What is a picana? A picana is a kind of cattleprod. It is an instrument used to drive or streer oxen pulling a wagon. Picana derives from "picar" to prick or puncture plus a Quechua suffix -na. The non-electric picana is a stick of approximately three meters in length with a one centimeter iron barb stuck in the point.

The electrical picana operates on direct current, but it can be plugged into the wall socket of the victim's home with the aid of a transformer. It is transported in a suitcase and usually powered by an automobile battery. It is manned by two people. The first worked the bobbin raising and reducing the voltage. The other applied the electricity by applying a pole to the victim. The sleeve is insulated and the bronze or copper tip applied to the body. The voltage of the first picanas varied between 12000 and 16000 volts with a thousandth of an ampere. This voltage is modest by comparison to modern tasers that offer up to 200,000 volts, but it is the amperage that's the key element: the low amperage made the picana electrica a useful tool in torture interrogations.

The picana's design has remained the same over the last decades; the only variant is the 'rake' which is a three pronged picana. Likewise, torturers employ the picana in the same way. Using the picana is a two person operation. The tortured are strapped to a wooden table and wetted down to aid the current. The prod operator applies the wand to sensitive parts of the body (head, temples, mouth, genitalia, breasts, ) while the machine operator regulates the voltage. The victim usually bites on rubber or lead to make sure that the tongue is not bit off during the shocks. Usually, there is a doctor present to make sure that the victim has no heart problems, can survive the interrogation. Other accounts indicate a doctor keeps tabs on the pulse of the victim during the interrogation. The doctor also intervenes if that is necessary during the torture process.