Monitoring systems for elderly require a compromise between reduced size and operational autonomy. The latter to get a system as independent as possible and to fit with our application needs for daily use. Our patch i...Monitoring systems for elderly require a compromise between reduced size and operational autonomy. The latter to get a system as independent as possible and to fit with our application needs for daily use. Our patch is developed as a surveillance system for old people;we chose to equip it with a wireless charging system for greater ease of use, imperceptible in the everyday life and waterproofing. This paper presents the development of a printed receiver coil to be integrated in a wireless charger to be used in an elderly tracking patch. The proposed design is validated using simulation that presents a good agreement with measurement results: Simulation (@150 KHz: L = 10.74 μH;R = 3 Ω) and Measurement (@150 KHz: L = 10.8 μH;R = 3.16 Ω). The receiver coil is elaborated on a polyimide substrate in the cleanroom of our laboratory LAAS-CNRS (Laboratory for Analysis and Architecture of Systems-National Center for Scientific Research) and a PCB (Printed Circuit Board) charger prototype is fabricated to test its performances before the integration of the wireless charging property in the tracking patch. The proposed coil presents a good compromise between small size and efficiency. For a charging current of 7.5 mA, this coil can ensure the recharging of the patch up to a distance of 4.8 mm between the Qi transmitter and receiver which is more than enough for our application.展开更多
In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and recei...In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and receiving circuits' topology were always determined by experiments.In order to build the relationship between these parameters and the total transfer efficiency,this paper developed a novel efficiency model based on the impedance model of the coil and the circuit model of the receiving circuits.According to the design constraints,the optimal design parameters in the worst case were derived.The results indicate that the combination of the two-layered receiving coil and half-bridge rectifier has more advantages in size,efficiency and safety,which is preferred in the receiving unit.Additionally,when the load resistance increases,the optimal turn number of the receiving coil basically keeps constant and the corresponding transmitting current and total efficiency decrease.For 100 Ω load,the transmitting current and total efficiency in the worst case were measured to be 5.30 A and 1.45% respectively,which are much better than the published results.In general,our work provides an efficient method to determine the design parameters of the wireless power transfer system for freely moving biomedical implants.展开更多
文摘Monitoring systems for elderly require a compromise between reduced size and operational autonomy. The latter to get a system as independent as possible and to fit with our application needs for daily use. Our patch is developed as a surveillance system for old people;we chose to equip it with a wireless charging system for greater ease of use, imperceptible in the everyday life and waterproofing. This paper presents the development of a printed receiver coil to be integrated in a wireless charger to be used in an elderly tracking patch. The proposed design is validated using simulation that presents a good agreement with measurement results: Simulation (@150 KHz: L = 10.74 μH;R = 3 Ω) and Measurement (@150 KHz: L = 10.8 μH;R = 3.16 Ω). The receiver coil is elaborated on a polyimide substrate in the cleanroom of our laboratory LAAS-CNRS (Laboratory for Analysis and Architecture of Systems-National Center for Scientific Research) and a PCB (Printed Circuit Board) charger prototype is fabricated to test its performances before the integration of the wireless charging property in the tracking patch. The proposed coil presents a good compromise between small size and efficiency. For a charging current of 7.5 mA, this coil can ensure the recharging of the patch up to a distance of 4.8 mm between the Qi transmitter and receiver which is more than enough for our application.
基金supported by the National Natural Science Foundation of China(Grant No.61473281)the National Sciences and Technology Support Project(Grant No.2015BAI01B13)State Key Laboratory of Robotics Self-plan Project(Grant No.2016-Z06)
文摘In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and receiving circuits' topology were always determined by experiments.In order to build the relationship between these parameters and the total transfer efficiency,this paper developed a novel efficiency model based on the impedance model of the coil and the circuit model of the receiving circuits.According to the design constraints,the optimal design parameters in the worst case were derived.The results indicate that the combination of the two-layered receiving coil and half-bridge rectifier has more advantages in size,efficiency and safety,which is preferred in the receiving unit.Additionally,when the load resistance increases,the optimal turn number of the receiving coil basically keeps constant and the corresponding transmitting current and total efficiency decrease.For 100 Ω load,the transmitting current and total efficiency in the worst case were measured to be 5.30 A and 1.45% respectively,which are much better than the published results.In general,our work provides an efficient method to determine the design parameters of the wireless power transfer system for freely moving biomedical implants.
