A body-mountable electronic device (120, 400) comprising: a motion sensor (122, 430) adapted to detect, during a first phase of a two-phase wakeup mechanism while the body-mountable electronic device is in a sleep state, a first deployment indicator comprising an acceleration event indicative of deployment of the body-mountable electronic device onto a body of a user; and control circuity adapted to: transition the body-mountable electronic device from the sleep state to a wakeup verification state responsive to detecting the first deployment indicator; verify that the body-mountable electronic device is deployed onto the body of a user during a second phase of the two-phase wakeup mechanism, wherein the control circuitry detects a second deployment indicator responsive to a verification that the body-mountable electronic device is so deployed; and transition the body-mountable electronic device from the wakeup verification state to an operational state responsive to detecting the second deployment indicator, characterised in that the body-mountable device further comprises: either a biosensor operably coupled with the control circuitry and adapted to detect an analyte or interstitial fluid, wherein the control circuitry is configured to detect the second deployment indicator when an electrical current measured across the biosensor exceeds a predetermined threshold value; or a wireless transmitter operably coupled with the control circuitry and adapted to transmit information to a communication device, wherein detection of the second deployment indicator is responsive to establishment of a wireless connection between the wireless transmitter and the communication device prior to expiry of a timeout. a motion sensor (122, 430) adapted to detect, during a first phase of a two-phase wakeup mechanism while the body-mountable electronic device is in a sleep state, a first deployment indicator comprising an acceleration event indicative of deployment of the body-mountable electronic device onto a body of a user; and control circuity adapted to: transition the body-mountable electronic device from the sleep state to a wakeup verification state responsive to detecting the first deployment indicator; verify that the body-mountable electronic device is deployed onto the body of a user during a second phase of the two-phase wakeup mechanism, wherein the control circuitry detects a second deployment indicator responsive to a verification that the body-mountable electronic device is so deployed; and transition the body-mountable electronic device from the wakeup verification state to an operational state responsive to detecting the second deployment indicator, characterised in that the body-mountable device further comprises: either a biosensor operably coupled with the control circuitry and adapted to detect an analyte or interstitial fluid, wherein the control circuitry is configured to detect the second deployment indicator when an electrical current measured across the biosensor exceeds a predetermined threshold value; or a wireless transmitter operably coupled with the control circuitry and adapted to transmit information to a communication device, wherein detection of the second deployment indicator is responsive to establishment of a wireless connection between the wireless transmitter and the communication device prior to expiry of a timeout. transition the body-mountable electronic device from the sleep state to a wakeup verification state responsive to detecting the first deployment indicator; verify that the body-mountable electronic device is deployed onto the body of a user during a second phase of the two-phase wakeup mechanism, wherein the control circuitry detects a second deployment indicator responsive to a verification that the body-mountable electronic device is so deployed; and transition the body-mountable electronic device from the wakeup verification state to an operational state responsive to detecting the second deployment indicator, characterised in that the body-mountable device further comprises: either a biosensor operably coupled with the control circuitry and adapted to detect an analyte or interstitial fluid, wherein the control circuitry is configured to detect the second deployment indicator when an electrical current measured across the biosensor exceeds a predetermined threshold value; or a wireless transmitter operably coupled with the control circuitry and adapted to transmit information to a communication device, wherein detection of the second deployment indicator is responsive to establishment of a wireless connection between the wireless transmitter and the communication device prior to expiry of a timeout. either a biosensor operably coupled with the control circuitry and adapted to detect an analyte or interstitial fluid, wherein the control circuitry is configured to detect the second deployment indicator when an electrical current measured across the biosensor exceeds a predetermined threshold value; or a wireless transmitter operably coupled with the control circuitry and adapted to transmit information to a communication device, wherein detection of the second deployment indicator is responsive to establishment of a wireless connection between the wireless transmitter and the communication device prior to expiry of a timeout.