Abstract: There is described a method of use of a mass exchanger. In the method the mass exchanger comprises: a first channel for accommodating flow of a liquid to be treated; and a second channel for accommodating flow of a treatment agent, the first and second channels have a permeable membrane provided between them, so as to allow transfer of selected species between the first channel and the second channel. The steps of the mass transfer method comprise passing the liquid to be treated along the first channel and introducing a mixture of liquid and gas into the second channel to provide a two-phase treatment agent. It is desirable to provide a means of adjusting the concentration of gas species in a liquid such as blood, while simultaneously controlling the temperature of the liquid and optionally adjusting the concentration of ionic and/or dissolved species in that liquid. By this method and mass exchanger providing a two-phase treatment agent, it is possible to simultaneously deliver gaseous species (e.g.

Abstract: There is described a method of use of a mass exchanger. In the method the mass exchanger comprises: a first channel for accommodating flow of a liquid to be treated; and a second channel for accommodating flow of a treatment agent, the first and second channels have a permeable membrane provided between them, so as to allow transfer of selected species between the first channel and the second channel. The steps of the mass transfer method comprise passing the liquid to be treated along the first channel and introducing a mixture of liquid and gas into the second channel to provide a two-phase treatment agent. It is desirable to provide a means of adjusting the concentration of gas species in a liquid such as blood, while simultaneously controlling the temperature of the liquid and optionally adjusting the concentration of ionic and/or dissolved species in that liquid. By this method and mass exchanger providing a two-phase treatment agent, it is possible to simultaneously deliver gaseous species (e.g.

Abstract: An oscillating rheometer adapted for use in measuring rheological properties of blood or the propensity of blood to clot, the rheometer including at lease two surfaces between which a blood sample is introduced, said surfaces being provided as: A first surface, providing a sample receiving member defining a surface for receipt of a blood sample; A second surface, providing a sample contact surface in movable relationship to said first surface. Wherein in use, said first and second surfaces move towards each other so as to sandwich said blood sample between the first and second surfaces, with the blood sample being subjected to a controlled environment provided by way of one or more of the surfaces in contact with the blood to allow for measurement of the rheological properties of the blood or the propensity of the blood to clot.