Swimming With the Omnipod 5 Automated Insulin Delivery System: Connectivity in the Water

Individuals with type 1 diabetes face unique glycemic challenges during exercise, and glucose responses can vary depending on the type, intensity, and duration of activity (1). Automated insulin delivery (AID) systems can help by adjusting insulin delivery as glucose changes occur during exercise (2). Swimming poses additional challenges for glycemic management with continuous glucose monitoring (CGM) and AID devices. Waterproof reliability is crucial, but accumulated cracks or leaks can compromise water-resistant integrity over time. The Omnipod 5 Automated Insulin Delivery System addresses this with a waterproof “Pod” (ingress protection rating 28 [IP28], up to 25 feet for 60 min), which is replaced every 3 days. However, submersion in water also attenuates Bluetooth signal strength, even with robust antennas (3,4). In the Omnipod 5 pivotal trial (5), some participants reported continued system function in the water. To investigate inwater system functionality, a single-center observational substudy was conducted from September 2021 until April 2022 among individuals in the Omnipod 5 pivotal extension study at Stanford University (5). Individuals eligible for substudy participation were $6 years old and swimming$2 times per month for $30 min per swim. On swim days, participants used a study-provided Garmin Swim 2 activity tracker to log swims and completed an electronic postswim survey on REDCap (Vanderbilt University, Nashville, TN). The survey collected information related to swims, including measured interdevice distance and device placement on the body. Participants followed their usual device placement and glucose management practices. Swim times were recorded using the activity tracker and swim logs. Insulet provided Pod data for each swim. Only swims with$70% active CGM data on Dexcom Clarity were analyzed. Using a two-tailed t test, the coefficient of determination (R) and P value were calculated from the trend line of each swim’s percent successful CGM-to-Pod communication. Seven eligible pivotal trial participants were enrolled in the substudy. Four (57%) participants were female, six (86%) identified as non-Hispanic White, and one (14%) identified as Hispanic. Of 137 recorded swimming events, 124 (91%) met CGM data requirements for analysis. The median swim duration was 62 min (interquartile range [IQR] 48–86 min). While all participants contributed swims, data from two participants accounted for most of the observations (103/124 swims). From the 124 swims, the median successful CGM-to-Pod communication rate was 9.1% (IQR 0–27.4%). Median interdevice distance was 33 cm (IQR 23–38 cm). Figure 1A plots CGM-to-Pod communication success rate against interdevice distance for the 88 (71%) swims with completed swim logs that reported <10% of time spent out of the water. The six (7%) swims with closest interdevice distances (2.5–10 cm) had communication success rates of $71%. The swim with the next closest device distance (14 cm) had a success rate of 57%. A subsequent study used in vivo, onbody testing to determine the optimal line-of-sight interdevice distance for underwater CGM-to-Pod communication. A Dexcom G6 CGM (Dexcom, Inc., San Diego, CA) was inserted on the right thigh. A Pod was activated off-body and secured against the skin at distances ranging from 10–17 cm from the CGM in 1-cm increments. The thigh was kept stationary and parallel to the water surface at a depth of 33–35 cm (median 33 cm). Communication was evaluated at each distance in four 20-min intervals, resulting in 80 min per distance (16 CGMto-Pod communication opportunities) and 24 total hours of cumulative communication data. Testing was conducted in still, chlorinated water at a controlled temperature of 33.9 C (93 F) and a pH of 7.4– 7.5 on four separate days. The communication rate was 100% at 10 cm and remained >68% up to a 13-cm distance. However, at 14 cm, the rate decreased to <44%, and at 17 cm there was no communication (Fig. 1C). The Omnipod 5 AID system’s waterproof features may benefit individuals with type 1 diabetes who swim regularly by providing effective automated insulin delivery and glycemic management during exercise. This substudy examined interdevice communication in the water and found a median CGMto-Pod communication success rate of 9.1% with usual Pod and CGM wear, noting higher success rates (>50%) occurred