Development of a multi-parameter in vivo sensing platform for intrauterine studies and subfertility diagnostics

Abstract

Couples in the developed world are increasingly being confronted with subfertility issues. In over 18% of the cases no clear reason can be identified. It is suspected that abnormalities in the physiological parameters of the uterine environment have a significant influence on embryo implantation and development. However, data from human patients is highly limited and has not been revisited for decades. Empirical studies on in vitro fertilisation (IVF) have already confirmed that levels of pH and dissolved oxygen (DO) can inhibit embryo development and decrease implantation success rates. As the current success rate for IVF remains stagnant at 33%, information on the intrauterine environment can be of great importance. Hitherto, diagnostic capabilities to assess these parameters in vivo are still lacking. This thesis describes the development of a system to monitor levels of pH and DO in utero. A pH and DO sensor together with a miniature reference electrode (RE) are incorporated onto a single, double sided sensor die sized 2.3 x 4.3 mm. The performance of the reference electrode and the individual sensors has been assessed to determine their applicability in an implantable system with power constraints, measuring unobtrusively for a period of 30 days. It is key that the biological relevancy is not compromised by sensor characteristics such as accuracy, precision and long-term drift. Both pH and DO sensors used a miniature silver silver chloride (Ag-AgCl) reference electrode, formed through the electrochemical deposition of Silver onto Platinum electrodes. Excellent performance has been observed over a 40 day period with a yield of 90% by employing a two day preliminary test. The use of an internal biocompatible electrolyte has been investigated, developed and tested. Although no added advantage was noted the described theory, simulation and results have led to an integrated sensor package developed in parallel with the sensors.

More information

Identifiers

ORCID for Hywel Morgan: orcid.org/0000-0003-4850-5676

Catalogue record

Export record