Contactless energy transfer at the bedside featuring an online power optimization strategy

This paper introduces the principle of contactless energy transfer to wearable bedside electronics. As a proof of concept, a platform containing a matrix of magnetic energy transmitters has been developed and integrated into a mattress. This system is able to feed one or more wearable sensor nodes, attached to the patient, with the purpose of wirelessly recording vital signals over an extended period of time. Each of these power transmitters is designed to transfer up to 10 mW of power over a maximal distance of 300 mm. Moreover, the platform embeds online optimization software to deal with vertical as well as horizontal sensor node movements. The position and orientation of each freely moving sensor node can be dynamically determined and a local magnetic field, with a matching radiated power level, can be selectively induced in the area where the sensor nodes are positioned. This approach therefore limits the radiation exposure to the patient to the minimum viable level. The prototype is successfully tested in a laboratory set-up.