Accuracy of insulin pumps is of current interest, especially with regard to development of closed loop systems. This study evaluated accuracy of the three most recent durable insulin pumps with regard to bolus and basal rate delivery.
The three durable pumps MiniMed® 670G [670G], t:slim X2 [TS] and mylife™ YpsoPump® [YP] were tested. Experimental testing was based on EN 60601-2-24 which requires a microgravimetric procedure. Basal rates of 0.1 U/h and 1 U/h, and boluses of 0.1 U, 1 U and 10 U were tested in 9 repetitions each. Basal rate delivery was assessed for 72 h evaluating each hour separately. Limits of ±15% from target were applied.
The results are shown in the table.
| Basal rate | Bolus | |||||
| 0.1 U/h | 1 U/h | 0.1 U | 1 U | 10 U | ||
| n | 9 | 9 | 225 | 225 | 108 | |
| 670 G | Mean deviation | 10.6% | 0.1% | 6.0% | 0.3% | -0.8% |
| % of 1-h windows/boluses within ±15% of target | 59% | 99% | 85% | 100% | 100% | |
| TS | Mean deviation | 2.2% | 0.6% | 2.5% | 1.9% | 0.4% |
| % of 1-h windows/boluses within ±15% of target | 63% | 100% | 96% | 100% | 100% | |
| YP | Mean deviation | 4.2% | 1.2% | -2.3% | 1.1% | 0.7% |
| % of 1-h windows/boluses within ±15% of target | 67% | 99% | 88% | 100% | 100% | |
Accuracy of the new pumps fits well into the picture of previously tested durable insulin pumps. In general, accuracy is higher with larger boluses or basal rates.