A control device includes: generation circuitry configured to output a field signal to a medical imaging device; first detection circuitry configured to detect a horizontal synchronization signal from video data output from the medical imaging device, the video data including at least the horizontal synchronization signal; and a monitoring circuitry configured to monitor whether or not an abnormality occurs in one frame period of the video data based on a period of the horizontal synchronization signal detected by the first detection circuitry for a predetermined n-th time after polarity of the field signal is switched.

Techniques are described for the exchange of control signals between a controlled unmanned aircraft (i.e. drone) and a ground control station and for the transmission of communication signals, such as video, from the drone to the ground control station so that the signals are more difficult to intercept or jam. The video signal transmitted from the drone can be an analog RF signal employing one or more of video scrambling, RF signal inversion, hopping, usage of a wide frequency range and other techniques. To secure the control signals between the drone and the ground control station, techniques can include hopping, encryption and use of a wide frequency range.

A control device includes: generation circuitry configured to output a field signal to a medical imaging device; first detection circuitry configured to detect a horizontal synchronization signal from video data output from the medical imaging device, the video data including at least the horizontal synchronization signal; and a monitoring circuitry configured to monitor whether or not an abnormality occurs in one frame period of the video data based on a period of the horizontal synchronization signal detected by the first detection circuitry for a predetermined n-th time after polarity of the field signal is switched.

Techniques are described for the exchange of control signals between a controlled unmanned aircraft (i.e. drone) and a ground control station and for the transmission of communication signals, such as video, from the drone to the ground control station so that the signals are more difficult to intercept or jam. The video signal transmitted from the drone can be an analog RF signal employing one or more of video scrambling, RF signal inversion, hopping, usage of a wide frequency range and other techniques. To secure the control signals between the drone and the ground control station, techniques can include hopping, encryption and use of a wide frequency range.