ISL7 Head Fixture

The photograph below shows our first ISL Head Fixture (A3024HFD-B). Version D of the head fixture has the guide cannula cemented parallel to the optical fiber.


Figure: ISL7 Head Fixture with Blue LED (A3024HFD-B).

This guide cannula may be used to hold the head fixture in place during implantation. Once the head fixture is covered by cement, the silica guide cannula tube may be crushed with scissors, or a thin pair of cutters, just below the thread. We now have a more compact head fixture, with no guide cannula thread protruding from it, and the hole in the animal's skull must accommodate only the optical fiber. With our previous head fixtures, the skull hole had to accommodate both the fiber and the guide cannula.

In the above example we have roughly 3 mm space between the circuit board and the guide cannula thread. We believe this is sufficient to allow cement over the circuit board and still have space enough to cut the guide tube. But we await comments from ION before deciding the final geometry.

UPDATE [24-JUN-15]: ION tells us they would rather have the older A3024HFC-B.