Figure 1.

Four, five mm long, small diameter tubes were inserted into a nine mm long large diameter silicon tube ((a) and (b)). Two constructs were made: one without ((a) and (c)) and one with electrodes ((b) and (d)). In the latter case, a long silicone catheter was attached to the “tubes within a tube” chamber resulting in T-shaped chamber. The long tube housed the approximately 4 cm long Pt/Ir electrodes, which ended inside two of the smaller tubes. Figure 1(c) shows the catheter with the electrode wires before it is glued to the “tubes within a tube” chamber. Figure 1(d) shows the T-tube construct in situ. The long catheter containing the electrode leads was positioned in a pocket made subcutaneously before the wounds were closed by Agraff clips.