twiist system

The twiist system is a wearable insulin infusion pump for subcutaneous delivery of insulin at set and variable rates to manage diabetes in persons ages 6 and above. The pump communicates wirelessly with compatible digitally-connected devices, including automated insulin dosing software, to receive and execute commands. It includes a bolus calculator to aid users in determining insulin dosage based on carbohydrates, blood glucose, and other parameters.

The device uses the same microprocessor-controlled micro-dosing pump mechanism with acoustic volume sensing (AVS) feedback as the predicate. It delivers 0–30 units/hour basal rates and 0.05–25.00 unit boluses in 0.01 unit increments, with identical basal and bolus accuracy, occlusion detection timing, battery life (72 hours), compatible insulins (Humalog and Novolog U-100), and environmental specifications. The primary modification is the addition of three ConvaTec infusion set models to the compatible infusion set list.

The device complies with IEC 60601-1, IEC 60601-1-2, IEC 60601-1-6, IEC 60601-1-8, IEC 60601-1-10, IEC 60601-1-11, IEC 60601-2-24, ISO 11137-1 (gamma sterilization), ISO 14971, and ISO 13485:2016. Biocompatibility is established per ISO 10993.

The twiist system is substantially equivalent to the predicate DEKA ACE Pump System (K233952) because no changes to hardware or software were necessary; only labeling was modified to add three ConvaTec infusion sets. Bench performance testing using the same established test methodology and acceptance criteria from the predicate clearance demonstrated that the new ConvaTec infusion sets perform equivalently to the previously-cleared infusion sets. Since the ConvaTec sets have similar physical characteristics to existing compatible sets and the device's core performance parameters remain unchanged, no new safety or effectiveness questions are raised.