Patent ID: 8041422

Claim:
A swallowable capsule endoscope comprising; a swallowable case configured to be introduced into a patient; a function executing unit configured to realize a predetermined function inside the patient when the swallowable case travels inside the patient, the function executing unit being accommodated in the case; a plurality of silver-oxide button cells accommodated in the swallowable case each of the plurality of silver-oxide button cells having a diameter less than 10 mm; and a converter configured to convert an output voltage output from the plurality of silver-oxide button cells to an operational voltage required to operate the function executing unit, wherein the converter includes a step-up converter that steps-up the output voltage of the plurality of silver-oxide button cells to the operational voltage higher than the output voltage when the plurality of silver-oxide button cells are electrically connected in parallel or a step-down converter that steps-down the output voltage of the plurality of silver-oxide button cells to the operational voltage lower than the output voltage when the plurality of silver-oxide button cells are electrically connected in series.