ABSTRACT
Objective To design a temperature control strategy for riptide bioreactor to eliminate integral saturation by conventional proportion integration differentiation (PID) control.Methods According to the requirement of the riptide bioreactor for the temperature control,the temperature control system model determined by experiment was got,then the effectiveness of the integral limiter PID control method was verified,and finally the integral limiter PID control method wasimproved further using the integral separation combined with the actual experimental results and its effectiveness was tested.Results The simulation results showed that the control effects of the integral limiter PID was good.However,the actual tests proved that there was still deficiencies in large overshoot and long stable time,and good experimental results were obtainedafter improving the integral limiter PID by the integral separation method.Conclusion The improved integral limiter PID control method effectively avoids the overshoot of the system caused by the integral saturation,achieves high control precision,has a very good control performance for the temperature control of riptide bioreactor,and well meets the requirements of mammalian cell culture.
ABSTRACT
Objective To develop a BP neural network to differentiate between ventricular fibrillation( VF) and non-VF rhythms.Methods Eighteen metrics were extracted from the ECG signals.Each of these metrics respectively characterized each aspect of the signals, such as morphology, gaussianity, spectra, variability, and complexity.These metrics were regarded as the input vector of the BP neural network.After training, a classifier used for VF and non-VF rhythm classification was obtained.Results and Conclusion The constructed BP neural network was tested with the databases of VFDB and CUDB, and the accuracy was 98.61%and 95.37%, respectively.
ABSTRACT
Objective To design a temperature control strategy for wave bioreactors.Methods According to the requirements of temperature control precision and response speed of wave bioreactors,the traditional PID control method was combined with fuzzy control method which was used to adjust the parameters of the PID control in real time online in order to strengthen the ability of the temperature control strategy to regulate temperature.Results A fuzzy PID controller was completed and simulation results were compared with the traditional PID controller.Conclusion The fuzzy PID control method has a smaller overshoot and shorter stability than the traditional one, so it has a higher temperature control performance.
ABSTRACT
Objective To develop a multi-channel dry type biochemistry sensor with a compact structure and high measurement accuracy.Methods The principle of double beam compensation based on reference LED was applied to improve the measurement accuracy.The complex splitting system was replaced by MXN fiber bundle and free-form surface lens to make the instrument more compact and lightweight.Use of the adaptive amplification photoelectric detection improved the measurement accuracy while simplifying the process.Results and Conclusion It has been proved by experiments that this sensor has the advantages of high measurement accuracy, little interference and compact construction. This sensor may well meet the requirements of dry type biochemistry analysis.