ABSTRACT
Hyperglycemia is a common complication of critical patients. Currently, clinical assessment of the changes in the blood glucose of critical patients is mainly based on the intermittent monitoring of peripheral blood glucose at a certain time point. This method cannot get the true blood glucose fluctuation, and it is more difficult to find asymptomatic hyperglycemia and hypoglycemia, so the guiding value of blood glucose control is limited. Arterial blood is the most accurate sample of blood glucose monitoring, so it is urgent to ensure the accuracy of arterial blood sample. A continuous arterial blood glucose monitoring equipment was independently developed by general surgical intensive care unit (ICU) of the First Affiliated Hospital of Nanjing Medical University, and National Utility Model Patent of China was obtained. It could greatly improve the efficiency of medical staff, and provide accurate and dynamic statistic data that would be an important basis for doctors' clinical decision-making. The continuous arterial blood glucose monitoring equipment was mainly composed of arterial pressure measuring monitor, program-controlled dynamic blood glucose meter, wire, electric switch, integrated collecting syringe, electric clip, rotary electric bracket, and blood glucose test strips, etc., which could be continuously and dynamically monitor patient blood glucose levels and perform various additional value-added functions such as automatic recording and alarming.
ABSTRACT
Objective To develop a cellular shear stress loading system with an adjustable stress mode and relevant parameters, and subsequently verify the effectiveness and feasibility of this system. Methods The hardware of the system was developed by using a peristaltic pump and self-designed multi-channel flow chamber, and the mode control program of shear stress based on LabVIEW was designed to control the device via RS485 interfacing and Modbus protocol. Additionally, the relationship between the shear stress and system parameters was calibrated, and finite element analysis was also conducted. Finally, the feasibility of the system was confirmed via the in vitro cell experiment. Results The mode and magnitude of shear stress of the system could be controlled via either the peristaltic pump or computer, and the cellular long-term effect was also able to be detected. The calibration results of the system indicated that the level of shear stress exhibited significantly linear positive correlation with the revolution of the peristaltic pump (P<0.001). Finite element analysis demonstrated that the level of shear stress on the slide was uniformly distributed and the result of simulation was accordant with calibration. Cytoskeleton staining suggested that cellular morphology of MLO-Y4 cells was changed, and microfilament increased and arrayed along fluid flow direction. Conclusion The system is stable and reliable enough to provide different loading modes and magnitude of cellular shear stress to offer a convictive platform of the research for different cellular stress signal transduction mecha-nisms.