The Medtronic continuous glucose monitor that I wear has sensors that are FDA approved for 3 days at a time. Given, however, the expense and the pain involved with replacing the sensor, I, like many others, try to wear the sensors for as long as they will last.
Typically, I replace the sensor after five or six days, when it loses all signal and stops tracking glucose levels at all. I can tell its time has come when it shows a gradual decline in blood sugar, finally reporting that my blood glucose is tanking, displaying the threatening “Below 40” message, when I know my blood sugar to be higher than that. Usually, I try to save the sensor, resetting it and pushing it around in the (often but not always futile) hope that it will revive itself and find my interstitial current again.
The last few sensors, though, have not shown this gradual decline and loss of signal. Rather, the signal is strong, tracking closely my glucose-meter blood sugar measurements. Then, all of the sudden, bam! Nothing. Weak signal alerts, and, after an hour or so of no data, a “Lost Sensor” alert. Game Over.
I assumed the first couple of times that this was just an alternate form of sensor death, similar to the typical decline but more sudden and disappointing. The third time around, though, something occurred to me– maybe the sensor itself is fine, but I’m losing power in the transmitter. That would explain the strong signal, but sudden loss of reception from the pump.
So, last night, when I was awoken at 2 AM by a buzzing “Lost Sensor” alert, I decided not to remove the existing sensor and replace it. Instead, I disconnected the transmitter and recharged it, leaving the sensor in. (If I were really clever, I would have tried to disconnect and immediately reconnect the transmitter, to check to make sure that the issue was one of power and not just stability of connection. However, it was two in the morning, so clever I was not.)
Once recharged, I reconnected the transmitter to the old sensor. Et voile! Success! The sensor had to re-start and re-calibrate, but the signal was strong and I was good to go. A few more precious days squeezed out of the sensor, and the mysterious problem of Sudden Sensor Death Syndrome solved!