Raşit Ahiska

Design and testing of a microprocessor-controlled portable thermoelectric medical cooling kit

Blood cells, vaccines, and other drugs and biological products should be kept at a temperature within certain range. In this paper, a medical thermoelectric cooling kit is introduced. The kit keeps medical products at temperatures between 6 and 10 °C while being stored or transported. This range is within the standards recommended by WHO to keep biological, medical and food products. Tests were carried out under various environmental temperatures in laboratory conditions as well as outside the laboratory and on a transportation vehicle. Under all these conditions, the kit provided cooling at a satisfactory level. This paper presents the technical specifications of the kit, theory of its operation, and test results. The kit is supported with a microprocessor unit. The block diagram of the microprocessor program is also presented in the paper.

A New Microcontroller-Based Human Brain Hypothermia System

Many studies show that artificial hypothermia of brain in conditions of anesthesia with the rectal temperature lowered down to 33∘C produces pronounced prophylactic effect protecting the brain from anoxia. Out of the methods employed now in clinical practice for reducing the oxygen consumption by the cerebral tissue, the most efficacious is craniocerebral hypothermia (CCH). It is finding even more extensive application in cardiovascular surgery, neurosurgery, neurorenimatology and many other fields of medical practice. In this study, a microcontroller-based designed human brain hypothermia system (HBHS) is designed and constructed. The system is intended for cooling and heating the brain. HBHS consists of a thermoelectric hypothermic helmet, a control and a power unit. Helmet temperature is controlled by 8-bit PIC16F877 microcontroller which is programmed using MPLAB editor. Temperature is converted to 10-bit digital and is controlled automatically by the preset values which have been already entered in the microcontroller. Calibration is controlled and the working range is tested. Temperature of helmet is controlled between −5 and +46∘C by microcontroller, with the accuracy of ± 0.5∘C.

Analysis of a New Method for Measurement of Parameters of Real Thermoelectric Module Employed in Medical Cooler for Renal Hypothermia

Abstract In the present study, a new method for searching all exit parameters of the thermoelectric module has been realized. The new method is based on measurement of thermo-emf of a working module and comparing the results obtained with those of classical methods. The new method is used for investigation of the values of parameters of a standard thermoelectric module of Melcor with production code of CP1.0-127-05L, used in medical coolers for renal hypothermia. The theoretical results calculated by the means of new and classical methods for the parameters of an actual thermoelectric module have been compared with the experimental results and the advantage of the new method in terms of approximation accuracy has been proven.

Development and application of a new power analysis system for testing of geothermal thermoelectric generators

ABSTRACT This article presents a new thermoelectric generator power analysis system (TEG-PAS) for the examination of all parameters of the thermoelectric generators (TEGs) operated by geothermal or any liquid heat. As a sample application, the developed TEG-PAS has been tried on a TEG of 100 W. During electrical energy generation, the values of the electrical, the thermo-electrical and the thermal variables of the TEG have been transmitted to the TEG-PAS by the employed sensors. Thus, the using of several devices simultaneously has been eliminated while the power performance analyses are being carried out.

Control of a Thermoelectric Brain Cooler by Adaptive Neuro-Fuzzy Inference System

Abstract In this study, neuro-fuzzy control of a thermoelectric head cooler system (thermoelectric helmet) is developed for brain hypothermia applications. Hypothermia is a medical treatment method of protecting the brain, in which the temperature of the brain drops below the critical level for reducing oxygen consumption of tissues. The brain should be kept at a certain temperature by a suitable control for hypothermia applications. The temperature of the thermoelectric head cooler system changes according to the current intensity supplied. The control of the thermoelectric head cooler system was performed according to the initial membership functions, which was determined by an expert using fuzzy logic control. The system was modeled by an adaptive neuro-fuzzy inference system (ANFIS). The data were then entered into the system and new membership functions were determined. By this way, learning ability of the artificial neural network and the abilities of fuzzy logic, such as decision making, were combined and a more effective solution was developed. The system software can be reprogrammed with the new membership functions.

A Survey on Application of Quantitative Methods on Analysis of Brain Parameters Changing with Temperature

Brain temperature fluctuations occur in consequence of physiological and pathophysiological conditions and indicate changes in brain metabolism, cerebral blood flow (CBF), brain functions and neural damage. Lowering the brain temperature of patients with traumatic brain injuries achieves considerable improvements. When the human brain is cooled down to 30°C, it switches to a sub functional regime where it can live longer with less oxygen, glucose and other supplies. Fluctuations in brain temperature cause changes in brain parameters which can be measured by electroencephalogram (EEG) and transcranial Doppler (TCD). It is very important to understand the temperature dependencies of brain’s electrical activity and blood flow and their interrelations considering the good clinical results achieved by lowering the brain temperature of neurologically injured patients. Since protecting the patient’s brain is of primary importance in many fields including cardiology, neurology, traumatology and anesthesia it can be clearly seen that this subject is very important. In this study, we survey the “state-of-the-art” in analysis of EEG and TCD brain parameters changing with temperature and present further research opportunities.

Farklı Sıcaklık Kontrol Sistemlerinin Termoelektrik Tıp Kitinin Performansına Etkisi

Kan, asi, serum, ilac v.b. tibbi maddelerin bozulmadan saklanabilmesi icin belirli sicaklik kosullarinda tutulmasi gerekmektedir. Bu amaca yonelik olarak gelistirilmis olan Tasinabilir Termoelektrik Tip Kiti hem birey hem de toplum sagligi acisindan buyuk onem tasimaktadir. Dunya Saglik Orgutu (WHO) tarafindan belirlenen standartlara gore kanin depolanma sicakligi 2oC ile 10oC arasinda olmalidir. Bu calismada, bu standartlara uygun olarak isitma ve sogutma yapabilen Mikrodenetleyici Kontrollu Tasinabilir Termoelektrik Tip Kiti cihazinin elektronik kontrol devreleri gelistirilmistir. Cihazin ic sicaklik kontrolu iki farkli yontemle yapilmis ve kontrol sonuclari karsilastirilmistir. Birinci yontemde analog sensorlu, ikinci yontemde ise dijital sensorlu devre kullanilarak cihazin sicaklik kontrolu gerceklestirilmistir. Karsilastirma sonuclarina gore, Dijital Sicaklik Sensorlu Kontrol Sistemi (DSSKS) ile yapilan sogutma ve isitma isleminin daha fazla enerji tasarrufu sagladigi gorulmustur.