Provided is a medical apparatus for a patient comprising an external system and an implantable system. The external system can be configured to transmit one or more transmission signals, each transmission signal comprising at least power or data. The implantable system can be configured to receive the one or more transmission signals from the external system. The external system comprises a first external device comprising at least one external antenna configured to transmit a first transmission signal to the implantable system. The implantable system comprises a first implantable device comprising at least one implantable antenna configured to receive the first transmission signal from the first external device. At least one of the external antenna or implantable antenna comprises an antenna assembly comprising: at least one transmitting/receiving antenna； and at least one shielding element positioned between the at least one transmitting/receiving antenna and an interfering component.
