BACKGROUND: Spatial disorientation (SD) is a problem that pilots often encounter during a flight. One reason for this problem is that among the three types of SD, there is no validated method to detect the Type I (unrecognized) SD. OBJECTIVE: In this pursuit, initially we reviewed the problems and the evaluation methods of associated with SD. Subsequently, we discussed the advantages and disadvantages of the subjective questionnaire evaluation method and the behavior evaluation method. METHODS: On the basis of these analyses, we proposed a method to detect the unrecognized SD that improved the assessment of SD to a significant extent. We developed a new direction to study the unrecognized SD based on the subjective report and the center of pressure (CoP). RESULTS: The proposed evaluation method can assist the pilots to understand the feelings and physical changes, when exposed to unrecognized SD. CONCLUSION: We hope that this evaluation method can provide a strong support in developing a countermeasure against the unrecognized SD and fundamentally solve the severe flight accidents arising due to them.

Spatial disorientation (SD) is the pilot's wrong judgment of flight altitude, position, and motion in three-dimensional space during flight. SD is among the significant causes of flight accidents that seriously affect flight safety. Unrecognized SD causes most of these accidents. In this study, we analyzed the mechanism of unrecognized SD based on the brain's perceptual process. According to the process of sensation and perception, we put forth a new hypothesis of a classification method for unrecognized SD: unrecognized SD might be subdivided into insensate SD, unperceived SD, and perceived SD. There might be some meaningful differences in brain activity in EEG signals or fMRI between unperceived SD and perceived SD. The classification method in this study was proposed based on some related research reports and provided new ideas and methods for scholars to study unrecognized SD. If the hypothesis can be proved, it will provide a basis for scholars learning the mechanism of unrecognized SD and subsequently putting forward countermeasures in SD training. Moreover, as a consequence, the subdivision will contribute to pilot selection, and some specialized SD training for countermeasures could be put forward to reduce aircraft accidents.

Abstract. Unrecognized spatial disorientation (SD) which is intimately linked with brain cognitive function is always a fatal issue for the safety of pilots. To explore its effects on human brain cognitive functions, electroencephalography (EEG) functional network analysis methods were adopted to examine topological changes in the connection of cognitive regions when experiencing unrecognized SD. Twelve male pilots participated in the study. They were subjected to a SD scene, namely visual rotation, which evoked unrecognized SD. For the main EEG frequency intervals, the phase lag index (PLI) and normalized mutual information (NMI) were calculated to quantify the EEG data. Then weighted connectivity networks were constructed and their properties were characterized in terms of an average clustering coefficient and global efficiency. A T-test was performed to compare PLI, NMI and network measures under unrecognized SD and non-SD conditions. It indicated a weak functional connectivity level in the theta band under unrecognized SD based on the significant decrease of mean values of PLI and NMI (p<0.05). Meanwhile, both the average clustering coefficient and global efficiency in the theta band reduced under the unrecognized SD condition. The decrease of the average clustering coefficient and global efficiency demonstrates a lack of small-world characteristics and a decline in processing efficiency of brain cognitive regions. All the experimental results show that unrecognized SD may have a negative effect on brain functional networks in the theta band. S1115With the development of aviation and space technology, astronauts and pilots are being sent into space on board various aircrafts and planes. Meanwhile, a series of problems is emerging, and spatial disorientation (SD) is one of these problems that have to be studied. During flight, three sensory systems named visual, vestibular and proprioceptive system often send conflicting information to the brain, and then three types of SD may happen, namely recognized SD, unrecognized SD and incapacitating SD [1]. SD often causes flying accidents, and statistics show that from 5% to 10% of all aviation accidents can be attributed to SD, while 90% of these accidents are fatal [2]. One thing to note is that accidents caused by unrecognized SD account for 80% of the total caused by SD [3]. The brain is considered to be a complex system, comprising spatially interconnected areas [4]. Similar with the connectivity of complex network, the structural and functional brain network possesses the small-world properties found by Watts and Strogatz [5]. It has been suggested that small-world properties support rapid adaptive reconfiguration of functional connectivity in response to varying cognitive demands [6] when listening to music [4] and learning [7]. Also many researches indicate that network measures show a great change in neurological diseases like Alzheimer's [8] and schizophrenia [9]. These findings indicate that the brain functional network has a dynamic feature according to...

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BACKGROUND: The results of urine tests are often affected by improper midstream urine collection time, urine spilling, and urine pollution, all of which can lead to an increase in the test error. OBJECTIVE: To solve this problem, aiming at improving the toilet environment at the hospitals and public physical examination centers, this paper designs an automatic urine collection system. It can automatically adjust the position of the urine cup with an infrared remote controller, or manually, adjust the position of the urine cup in special situations according to the needs of the user. It also, has an alarm function. METHODS: The overall size and shape are designed based on the squatting pan, suitable for disposable plastic urine cups of different shapes and sizes. It can realize the automatic collection of midstream urine, manual collection in exceptional cases, emergency stops, and rescue calls. RESULTS: Through the trial survey, there was a significant difference between the statistical results of using the device and not using the device (t= 13.937, P= 0.000). 96% of the subjects thought that the design of the system was reasonable, 22% thought that it was inconvenient to use, and 91.7% of the medical staff thought that the system met the sampling requirements. CONCLUSIONS: Therefore, the trial evaluation is satisfactory, and the proposed collection system is suitable for use in hospitals at all levels and public health examination centers with a large amount of inspection.