Wire With Inspection Ports

Wire is lovely. A safe haven of conductivity, hidden from the world inside some innocuous plastic insulator. It's a disgraceful copy of the axon, but I'll let that slide. Now, wires are often used to make circuits, these are often complex. They need testing. Frequently, the conductor is not accessible, either because it's simply difficult to get to, or because you can't get to the end when the wire is in use.

How about little ports in the wire? I'm not talking about regular holes, that would just be bad wire. I'm thinking of those self-sealing rubber thingummies they have in the medical world for injecting through. They allow you to push a hypodermic needle through 3-4 mm of rubber, inject and then withdraw and the rubber manages to seal itself behind.

If this were on wire at, say, 10 cm intervals, you could insert a specially sharp probe and use it to test wiring, or indeed connectors... if one connector out of a pair is faulty, it would be useful to be able to test the wire non- destructively to establish which one.