ABSTRACT
An ECG signal, generally filled with noise, when de-noised, enables a physician to effectively determine and predict the condition and health of the heart. This paper aims to address the issue of denoising a noisy ECG signal using the Fast Fourier Transform based bandpass filter. Multi-stage adaptive peak detection is then applied to identify the R-peak in the QRS complex of the ECG signal. The result of test simulations using the MIT/BIH Arrhythmia database shows high sensitivity and positive predictivity (PP) of 99.98 and 99.96% respectively, confirming the accuracy and reliability of proposed algorithm for detecting R-peaks in the ECG signal.
Subject(s)
Arrhythmias, Cardiac , Electrocardiography , Fourier Analysis , Heart , NoiseABSTRACT
El análisis acústico de la voz es un método de evaluación vocal objetivo y no invasivo, utilizado con fines diagnósticos, terapéuticos e investigativos. Utiliza registros acústicos obtenidos directamente de la voz del paciente mediante el uso de un micrófono profesional. Existe una gran variedad de programas y métodos de graficación disponibles, que favorecen la versatilidad y especificidad del proceso. Esta revisión muestra los métodos de graficación de la voz más utilizados.
The acoustic voice analysis is an objective and non invasive vocal assessment method, used for voice diagnosis, therapy and research. It uses acoustic records obtained from the patient's voice using professional microphones. There is a variety of softwares and graphing programs available that allows process versatility and specificity. This review presents the most utilized methods of voice graphing.
Subject(s)
Humans , Speech , Speech Acoustics , Speech Production Measurement/methods , Voice Disorders/diagnosis , Sound Spectrography , Voice Quality , Acoustics , Software , Voice Disorders/physiopathologyABSTRACT
Abstract Introduction: Despite of more than a hundred years of electrosurgery, only a few electrosurgical equipment manufacturers have developed methods to regulate the active power delivered to the patient, usually around an arbitrary setpoint. In fact, no manufacturer has a method to measure the active power actually delivered to the load. Measuring the delivered power and computing it fast enough so as to avoid injury to the organic tissue is challenging. If voltage and current signals can be sampled in time and discretized in the frequency domain, a simple and very fast multiplication process can be used to determine the active power. Methods This paper presents an approach for measuring active power at the output power stage of electrosurgical units with mathematical shortcuts based on a simple multiplication procedure of discretized variables – frequency domain vectors – obtained through Discrete Fourier Transform (DFT) applied on time-sampled voltage and current vectors. Results Comparative results between simulations and a practical experiment are presented – all being in accordance with the requirements of the applicable industry standards. Conclusion An analysis is presented comparing the active power analytically obtained through well-known voltage and current signals against a computational methodology based on vector manipulation using DFT only for time-to-frequency domain transformation. The greatest advantage of this method is to determine the active power of noisy and phased out signals with neither complex DFT or ordinary transform methodologies nor sophisticated computing techniques such as convolution. All results presented errors substantially lower than the thresholds defined by the applicable standards.
ABSTRACT
The worldwide increase in the use of antibiotics as an integral part of poultry and livestock production industry has recently received increasing attention as a contributory factor in the international emergence of antibiotic-resistant bacteria in human beings. To gauge the presence of the aforementioned scenario in the Indian context, a preliminary survey was conducted to assess the use of chlortetracycline (CTC) in 12 commercial layer farms and to quantify and confirm its residue in the egg. Samples of feed and eggs were collected at day 0 (prior to CTC addition), 3rd, 5th and 7th day during treatment and on the 9th and 14th day (2nd and 7th day after withdrawal of CTC) from each of the 12 commercial poultry farms studied. Concentration of CTC in feed was significantly (P<0.01) high on the 3rd, 5th and 7th day. On the 9th day and 14th day CTC concentration in feed was significantly (P<0.01) lower compared to the earlier 3 days studied. A highly significant difference (P<0.01) of the antibiotic residue in egg was observed in all the 5 days with high residual levels of CTC in egg. CTC in feed and its residue in egg were detected even on the 9th and 14th day respectively.
ABSTRACT
ObjectiveTo design a fast fourier transform (FFT) processor to meet the needs for high-speed and real-time signal processing. MethodsA 1 024-point, 32-bit, fixed, complex FFT processor was designed based on field programmable gate array (FPGA) by using radix-2 decimation in frequency(DIF) algorithm and pipeline structure in the butterfly module and ping-pong operation in data storage unit. ResultsWhen the primary clock was 100 MHz, 1 024-point FFT calculation took about 62.95us. The processor was fast enough for processing highspeed and real-time signals. ConclusionThe results provides reference value that theoretical study of the FFT algorithm can be applied in the adaptive dynamic filter of ultrasonic diagnostic system and ultrasonic doppler flow measurement system.
ABSTRACT
The purpose of the present study was to evaluate cardiovascular regulation during passive standing (PS) after ethanol ingestion by spectral analysis of heart rate variability (HRV) in flushed and nonflushed subjects. Of 24 young male subjects, 8 belonged to flushed group (F) and 16 to nonflushed group (NF). Two sessions of 10-min PS were performed before and after ethanol (0.5 g/kg) ingestion. Powers of R-R interval variability in very low frequency (VLF, 0~0.05 Hz), low frequency (LF, 0.05~0.15 Hz) and high frequency (HF, 0.15~0.50 Hz) bands, normalized powers (LFn and HFn) and LF/HF ratio were obtained. After ethanol ingestion, F showed higher heart rate than NF. PS increased LFn (+ 22.9+/-3.6 in NF, + 12.8+/-4.7 in F, in normalized units) and LF/HF (+ 3.10+/-0.57 in NF, + 3.00+/-1.08 in F) and decreased HFn powers. Ethanol ingestion increased LFn and LF/HF and decreased HFn. PS after ethanol resulted in higher LFn and LF/HF and lower HFn than the prior PS. F showed a greater and more sustained HRV change than NF after ethanol. In conclusion, PS or ethanol ingestion increased LFn and LF/HF and decreased HFn. Flushed subjects showed an accentuated HRV response to ethanol.