NOSE-TO-BRAIN DRUG DELIVERY: AN UPDATE TO THE ALTERNATIVE PATH TO SUCCESSFUL TARGETED ANTI-MIGRAINE DRUGS

The Blood-Brain Barrier (BBB) limits transportation to the brain of possible treatment moieties. Specific stimulation of the brain through olfactory and trigeminal neural pathways by BBB has been taken into consideration for the development of a wide spectrum of brain therapeutics. The intranasal delivery path delivers the drugs through the brain, eliminating any side effects and increasing neurotherapeutics performance. Diverse drug delivery systems (DDDss) for reaching the brain via the nasal route have been researched over the past few decades. Large-scale molecular biologics, such as Deoxyribonucleic acid (DNA), gene vectors, and stem cells, can be administered intranasally, as a method for the management of a range of CNS illnesses, including stroke, Parkinson's diseases, multiple sclerosis, Migraine, Alzheimer's diseases, epilepsy, and mental disorders. New DDSs, including nanoparticles, liposomes, and polymeric micelles, have acquired potentials in the nasal mucosa and central nervous system (CNS), as effective means of concentrating the brain without toxicity. Differential nasal cavity structures posed a significant obstacle in ineffective drugs beyond the nasal valve. Pharmaceutical firms have increasingly used emerging techniques for the production of new nasal pharmaceutical drugs to overcome these obstacles. This review aims to identify the new advances in the nasal administration of brain-based DDSs for Migraines

Digital Implementation of a Line Current Shaping Algorithm for Three Phase High Power Factor Boost Rectifier without Input Voltage Sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase boost rectifier is described. The indicated objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses the concept of resistance emulation for shaping of input current like input voltage in digital implementation. Two decoupled fixed frequency current mode controllers calculate the switching instants for equivalent single phase boost rectifiers. A combined switching strategy is developed in the form of space vectors to simultaneously satisfy the timing requirements of both the current mode controllers in a switching period. Conventional phase locked loop (PLL) is not required as converter switching is self-synchronized with the input voltage. Analytical formula is derived to obtain the steady state stability condition of the converter. A linear, low frequency, small signal model of the three phase boost rectifier is developed and verified by measurement of the voltage control transfer function. In implementation Texas Instruments's DSP TMS320F240F is used as the digital controller. The algorithm is tested on a 10-kW, 700-V dc, three phase boost rectifier

Digital Implementation of a Line Current Shaping Algorithm for Three Phase High Power Factor Boost Rectifier without Input Voltage Sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase Boost rectifier is explained. This objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses resistor emulator concept for shaping of input current like input voltage in discrete domain. In implementation Texas Instruments's DSP based unit TMS320F240F EVM is used as the digital hardware platform. The algorithm is tested on a 4Kw ,670V DC Output, Boost rectifier. The execution time of the control algorithm is found to be less than $40\mu{sec}$

Digital Implementation of a Line Current Shaping Algorithm for Three Phase High Power Factor Boost Rectifier without Input Voltage Sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase boost rectifier is described. The indicated objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses the concept of resistance emulation for shaping of input current like input voltage in digital implementation. Two decoupled fixed frequency current mode controllers calculate the switching instants for equivalent single phase boost rectifiers. A combined switching strategy is developed in the form of space vectors to simultaneously satisfy the timing requirements of both the current mode controllers in a switching period. Conventional phase locked loop (PLL) is not required as converter switching is self-synchronized with the input voltage. Analytical formula is derived to obtain the steady state stability condition of the converter. A linear, low frequency, small signal model of the three phase boost rectifier is developed and verified by measurement of the voltage control transfer function. In implementation Texas Instruments's DSP TMS320F240F is used as the digital controller. The algorithm is tested on a 10-kW, 700-V dc, three phase boost rectifier

Phase-Angle Balance Control for Harmonic Filtering of a Three-Phase Shunt Active Filter System

This paper proposes a new strategy for harmonic filtering of a three-phase shunt active filter system. The shunt harmonic filter's control objective is defined as: balance the phase angle of the input current with the phase angle of the line frequency component of the load current. This objective is achieved in digital implementation without sensing the input voltages. The controller uses a phase-shifting method on the sensed input current and then applies the resistor-emulator-type input-current-shaping strategy on the phase-shifted current. In implementation, Texas Instrument's digital-signal-processor-based unit TMS320F240 EVM is used as the digital hardware platform. The control algorithm is computationally simple yet the harmonic filtering performance is high. The analysis, simulation, and experimental results of a three-phase shunt active filter prototype on a 25-A nonlinear load are presented

A Voltage Sensorless Control Method to Balance the Input Current of the Boost Rectifier Under Unbalanced Input Voltage Condition

This paper proposes a control method that can balance the input current of the three phase, three wire, Boost rectifier under unbalanced input voltage condition. The control objective is to operate the rectifier in the high power factor mode under normal operating condition but to give overriding priority to the current balance function in case of unbalance in the input voltages. The inner loop implements resistor emulator type input current shaping strategy. The outer control loop performs magnitude scaling and phase shifting operations on current of one of the axis to make it balanced with respect to the current on the other axis. The coefficients of scaling and shifting functions are determined by two closed loop PI controllers. The control method is input voltage sensorless. In implementation Texas Instrument's DSP TMS320F240F is used as the digital controller

A Single-Reset-Integrator-Based Implementation of Line-Current-Shaping Controller for High-Power-Factor Operation of Flyback Rectifier

The objective of this paper is to present a simple yet accurate implementation of a resistor-emulator-type line-current-shaping controller for high-power-factor operation of a flyback rectifier. The important feature is that input voltage sensing is not required. In the circuit realization of the controller, no multiplier is used. Current shaping is performed directly on the input filter inductor current. The modulator uses only one reset integrator for the generation of duty ratio. The analysis presented in this paper shows the effect of input filter capacitance on discontinuous conduction mode of operation of the flyback inductor. Design equations for selection of the input filter components are derived. A low-frequency small-signal model of the rectifier is developed and verified by measurement up to 1 kHz. The performance of the controller is first tested by the SABER circuit simulator package. Then, a 100-W 110-V AC input 50-V DC output single-phase flyback rectifier prototype is built for experimental verificatio

Phase Angle Balance Control for Harmonic Filtering of A Three Phase Shunt Active Filter System

This paper proposes a new strategy for harmonic filtering of a three-phase shunt active filter system. The shunt harmonic filter's control objective is defined as: balance the phase angle of the input current with the phase angle of the line frequency component of the load current. This objective is achieved in discreet implementation without sensing the input voltages. The controller uses a phase shifting method on the sensed input current and then applies the resistor emulator type input current shaping strategy on the phase-shifted current. In implementation Texas Instrument's DSP based unit TMS320F240 EVM is used as the digital hardware platform. The control algorithm is computationally simple yet the harmonic filtering performance is high. The analysis, simulation and experimental results of a three-phase shunt active filter prototype on a 25A nonlinear load are presented