International audienceThis paper proposes a novel quaternion-basedattitude estimator with magnetic, angular rate, and gravity (MARG) sensor arrays. A new structure of a fixed-gaincomplementary filter is designed fusing related sensors. To avoidusing iterative algorithms, the accelerometer-based attitude determination is transformed into a linear system. Stable solutionto this system is obtained via control theory. With only onematrix multiplication, the solution can be computed. Using theincrement of the solution, we design a complementary filter thatfuses gyroscope and accelerometer together. The proposed filteris fast, since it is free of iteration. We name the proposed filter thefast complementary filter (FCF). To decrease significant effectsof unknown magnetic distortion imposing on the magnetometer, a stepwise filtering architecture is designed. The magneticoutput is fused with the estimated gravity from gyroscope andaccelerometer using a second complementary filter when thereis no significant magnetic distortion. Several experiments arecarried out on real hardware to show the performance andsome comparisons. Results show that the proposed FCF canreach the accuracy of Kalman filter. It successfully finds abalance between estimation accuracy and time consumption.Compared with iterative methods, the proposed FCF has muchless convergence speed. Besides, it is shown that the magneticdistortion would not affect the estimated Euler angles

Laparoscopic cholecystectomy is performed with increasing frequency in aging populations. However, in elderly patients, cognitive dysfunction following surgery may impair the outcome of surgical procedures. Dexmedetomidine (DEX) has been demonstrated to have a neuroprotectve effect in animal experiments. However, it is unclear whether DEX also has a neuroprotective effect in human patients. The present study was a randomized, placebo-controlled double-blind trial of 126 patients who had undergone laparoscopic cholecystectomy, using clinical interviews to determine whether intravenously administrated DEX during general anesthesia ameliorates cognitive function impairment. The cognitive deficit of each patient was assessed using the Mini-Mental State Examination (MMSE). The scores on the MMSE for the DEX and control groups one week after surgery (DEX group, 27.6±1.2; control group, 25.7±1.5) were significantly different (P=0.005). The MMSE scores of patients ≤65 years old were significantly higher than those of patients >65 one week after surgery. The MMSE scores were significantly different between the two age groups in the control patients (≤65 years old, 28.3±1.2; >65 years old, 26.6±2.1; P=0.036), while the difference was not statistically significant in the DEX-treated patients. Eight patients in the DEX group and 15 patients in the control group had mild cognitive impairment (26≥ MMSE score ≥21) although the difference was not statistically significant. The findings of the present study support the hypothesis that DEX administration may be an effective method for ameliorating postoperative cognitive impairment in elderly patients who have undergone laparoscopic cholecystectomy. Further research is required to confirm the findings of the present study.

For vehicle-to-vehicle (V2V) communication, such issues as continuity and reliability still have to be solved. Specifically, it is necessary to consider a more scalable physical layer due to the high-speed mobility of vehicles and the complex channel environment. Adaptive transmission has been adapted in channel-dependent scheduling. However, it has been neglected with regards to the physical topology changes in the vehicle network. In this paper, we propose a physical topology-triggered adaptive transmission scheme which adjusts the data rate between vehicles according to the number of connectable vehicles nearby. Also, we investigate the performance of the proposed method using computer simulations and compare it with the conventional methods. The numerical results show that the proposed method can provide more continuous and reliable data transmission for V2V communications.

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This paper reports an approach to designing compact high efficiency millimeter-wave fundamental oscillators operating above the fmax/2 of the active device. The approach takes full consideration of the nonlinearity of the active device and the finite quality factor of the passive devices to provide an accurate and optimal oscillator design in terms of the output power and efficiency. The 213-GHz single-ended and differential fundamental oscillators in 65-nm CMOS technology are presented to demonstrate the effectiveness of the proposed method. Using a compact capacitive transformer design, the single-ended oscillator achieves 0.79-mW output power per transistor (16 µm) at 1.0-V supply and a peak dc-to-RF efficiency of 8.02% (VDD=0.80 V) within a core area of 0.0101 mm 2 , and the measured phase noise is −93.4 dBc/Hz at 1-MHz offset. The differential oscillator exhibits approximately the same performance. A 213-GHz fundamental voltage-controlled oscillator (VCO) with bulk tuning method is also developed in this work. The measured peak efficiency of the VCO is 6.02% with a tuning rang of 2.3% at 0.6-V supply.