Baseline drift is the main noise of ECG signals which affects the detection accuracy so its removal plays a significantrole in the ECG signal preprocessing. Complex calculation and non-optimal signal processing cause problems of ineffective results and low real-time effects in traditional methods. This paper designs a new filter to remove baseline drift based on the theory of mathematical morphology, which is created by the geometric parameters of the ECG signal. Experiments show that the method can effectively remove the noise of baseline drift by simple computation and is helpful to improve the detection accuracy.

A high-order bandgap voltage reference (BGR) is designed by adopting a current which is proportional to absolute temperature T1.5. The high-order BGR is analyzed and simulated in SMIC 0.18μm CMOS process. Simulation results show that the designed high-order BGR achieves temperature coefficient of 2.54ppm/°C when temperature ranging from-55°C to 125°C. The high-order BGR at 10Hz, 100Hz, 1kHz, 10kHz and 100kHz achieves, respectively, the power supply rejection ratio of-64.01dB, -64.01dB, -64dB, -63.5dB and-53.2dB. When power supply voltage changes from 1.7V to 2.5V, the output voltage deviation of BGR is only 617.6μV.

This paper designs a high-gain wide-bandwidth multistage amplifier by employing the dual-miller compensation with nulling-resistor and dual-feedforward compensation (DMCNR-DFC) in 0.35μm BCD process. The designed DMCNR-DFC multistage amplifier achieves well performance including gain-bandwidth product (GBW) and slew rate (SR). Simulation results show that the DMCNR-DFC multistage amplifier achieves a dc gain of about 121.1dB and GBW of about 6.1MHz with 52o phase margin.

In this paper, a low temperature coefficient bandgap voltage (BGR) is designed for A/D converter by adopting piecewise-linear compensation technique. The designed BGR is analyzed and simulated in SMIC 0.18μm CMOS process. Simulation results show that the PSRR of the designed BGR achieves-72.51dB, -72.49dB, and-70.58dB at 10Hz, 100Hz and 1kHz respectively. The designed BGR achieve the temperature coefficient of 1.57 ppm/°C when temperature is in the range from-35°C to 125°C. When power supply voltage VDD changes from 1V to 7V, the deviation of the designed BGR output voltage VREF is only 4.465μV.

In this paper, a method of analyzing the reliability of tooth surface contact strength was presented and several kinds of errors of tooth shape were taken into consideration. In the method, experimental design method and Finite Element Method (FEM) were used to get the samples of tooth surface contact stress, and then Weibull distribution was used to fit these samples. On the basis of both stress and strength obeying to Weibull distribution, the reliability of tooth surface contact strength was calculated. The result of the calculation example indicates that the method is correct and effective.