Patent ID: 8801993

Claim:
A method of forming a polyurethane header on a device that is implantable in an animal, the method comprising the steps of: (a) mixing (i) a prepolymer comprising a mixture of a silicon-containing diol of formula (I) in which R 1 , R 2 , R 3 and R 4 are independently selected from C 1-6 alkyl; R 5 and R 6 are independently selected from C 1-6 alkylene; R 7 is C 1-6 alkylene, O, S or NR in which R is H or C 1-6 alkyl; and n is 1to 3and a diisocyanate; and (ii) a C 2-12 alkanediol (b) injecting the mixture of the prepolymer and the C 2-12 alkanediol into a vacant cavity of a mould chamber comprising an implantable device that comprises electrodes that project into the vacant cavity, wherein the vacant cavity is shaped to form a header; (c) allowing the mixture to cure and form a polyurethane header within the vacant cavity so that the header is secured to the implantable device and embeds the electrodes; and (d) releasing the implantable device and the formed polyurethane header from the mould.