In this paper, we introduce a passive mobile robot called PRP (Passive Robot Porter) to realize transportation of an object in cooperation with human, which is developed based on a concept of passive robotics. PRP consists of three omni-directional wheels with servo brakes and a controller. It can manipulate an object by controlling an external force/moment applied by a human based on the control of the servo brakes. We consider the characteristics of the servo brakes and control the brake torque of each wheel based on the brake force/moment constraint so that several motion functions of PRP are realized based on the applied force. This allows PRP to track a path which includes motion perpendicular to the pushing direction of the human without using servo motors. The impedance-based motion control is also realized with respect to the perpendicular to the pushing direction. These functions are implemented on PRP experimentally, and the experimental results illustrate the validity of PRP and its control method.

No abstract

No abstract

ObjectiveThis study aimed to determine the risk factors and establish a risk score for post‐transjugular intrahepatic portosystemic shunt (TIPS) overt hepatic encephalopathy (OHE).MethodsAltogether 299 and 62 cirrhotic patients receiving TIPS from January 2015 to March 2018 were divided into the derivation and validation cohorts, respectively. The data of the derivation cohort were analyzed for risk factors of post‐TIPS OHE. A risk score was established from the derivation cohort and verified by the validation cohort.ResultsDuring a median follow‐up of 112.6 weeks, 52 (17.4%) patients in the derivation cohort experienced post‐TIPS OHE. Logistic regression showed that alcoholic cirrhosis (odds ratio [OR] 3.068, 95% confidence interval [CI] 1.423‐6.613, P = 0.004), stent diameter of 10 mm (OR 12.046 [95% CI 2.308‐62.862], P = 0.003), portal pressure gradient (PPG) decrement ≥60% (OR 3.548 [95% CI 1.741‐7.230], P < 0.001), model for end‐stage liver disease (MELD) score ≥10 (OR 2.695 [95% CI 1.203‐6.035], P = 0.016), blood ammonia (OR 1.009 [95% CI 1.000‐1.018], P = 0.043) and notable hydrothorax (OR 4.393 [95% CI 1.554‐12.415], P = 0.005) were associated with an increased risk of post‐TIPS OHE. The risk score reached a promising risk evaluation of post‐TIPS OHE when verified by the validation cohort (sensitivity 71.4%, specificity 70.7%, accuracy 71.0%).ConclusionsAlcoholic cirrhosis and notable hydrothorax are independent risk factors for post‐TIPS OHE in liver cirrhosis, together with the stent diameter of 10 mm, PPG decrement ≥60%, MELD score ≥10 and blood ammonia. The established risk score is reliable to identify high‐risk individuals of developing post‐TIPS OHE.

No abstract