Advanced Bolus Calculator for Type 1 Diabetes (ABC4D) (ABC4D)

This study aims to assess the safety and efficacy of a novel advanced bolus calculator in subjects with Type 1 diabetes. Insulin bolus calculators have been developed to aid insulin dose adjustment and existing standard insulin bolus calculator consist of a simple algorithm that requires five subject-specific parameters as input to generate a recommended bolus insulin dose: current blood glucose (mmol/L) target blood glucose (mmol/L) insulin-to-carbohydrate ratio (grams of carbohydrate per 1 unit of insulin) total grams of carbohydrate in meals insulin sensitivity factor (reduction in glucose per 1 unit of insulin)

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. The clinical study has been designed to incrementally assess the device's ability to manage meal time insulin requirements at breakfast and lunch in a controlled supervised clinical environment over 8 hours (phase 1), followed by its use in the home environment over a 6 week period (phase 2) and finally over a 6 month period (phase 3).

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

For Phase 1 the time frame is 8 hours, for phase 2 it is 6 weeks and for phase 3 participants are followed-up for 6 months

Inclusion Criteria: Adults ≥18 years of age Diagnosis of T1DM for > 1 year On MDI using a basal-bolus insulin regime Structured education in previous 3 years HbA1c ≤ 86mmol/mol No severe hypoglycaemia (defined as needing 3rd party assistance) in previous year Exclusion Criteria: Recurrent severe hypoglycaemia Pregnant or planning pregnancy Breastfeeding Enrolled in other clinical trials Have active malignancy or under investigation for malignancy Addison's Disease Gastroparesis Autonomic neuropathy Concomitant use of GLP-1 analogues and gliptins Visual impairment Reduced manual dexterity

Reddy M, Pesl P, Xenou M, Toumazou C, Johnston D, Georgiou P, Herrero P, Oliver N. Clinical Safety and Feasibility of the Advanced Bolus Calculator for Type 1 Diabetes Based on Case-Based Reasoning: A 6-Week Nonrandomized Single-Arm Pilot Study. Diabetes Technol Ther. 2016 Aug;18(8):487-93. doi: 10.1089/dia.2015.0413. Epub 2016 May 19.