Abstract: A cochlear implant system using a compatible external device includes an external device that keeps mapping data, which are obtained by measuring a biological response to an electrical stimulation signal of an internal device implanted in a cochlear conduct of a user, for each internal device, determines whether there is compatibility with a target internal device, and converts sound into an electrical signal in accordance with mapping data of the target internal device of a plurality of pieces of mapping data, and a target internal device that receives an electrical signal from the external device, converts the electrical signal into an electrical stimulation signal, and stimulates the auditory nerve of a cochlea with the electrical stimulation signal when the external device is compatible.

Abstract: Provided is a transcutaneous electrical nerve stimulation (TENS) apparatus, which includes an electric signal generator configured to generate an electrical stimulation signal, an electrode configured to transmit an electrical stimulation corresponding to the electrical stimulation signal generated by the electric signal generator to a user, and a connection unit configured to connect the electric signal generator to the electrode, wherein the electrode includes a pair of annular contact points for an electrical connection with the electric signal generator. Here, the connection unit may include magnetic material.