scholarly journals Respiratory Induced Modulation in f-Wave Characteristics During Atrial Fibrillation

2021 ◽  
Vol 12 ◽  
Author(s):  
Mostafa Abdollahpur ◽  
Fredrik Holmqvist ◽  
Pyotr G. Platonov ◽  
Frida Sandberg
Keyword(s):  
Atrial Fibrillation ◽  
Respiration Rate ◽  
Frequency Modulation ◽  
Wave Frequency ◽  
Signal Quality ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Pass ◽  
F Wave ◽  
Respiratory Modulation

The autonomic nervous system (ANS) is an important factor in cardiac arrhythmia, and information about ANS activity during atrial fibrillation (AF) may contribute to personalized treatment. In this study we aim to quantify respiratory modulation in the f-wave frequency trend from resting ECG. First, an f-wave signal is extracted from the ECG by QRST cancelation. Second, an f-wave model is fitted to the f-wave signal to obtain a high resolution f-wave frequency trend and an index for signal quality control (S). Third, respiratory modulation in the f-wave frequency trend is extracted by applying a narrow band-pass filter. The center frequency of the band-pass filter is determined by the respiration rate. Respiration rate is estimated from a surrogate respiration signal, obtained from the ECG using homomorphic filtering. Peak conditioned spectral averaging, where spectra of sufficient quality from different leads are averaged, is employed to obtain a robust estimate of the respiration rate. The envelope of the filtered f-wave frequency trend is used to quantify the magnitude of respiratory induced f-wave frequency modulation. The proposed methodology is evaluated using simulated f-wave signals obtained using a sinusoidal harmonic model. Results from simulated signals show that the magnitude of the respiratory modulation is accurately estimated, quantified by an error below 0.01 Hz, if the signal quality is sufficient (S>0.5). The proposed method was applied to analyze ECG data from eight pacemaker patients with permanent AF recorded at baseline, during controlled respiration, and during controlled respiration after injection of atropine, respectively. The magnitude of the respiratory induce f-wave frequency modulation was 0.15 ± 0.01, 0.18 ± 0.02, and 0.17 ± 0.03 Hz during baseline, controlled respiration, and post-atropine, respectively. Our results suggest that parasympathetic regulation affects the magnitude of respiratory induced f-wave frequency modulation.

scholarly journals IMPLEMENTASI SISTEM SIARAN FM STEREO PLUS DATA-TEXT SCA (SUBSIDIARY COMMUNICATION AUTHORIZATION)

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Suryo Novantara ◽  
Heroe Wijanto ◽  
Basuki Rahmat
Keyword(s):  
Frequency Shift ◽  
Frequency Modulation ◽  
Narrow Band ◽  
Phase Locked Loop ◽  
Band Pass Filter ◽  
Frequency Shift Keying ◽  
Pass Filter ◽  
Shift Keying ◽  
Band Pass

Dengan ditertibkannya frekuensi siaran FM (Frequency Modulation) dalam spasi kanal 200 kHz, maka suatu sinyal siaran FM stereo yang hanya memerlukan lebar-pita frekuensi 112 kHz (2 ? 56 kHz multipleks pita-dasar FM stereo termodulasi secara narrow band FM) akan memberikan ruang spektral sisa selebar sekitar 94 kHz pada setiap spasi kanal. Penyisipan informasi lain pada ruang sisa spasi kanal tersebut biasa disebut SCA (Subsidiary Communication Authorization), yang bertujuan untuk meningkatkan efisiensi penggunaan alokasi spektral FM. Penelitian ini mengusulkan penyisipan informasi berupa sinyal Data Text digital termodulasi FSK (Frequency Shift Keying) sebagai fasilitas siaran tambahan. Informasi Data-Text diperoleh dari deretan kode biner serial berkecepatan 1200 bps yang dibangkitkan dari port RS-232 komputer. Sinyal FSK Data-Text tersebut dimodulasikan ke subcarrier 67 KHz untuk selanjutnya digabungkan dengan sinyalsinyal multipleks audio stereo. Seluruh sinyal komposit dipancarkan dalam modulasi narrow-band FM dengan frekuensi carrier sesuai alokasi siaran FM 88 � 108 MHz. Sinyal tambahan ini perlu dijaga agar tidak terjadi tumpang-tindih spektral dengan sinyal matriks audio stereo melalui BPF (Band Pass Filter) pada frekuensi tengah 67 kHz dan bandwith 13,4 kHz. Untuk proses demodulasi sinyal FSK-Data-Text SCA dapat digunakan rangkaian PLL (Phase-Locked Loop). Untuk tampilan Data-Text digunakan LCD.Kata kunci : SCA, multipleks audio stereo, FSK-Data-Text, narrow band FM, LCD

OBSERVATION AND SIMULATION OF TSUNAMIS INDUCED BY THE 2003 TOKACHI-OKI EARTHQUAKE (M 8.0)

2015 ◽  
Vol 2 (3) ◽  
Author(s):  
Tatsuo Ohmachi ◽  
Shusaku Inoue ◽  
Tetsuji Imai
Keyword(s):  
Rayleigh Wave ◽  
Water Pressure ◽  
Near Field ◽  
Source Region ◽  
Tsunami Source ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Tsunami Simulation ◽  
Sea Bed ◽  
Band Pass

The 2003 Tokachi-oki earthquake (MJ 8.0) occurred off the southeastern coast of Tokachi, Japan, and generated a large tsunami which arrived at Tokachi Harbor at 04:56 with a wave height of 4.3 m. Japan Marine Science and Technology Center (JAMSTEC) recovered records of water pressure and sea-bed acceleration at the bottom of the tsunami source region. These records are first introduced with some findings from Fourier analysis and band-pass filter analysis. Water pressure disturbance lasted for over 30 minutes and the duration was longer than those of accelerations. Predominant periods of the pressure looked like those excited by Rayleigh waves. Next, numerical simulation was conducted using the dynamic tsunami simulation technique able to represent generation and propagation of Rayleigh wave and tsunami, with a satisfactory result showing validity and usefulness of this technique. Keywords: Earthquake, Rayleigh wave, tsunami, near-field

A comparative study on the demodulation capability of a single loop optoelectronic oscillator with and without a dynamic band Pass filter

Optik ◽  
2021 ◽  
Vol 226 ◽  
pp. 165924
Author(s):  
Shantanu Mandal ◽  
Kousik Bishayee ◽  
Arindum Mukherjee ◽  
B N Biswas ◽  
Chandan Kumar Sarkar
Keyword(s):  
Comparative Study ◽  
Band Pass Filter ◽  
Optoelectronic Oscillator ◽  
Pass Filter ◽  
Single Loop ◽  
Band Pass
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