Design and Manufacture of a Micro-Ejector and the Testing Stand for Investigation of Micro-Ejector Refrigeration Systems.

This paper describes the procedure of design and manufacture of a micro-ejector proposed for miniature ejection refrigeration systems. It describes the procedure of design, fabrication, and experimentation on supersonic micro-ejectors and makes the case for isobutane as a working fluid for such systems. It was demonstrated that it is possible to design and fabricate a micro-ejector with a cooling capacity of approximately 3 W. The discussed micro-ejector was driven by a heat source with temperature below 60 °C. The evaporation temperature was approximately 15 °C. For these operating parameters, the reported entrainment ratio was approximately 0.20. The difficulties in fabricating the micro-ejector due to its small dimensions are discussed in the paper. Additionally, the potential difficulties and solutions related to ensuring and maintaining stable operation of the testing stand are presented. The performance of the proposed system is demonstrated and discussed, including relations between mass entrainment ratio, compression ratio, cooling capacity, and temperature.

Initial study on an expert system for spine diseases screening using inertial measurement unit.

In recent times, widely understood spine diseases have advanced to one of the most urgetn problems where quick diagnosis and treatment are needed. To diagnose its specifics (e.g. to decide whether this is a scoliosis or sagittal imbalance) and assess its extend, various kind of imaging diagnostic methods (such as X-Ray, CT, MRI scan or ST) are used. However, despite their common use, some may be regarded as (to a level) invasive methods and there are cases where there are contraindications to using them. Besides, which is even more of a problem, these are very expensive methods and whilst their use for pure diagnostic purposes is absolutely valid, then due to their cost, they cannot rather be considered as tools which would be equally valid for bad posture screening programs purposes. This paper provides an initial evaluation of the alternative approach to the spine diseases diagnostic/screening using inertial measurement unit and we propose policy-based computing as the core for the inference systems. Although the methodology presented herein is potentially applicable to a variety of spine diseases, in the nearest future we will focus specifically on sagittal imbalance detection.

Deterioration After Mild Traumatic Brain Injury: A Single-Center Experience With Cost Analysis.

Background: Most traumatic brain injuries (TBIs) are mild (GCS score of 13-15). Patients with mild TBI (mTBI) are generally in good condition. In some cases, a neurological deterioration (manifested by a drop of ≥1 point in GCS score) can occur and neurosurgical intervention (NI) may be needed. Because of that, these patients are frequently admitted to a hospital for observation. The aim of our study was to determine the number of patients with mTBI that deteriorate or need NI. We also considered an economic aspect of hospital admissions of these patients. Methods: The study group consisted of 186 adult patients admitted to the neurosurgical department due to mTBI. Patients were divided into three groups according to an initial GCS score. The occurrence of deterioration, need for NI, length of stay (LOS), cost of stay and occurrence of death were analyzed. Results: The deterioration was observed in 7 (3.76%) out of all cases. In 3 (1.61%) of them, the NI was needed. The average LOS was 7.96 days and it was closely linked with an initial GCS score (p < 0.001). The total cost of stay of all patients included in this study was about 1,188,668 PLN (306,357 USD). Conclusion: The deterioration occurred in a small number of patients with mTBI, the need for NI was even less common. Hospitalization of these patients is expensive. Further studies with prognostic model helping decide on admission/discharge are necessary.

Diagnostic Challenges and Surgical Strategies in Ossification of the Posterior Longitudinal Ligament. Case Study.

This article presents the case of a female patient suffering from cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) which was undiagnosed for a number of years. Besides presenting the clinical case, we describe the pathophysiology, symptoms, diagnostic methods and treatment options related to this condition, which is unusual in the European population.

[Psychometric and neurophysiological assessment of cognitive functions in patients with epilepsy].

BACKGROUND: The aim of the study was to assess cognitive functions in patients with epilepsy using the neurophysiological method and psychological tests, and analysis the relationship between clinical features of the disease and test results. MATERIAL AND METHODS: The study included 31 patients with epilepsy aged 37.3±18.4 years. The control group consisted of 40 healthy volunteers aged 33.5±12.2 years. Cognitive functions were assessed using endogenous evoked potential P300 and psychological tests - Mini-Mental State Examination (MMSE), three subtests of Wechsler Adult Intelligence Scale-Revised (WAIS-R), Trail Making Test (TMT), Benton Visual Retention Test (BVRT) and State-Trait Anxiety Inventory (STAI). RESULTS: Epileptic patients achieved significantly lower scores in all, except STAI-1, psychological tests in relation to the controls. A correlation between age and TMT-A (p<0.050) and BVRT (p<0.050) was observed. The disease duration affected results of MMSE (p<0.050), TMT-B (p<0.050) and BVRT (p<0.050). Type of seizures was related to results of MMSE (p=0.005), type of therapy - to results of STAI-1 (p=0.014) and TMT-B (p=0.008). The average latency of P300 was significantly prolonged (p=0.00003) in epileptic patients (348±38ms) in relation to the controls (324±26ms). The relationship between P300 and the duration of seizures (p=0.017) was observed. There was no correlation between P300 and age, sex, frequency and type of seizures and therapy. A correlation between P300 and TMT-B (p<0.050), BVRT-LPO(p<0.050) and STAI-1 (p<0.050) was noticed. CONCLUSION: In epileptic patients cognitive impairment is often found. It is advisable to perform regular neuropsychological testing; P300 can be used only as a preliminary assessment.