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I Güler

Publications and source records attributed to I Güler.

24 records · Page 2Linked to original sources
PubMed1995

Comparison of FFT- and AR-based sonogram outputs of 20 MHz pulsed Doppler data in real time.

Real time sonogram outputs of autoregressive (AR) and Fast Fourier Transform (FFT) spectral analysis of 20 MHz pulsed ultrasonic Doppler blood flowmeter are presented. Data obtained from coronary, renal, iliac, digital and mesenteric arteries were processed using AR- and FFT-based spectral analysis techniques and interpretable sonograms were constructed. In comparison with the FFT-based sonogram outputs. AR-based sonogram outputs for 20 MHz pulsed Doppler data provide better results. Hence, the AR modeling is strongly recommended for small vessels with diameters between 1 and 2 mm.

Adult↗
PubMed1995

Autoregressive-based sonogram outputs of 20 MHz pulsed Doppler data.

The sonogram outputs of autoregressive (AR) based spectral analysis of a 20 MHz pulsed ultrasonic Doppler blood flowmeter are presented. The data obtained from coronary and iliac arteries were processed using AR-based spectral analysis technique, and then the interpretable sonograms by the surgeons were constructed. When the sonogram outputs were compared to other sonograms which were analysed using the other techniques such as fast Fourier transform (FFT), it was observed that AR-based sonograms for 20 MHz pulsed Doppler data have provided better results. Therefore, the technique is strongly recommended in the examining of small vessels which are 1 to 2 mm in diameter.

Adult↗
PubMed1992

Application of autoregressive analysis to 20 MHz pulsed Doppler data in real time.

The real time application of autoregressive (AR) spectral analysis to a 20-MHz pulsed Doppler blood flowmeter is presented. The system consists of a TMS 320C25 digital signal processor with a 80286 based PC/AT microcomputer and associated interfacing circuitry. The AR method was used for in vivo spectral analysis of the signals obtained from a 20-MHz pulsed Doppler flowmeter in real time. The data obtained from digital and coronary arteries were processed using both AR and FFT spectral analysis methods. Also the data obtained from a stenosis coronary artery under surgical operation were processed using both methods. When the results are compared, it is seen that autoregressive analysis has given better results. Therefore the technique can be used in the examining of small vessels such as renal, iliac, mesenteric, coronary and digital arteries.

Adult↗
PubMedDate not supplied

Humidity control of an incubator using the microcontroller-based active humidifier system employing an ultrasonic nebulizer.

Relative humidity levels of an incubator were measured and controlled. An ultrasonic nebulizer system as an active humidifier was used to humidify the incubator environment. An integrated circuit-type humidity sensor was used to measure the humidity level of the incubator environment. Measurement and control processes were achieved by a PIC microcontroller. The high-performance and high-speed PIC provided the flexibility of the system. The developed system can be used effectively for the intensive care of newborns and/or premature babies. Since the humidifier generates an aerosol in ambient conditions, it is possible to provide the high relative humidity level for therapeutic and diagnostic purposes in medicine.

Biomedical Engineering↗
PubMedDate not supplied

Factors effecting the complications in the natural history of acute cholecystitis.

BACKGROUND/AIMS: Gangrenous cholecystitis, empyema, gallbladder perforation, and biliary peritonitis are severe complications of acute cholecystitis associated with increased morbidity and mortality. This study aimed to evaluate perioperative factors associated with complications of acute cholecystitis. METHODOLOGY: Between January 1993 and October 2000, we performed cholecystectomy in 368 patients with acute cholecystitis. All perioperative data were collected on age, sex, medical history, symptoms, laboratory tests, ultrasound, operative and microbiological findings, morbidity and mortality. RESULTS: There were 305 cases (83%) of acute uncomplicated cholecystitis, 26 (7.1%) of gangrenous cholecystitis, 23 (6.3%) of empyema of the gallbladder, 12 (3.3%) of gallblader perforation, and 2 (0.5%) emphysematous cholecystitis. Risk factors for complicated cholecystitis included male gender, advanced age, associated diseases, temperature above 38 degrees C, and white blood cell count on admission greater than 18,000. Laparoscopic cholecystectomy was attempted on 36 patients (11.8%) with uncomplicated and seven patients (11.1%) with complicated acute cholecystitis. The conversion rate to open cholecystectomy was 19.4% for uncomplicated cases, 28.6% for complicated cases. There were no differences in operative complications between complicated and uncomplicated cases, however, length of hospital stay, postoperative morbidity and mortality were significantly higher in complicated cases. CONCLUSIONS: Sex (male), advanced age, presence of associated disease, high temperature (> 38 degrees C) and leukocytosis are all remarkable risk factors inducing complications in acute cholecystitis. Laparoscopic cholecystectomy can be performed with success in uncomplicated cases.

Acute Disease↗