Suction

About: Suction is a research topic. Over the lifetime, 40114 publications have been published within this topic receiving 198884 citations. The topic is also known as: sucking.

Wearable, variable rate suction/collection device

Abstract: A compact, lightweight, variable rate suction and collection device is provided for the withdrawal and collection of fluid from a patient. The device includes a collection receptacle which is connected to the patient and to a pump through suction inlet, so that suction is created within the collection receptacle whereby fluids from the patient are drawn into the receptacle. A piezoelectric transducer or diaphragm pressure switch senses the suction created while a suction level selector permits an operator to select a given suction pressure within a predetermined range. A control circuit, responsive to the piezoelectric transducer or switch and to the suction level selector, controls the suction created within the receptacle. Among other features, the control circuit provides a selected suction pressure as well as controls delivery of fractional power to the pump motor to reduce noise. The entire unit including the pump and collection receptacle may be located within a carrying case so that the unit can be worn by a patient or hung at a patient's bedside.

Mechanical behaviour of heavily compacted bentonite under high suction changes

Abstract: The paper reports the results of an experimental study carried out on a bentonite compacted to a dry density of up to 1·7 Mg/m3, a high value for this type of soil. The soil fabric has been studied using a variety of techniques, revealing a clear bimodal pore distribution that corresponds to two distinct structural levels: a microstructural one and a macrostructural one. The main testing programme has been performed using oedometers especially designed to apply a very large range of suctions. By applying the axis-translation technique (using nitrogen as the gas fluid), it has been possible to reach suctions up to 15 MPa. The higher suction range has been achieved by applying a controlled atmosphere where the relative humidity has been fixed by a solution of sulphuric acid or salts. In this way suctions up to 550 MPa could be reached. The maximum vertical stress that could be applied in the apparatus was 10 MPa. Two types of test have been carried out: (a) tests in which a combination of loading paths at constant suction and drying/wetting paths at constant load were applied; (b) swelling tests under constant-volume conditions in order to determine the swelling pressure and the stress path followed during wetting. The results of the experimental programme are examined, taking into account the role of the soil fabric in controlling observed mechanical behaviour. In addition, the results of the laboratory tests are reproduced and interpreted using a generalised plasticity model that considers explicitly the interaction between macrostructure and microstructure. In this way, it is possible to achieve a more complete understanding of the mechanisms that underlie observed behaviour, and in particular the interplay between the two structural levels.

A dressing system providing fluid supply and suction drainage used for continuous or intermittent irrigation.

Abstract: In this article a dressing system is described that is capable of providing continuous or intermittent wound irrigation. It is based on a felt dressing provided with an adhesive cover and ports for fluid supply and suction drainage. At continuous irrigation (approximate rate, 70 ml/h), a 1-L fluid bag and a siphon about 30 cm in height are used; at intermittent irrigation (approximate rate, 60 ml/min), a 60-ml fluid bag and a suction balloon are used. In an experimental set-up it was shown that the supplied fluid diffused throughout the dressing felt and that the felt was partly saturated both during continuous and after intermittent irrigation, the effect of gravity being counteracted by capillary force and suction. The suction pressure at the drainage port and within the occlusively applied felt showed a linear relationship. The drainage of particles, while relatively impeded at low flow rates, was satisfactory at rates recommended for clinical use. The dressing felt was inert to adherence of bacteria and white blood cells. This dressing system would seem to provide access to the whole wound surface for active therapy through fluid supply and suction drainage.

Suction canister with unitary shut-off valve and filter features

Abstract: A suction canister assembly comprises an enclosed receptacle having a first opening for providing suction to the receptacle and a second opening for drawing fluids, including liquids and gases, into the receptacle during suction. A unitary shut-off valve/filter element is associated with the interior side of the first opening. This element is oriented within the receptacle so as to be contacted by liquid in the receptacle which rises therein. The element is porous and is adapted to filter particulate matter from gas passing therethrough. In addition, the valve/filter element is capable of developing sufficiently high surface tension under liquid contact to serve as a barrier against liquid passage therethrough at pressure differentials across the element when vacuum is applied on one side of the element. As a result, the element is adapted to terminate suction through the suction opening when liquid rises in the receptacle to completely cover the element.