Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted...Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.展开更多
Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy(HE) by elucidating the regularity an...Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy(HE) by elucidating the regularity and mechanism,as well as its influence on prognosis.Methods:327 HE patients admitted to our hospital from January 1990 to June 2010 were enrolled.Meanwhile 316 patients hospitalized in the medical department of the same hospital were chosen as the control group.Patients in both groups were given the same methods to measure arterial blood gas parameters(pH value,PaCO2,[HCO3-],TCO2,BE and SaO2),blood biochemistry([Na+],[K+],[Cl-]),liver function,kidney function and blood glucose,serum sodium,and thereupon tocalculate the anion gap(AG) and the potential [HCO3-],and acid-base balance disorder.Results:Among the 327 HE patients,hyponatremia was found in 188 cases(57.4%),of whom 132 patients died(70.2%).While among the 316 patients in control group,68 presented with hyponatremia(21.5%),and 19 died(27.9%).The incidence and mortality were significantly different between the two groups(P<0.001).All the 327 patients presented with different degrees of acid-base balance disorder and 178 died(54.4%),in whom 164(50.2%) belonged to simple acid-base balance disorder and 74(45.1%) died,136(41.6%) were dual acid-base balance disorder and 80(58.8%) died,27(8.2%) were triple acid-base disturbance and 24(88.9%) died.Whereas in the control group only 83 patients(26.2%) were recognized as simple and dual acid-base balance disorder,and 18(21.7%) died.There was higher incidence of acid-base balance disorder and mortality rate in HE group than control one(P<0.001).Conclusion:Hyponatremia is valuable to judge HE patients' prognosis.The key parameters in the judgment and evaluation on acid-base balance disorder among HE patients are the change of pH values and serum electrolyte values.When pH value ≤ 7.30 or > 7.55,it generally suggests a poor prognosis.展开更多
In order to diagnose accurately the type of acid梑ase disturbance (ABD) in patients with post梩raumatic multiple organ failure (PMOF), arterial blood gases and electrolytes were determined 645 times on 112 patients wi...In order to diagnose accurately the type of acid梑ase disturbance (ABD) in patients with post梩raumatic multiple organ failure (PMOF), arterial blood gases and electrolytes were determined 645 times on 112 patients with PMOF and the data were analyzed with the pre-estimated compensatory formula of ABD and the calculations of anion gap, potential bicarbonate, and blood chlorides. Simple ABD was found in 381 times of determinations and double ABD in 239 when only the formula was used in the analysis, while 264 times of simple ABD, 260 times of double ABD and 96 times of triple ABD were found when the formula was employed in combination with the calculations of anion gap, potential bicarbonate and blood chloride. The mixed types of ABD were increased by 49% (117 times) from 239 to 356 times and triple ABD was increased from 0 to 96 times. The findings indicate that the employment of the combined formula and the calculations of anion gap, potential bicarbonate and blood chloride is of great significance to assess ABD especially its mixed and complicate types in patients with PMOF. It is emphasized that along with the monitoring of blood gases, the determination of blood electrolytes and the calculation of anion gap and potential bicarbonate should be performed to determine the correct type of ABD.展开更多
目的 提出酸碱失衡的简易判断方法及代偿公式的编制。方法 选择动脉血气指标 PH、Pa CO2 和HCO3-三项指标 ,以 Pa CO2 × 0 .6和 HCO3-的正常低高值 2 1～ 2 7作为酸碱平衡共同中性区 ,并以 Pa CO2 和HCO3- 为对象 ,编制酸碱失衡...目的 提出酸碱失衡的简易判断方法及代偿公式的编制。方法 选择动脉血气指标 PH、Pa CO2 和HCO3-三项指标 ,以 Pa CO2 × 0 .6和 HCO3-的正常低高值 2 1～ 2 7作为酸碱平衡共同中性区 ,并以 Pa CO2 和HCO3- 为对象 ,编制酸碱失衡预计代偿公式 ,为单纯、复杂酸硷失衡的判断提供依据。结果 对大量临床病例及国内文献病例采用改进后的方法判断酸碱失衡 ,证实判断准确。结论 改进后的方法可准确判断酸碱失衡 ,易于掌握。展开更多
基金supported in part by the National Program on Key Basic Research Project 973 Program under Grant 2013CB733103the Program for New Century Excellent Talents in University under Grand NCET-10-0058
文摘Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.
文摘Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy(HE) by elucidating the regularity and mechanism,as well as its influence on prognosis.Methods:327 HE patients admitted to our hospital from January 1990 to June 2010 were enrolled.Meanwhile 316 patients hospitalized in the medical department of the same hospital were chosen as the control group.Patients in both groups were given the same methods to measure arterial blood gas parameters(pH value,PaCO2,[HCO3-],TCO2,BE and SaO2),blood biochemistry([Na+],[K+],[Cl-]),liver function,kidney function and blood glucose,serum sodium,and thereupon tocalculate the anion gap(AG) and the potential [HCO3-],and acid-base balance disorder.Results:Among the 327 HE patients,hyponatremia was found in 188 cases(57.4%),of whom 132 patients died(70.2%).While among the 316 patients in control group,68 presented with hyponatremia(21.5%),and 19 died(27.9%).The incidence and mortality were significantly different between the two groups(P<0.001).All the 327 patients presented with different degrees of acid-base balance disorder and 178 died(54.4%),in whom 164(50.2%) belonged to simple acid-base balance disorder and 74(45.1%) died,136(41.6%) were dual acid-base balance disorder and 80(58.8%) died,27(8.2%) were triple acid-base disturbance and 24(88.9%) died.Whereas in the control group only 83 patients(26.2%) were recognized as simple and dual acid-base balance disorder,and 18(21.7%) died.There was higher incidence of acid-base balance disorder and mortality rate in HE group than control one(P<0.001).Conclusion:Hyponatremia is valuable to judge HE patients' prognosis.The key parameters in the judgment and evaluation on acid-base balance disorder among HE patients are the change of pH values and serum electrolyte values.When pH value ≤ 7.30 or > 7.55,it generally suggests a poor prognosis.
文摘In order to diagnose accurately the type of acid梑ase disturbance (ABD) in patients with post梩raumatic multiple organ failure (PMOF), arterial blood gases and electrolytes were determined 645 times on 112 patients with PMOF and the data were analyzed with the pre-estimated compensatory formula of ABD and the calculations of anion gap, potential bicarbonate, and blood chlorides. Simple ABD was found in 381 times of determinations and double ABD in 239 when only the formula was used in the analysis, while 264 times of simple ABD, 260 times of double ABD and 96 times of triple ABD were found when the formula was employed in combination with the calculations of anion gap, potential bicarbonate and blood chloride. The mixed types of ABD were increased by 49% (117 times) from 239 to 356 times and triple ABD was increased from 0 to 96 times. The findings indicate that the employment of the combined formula and the calculations of anion gap, potential bicarbonate and blood chloride is of great significance to assess ABD especially its mixed and complicate types in patients with PMOF. It is emphasized that along with the monitoring of blood gases, the determination of blood electrolytes and the calculation of anion gap and potential bicarbonate should be performed to determine the correct type of ABD.
