Clinical Assessment of an Advanced Bolus Calculator for Type 1 Diabetes (ABC4D)

The Diabetes Technology team at Imperial College have developed a novel advanced bolus calculator. The complete integrated system consists of a commercially available smartphone that holds the novel advanced algorithm. The system requires regular updates of cases derived from retrospective blinded continuous glucose monitoring data and for this a commercially available glucose sensor will be used. Each new case includes information about the problem (e.g. capillary blood glucose, meal information and physical exercise), solution (recommended insulin dose) and outcome (blood glucose following a meal). The novel decision support algorithm is based on case-based reasoning (CBR). CBR is an artificial intelligence technique that tries to solve newly encountered problems by applying the solutions learned from solved problems encountered in the past.

The end-product is therefore a subject specific insulin bolus calculator that continues to improve with time. The project utilises commercially available glucose sensors and smartphones (iPhone), integrated with a novel algorithm for insulin bolus calculation. The aim of the ABC4D is to minimise high and low glucose excursions which are associated with the complications of diabetes including blindness, kidney failure, nerve damage and cardiovascular disease.

An interim analysis was conducted in Phase 4 after 25 participants completed the study (in line with the protocol) and it was agreed to stop the study at this stage. A further protocol amendment was approved by REC/MHRA to commence ABC4D phase 5 (different CT.gov number: NCT03963219).