A noise reduction device for a respiratory apparatus including a body with a gas outlet arranged to be mounted on the gas inlet of the respiratory apparatus, and a cover configured to be detachably engaged with the body for forming a gas inlet and a gas passage. The cover includes a guiding member to define at least a part of the gas passage and the guiding member is configured to be coupled with the body to form the gas passage between the body and the cover. The noise reduction device provides a longer and smooth passage for the gas to flow from the gas inlet to the gas outlet for reduction of turbulence and resistance of gas flow and hence reducing the noise caused by the friction between the fluctuated gas flow and the gas inlet of the respiratory apparatus.

An inlet tube of a circulatory support device includes a first end configured to receive incoming blood and a second end coupled to a first end of a blood pump. A lumen extends from the first end to the second end, and a spiral feature is disposed within the lumen and configured to support a spiral flow of the incoming blood.

An arterial air capture chamber (101) is used in dialysis. The arterial air capture chamber (101) includes an upwardly extending fluid inlet (102) terminating in a fluid inlet port (105) positioned at about a 90 turn relative to a fluid flow of a fluid inlet tube (107). The arterial air capture chamber (101) includes a draw tube (104) with an opposedly positioned beveled opening (306) at about 180 relative to the fluid inlet port (105). The arterial air capture chamber (101) provides improved fluid dynamics, reducing both stagnant flow and turbulence. The arterial air capture chamber (101) also provides for bidirectional flow of fluid through the arterial air capture chamber (101).