Trajectory Deformations from Physical Human-Robot Interaction

Robots are finding new applications where physical interaction with a human is necessary: manufacturing, healthcare, and social tasks. Accordingly, the field of physical human-robot interaction (pHRI) has leveraged impedance control approaches, which support compliant interactions between human and robot. However, a limitation of traditional impedance control is that---despite provisions for the human to modify the robot's current trajectory---the human cannot affect the robot's future desired trajectory through pHRI. In this paper, we present an algorithm for physically interactive trajectory deformations which, when combined with impedance control, allows the human to modulate both the actual and desired trajectories of the robot. Unlike related works, our method explicitly deforms the future desired trajectory based on forces applied during pHRI, but does not require constant human guidance. We present our approach and verify that this method is compatible with traditional impedance control. Next, we use constrained optimization to derive the deformation shape. Finally, we describe an algorithm for real time implementation, and perform simulations to test the arbitration parameters. Experimental results demonstrate reduction in the human's effort and improvement in the movement quality when compared to pHRI with impedance control alone

The Crunch Continues: Medicaid Spending, Coverage and Policy in the Midst of a Recession

Presents results from a state-by-state Medicaid budget survey for fiscal years 2009 and 2010. Examines the effects of the recession on spending, how states used Medicaid fiscal relief funds from the federal stimulus package, and the outlook for 2011

Low Medicaid Spending Growth Amid Rebounding State Revenues: Results From a 50-State Medicaid Budget Survey State Fiscal Years 2006 and 2007

Examines the implementation of the new Medicare prescription drug benefit and the rate of Medicaid spending growth and enrollment in 2006. Identifies possible state level changes in eligibility requirements, program expansion, and enrollment processes

Attachment style and dietary self-regulation in persons at risk for type II diabetes

Introduction: Attachment theory and Self-Determination Theory were used as explanatory frameworks for understanding diet-related health behaviour for persons identified at risk for type II diabetes. The effect of attachment models of self and others on treatment motivation (autonomous, controlled, and amotivation) was examined. Furthermore, it was predicted that accurate illness perceptions of type II diabetes and ability to regulate emotions would determine autonomous motivation. Method: A sample of 116 volunteer participants (73 female, 43 male) aged between 40 to 65 years (mean age of 51.28 years) completed an online survey. The measures used were the Relationship Questionnaire, the Brief Illness Perception Questionnaire, the Self-Regulation Scale, the Perceived Competence Scale and the Treatment Self-Regulation Questionnaire. Results: Using hierarchical regression, models of self and others were not found to add significantly to the prediction of diet amotivation, autonomous motivation or controlled motivation for diet. Gender was found to be the most significant contributor to the prediction of controlled motivation for diet. Positive models of self (secure attachment) were associated with self-regulation, perceived competence to make dietary changes and lower amotivation. Negative models of self and others (fearful, dismissing attachment) were not related to treatment motivation to make dietary changes. Conclusions: An attachment framework does not appear to be useful in understanding treatment motivation for persons at risk for Type II diabetes. This finding needs to be replicated with other chronic illnesses and has significance for self-management

Aging and Human Hormonal and Pressor Responsiveness to Angiotensin II Infusion With Simultaneous Measurement of Exogenous and Endogenous Angiotensin II

A decline in the function of the renin angiotensin aldosterone system may induce adaptive changes in response to angiotensin II (ANG II) with age. We have examined platelet ANG II receptor density, blood pressure and aldosterone responses to ANG II [Asn1, Val5-ANG II] (Hypertensin, Ciba Geigy, Horsham, Sussex, England) infusion in 8 young, 24 to 30 years, and 8 older, 54 to 65 years, healthy volunteers. To measure circulating ANG II, we established a new method for specific and simultaneous measurement of exogenous [Asn1,Val5] (Hypertensin) and endogenous [Asp1,Ile5] ANG II in plasma by using isocratic HPLC and radioimmunoassays with cross-reacting antibodies and compared results with immunoreactive ANG II which was measured conventionally using monoclonal antibodies. Baseline endogenous ANG II (Asp1,Ile5-ANG II) levels in venous plasma were marginally, but not significantly, lower in the old [mean (95% confidence limits): 3.4 (< 0.1 to 7.7) ν 3.7 (1.2 to 6.2), fmol/ mL] and during suppression by the Hypertensin infusion appeared consistently, but not significantly, lower in the old [0.9 (0 to 3.1) ν 2.1 (0.6 to 3.7), after 3 ng/kg/min], while the same infusion rate in young and old resulted in similar plasma Hypertensin levels. Baseline systolic blood pressure (SBP) was similar in both groups but the percentage increases in SBP at infusion rates of 1, 3.0, and 10 ng/kg/min were greater in the old than in the young (9.1 ν 2.8, Ρ<.05; 16.3 ν 8.0, Ρ<.01; 30.4 ν 14.0%, Ρ<.001, respectively). The increment in diastolic blood pressure or mean arterial pressure during infusion did not differ significantly between the groups. Heart rate fell significantly during ANG II infusion in young (P < .05) but not old subjects. Basal plasma aldosterone was similar in both groups. However, the percentage increases in plasma aldosterone were greater in young than old at infusion rates of 1.0, 3.0, and 10.0 ng/kg/min (94 ν - 5 ; 238 ν 28; 462 ν 69%, all Ρ<.001). Platelet ANG II receptor density was elevated in the old [6.5 (1.9 to 11.1) ν 1.14 (0.21 to 2.07), fmol/109 cells, Ρ<.01]. Our findings demonstrate that it is possible to measure specifically and simultaneously exogenous and endogenous ANG II in plasma during Hypertensin infusion and that endogenous ANG II concentrations decrease with increasing levels of exogenous ANG II. During infusion, similar plasma Hypertensin levels were attained in both young and old, but systolic blood pressure responsiveness was increased in the old, while adrenal responsiveness was reduced. Am J Hypertens 1993;6:641-64