There is provided an attachment device for maintaining positive fluid pressure, the attachment device comprising a body having a fluid outlet port and at least two positive pressure fluid inlet ports; wherein each of the at least two positive pressure fluid inlet ports is connectable to a respective fluid source; wherein each of the at least two positive pressure fluid inlet ports is in fluid communication with the fluid outlet port; wherein each of the at least two positive pressure fluid inlet ports comprises an attachment device mechanism for selectively starting and stopping a flow of fluid from the respective fluid source to the fluid outlet port, and wherein the attachment device mechanism comprises a valve moveable between an open valve position and a closed valve position. An attachment device, connector, and method of using an apparatus suitable for a ventilator is also disclosed.

There is described herein a system for determining the interaction between a test atmosphere and a simulated respiratory tract, said system comprising: (a) a first pump comprising: (i) a chamber configured for containing a first volume of gas comprising a test atmosphere; (ii) a first port adapted for receiving and outputting gas and comprising a valve for regulating the flow of gas through the first port, said valve being moveable between open and closed positions, wherein in the open position said valve is openable towards a test atmosphere or surrounding air; (iii) a second port adapted for outputting and receiving gas and comprising a valve for regulating the flow of gas through the second port, said valve being moveable between open and closed positions; (iv) a piston plate in the chamber, said piston plate comprising one or more apertures for the uptake or inflow of gas into the chamber wherein one or more, or each, of the apertures include a valve that is movable between open and closed positions and is capable of regulating the uptake or inflow of gas; (b) a second pump comprising: (i) a chamber configured for containing a second volume of gas, wherein the first and second volumes of gas are different; (ii) a port adapted for receiving and outputting gas; and (iii) a motor for controlling the operation of the second pump; (c) a connecting structure operable to transmit the gas from the first pump into the second pump; and (d) one or more openings in the first pump or the second pump or the walls of the connecting structure or a combination of two or more thereof, said openings being capable of receiving a module for containing a cell culture medium or for monitoring conditions in the chamber or for gas sampling or for gas characterisation.

The present technology relates to the field of medical monitoring, and, in particular, to non-contact detecting and monitoring of patient breathing. Systems, methods, and computer readable media are described for calculating a change in depth of a region of interest (ROI) on a patient. In some embodiments, the systems, methods, and/or computer readable media can identify steep changes in depths. For example, the systems, methods, and/or computer readable media can identify large, inaccurate changes in depths that can occur at edge regions of a patient. In these and other embodiments, the systems, methods, and/or computer readable media can adjust the identified steep changes in depth before determining one or more patient respiratory parameters.