Design and Research of Wearable Fall Protection Device for the Elderly / 中国医疗器械杂志

A protective device was designed that can be worn on the elderly, which consists of protective airbag, control box and protective mechanism. The combined acceleration, combined angular velocity and human posture angle are selected as the parameters to determine the fall, and the threshold algorithm and SVM algorithm are used to detect the fall. The protective mechanism is an inflatable device based on CO2 compressed air cylinder, and the equal-width cam structure is applied to its transmission part to improve the puncture efficiency of the compressed gas cylinder. A fall experiment was designed to obtain the combined acceleration and angular velocity eigenvalues of fall actions (forward fall, backward fall and lateral fall) and daily activities (sitting-standing, walking, jogging and walking up and down stairs), showing that the specificity and sensitivity of the protection module reached 92.1% and 84.4% respectively, which verified the feasibility of the fall protection device.

Research progress of mechanical power in ventilator-induced lung injury / 国际生物医学工程杂志

ICU acute respiratory distress syndrome has a high morbidity and mortality rate, and these patients usually need mechanical ventilation to maintain their respiratory function during treatment. However, improper setting of mechanical ventilation parameters may lead to ventilator-induced lung injury (VILI). In order to effectively prevent the occurrence of VILI, ARDSnet recommends the use of a protective ventilation strategy with low tidal volume and limited airway plateau pressure. However, from the perspective of ventilator energy transfer, VILI is actually the result of a combination of respiratory parameters such as tidal volume, airway pressure, and respiratory rate. The mechanical power well reflects the combined effect of the above parameters and is increasingly becoming a hot topic in clinical research. In this review paper, the definitions of mechanical energy and mechanical power were introduced, and the calculation methods of mechanical power under different respiratory modes are summarized. Moreover, the clinical studies related to mechanical power and VILI and further exploration of the safety threshold of mechanical power are reviewed. It is expected to provide new ideas for the future clinical development of personalized mechanical ventilation strategies and the effective prevention of VILI.

Clinical Significance and Method of Measuring Lung Fluid Viscosity and Surface Tension / 医用生物力学

Pulmonary fluid refers to a thin and continuous liquid layer mainly consisting of airway mucus and lining liquid on the inner surface of alveoli, which is essential for maintaining a healthy lung. The clinical significance of rheological properties of pulmonary fluid in airway stability, pulmonary barrier and clearance functions, ventilator induced lung injury and surfactant replacement therapy in infant respiratory distress syndrome was introduced in this paper. Furthermore, a variety of classical methods for measuring surface tension and liquid viscosity, such as Langmuir-Wilhelmy balance, captive bubble method, glass capillary viscometer and rotational viscometer, and emerging techniques (e.g. particle tracking microrheometer and axisymmetric drop shape analysis) were reviewed, and their advantages and drawbacks were also compared, in order to provide an important reference for the assisted diagnosis and treatment of lung diseases in clinical practice.

The study of simulation system for cardiopulmonary bypass cardiac surgery / 中国医疗器械杂志

According to the clinical requirements of cardiopulmonary bypass surgery, this paper established a simulation system for cardiac surgery which consists of venous reservoir, variable balance chamber, blood suction bag, ventricle suction bag, resistance valves, pressure gauges and tubings. Using the proposed system, perfusionists can mimic the implementation of pre-established surgery strategy, predict various abnormal conditions in the operation, and accordingly take the urgent actions so as to improve the success rate of surgery and to ensure the safety of patients.

Control and testing methods for blood bump in heart assistant and replacement devices / 中国医疗器械杂志

Using extracorporeal circulation for cardiopulmonary bypass is the first step for the successful cardiac surgery, and the blood pump is the key component in extracorporeal circulation devices, the control and measurement of mechanical-fluid parameters such as flow rate and pressure are very important to guarantee the successful cardiac surgery. This paper reviews several control methods of the blood pump based on the flow rate/pressure, heart rate, ventricular work and blood assist index, and also discusses the direct and indirect measurements of the flow rate and pressure. This review concludes with the main possible trends for the further development of the blood pump control and testing methods.

Magnetic field numerical calculation and analysis for magnetic coupling of centrifugal blood pump for extracorporeal circulation / 生物医学工程学杂志

This paper mainly studies the driving system of centrifugal blood pump for extracorporeal circulation, with the core being disc magnetic coupling. Structure parameters of disc magnetic coupling are related to the ability of transferring magnetic torque. Therefore, it is necessary to carry out disc magnetic coupling permanent magnet pole number (n), air gap length (L(g)), permanent magnet thickness (L(m)), permanent magnet body inside diameter (R(i)) and outside diameter (R(o)), etc. thoroughly. This paper adopts the three-dimensional static magnetic field edge element method of Ansys for numerical calculation, and analyses the relations of magnetic coupling each parameter to transmission magnetic torque. It provides a good theory basis and calculation method for further optimization of the disc magnetic coupling.

Study on optimal selection of structure of vaneless centrifugal blood pump with constraints on blood perfusion and on blood damage indexes / 生物医学工程学杂志

This paper is aimed to study the optimal selection of structure of vaneless centrifugal blood pump. The optimal objective is determined according to requirements of clinical use. Possible schemes are generally worked out based on structural feature of vaneless centrifugal blood pump. The optimal structure is selected from possible schemes with constraints on blood perfusion and blood damage indexes. Using an optimal selection method one can find the optimum structure scheme from possible schemes effectively. The results of numerical simulation of optimal blood pump showed that the method of constraints of blood perfusion and blood damage is competent for the requirements of selection of the optimal blood pumps.

Development and New Technology of Sleep Non-invasive Ventilator / 医疗卫生装备

Sleep apnea syndrome(SAS) and its harm to the health are briefly introduced,the review on history and classification of sleep non-invasive ventilator is presented,and therapy mechanism of CPAP on SAS is described.Furthermore,the specifications of three popular CPAP in the market are compared and some new technologies of CPAP are discussed.