scholarly journals Pulse-Width Modulation-based TMS mimics effects of conventional TMS on human primary motor cortex

2021 ◽  
Author(s):  
Majid Memarian Sorkhabi ◽  
Karen Wendt ◽  
Jacinta Oshea ◽  
Timothy Denison
Keyword(s):  
Pulse Width ◽  
Pulse Shaping ◽  
Primary Motor Cortex ◽  
Pulse Width Modulation ◽  
Human Study ◽  
Output Curve ◽  
Magnetic Pulse ◽  
The Novel ◽  
Motor Threshold ◽  
Healthy Participants

Objective: We developed a novel transcranial magnetic stimulation (TMS) device to generate flexible stimuli and patterns. The system synthesizes digital equivalents of analog waveforms, relying on the filtering properties of the nervous system. Here, we test the hypothesis that the novel pulses can mimic the effect of conventional pulses on the cortex. Approach: A second-generation programmable TMS (pTMS2) stimulator with magnetic pulse shaping capabilities using pulse-width modulation (PWM) was tested. A computational and an in-human study on twelve healthy participants compared the neuronal effects of conventional and modulation-based stimuli. Main results: Both the computational modeling and the in-human stimulation showed that the PWM-based system can synthesize pulses to effectively stimulate the human brain, equivalent to conventional stimulators. The comparison includes motor threshold, MEP latency and input-output curve measurements. Significance: PWM stimuli can fundamentally imitate the effect of conventional magnetic stimuli while adding considerable flexibility to TMS systems, enabling the generation of highly configurable TMS protocols.

Modulation Waveform Cycle Normalization Based Unipolar SPWM Controller

2013 ◽  
Vol 791-793 ◽  
pp. 681-685
Author(s):  
Chao Jiang ◽  
Yue Li Hu ◽  
Ke Ke Zhang ◽  
Yang Cao
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Design Method ◽  
Practical Significance ◽  
The Novel ◽  
Sinusoidal Modulation ◽  
Sinusoidal Pulse Width Modulation ◽  
Novel Design

The thesis mainly proposed a novel design method for Sinusoidal Pulse Width Modulation (SPWM) controller based on modulation waveform cycle normalization. T is the period of sinusoidal modulation waveform, and T/n is the cycle of triangular carrier. Shift registers and adders of SPWM controller were designed to translate the 2n numerical value for SPWM waveform on-off switching points, which were calculated offline, to control the level of the outpout SPWM waveform,which is the key point of modulation waveform cycle normalization. In the thesis RTL function simulation verification by ModelSim and testing for FPGA have been achieved successfully. The results show that the novel SPWM controller is reliable, which has practical significance.

scholarly journals A simplified SVPWM method for cascaded multilevel inverters

2021 ◽  
Vol 2062 (1) ◽  
pp. 012032
Author(s):  
Nishant Matale ◽  
Mohan Thakre ◽  
Rakesh Shriwastava
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Strategies ◽  
Harmonic Distortion ◽  
Superior Performance ◽  
The Novel ◽  
Multilevel Converters ◽  
Medium Voltage ◽  
Multilevel Inverters ◽  
Bus Voltage

Abstract A highly popular alternative in medium voltage and high-power applications is multilevel converters because of their superior performance over conventional two-level converters. The most commonly used control methods in the case of multilevel inverters are sine pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) methods. Among these two control strategies, SVPWM has superior performance over SPWM in terms of DC bus voltage utilization along with a reduction in total harmonic distortion (THD) of line voltages. The classical SVPWM method has various drawbacks such as computational complexity for identifying the location of reference voltage vector, sector identification, region identification, memory requirement to store lookup tables for switching vectors. The novel simplified SVPWM technique is presented for cascaded H-Bridge multilevel inverter (CHBMLI) in this paper. This simplified SVPWM method has overcome the drawbacks of the classical SVPWM method. This new technique has been implemented into a five-level CHBMLI to evaluate performance and also to compare with the SPWM method. The simulation has been performed in MATLAB software.

scholarly journals Novel MSVPWM to Reduce the Inductor Current Ripple for Z-Source Inverter in Electric Vehicle Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qianfan Zhang ◽  
Shuai Dong ◽  
Ping Xue ◽  
Chaowei Zhou ◽  
ShuKang Cheng
Keyword(s):  
Beneficial Effect ◽  
Electric Vehicle ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
The Novel ◽  
Space Vector ◽  
Current Ripple

A novel modified space vector pulse width modulation (MSVPWM) strategy for Z-Source inverter is presented. By rearranging the position of shoot-through states, the frequency of inductor current ripple is kept constant. Compared with existing MSVPWM strategies, the proposed approach can reduce the maximum inductor current ripple. So the volume of Z-source network inductor can be designed smaller, which brings the beneficial effect on the miniaturization of the electric vehicle controller. Theoretical findings in the novel MSVPWM for Z-Source inverter have been verified by experiment results.

Space Vector and Sinusoidal Pulse Width Modulation of Quasi Z-Source Inverter for Photovoltaic System

2016 ◽  
Vol 7 (3) ◽  
pp. 601 ◽  
Author(s):  
G. Prakash ◽  
C. Subramani
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Photovoltaic System ◽  
The Novel ◽  
Matlab Simulation ◽  
Space Vector ◽  
Course Of Action ◽  
Dc Current ◽  
Sinusoidal Pulse Width Modulation ◽  
The Way

<p>This paper compares the execution of Sinusoidal Pulse width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVM) methods for a Quasi Z-source inverter (QZSI) is an another topology got from the standard Z-source inverter (ZSI).The QZSI gets each one of the upsides of the ZSI, which can comprehend buck/boost, inversion and power forming in a singular stage with upgraded trustworthiness. In like manner, the proposed QZSI has the novel purposes of enthusiasm of lower part evaluations and unfaltering dc current from the source. The QZSI highlights a broad assortment of voltage expansion which is reasonable for applications in photovoltaic (PV), as a result of the way that the PV cells yield contrasts comprehensively with temperature and daylight based enlightenment. The working qualities of the proposed course of action is analyzed in inconspicuous component and appeared differently in relation to that of the SPWM and SVM. Speculative examination of voltage help and direction methods for the QZSI in PV is explored in this paper. Amusement of the circuit setup for the previously stated equalization procedures have been taken a gander at in MATLAB/Simulation. Besides, the THD examination of both SPVM and SVM is compared.</p>

The 1-Bit Instrument

2020 ◽  
Vol 1 (1) ◽  
pp. 44-74
Author(s):  
Blake Troise
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Interleaving Techniques ◽  
Sonic Environment

The 1-bit sonic environment (perhaps most famously musically employed on the ZX Spectrum) is defined by extreme limitation. Yet, belying these restrictions, there is a surprisingly expressive instrumental versatility. This article explores the theory behind the primary, idiosyncratically 1-bit techniques available to the composer-programmer, those that are essential when designing “instruments” in 1-bit environments. These techniques include pulse width modulation for timbral manipulation and means of generating virtual polyphony in software, such as the pin pulse and pulse interleaving techniques. These methodologies are considered in respect to their compositional implications and instrumental applications.

An Equivalent Circuit Model for Vertical Comb Drive MEMS Optical Scanner Controlled by Pulse Width Modulation

2012 ◽  
Vol 132 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Satoshi Maruyama ◽  
Muneki Nakada ◽  
Makoto Mita ◽  
Takuya Takahashi ◽  
Hiroyuki Fujita ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Comb Drive ◽  
Optical Scanner
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