A monitoring device is presented. The monitoring device has a circuit-board enclosure having a cradle containing a removable battery, wherein the cradle is in engagement with a transceiver module for contacting a wrist of a person. A wrist strap is described for attaching the wearable device to the wrist of a user. The monitoring device has a sensor for sensing change in a blood-related parameter and a memory device for storing the blood-related parameters. The memory device is connected to the circuit-board and a display so that the display can show the result of the determined blood-related parameter information.
