SUPPLEMENTAL DEVICE FOR USE WITH AN INJECTION DEVICE, A METHOD OF OPERATION THEREOF, AND A COMPUTER PROGRAM FOR CONTROLLING A SUPPLEMENTAL DEVICE TO PERFORM THE METHOD.

摘要

A supplemental device for use with an injection device, the supplemental device comprising: a plurality of light sources each being configured to illuminate a surface portion of an injection device, in use, with light of a different wavelength; at least one sensor for generating sensor outputs indicative of the respective intensities of light of different wavelengths reflected from the surface portion; and a processor for: controlling the plurality of light sources to illuminate the surface portion with light of first to third different wavelengths; obtaining first to third values for sensor outputs corresponding to the first to third different wavelengths respectively; performing one or more calculations using at least the first and second values to provide one or more further values; and using the third value and the or each further value, but not the first and second values, to determine a property of the injection device.