Energy-Efficient Wireless Connectivity and Wireless Charging For Internet-of-Things (IoT) Applications

During the recent years, the Internet-of-Things (IoT) has been rapidly evolving. It is indeed the future of communication that has transformed Things of the real world into smarter devices. To date, the world has deployed billions of “smart” connected things. Predictions say there will be 10’s of billions of connected devices by 2025 and in our lifetime we will experience life with a trillion-node network. However, battery lifespan exhibits a critical barrier to scaling IoT devices. Replacing batteries on a trillion-sensor scale is a logistically prohibitive feat. Self-powered IoT devices seems to be the right direction to stand up to that challenge. The main objective of this thesis is to develop solutions to achieve energy-efficient wireless-connectivity and wireless-charging for IoT applications. In the first part of the thesis, I introduce ultra-low power radios that are compatible with the Bluetooth Low-Energy (BLE) standard. BLE is considered as the preeminent protocol for short-range communications that support transmission ranges up to 10’s of meters. Number of low power BLE transmitter (TX) and receiver (RX) architectures have been designed, fabricated and tested in different planar CMOS and FinFET technologies. The low power operation is achieved by combining low power techniques in both the network and physical layers, namely: backchannel communication, duty-cycling, open-loop transmission/reception, PLL-less architectures, and mixer-first architectures. Further novel techniques have been proposed to further reduce the power the consumption of the radio design, including: a fast startup time and low startup energy crystal oscillators, an antenna-chip co-design approach for quadrature generation in the RF path, an ultra-low power discrete-time differentiator-based Gaussian Frequency Shift Keying (GFSK) demodulation scheme, an oversampling GFSK modulation/demodulation scheme for open loop transmission/reception and packet synchronization, and a cell-based design approach that allows automation in the design of BLE digital architectures. The implemented BLE TXs transmit fully-compliant BLE advertising packet that can be received by commercial smartphone. In the second part of the thesis, I introduce passive nonlinear resonant circuits to achieve wide-band RF energy harvesting and robust wireless power transfer circuits. Nonlinear resonant circuits modeled by the Duffing nonlinear differential equation exhibit interesting hysteresis characteristics in their frequency and amplitude responses that are exploited in designing self-adaptive wireless charging systems. In the magnetic-resonance wireless power transfer scenario, coupled nonlinear resonators are proposed to maintain the power transfer level and efficiency over a range of coupling factors without active feedback control circuitry. Coupling factor depends on the transmission distance, lateral, and angular misalignments between the charging pad and the device. Therefore, nonlinear resonance extends the efficient charging zones of a wireless charger without the requirement for a precise alignment.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169842/1/omaratty_1.pd

Intussusception in preterm neonate

Introduction: While necrotizing enterocolitis (NEC) is more commonly encountered in premature infants in the neonatal intensive care unit, intussusception is extremely rare and usually forgotten in differential diagnosis. This is because both diseases share common clinical findings including abdominal distension, bilious gastric residuals and bloody stool. Presentation of case: A 33-gestational week-male baby was referred on 23rd postnatal day with bleeding per rectum, intolerance to feed and absolute constipation 2 days earlier. He was misdiagnosed as necrotizing enterocolitis and received conservative treatment. Later, because of deterioration of general condition, he was explored and an intussusception was found. Resection and anastamosis were done and the child was discharged on the 11th day postoperative. Conclusion: Although extremely rare, intussusception should be included in the differential diagnosis of neonatal intestinal obstruction, even in the preterms as delayed diagnosis will further result in gangrene and perforation as well as deterioration of the baby's general condition. Keywords: Intussusception, Preterm- NE

Nutrigenomic effect of conjugated linoleic acid on growth and meat quality indices of growing rabbit.

Conjugated linoleic acid was detected in rabbit caecotrophs, due to the presence of microbial lipid activity in rabbit cecum. However, the effect of CLA as a functional food in growing rabbit is not well established. Therefore, this study was conducted to determine the effect of CLA on production, meat quality, and its nutrigenomic effect on edible parts of rabbit carcass including skeletal muscle, liver, and adipose tissue. Therefore, seventy five weaned V-Line male rabbits, 30 days old, were randomly allocated into three dietary treatments receiving either basal control diet, diet supplemented with 0.5% (CLAL), or 1% CLA (CLAH). Total experimental period (63 d) was segmented into 7 days adaptation and 56 days experimental period. Dietary supplementation of CLA did not alter growth performance, however, the fat percentage of longissimus lumborum muscle was decreased, with an increase in protein and polyunsaturated fatty acids (PUFA) percentage. Saturated fatty acids (SFA) and mono unsaturated fatty acids (MUFA) were not increased in CLA treated groups. There was tissue specific sensing of CLA, since subcutaneous adipose tissue gene expression of PPARA was downregulated, however, CPT1A tended to be upregulated in liver of CLAL group only (P = 0.09). In skeletal muscle, FASN and PPARG were upregulated in CLAH group only (P ≤0.01). Marked cytoplasmic vacuolation was noticed in liver of CLAH group without altering hepatocyte structure. Adipocyte size was decreased in CLA fed groups, in a dose dependent manner (P <0.01). Cell proliferation determined by PCNA was lower (P <0.01) in adipose tissue of CLA groups. Our data indicate that dietary supplementation of CLA (c9,t11-CLA and t10,c12- CLA) at a dose of 0.5% in growing rabbit diet produce rabbit meat rich in PUFA and lower fat % without altering growth performance and hepatocyte structure