Novo Nordisk A/S
Pen-type drug injector and add-on module with magnetic dosage sensor system and error detection

Abstract:

Add-on module (100) for logging the value of an expelled dose from a pen-type drug injector (200), comprising a magnetic sensor system comprising first and second sensor means (745/746) as well as a mechanical dose setting and expelling mechanism comprising a magnetic clutch element (240/740) which rotates during drug expelling. The system further comprises processor means configured to determine (i) on the basis of measured values from the first sensor means, a rotational position of the clutch element, (ii) on the basis of measured values from the second sensor means, a high-speed condition in which the rotational speed of the clutch element exceeds a given threshold level, and (iii) indicate an error state if the high-speed condition is detected.