CHARACTERISTICS OF LIP-MOUTH REGION IN SMILING POSITION FROM 80 PERSONS WITH ACCEPTABLE FACES AND INDIVIDUAL NORMAL OCCLUSIONS

OBJECTIVE: The characteristics of lip-mouth region including the soft and hard tissues in smiling position with frontal fixed position photographic computer-aided analysis were studied. METHODS: The subjects were 80 persons (40 male and 40 females, age range: 17 to approximately 25 years) with acceptable faces and individual normal occlusions. The subjects were asked to take maximum smiling position to accept photographic measurement with computer-aided analysis. RESULTS: The maximum smile line could be divided into 3 categories: low smile line (16.25%), average smile line (68.75%), and high smile line (15%). CONCLUSION: The method adopting maximum smiling position to study the lip-month region is reproducible and comparable. This study would be helpful to provide a quantitative reference for clinical investigation, diagnosis, treatment and efficacy appraisal.

Reference satellite selection method for GNSS high-precision relative positioning

Selecting the optimal reference satellite is an important component of high-precision relat/ve positioning because the reference satellite directly influences the strength of the normal equation. The reference satellite selection methods based on elevation and positional dilution of precision （PDOP） value were compared. Results show that all the above methods cannot select the optimal reference satellite. We introduce condition number of the design matrix in the reference satellite selection method to improve structure of the normal equation, because condition number can indicate the ill condition of the normal equation. The experimental results show that the new method can improve positioning accuracy and reliability in precise relative positioning.

A Suitable Active Control for Suppression the Vibrations of a Cantilever Beam

In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out.Those four types are the linear velocity feedback control,the cubic velocity feedback control,the non-linear saturation controller(NSC)and the positive position feedback(PPF)controller.The suitable type is the PPF controller for suppression the vibrations of the cantilever beam.The approximate solution obtained up to the first approximation by using the multiple scale method.The PPF controller effectiveness is studied on the system.We used frequency-response equations to investigate the stability of a cantilever beam.We notified that,there is a good agreement between the analytical solution and the numerical solution.

Effects of extrinsic positive end-expiratory pressure on cardiopulmonary function in patients with chronic obstructive pulmonary disease

Objective To choose one optimal extrinsic positive end-expiratory pressure (PEEPe) for ventilated patients with chronic obstructive pulmonary disease (COPD) and to compare two methods for choosing the optimal level of PEEPe.Methods Ten ventilated patients with COPD were included in the study. First, static intrinsic positive end-expiratory pressure (PEEPi,st) was measured when PEEPe was zero, and the PEEPi,st was called PEEPi,stz. PEEPe at 0%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of PEEPi,stz, respectively, were applied randomly. Respiratory mechanics, hemodynamics, and oxygen dynamics were recorded 30 minutes after the level of PEEPe was changed.Results When PEEPe was not higher than 80% of PEEPi,stz, no measurement changed significantly. When PEEPe was increased to 90% and 100% of PEEPi,stz, PEEPi,st, peak inspiratory pressure, plateau pressure, pulmonary capillary wedge pressure and central venous pressure increased significantly, P<0.01. Cardiac output and left ventricular work index decreased significantly, P<0.01. Oxygen delivery decreased significantly, P<0.05. When PEEPe was increased to 100% of PEEPi,stz, the right ventricular work index decreased significantly, P<0.05.Conclusion Eighty percent of PEEPi,stz was the upper limit of PEEPe. The results of the two methods used to set the level of PEEPe were identical.

Pulmonary infection control window in treatment of severe respiratory failure of chronic obstructive pulmonary diseases: a prospective, randomized controlled, multi-centred study

Background Early withdraw from invasive mechanical ventilation （MV） followed by noninvasive MV is a new strategy for changing modes of treatment. This study was conducted to estimate the feasibility and the efficacy of early extubation and sequential noninvasive MV commenced at beginning of pulmonary infection control window in patients with exacerbated hypercapnic respiratory failure caused by chronic obstructive pulmonary diseases （ C OPD ）. Methods A prospective, randomized controlled study was conducted in eleven teaching hospitals＇ respiratory or medical intensive care units in China. Ninety intubated COPD patients with severe hypercapnic respiratory failure triggered by pulmonary infection （pneumonia or purulent bronchitis） were involved in the study. When the pulmonary infection had been controlled by antibiotics and comprehensive therapy, the “pulmonary infection control window （PIC window）” has been reached. Each case was randomly assigned to study group （extubation and noninvasive MV via facial mask immediately） or control group （ invasive MV was received continuously after PIC window by using conventional weaning technique）. Results Study group （n = 47 ） and control group （n = 43 ） had similar clinical characteristics initially and at the time of PIC window. Compared with control group, study group had shorter duration of invasive MV [ （6. 4±4. 4） days vs （ 11.3±6. 2） days, P =0. 0001, lower rate of ventilator associated pneumonia （VAP） （3/47 vs 12/43, P=0.014）, fewer days in ICU [（12 ＋8） days vs 16 ＋ 11） days, P =0.047] and lower hospital mortality （ 1/47 vs 7/43, P =0. 025）. Conclusions In COPD patients requiring intubation and lnvasive MV for hypercapnic respiratory failure, which is exacerbated by pulmonary infection, early extubation followed by noninvasive MV initiated at the start of PIC window may decrease significantly the duration of invasive MV, the risk of VAP and hospital mortality.