A system for communication of information, comprising: a medical implant for implantation in a patient's body; and an external communication unit adapted to be arranged outside the patient's body and to be placed in contact with, or in close vicinity of, the patient's body when in use; wherein: the information is communicated between the medical implant, when implanted in the patient's body, and the external communication unit; the medical implant is connected to or comprises an internal communication unit; the external communication unit comprises a first dual capacitor plate formed of two plates; the internal communication unit comprises a second dual capacitor plate formed of two plates; the external communication unit and the internal communication unit communicate with each using a capacitive coupling between the first dual capacitor plate and the second dual capacitor plate, using a part of the patient's body as a communication path; the communicated information is digitally represented as transitions of a signal, wherein the transitions of the signal are transitions between states or levels of a signal, or variations of the derivative of a signal, wherein the transitions occur at a fixed rate, wherein said fixed rate is obtained by a receiving one of the external and the internal communication unit by transmitting, from a transmitting one of the external and the internal communication unit, a sequence of transitions at the fixed rate. a medical implant for implantation in a patient's body; and an external communication unit adapted to be arranged outside the patient's body and to be placed in contact with, or in close vicinity of, the patient's body when in use; wherein: the information is communicated between the medical implant, when implanted in the patient's body, and the external communication unit; the medical implant is connected to or comprises an internal communication unit; the external communication unit comprises a first dual capacitor plate formed of two plates; the internal communication unit comprises a second dual capacitor plate formed of two plates; the external communication unit and the internal communication unit communicate with each using a capacitive coupling between the first dual capacitor plate and the second dual capacitor plate, using a part of the patient's body as a communication path; the communicated information is digitally represented as transitions of a signal, wherein the transitions of the signal are transitions between states or levels of a signal, or variations of the derivative of a signal, wherein the transitions occur at a fixed rate, wherein said fixed rate is obtained by a receiving one of the external and the internal communication unit by transmitting, from a transmitting one of the external and the internal communication unit, a sequence of transitions at the fixed rate. the information is communicated between the medical implant, when implanted in the patient's body, and the external communication unit; the medical implant is connected to or comprises an internal communication unit; the external communication unit comprises a first dual capacitor plate formed of two plates; the internal communication unit comprises a second dual capacitor plate formed of two plates; the external communication unit and the internal communication unit communicate with each using a capacitive coupling between the first dual capacitor plate and the second dual capacitor plate, using a part of the patient's body as a communication path; the communicated information is digitally represented as transitions of a signal, wherein the transitions of the signal are transitions between states or levels of a signal, or variations of the derivative of a signal, wherein the transitions occur at a fixed rate, wherein said fixed rate is obtained by a receiving one of the external and the internal communication unit by transmitting, from a transmitting one of the external and the internal communication unit, a sequence of transitions at the fixed rate.