indicate, as expected, that the magnitude of the impedance is inversely proportional to the frequency, indicating capacitive impedance.

Conclusion: Preliminary results were very encouraging. However, further measurements must be performed to correlate the impedance to the cervical ripening.


Human uterine cervix, Cervical ripening, Electrical impedance measurement, Electrical impedance probe


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