Abstract: A monitoring system having a device on a person which can process and transmit signals from at least one biosensor and a receiver located close to the patient, which can receive these signals. The receiver, which may be a portable telephone, can process the signals and provide an indication of the parameter(s) being monitored and may also, or as an alternative, forward the received signals to a remote monitor. The monitoring system may further include a device for indicating when the transmitter is not receiving a signal from the transmitter and can also include a device so that when a parameter reaches a critical care level, a warning signal is given. The monitoring system is such that the person being monitored is effectively not limited to remaining within a required distance of a fixed part of the system.