18 May 2015
Medtronic launched their latest pump which is one step nearer to achieving the artificial pancreas. Some earlier pumps have had a low suspend feature which, when linked to a continuous blood glucose monitoring system, stops the delivery of insulin if you go hypo, particularly at night. The pump then restarts after two hours, by which time your blood glucose should have returned to normal levels in the absence of any active insulin.
With the MiniMed 640G, Medtronic have taken this a step further and the pump can automatically suspend if the CGM predicts that your blood glucose levels will fall into the hypo range within the next 30 minutes. The level at which it suspends can be set by the user, if they are particularly concerned about avoiding hypos. The pump then restarts either:
- when instructed to do so by the user;
- once the blood glucose is 1.1mmol/l above the hypo target set and predicted to be greater than 2.2mmol/l above that target within the next 30 minutes; or
- after the pump has been suspended for 2 hours
The pump also alarms to warn the user of the oncoming hypo.
In practice, people who trialled the pump found it took them some weeks to become confident enough to trust the technology. Many initially still ate extra carbs to avoid the hypo – which they didn’t need to do as the insulin suspend meant that their blood glucose levels would rise automatically quite quickly. However, once they started to trust the system, most people found it an incredibly useful tool.
Although the pump is available at a similar cost to other pumps on the market, the low suspend technology also relies on the use of a CGM system, which are still not widely available on the NHS. This may limit its use in the UK. However, new NICE guidance may enable more people to begin accessing CGM technology.