A self-configured body sensor network controller and a high efficiency wirelessly powered sensor are presented for a wearable, continuous health monitoring system. The sensor chip harvests its power from the surrounding health monitoring band using an Adaptive Threshold Rectifier (ATR) with 54.9% efficiency, and it consumes 12 W to implement an electrocardiogram (ECG) analog front-end and an ADC. The ATR is implemented with a standard CMOS process for low cost. The adhesive bandage type sensor patch is composed of the sensor chip, a Planar-Fashionable Circuit Board (P-FCB) inductor, and a pair of dry P-FCB electrodes. The dry P-FCB electrodes enable long term monitoring without skin irritation. The network controller automatically locates the sensor position, configures the sensor type (self-configuration), wirelessly provides power to the configured sensors, and transacts data with only the selected sensors while dissipating 5.2 mW at a single 1.8 V supply. Both the sensor and the health monitoring band are implemented using P-FCB for enhanced wearability and for lower production cost. The sensor chip and the network controller chip occupy 4.8 mm 2 and 15.0 mm 2 , respectively, including pads, in standard 0.18 m 1P6M CMOS technology.Index Terms-Body sensor network, continuous health monitoring, dry electrode, electrocardiogram (ECG), planar-fashionable circuit board (P-FCB), rectifier, self-configuration, wearable network, wireless power transmission.

Abstract-A method to fabricate circuits on the cloth, planar fashionable circuit board (P-FCB), is proposed. And its applications such as fabric passive elements, user I/O interface, and the fabric package are introduced. The electrical and the mechanical characteristic analysis of P-FCB and the system integration methodology establishment improve the system performance and productivity. A complete wearable system is implemented by P-FCB technology for the continuous sweat monitoring and the RFID tag antenna applications.

Recently, several research results have been reported on the integration of electronics with textiles such as the wearable computer and e-textiles [1][2][3]. Most of the previous works were based mainly on conducting threads, yarns, and woven fabrics to implement the interconnections, like the wearable motherboard [4]. For the integration of the IC with fabric, they placed the silicon chip on a flexible plastic board and then integrated the plastic board on the fabric [1][2][3][4]. However, the plastic board is harder than fabric and may generate a stiff feeling in the clothes, not withstanding the long integration process. In addition, its durability is poor due to its different hardness and temperature expansion coefficient.

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A pixel circuit that compensates for the non-uniform thin-film transistor (TFT) characteristics across a display panel is inevitably used in the organic light-emitting diode (OLED) display to exhibit uniform brightness. The existing pixel circuits aim to compensate only for the non-uniformity of the threshold voltage (V th ). They do not compensate for the deviation of the other parameters, such as the mobility and the subthreshold swing. In this study, how the OLED current changes when the mobility of a TFT in the V th compensation circuit increases was examined. If the mobility increases, the enhanced drain current drives the TFT into a deeper subthreshold mode during the V th compensation phase, and the |V GS | of the TFT decreases compared with the normal mobility case. The resultant OLED current, however, can be higher or lower than the normal mobility case depending on the gray level because the effects of the current increase due to the higher mobility and of the current decrease due to the reduced |V GS | appear simultaneously but differently depending on the V GS value of the TFT. The analysis results show that the OLED current increases for the high gray level but decreases for the low gray level. It remains almost unaffected by the mobility increase for the mid-gray level. ARTICLE HISTORY

A low cost quadratic level compression algorithm is proposed for body sensor network system. The proposed algorithm reduces the encoding delay and the hardware cost, while maintaining the reconstructed signal quality. The quadratic compression level determined by the mean deviation value is used to preserve the critical information with high compression ratio. The overall CR is 8.4:1, the PRD is 0.897% and the encoding rate is 6.4 Mbps. The 16-bit sensor node processor is designed, which supports the proposed compression algorithm. The processor consumes 0.56 nJ/bit at 1 V supply voltage with 1 MHz operating frequency in 0.25-microm CMOS process.

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