Research Of Manipulator For Nonimvasive Positive Pressure Ventilation

Compared to conventional ventilation methods, noninvasive positive pressureventilation has no trauma, little pain, results in little chance of complications and shorterrecovery cycle. Clinical studies have found that noninvasive positive pressureventilation using masks adapts to a part of patients who are in general anesthesia. Butduring the operation, doctors need to hold the patients’ head for a long time, whichrequires a lot of physical labor and easily leads to instability ventilation, thus limitingthe use of mask ventilation. Therefore it is necessary to design a mechanical arm, usingto assist physicians to fix patients’ head, so that the patients can use the mask fornoninvasive ventilation. For this paramedic mechanical arms, has not yet appearedrelated researches, which adds to the urgency of this study.Based on the requests of the Fourth Affiliated Hospital of Harbin MedicalUniversity, the author research on the status of the airway during anesthesia care as wellas several active and passive medical manipulator at home and abroad, the author designa set of passive mechanical arm on this basis, used to assist physicians in patients withmask ventilation. The robot arm has3+1degrees of freedom, passive control and thejoint can be locked quickly and safely.The author completes the design of arm’s overall program, the mechanicalstructure and the way of each joint locking firstly. Through the configuration of theintegrated, the author determines the mechanical arm’s configuration for tandemthree-DOF. Under the existing domestic and international joint locking mode, andultimately determine the first joint locking means for the electric lock, electromagneticlock the remaining three joints. In accordance with the arm’s workspace, the authorcompletes the arm’s scale integrated and length optimization. And the author conducts aclever design for the first joint’s electric locking mechanism and completes componentsselection of all joints. The author also designs the whole mechanical structure of the armin detail and optimizes the key components and checks their strength.The author completes the optimization of the locking means for the first joint. Theauthor deduces the relationship between the clutch block’s wear and tear and frictionsurface contact area by analyzing the Hertz contact theory and the theory of friction,which can be used as the friction surface’s theoretical optimization goals. According tothe optimization goal the author optimize the frictional surface slope by using theknowledge of mechanics of materials and elasticity.And the author establishes thedimensional model of the contact friction surfaces in Workbench and completes thefinite element simulation. Then the author deduces the tightening torque derivation forthe formula locking model and extracts a number of points’ friction stress value on thecontact surface and calculates the locking torque. Finally, the designs the control system for the mechanical arm and takes somerelated experiments. According to the needs, the author determines the control way ofwireless remote locking and completes the design and selection of the control unit. Ahigh-power driver drives three electromagnetic clutches and the locking force of thefirst joint is adjustable. The author verifies that the mechanical arm can complete thedesigned features by experiments, which concludes locking force experiments, lockinglevel calibration and clinical applications experiments.