J. T. MORTIMER AND P. H. PECKHAM 
1189 
Figure 1. — Cut-away drawing of implanted dacron mesh interface. 
ward movement of the wires is restrained by 
the Dacron mesh through which connective tis- 
sue of the skin and the subcutaneous space 
rapidly grow. The ingrowth of tissue acts as a 
mechanical lock on the interface, substituting 
for the ideal case of tissue attachment to the 
interface. 
The procedure for fabrication of the interface 
is slightly modified from that given by Gertler 
et al.^ and is as follows : 
1. Dacron mesh is cut into a strip measuring 
1.5 by 6 cm. (These dimensions are suit- 
able for a two lead interface with 2 mm 
O.D. leads.) 
2. The Dacron strip is folded in the middle, 
forming a 1.5 by 3 cm double strip. Metal 
rods with the same diameters as the lead 
wires are placed through the folded mesh 
in the same position the lead wires are to 
occupy. Experimentally it has been found 
that the wires should be at least 6 mm 
apart and no closer to the edge of the strip 
than 4 mm. (Wires placed too closely to- 
gether or too near the edge of the strip 
result in poor anchoring.) 
3. Silicone rubber (RTV) is then applied to 
the folded portion of the Dacron and 
around the metal rods to form the silicone 
rubber ridge. After the silicone rubber 
has vulcanized, the metal rods are with- 
drawn from the interface. At this point 
the interface appears as shown in Figure 
2 and is suitable for autoclave steriliza- 
tion. 
Implantation of the interface is as follows: 
1. The implant site is shaved and swabbed 
with an antiseptic solution ; 
2. An incision, approximately 2 cm, is made 
in the skin at the desired site and the sub- 
cutaneous tissues are separated to allow 
placement of the Dacron tabs ; 
3. The lead wires from the electrode site are 
