Medfusion Syringe Pump, Model 3500-500, v3, v4, v5, and v6

Reason for Recall

A force sensor in the occlusion detector may drift out of calibration leading to increased occlusion detection times, false occlusion alarms, or a System Failure Alarm. If the force sensor calibration shift is large enough, the pump will display a System Failure Alarm (including Force Sensor BGND Test, Force Sensor Bridge Test, or Force Sensor Test). However, if the calibration shift is not large enough to trigger a System Failure Alarm, the threshold to detect an occlusion may increase, increasing the time to occlusion detection, or the threshold may decrease, leading to false occlusion alarms. Although shifts in the force sensor calibration may occur over time with any device, an increased potential for such shifts has been reported in devices produced before April 2022 due to mechanical interference between parts of the plunger head assembly. Out of an abundance of caution, we are notifying all customers of this potential issue.