A&E tipping points
248 British Journal of Healthcare Management 2015 Vol 21 No 5 © 2 01 5 M A H ea lth ca re L td Figure 2 clearly shows the impact of the last two of these tipping points on AE 2013). No sane health care administration would ever expect to run hospitals at the level of occupancy common in the UK—but sanity appears to be sadly lacking in this case, and the consequences are entirely predictable. The reasons for the sudden jumps in AE Jones and Beauchant, 2015)—although politicians appear determined to avoid any discussion of the real issues for fear of jeopardising their own pet policies. There will be Rod Jones A&E tipping points
Hospital bed occupancy demystified and why hospitals of different size and complexity must run at different average occupancy levels
Part one of this series investigated the adequacy o f current models used to forecast bed demand. This part explores the issues surrounding t he correct level of occupancy required to deliver effective and safe health care. Economy of scale as explained by queuing theory is a significant factor in understanding bed occupancy. However, irrespective of the occupancy specific to different sized hospitals an absolute maximum occupancy (even during the winter months) in the range 82% to 85% is required to maintain the level of hospital acquired infection at the minimum possi ble level.
Properties of a monopivot centrifugal blood pump manufactured by 3D printing
An impeller the same geometry as the impeller of a commercial monopivot cardiopulmonary bypass pump was manufactured using 3D printing. The 3D-printed impeller was integrated into the pump casing of the commercially available pump to form a 3D-printed pump model. The surface roughness of the impeller, the hydraulic performance, the axial displacement of the rotating impeller, and the hemolytic properties of the 3D-printed model were measured and compared with those of the commercially available model. Although the surface roughness of the 3D-printed model was significantly larger than that of the commercially available model, the hydraulic performance of the two models almost coincided. The hemolysis level of the 3D-printed model roughly coincided with that of the commercially available model under low-pressure head conditions, but increased greatly under high-pressure head conditions, as a result of the narrow gap between the rotating impeller and the pump casing. The gap became narrow under high-pressure head conditions, because the axial thrust applied to the impeller increased with increasing impeller rotational speed. Moreover, the axial displacement of the rotating impeller was twice that of the commercially available model, confirming that the elastic deformation of the 3D-printed impeller was larger than that of the commercially available impeller. These results suggest that trial models manufactured by 3D printing can reproduce the hydraulic performance of the commercial product. However, both the surface roughness and the deformation of the trial models must be considered to precisely evaluate the hemolytic properties of the model.