Replaceable filter systems for mechanical ventilation

A ventilation system, comprising:

• an inspiratory limb that carries breathing gases from a medical ventilator towards a patient;
• an expiratory limb that carries expiratory gases from the patient towards the medical ventilator;
• and
• a dual-channel expiratory filtration system coupled to the expiratory limb and configured to receive unfiltered expiratory gases carried by the expiratory limb, the dual-channel expiratory filtration system comprising:
• an inlet that receives the unfiltered expiratory gases from the expiratory limb;
• a first channel, pneumatically coupled to the inlet, including a first filter that filters the unfiltered expiratory gases to form filtered expiratory gases;
• a second channel, pneumatically coupled to the inlet, including a second filter that filters the unfiltered expiratory gases to form filtered expiratory gases;
• at least one valve, wherein when the valve is in a first state, the unfiltered expiratory gases from the inlet flow through the first channel, and when the valve is in a second state, the unfiltered expiratory gases from the inlet flow through the second channel;
• and
• an outlet, pneumatically coupled to the first channel and the second channel, that carries the filtered expiratory gases towards the ventilator.