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Biomedical subjects

I Güler

Publications and source records attributed to I Güler.

At least 19 recordsLinked to original sources
PubMed2001

Determination of aorta failure with the application of FFT, AR and wavelet methods to Doppler technique.

In this study, Doppler signals recorded from the output of aorta valve of 24 patients were transferred to a personal computer (PC) by using a 16-bit sound card. Doppler difference frequencies were recorded from each of the patients, and then analyzed using fast Fourier transform, autoregressive and wavelet transform analyzer to obtain their sonograms. These sonograms are then used to compare with the applied methods in terms of medical evaluation.

Aortic Valve Insufficiency↗
PubMed2001

A model approach to sharing electronic medical records between and within the state hospitals in Turkey.

It has always been a research interest to solve hospital management problems with systematic approach by using modern management tools. Almost all the Hospital Information System (HIS) software packages in Turkey keep track of local transactions in administrative activities and material flow. In state hospitals in Turkey, very little medical information is processed and most of the records are still kept manually and archived on papers. In this paper, a cost-effective, flexible and easy-to-use Hospital Information System model is proposed in order to give better diagnostic and treatment services. It is also demonstrated that this model makes it possible to exchange information between and within the hospitals over Transmission Control Protocol/Internet Protocol (TCP/IP) network. User needs are taken into consideration during model development and the benefits of model implementation to the hospital administration are stated. According to the model proposed in this paper, only a single health care record number (HCRN) is required for a patient to access all her/his medical records stored in different locations, from any state hospital in Turkey.

Computer Simulation↗
PubMed2001

AR spectral analysis of EEG signals by using maximum likelihood estimation.

In this study, EEG signals were analyzed using autoregressive (AR) method. Parameters in AR method were realized by using maximum likelihood estimation (MLE). Results were compared with fast Fourier transform (FFT) method. It is observed that AR method gives better results in the analysis of EEG signals. On the other hand, the results have also showed that AR method can also be used for some other researches and diagnosis of diseases.

Brain Diseases↗
PubMed2000

Design of low-cost general purpose microcontroller based neuromuscular stimulator.

In this study, a general purpose, low-cost, programmable, portable and high performance stimulator is designed and implemented. For this purpose, a microcontroller is used in the design of the stimulator. The duty cycle and amplitude of the designed system can be controlled using a keyboard. The performance test of the system has shown that the results are reliable. The overall system can be used as the neuromuscular stimulator under safe conditions.

Electric Stimulation↗
PubMed2000

Control of dental prosthesis system with microcontroller.

In this study, a microcontroller-based electronic circuit was designed and implemented for dental prosthesis curing system. Heater, compressor and valve were controlled by 8-bit PIC16C64 microcontroller which is programmed using MPASM package. The temperature and time were controlled automatically by preset values which were inputted from keyboard while the pressure was kept constant. Calibration was controlled and the working range was tested. The test results showed that the system provided a good performance.

Algorithms↗
PubMed2000

Remote control of microcontroller-based infant stimulating system.

In this paper, a remote-controlled and microcontroller-based cradle is designed and constructed. This system is also called Remote Control of Microcontroller-Based Infant Stimulation System or the RECOMBIS System. Cradle is an infant stimulating system that provides relaxation and sleeping for the baby. RECOMBIS system is designed for healthy full-term newborns to provide safe infant care and provide relaxation and sleeping for the baby. A microcontroller-based electronic circuit was designed and implemented for RECOMBIS system. Electromagnets were controlled by 8-bit PIC16F84 microcontroller, which is programmed using MPASM package. The system works by entering preset values from the keyboard, or pulse code modulated radio frequency remote control system. The control of the system and the motion range were tested. The test results showed that the system provided a good performance.

Algorithms↗
PubMed1999

A Pascal-based decision support system model for diagnosis and treatment processes in urology.

This program is designed for a urologist as a Decision Support System to facilitate the pre-diagnosis and identify the definite diagnosis as quickly as possible with the help of symptoms and physical examination by taking into consideration all the possible diseases with cross-questioning. The aim is to enable the physician to display on the monitor all the possible diseases causing the arising symptoms by entering the symptoms and the physician's observations into the database with "yes" or "no" type answers.

Decision Support Systems, Clinical↗
PubMed1999

Efficacy and safety of rectal thiopental: sedation for children undergoing computed tomography and magnetic resonance imaging.

PURPOSE: We evaluated the clinical safety, effectiveness, efficiency and potential side effects of rectally administered thiopental in 30 children undergoing computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: The doses of thiopental used were 50 mg/kg for infants under 6 months of age, 35 mg/kg for infants between 6 and 12 months of age and 25 mg/kg for older children. After administration of the sedative, oxygen saturation was continuously monitored and vital signs were recorded every 20 min during the imaging procedure and then every 20 min until discharge. RESULTS: Successful sedation and adequate imaging were obtained in 29 of 30 (96.7%) patients. Respiratory depression was not observed in any patient. However, oxygen saturation dropped below 90% transiently (to 88%) in three patients (10.0%) and this was immediately corrected by repositioning the child's neck to open the upper airway. All successfully sedated patients were asleep within 15 min (mean +/- SD 7.3 +/- 2.7 min) and sedation was sufficient for at least 30 min. Prolonged sedation was observed in two patients. CONCLUSIONS: We believe that rectal thiopental is a safe, effective and efficient form of sedation for pediatric imaging.

Administration, Rectal↗
PubMed1998

Smart cards: a specific application in the hospital.

Computers have the ability to process and access tremendous amounts of information in our daily lives. But, now, individuals have this ability by carrying a smart card in their own wallets. These cards provide us the versatility, power, and security of computers. This study begins with a short description of smart cards and their advantages. Then, an electronic circuit that is designed for healthcare application in hospitals is introduced. This circuit functions as a smart card holder identifier, access controller for hospital doors and also can be used as a smart card reader/writer. Design steps of this electronic circuit, operation principles, serial communication with P.C., and the software are examined. Finally a complete access control network for hospital doors that functions with smart cards is discussed.

Analog-Digital Conversion↗
PubMed1998

Construction and testing of ultrasound broadband transducers for blood flow sensing.

Ultrasound pulsed transducers are very important for blood flow measurement and imaging. Ultrasound pulsed transducers are broadband transducers which require relatively heavy external damping to achieve a good axial resolution and an adequately wide bandwidth. In this work, using a simple RLC circuit model, broadband transducers were constructed and tested. The results are quite applicable for pulsed Doppler blood flow measurements.

Equipment Design↗
PubMed1998

Design parameters of pulsed wave ultrasonic Doppler blood flowmeter.

Pulse wave Doppler techniques promise the ability to make more effective measurements of dynamic cardiovascular functions. Quantitative measurement of blood flow can be achieved by using the pulse wave Doppler system. This paper discusses the design parameters of the pulse wave Doppler blood flowmeter (PW Doppler) with respect to the physiological system.

Amplifiers, Electronic↗
PubMed1997

Quantization errors of the echoes in ultrasonic pulsed flowmeter employing time domain correlation.

The implementation of Time Domain Correlation Method for blood flow velocity estimation requires the conversion of the reflected ultrasonic signals into digital format in order that the computer can be utilized to investigate the technique. A number of quanitization errors, namely, that the A/D has a finite bit resolution, only a limited number of samples of the waveform may be taken per wavelength and correlation function only exits at discrete points, have an effect on the velocity estimate. This paper discusses the effect of errors associated with A/D conversion process on the accuracy of the velocity estimate. A computer simulation was performed to achieve this goal. A band passed white Gaussian noise segment was used to simulate the reflected ultrasonic signal. The jitters of the velocity estimates corresponding various A/D resolutions were calculated and plotted. Effects of interpolating the correlation function rather than determining the complete function were presented.

Algorithms↗
PubMed1997

Derivation of correlation coefficient formula for determination of Doppler angle using time domain correlation ultrasonic flowmeter.

Calculation of the Doppler angle from the correlation coefficient of two aligned windowed data sets of two echoes in the time domain correlation method has been demonstrated. By assuming ideal sound and velocity fields, it is shown that the Doppler angle can be obtained from the statistics of the reflected ultrasonic signals in time domain correlation ultrasonic flowmeter. The resolution cell is chosen to be much longer than the impulse response of the system in order that the signals reflected from the scatterers preceding and following the resolution cell will be sufficiently small that they do not contribute to the resolution cell. Hence, the truncation effects of the resolution cell on the nearby scatterers may be ignored. The mathematical derivation of correlation coefficient is presented clearly. The measurement method of Doppler angle is given from the position of two aligned resolution cells.

Blood Flow Velocity↗
PubMed1996

Order determination in autoregressive modeling of diastolic heart sounds.

Previous studies demonstrated that spectral analysis of diastolic heart sounds may provide valuable information for the detection of coronary artery disease. Although parametric modeling methods were successfully used to achieve this goal, and showed considerable performance, the accuracy and precision of the analysis is strongly dependent on the model order selected. In order to investigate the effects of model order selection on the analysis, diastolic heart sound recorded from both normal and diseased patients were analyzed using the AR modeling, which is computationally the most efficient parametric spectral analysis method. The model order were determined by using four different model order selection criteria. The results showed that the four criteria yielded different order for the same data set. On the other hand, different criteria showed different performance in different measurement conditions. Effect of arbitrary order selection was also discussed. As a result, an optimal AR model order that may be used for every case was determined.

Computer Simulation↗
PubMed1996

A low-cost biotelemetry system for long time monitoring of physiological data.

A biotelemetry system based on digital data processing and transmission is implemented. The transmitter digitizes analog physiological signal, converts into serial form, forms a digital data packet by summing data and synchronization information and transmits the packets via an FM transmitter. The receiver side amplifies and pulse-shapes the received data packet, separates the data and synchronization information, converts serial data into 8-bit parallel form and then into analog signal. A special coding method provides high noise immunity and proper synchronization between transmitter and provides high noise immunity and proper synchronization between transmitter and receiver. The system shows a stable and high performance within a distance of 100 m.

Analog-Digital Conversion↗
PubMed1996

Application of autoregressive and Fast Fourier Transform spectral analysis to tricuspid and mitral valve stenosis.

Tricuspid and mitral valve flow area was determined from an apical four-chamber view. Doppler signals were recorded from normal subjects and patients with tricuspid and mitral valve stenosis by using a pulsed Doppler unit. The location of sample volume was chosen at the ventricular side of the valve orifice and within the right ventricular tract. This was done with the aid of an integrated cardiac imaging facility. The analog signal at the output of the Doppler unit was sampled and digitized using an analog/digital interface board and transferred to a personal computer. The data were then analyzed using the Fast Fourier Transform (FTT) and autoregressive (AR) modeling methods of spectral analysis and all the sonograms were obtained. Statistical comparison between the FFT and AR methods was made. The results show that the AR method offers a superior performance over the FFT method as regards the assessment of tricuspid and mitral valve stenosis.

Adult↗