Abstract: The present disclosure relates to medicament injection devices. An injection device includes: a movable dosage programming component comprising a rotary encoder system having a predefined angular periodicity, a sensor arrangement including a first optical sensor configured to detect movement of the movable dosage programming component relative to the sensor arrangement during dosing of a medicament, wherein the first optical sensor is configured to operate in a strobe-sampling mode at a first frequency, a second optical sensor configured to detect movement of the rotary encoder system relative to the second optical sensor wherein the second optical sensor is configured to operate in a strobe-sampling mode at a second frequency lower than the first frequency, and a processor arrangement configured to, based on the detected movement, determine a medicament dosage administered by the injection device.

Abstract: A wheel securing means (10) for securing a wheel (12) comprising a rim (14) and a tire (16). The wheel securing means (10) comprises first and second arm members (18,20). Each of the first and second arm members (18,20) has a first end arranged to engage with the rim (14) on a first side thereof and extends from the first end to a second end adjacent a point on the outer circumference of the tire (16). A locking means (28) is provided to secure the second end of the first arm member (18) to the second end of the second arm member (20) and the first and second arm members (18,20) are shaped to engage with the outer surface of the tire (16) in use such that rotation of the wheel (12) causes rotation of the wheel securing means (10).