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1.2.7 Syringe Cartridge
The syringe cartridge is the biggest change seen in this design. It is an extruded pentagon, with
each side containing a syringe bay. Each of these bays has two sensors, a syringe clip, and two
syringe stabilizers (see Fig 14). The first sensor is used to detect the presence of a syringe. If the
sensor does not detect a syringe, the device knows that bay to be empty. When loading is about
to occur, the device will cycle through the syringe bays until a syringe is located for filling.
When the user wishes to add more syringes to the cartridge, the device will present the empty
bays to the user. The second sensor detects the size of the syringe. When a ½ cc syringe is in a
bay, it does not depress the second sensor. A 1cc syringe, however, will depress the second
sensor. This information is used to tell the servo that moves the insulin bottle how far to travel.
When the device is ready to load, it will move the syringe bay in position below the insulin
bottle, then lower the bottle the required distance. This information is also used when the user
inputs the dosage amount they require. If the syringe in the bay is too small to hold the requested
dosage, the device will search the bays for a larger syringe.
Syring Clip
Foam
Sensor 2
Sensor 1
Figure 14: The Syringe Bay