Title: Potential prediction of preterm labour and birth by Magnetic Induction Spectroscopy
Funder: Department of Health (England)

Abstract: We hypothesise that a device based on magnetic induction spectroscopy (MIS) is able to detect the changes associated with cervical remodelling long before labour. If this were possible, treatment interventions can be instituted early enough to prevent premature labour and or prolonged pregnancy causing failed induction of labour. MIS will better predict premature labour because it enables a time varying magnetic field to induce current in the cervical tissue without the very high current densities produced by application of surface electrodes. The magnetic field perturbations produced by the induced currents can then be detected using a field coil, thus removing the need for any electrodes. However, there is a very considerable scientific challenge involved in obtaining adequate sensitivity to the known conductivity properties of cervical tissue. The size of the magnetic field perturbations produced by current flow in human tissue rises as a power of the frequency of the applied alternating field. Making such measurements at frequencies of several MHz is relatively easy but our previous work on cervical tissue and by computational modelling has shown that the spectral properties at frequencies down to about 50 kHz are needed in order to characterise the tissue. In order to achieve the required sensitivity at low frequencies we propose to investigate several approaches. Current approaches to improving the low frequency sensitivity of the system involve the use of a rotating magneto-gradiometer based on a pair of planar coils. Space limitations render this approach unsuitable for use within the vagina. We will investigate other approaches that include: vibrating the coils along their axes or detecting the magnetic field directly using a magneto-resistive element. In addition, we will design the coil interface such that the cervical tissue can be mechanically deformed, by the application of reduced pressure or other means, into a defined volume within the coil assembly where maximum sensitivity and minimum variability can be obtained. We will hold a series of consultation meetings with women with a history of preterm birth to discuss the feasibility of the approaches set out above from their perspective. In recent years research investigating Magnetic Impedance Imaging (Watson 2008) has identified problems that are similar to those that we will encounter in our proposed research. Learning and building on these results, we will develop a MIS device for studies of: a) women at high risk of preterm labour (to assess predictive utility for premature delivery) and: b) women prior to induced/spontaneous labour (to assess predictive accuracy of labour and vaginal delivery). Our group have a track record in developing and manufacturing EIS and EIT devices used in several organ systems including the cervix. Over the last 6 years we have acquired considerable experience with clinical trials of cervical EIS devices. Upon successful development of the MIS device we have the capability to undertake the needed clinical trials with relative ease. We propose to carry out these studies in 3 phases: Phase1 - development of a MIS system for assessing the human cervix (24 months). Phase 2 - upgrade of the MIS system to clinical grade suitable for human experimentation. Phase 3 Development of firmware and software for data capture, as well as cost analysis of the device (12 months). As soon as a working prototype is completed the health economic analysis will be used to demonstrate competitive pricing (compared to current standard care) and estimate ‘headroom’ for producing a cost-effective device. Advice with regard to IPs and commercial exploitation will be provided by Fusion IP of the of the University of Sheffield working closely with Medipex that manages IPs for the Sheffield Teaching Hospitals NHS Foundation Trust.


Research activity codes: 4.1 DISCOVERY AND PRECLINICAL TESTING OF MARKERS AND TECHNOLOGIES
Health categories: REPRODUCTIVE HEALTH AND CHILDBIRTH