Cognitive vision system for control of dexterous prosthetic hands: Experimental evaluation

<p>Abstract</p> <p>Background</p> <p>Dexterous prosthetic hands that were developed recently, such as SmartHand and i-LIMB, are highly sophisticated; they have individually controllable fingers and the thumb that is able to abduct/adduct. This flexibility allows implementation of many different grasping strategies, but also requires new control algorithms that can exploit the many degrees of freedom available. The current study presents and tests the operation of a new control method for dexterous prosthetic hands.</p> <p>Methods</p> <p>The central component of the proposed method is an autonomous controller comprising a vision system with rule-based reasoning mounted on a dexterous hand (CyberHand). The controller, termed cognitive vision system (CVS), mimics biological control and generates commands for prehension. The CVS was integrated into a hierarchical control structure: 1) the user triggers the system and controls the orientation of the hand; 2) a high-level controller automatically selects the grasp type and size; and 3) an embedded hand controller implements the selected grasp using closed-loop position/force control. The operation of the control system was tested in 13 healthy subjects who used Cyberhand, attached to the forearm, to grasp and transport 18 objects placed at two different distances.</p> <p>Results</p> <p>The system correctly estimated grasp type and size (nine commands in total) in about 84% of the trials. In an additional 6% of the trials, the grasp type and/or size were different from the optimal ones, but they were still good enough for the grasp to be successful. If the control task was simplified by decreasing the number of possible commands, the classification accuracy increased (e.g., 93% for guessing the grasp type only).</p> <p>Conclusions</p> <p>The original outcome of this research is a novel controller empowered by vision and reasoning and capable of high-level analysis (i.e., determining object properties) and autonomous decision making (i.e., selecting the grasp type and size). The automatic control eases the burden from the user and, as a result, the user can concentrate on what he/she does, not on how he/she should do it. The tests showed that the performance of the controller was satisfactory and that the users were able to operate the system with minimal prior training.</p

Elevated expression of polymorphonuclear leukocyte elastase in breast cancer tissue is associated with tamoxifen failure in patients with advanced disease

Besides a variety of other proteases, polymorphonuclear leukocyte elastase (PMN-E) is also suggested to play a role in the processes of tumour cell invasion and metastasis. Yet, there is only limited data available on the relation between the tumour level of PMN-E and prognosis in patients with primary breast cancer, and no published information exists on its relation with the efficacy of response to systemic therapy in patients with advanced breast cancer. In the present study, we have measured with enzyme-linked immunosorbent assay the levels of total PMN-E in cytosolic extracts of 463 primary breast tumours, and have correlated their levels with the rate and duration of response on first-line tamoxifen therapy (387 patients) or chemotherapy (76 patients) in patients with locally advanced and/or distant metastatic breast cancer. Furthermore, the probabilities of progression-free survival and postrelapse survival were studied in relation to the tumour levels of PMN-E. Our results show that in logistic regression analysis for response to tamoxifen treatment in patients with advanced disease, high PMN-E tumour levels were associated with a poor rate of response compared with those with low PMN-E levels (odds ratio: OR, 0.40; 95% CI, 0.22-0.73; P = 0.003). After correction for the contribution of the traditional predictive factors in multivariate analysis, the tumour PMN-E status was an independent predictor of response (P = 0.01). Furthermore, a high tumour PMN-E level was related with a poor progression-free survival (P<0.001) and postrelapse survival (P = 0.002) in a time-dependent analysis. In contrast, the tumour level of PMN-E was not significantly related with the efficacy of response to first-line chemotherapy in patients with advanced breast cancer. Our present results suggest that PMN-E is an independent predictive marker for the efficacy of tamoxifen treatment in patients with advanced breast cancer

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

EFFECT OF IMMUNOSUPPRESSIVE DRUGS ON THE RELEASE OF METALLOPROTEINASES FROM HUMAN POLYMORPHONUCLEAR LEUKOCYTES

HEMPELMANN U, HAAGWEBER M, HORL WH, Tschesche H. EFFECT OF IMMUNOSUPPRESSIVE DRUGS ON THE RELEASE OF METALLOPROTEINASES FROM HUMAN POLYMORPHONUCLEAR LEUKOCYTES. TRANSPLANT INTERNATIONAL. 1991;4(1):26-30.The concentration of the metalloproteinases type I collagenase and gelatinase was measured in isolated polymorphonuclear leukocytes (PMNLs) of renal transplant recipients treated either with cyclosporin A (CyA) and prednisolone (Pr) (n = 8) or azathioprine (Aza) and Pr (n = 8), and of healthy subjects (n = 12). PMNLs of CyA- and Aza-treated transplant patients displayed markedly higher gelatinase content (2427 +/- 489 and 3284 +/- 357 ng/10(7) cells) than PMNLs of controls (528 +/- 83 ng/10(7) cells). There was also a higher content of type I collagenase in PMNLs (3374 +/- 292 ng/10(7) cells) of Aza-treated patients and significantly elevated levels in PMNLs of patients receiving CyA (3625 +/- 229 ng/10(7) cells) compared with healthy subjects (2878 +/- 151 ng/10(7) cells). In contrast, neutrophil lactoferrin content was lower in transplant patients. Thus, immunosuppressive drugs may reduce the release of leukocyte proteinases, which are known for their deleterious role in proteolytic tissue and matrix breakdown. In vitro, the effects of different immunosuppressive drugs on the release of lactoferrin, collagenase and gelatinase were investigated on FMLPNTL-stimulated PMNLs isolated from healthy subjects. CyA but not Aza or Pr caused inhibition of gelatinase, collagenase and lactoferrin release