A medical device includes a structural element comprising an outer surface and a material on the outer surface of the structural element. The material defines void spaces containing a gas entrained within the void spaces. The material, upon contact with physiological fluid, is configured to release the gas in an amount sufficient for the gas to be imaged by ultrasound.

Aspects of the present technology comprise a positioning and stabilising structure to hold a seal-forming structure in a therapeutically effective position on a head of a patient. The seal-forming structure may be constructed and arranged to form a seal with a region of the patients face surrounding an entrance to the patients airways for sealed delivery of a flow of air at a therapeutic pressure of at least 4 cmH2O with respect to ambient air pressure throughout the patients respiratory cycle in use. The positioning and stabilising structure may comprise a front hoop arranged to contact, in use, at least a region of the patients head superior to an otobasion superior of the patients head and a rear strap. The positioning and stabilising structure may comprise an adjustment mechanism for adjustment of the front hoop and the rear strap relative to the patients head, the adjustment mechanism being arranged in a single operation to adjust both the front hoop and rear strap to enable the positioning and stabilising structure to fit different size heads.

Aspects of the present technology comprise a positioning and stabilising structure to hold a seal-forming structure in a therapeutically effective position on a head of a patient. The seal-forming structure may be constructed and arranged to form a seal with a region of the patients face surrounding an entrance to the patients airways for sealed delivery of a flow of air at a therapeutic pressure of at least 4 cmH2O with respect to ambient air pressure throughout the patients respiratory cycle in use. The positioning and stabilising structure may comprise a front hoop arranged to contact, in use, at least a region of the patients head superior to an otobasion superior of the patients head and a rear strap. The positioning and stabilising structure may comprise an adjustment mechanism for adjustment of the front hoop and the rear strap relative to the patients head, the adjustment mechanism being arranged in a single operation to adjust both the front hoop and rear strap to enable the positioning and stabilising structure to fit different size heads.

The present invention is directed to a spray applicator for spraying a tissue treatment medicant onto a tissue that has a container containing the medicant and is positioned at a proximal end of the spray applicator; a spray tip positioned at a distal end of the spray applicator; a cannula connecting the container with the spray tip; an actuatable dispensing mechanism at a proximal end of the applicator to express the medicant from the container through the cannula and through the spray tip toward the tissue; an optional pressurized gas source discharging a gas through the cannula in the vicinity of the spray tip or inside the spray tip; and a distance indicator that provides indicia of the distance between the spray tip and the tissue but does not prevent positioning the spray tip closer to the tissue than a defined distance for the distance indicator.

An arrangement and a method for cardiopulmonary bypass is provided. The arrangement includes a reservoir configured to receive blood from the cardiotomy of a patient. An oxygenator receives the blood from the reservoir. An arterial connection is connected to the patient for supplying the blood from the oxygenator. A pump is provided for pumping the blood through the oxygenator to the arterial connection and the patient. The arrangement includes a supply device including a supply conduit attached to the reservoir. The supply device supplies a displacing gas to the reservoir via the supply conduit.

A patient interface comprises a plenum chamber and a seal-forming structure. The seal-forming structure comprises a support structure arranged to support a sealing portion that is adapted to sealing engage the patient's face in use. The seal-forming structure may also include a seal biasing portion configured to inflate under pressurization within the cavity in the cushion assembly in use to extend the reach of the sealing portion and decouple the sealing portion from external forces.

A patient interface comprises a plenum chamber and a seal-forming structure. The seal-forming structure comprises a support structure arranged to support a sealing portion that is adapted to sealing engage the patient's face in use. The seal-forming structure may also include a seal biasing portion configured to inflate under pressurization within the cavity in the cushion assembly in use to extend the reach of the sealing portion and decouple the sealing portion from external forces.

A patient interface includes: a plenum chamber; a seal-forming structure; a positioning and stabilising structure; a plenum chamber insert configured to be positioned and retained within the plenum chamber; and a vent structure; wherein the plenum chamber insert has a plenum chamber insert port; wherein the plenum chamber insert has an exterior surface configured to be positioned adjacent to an interior surface of the plenum chamber; wherein when the plenum chamber insert is positioned and retained within the plenum chamber, a radial channel is formed by the interior surface of the plenum chamber and the exterior surface of the plenum chamber insert such that gas is able to pass between a patient-proximal side plenum chamber insert and a patient-distal side of the plenum chamber insert via the radial channel during use.

A patient interface includes: a plenum chamber; a seal-forming structure; a positioning and stabilising structure; a plenum chamber insert configured to be positioned and retained within the plenum chamber; and a vent structure; wherein the plenum chamber insert has a plenum chamber insert port; wherein the plenum chamber insert has an exterior surface configured to be positioned adjacent to an interior surface of the plenum chamber; wherein when the plenum chamber insert is positioned and retained within the plenum chamber, a radial channel is formed by the interior surface of the plenum chamber and the exterior surface of the plenum chamber insert such that gas is able to pass between a patient-proximal side plenum chamber insert and a patient-distal side of the plenum chamber insert via the radial channel during use.

A gas washout vent, and a patient interface with the gas washout vent, configured to allow patient-exhaled CO.sub.2 to flow to an exterior of the plenum chamber to minimise rebreathing of exhaled CO.sub.2 by the patient, the gas washout vent including at least one outlet orifice; a diffusing member at least partly covering the outlet orifice; and a blocking member having an air-impermeable material, the blocking member preventing gas exiting from the outlet orifice from flowing straight through the diffusing member.