Active drains and causality

Closed suction drains, reinfusion drains or no drains in primary total knee replacement?

INTRODUCTION Controversy still surrounds the use of drains after total knee replacement (TKR). We compared closed suction drains, reinfusion drains and no drains by studying haemoglobin (Hb) levels, blood transfusion requirements and functional knee outcome scores in a single surgeon series. METHODS A total of 102 consecutive primary TKRs were performed by the senior author between September ...

Removal of drains and sutures.

..*.. person who decides on removal. ,'A ... I l l IDrains provide a mechanical meanso removig matera that wod otherwise be harmful to the patient, and this may be pus, air, blood, 9\S,i.': '.:.: !_F '' ',:,.,, _,urme, or alimentary secretions. There are three main reasons for inserting drains-namely, to remove air and blood that wil delay healing and recovery, to drain abscesses, and to provid...

Rains, drains and active strains: towards online assessment of wastewater bacterial communities.

Wastewater treatment is one of the largest scale and arguably the most commercially important biotechnological process in the world. Bacterial breakdown of waste materials facilitates the safe disposal of effluents into receiving water bodies. Given this significance, research has focused on identifying the keystone species on which efficient treatment is based. However, unravelling the microbi...

Intraocular Tumor Antigen Drains

Infinite non-causality in active cancellation of random noise

Active cancellation of broadband random noise requires the detection of the incoming noise with some time advance. In an duct for example this advance must be larger than the delays in the secondary path from the control source to the error sensor. In this paper it is shown that, in some cases, the advance required for perfect noise cancellation is theoretically infinite because the inverse of ...