The Cellnovo semi-patch pump (patch pump with a nearby infusion site) got a lot of attention in 2009 when it was first announced because of it's small size and iPhone like handset. Cellnovo, a London based company, has now joined forces with Osaka, Japan based Nipro Diagnostics, a blood glucose meter company, for integration of a meter into the Cell-Novo controller for the pod. We saw the pump at this year's ADA, but we were unable to handle it since it wasn't FDA approved yet. The device received CE approval in September 2011. Clinical trials are set to begin this fall.
The pump includes a small and light wearable pump, a nearby infusion site, and a controller that has an integrated meter and an internal phone communication system that sends glucose directly over the phone lines for texting glucose values and integration of data into an online secure web site that you can allow others to access. The pump itself is very small, a definite trend we are seeing as more and more pumps are released. Unlike Omnipod, the electronics in the pump are reusable and the battery is rechargeable. The wax motor is attached to a cartridge of insulin that sits on top of the pump and is disposed of when empty. Cellnovo plans to put two pumps in the kit, one to use and one to recharge, eliminating the cost of buying batteries.
Bolusing works with a wax actuator instead of a normal motor. A diode is used to heat a tiny block of wax that expands to push a plunger that then pushes 0.05 units of insulin from the main reservoir into a smaller chamber for delivery. According to Cellnovo, this process causes the delivery to be more accurate than the process used by normal motor pumps. Technician Brian's website says "Wax motors are often used where a slow, gentile movement is desired over the quick snap of a solenoid. They are slow to actuate and to return..."
This seems like a nice way to reduce the size of the pump, but I have to wonder what happens when this device overheats. To avoid accidental delivery with global warming, I would assume the heat needed to melt the wax block would need to be higher than 120 to 130 degrees Fahrenheit. Bolus doses would likely be slow because 20 cycles of heating and cooling would be required to deliver a 1.0 unit bolus, and basal delivery needs to be maintained at the same time.
The pump is attached to a standard infusion set with a short, 4 inch line. Although this allows quick replacement for a site problem, the current trend is towards pumps without a separate infusion site so you can avoid snags on clothes or other objects. There's no word on whether they are working to cut this down to just the pump and the housing unit.
The oohs and ahs for this patch pump system are mostly generated by the wireless touch screen handset, which resembles current smartphones on the market. The built-in applications include a programmable basal and bolus, a blood glucose meter, food library, "text-like" features and activity monitor. All your information and programming will be inputted from the handset, including checking the glucose with the built in blood glucose meter. They also state the device is Continuous Glucose Monitor ready with a multi sensor radio so your readings from the CGM could automaticaly be pulled into the handset.
The handset has GPS and cellular internet capabilities so it can communicate with their Cellnovo Online service, a web interface that allows your healthcare team to see your readings without you actually having to meet up with them. Instead of making an appointment with your doctor and talking about readings, the doctor can sign in, view your readings and call or send you any suggestions they have. This would also help parents keep an eye on their children's readings while they are away. There hasn't been any word on the specific reason's GPS is included, but the ability to find a person who is exhibiting lows would be my first guess. I do have some questions about how the cellular network will be set up. I wonder if user's will be able to choose their own network (i.e.AT&T, Verizon, etc) or if Cellnovo plans to have only 1 carrier or create their own network. If they have their own network, like Amazon does for the Kindle, will they charge for connectivity or will it be free? These are important questions when it's time to start considering cost.
Early news has the pump unit coming in 2 forms:
- the Cellnovo 150 pump - a 3 day adult pump that holds 150 units of insulin
- and the Cellnovo 50 pump - a 3 day pump for children that holds 50 units of insulin.
Overall, the Cellnovo pump seems very promising. I'm looking forward to hearing more news from them this fall.