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Mohammad Ali Ahmadi-Pajouh

Publications and source records attributed to Mohammad Ali Ahmadi-Pajouh.

2 recordsLinked to original sources

Motor Imagery Task Alters Dynamics of Human Body Posture

Motor Imagery (MI) is gaining traction in both rehabilitation and sports settings, but its immediate influence on human postural control is not yet clearly understood. The focus of this study is to examine the effects of MI on the dynamics of the Center of Pressure (COP), a crucial metric for evaluating postural stability. In the experiment, thirty healthy young adults participated in four different scenarios: normal standing with both open and closed eyes, and kinesthetic motor imagery focused on mediolateral (ML) and anteroposterior (AP) sway movements. A mathematical model was developed to characterize the nonlinear dynamics of the COP and to assess the impact of MI on these dynamics. Our results show a statistically significant increase (p-value<0.05) in variables such as COP path length and Long-Range Correlation (LRC) during MI compared to the closed-eye and normal standing conditions. These observations align well with psycho-neuromuscular theory, which suggests that imagining a specific movement activates neural pathways, consequently affecting postural control. This study presents compelling evidence that motor imagery not only has a quantifiable impact on COP dynamics but also that changes in the Center of Pressure (COP) are directionally consistent with the imagined movements. This finding holds significant implications for the field of rehabilitation science, suggesting that motor imagery could be strategically utilized to induce targeted postural adjustments. Nonetheless, additional research is required to fully understand the complex mechanisms that underlie this relationship and to corroborate these results across a more diverse set of populations.

q-bio.NC↗

Fabrication of a Low-Cost Real-Time Mobile ECG System for Health Monitoring

The electrocardiogram (ECG) signal is one of the most vital signals that can be used to investigate the performance of heart. Based on the ECG graph, we can identify different disorders and diseases. Therefore, monitoring this signal is of great importance. Many electrodes (usually 12) are employed to acquire this signal in clinics and hospitals; therefore, a nurse must install them on the body of the patient to record the signal. In this project, we built a device that can acquire the real-time ECG signal and display it on the mobile screen with the least number of electrodes (three electrodes) without requiring a nurse to install the electrodes using the simplest and cheapest type of ICs and transmitters including STM32F030F4P6 microcontroller, AD620 instrumentation amplifier, TL084 amplifier, TC7660 voltage converter, LM1117 regulator, and HC-05 Bluetooth module. Moreover, the device was designed in a way that could operate using a single 9V battery or power adaptor. First, to amplify the signal and remove a part of its noise, the ECG signal is given to the primary analog circuit. Then, in the digital section, using a microcontroller, the signal is discretized, processed, and finally transmitted to a mobile phone for final processing, information extraction, and displaying. In the mobile-written application, we developed a mathematical algorithm based on Pan-Tompkins algorithm to calculate the heartbeat rate, in which the signal peaks are determined after several processing steps using a threshold. In this regard, the ECG signals of 10 subjects were recorded and analyzed to calculate the optimum threshold. Finally, the power spectral density (PSD) and input referred noise were calculated and plotted to check the output signal quality. Based on the PSD and input referred noise amplitudes, we achieved a signal-to-noise ratio of 50dB.

eess.SP↗