System and method for monitoring composition in a sidestream system using a disposable sampling chamber

A method of measuring composition of a flow of breathable gas received from a respiratory circuit, the method comprising acts of:

• removably docking a flow path element with a housing of a detector device, the removable flow path element having an inlet, a sampling chamber, a pump section comprising a membrane and an actuator interface coupled to the membrane, and an outlet, wherein the inlet and the outlet of the removable flow path element are positioned on adjacent sides of the housing;
• emitting electromagnetic radiation from a radiation source into the sampling chamber of the removable flow path element while the removable flow path element is docked with the housing, wherein the radiation source is housed within the housing;
• receiving electromagnetic radiation that has been emitted by the radiation source and has passed through an enclosed flow path of the removable flow path element onto a sensor assembly housed within the housing;
• generating an output signal conveying information related to one or more parameters of the electromagnetic radiation received onto the sensor assembly;
• actuating the membrane of the flow path element by moving the actuator interface of the removable flow path element through movement of a pump actuator carried by the housing in a separate portion from the removable flow path element to draw the flow of breathable gas through the enclosed flow path;
• controlling, with a controller housed within the housing:
• (i) the pump actuator to maintain a flow rate of the flow of breathable gas through the enclosed flow path;
• and
• (ii) an intensity of the radiation source;
• and
• measuring the flow rate of the breathable gas with a pressure sensor directly contacting the membrane;
• wherein the housing comprises:
• a first section carrying the pump actuator and a pump motor, the removable flow path element being positioned on the first section;
• and
• a second section carrying the radiation source, the sensor assembly and the controller, and the second section being configured to pivot with respect to the first section and the removable flow path element.

A detector device for measuring composition of a flow of breathable gas received from a respiratory circuit, the detector device comprising:

• a housing means for housing the detector device;
• a docking means for removably docking a removable flow path element with the housing means the detector device, the removable flow path element having an inlet, a sampling chamber, a pump section including a movable membrane, an actuator interface coupled to the movable membrane, and an outlet, wherein the inlet and the outlet of the removable flow path element are positioned on adjacent sides of the housing means;
• a radiation emitting means for emitting electromagnetic radiation into the sampling chamber of the removable flow path element while the removable flow path element is docked with the housing means, wherein the radiation emitting means for emitting electromagnetic radiation is housed within the housing means;
• a radiation receiving means for receiving electromagnetic radiation that has been emitted by the radiation emitting means for emitting and has passed through the sampling chamber of the removable flow path element, wherein the radiation receiving means for receiving is housed within the housing means;
• a generating means for generating an output signal conveying information related to one or more parameters of the electromagnetic radiation received onto the radiation receiving means for receiving;
• an actuating means for actuating the movable membrane in the pump section of the removable flow path element through movement of the actuator interface to draw the flow of breathable gas through the sampling chamber, wherein the actuating means for actuating is carried by the housing means in a separate portion from the removable flow path element;
• a pressure sensing means for pressure sensing that contact the membrane and measure a flow rate of the flow of breathable gas;
• and
• a control means for controlling that control:
• (i) the actuating means for actuating to maintain the flow rate of the flow of breathable gas through the sampling chamber;
• and
• (ii) an intensity of the radiation emitting means for emitting electromagnetic radiation;
• wherein the housing means comprises:
• a first section carrying the actuating means for actuating and a pump motor, the removable flow path element being positioned on the first section;
• and
• a second section carrying the radiation emitting means for emitting electromagnetic radiation, the radiation receiving means for receiving electromagnetic radiation and the control means for controlling, and the second section being configured to pivot with respect to the first section and the removable flow path element.