Methods and devices for passive residual lung volume reduction and functional lung volume expansion
The volume of a hyperinflated lung compartment is reduced by sealing a distal end of the catheter in an airway feeding the lung compartment. Air passes out of the lung compartment through a passage in the catheter while the patient exhales. A one-way flow element associated with the catheter prevents air from re-entering the lung compartment as the patient inhales. Over time, the pressure of regions surrounding the lung compartment cause it to collapse as the volume of air diminishes. Residual volume reduction effectively results in functional lung volume expansion. Optionally, the lung compartment may be sealed in order to permanently prevent air from re-entering the lung compartment.
1. A method for detecting collateral ventilation into a lung compartment in a patient, said method comprising:
sealing a distal end of a catheter in an airway feeding the lung compartment by using an occluding member that is adapted to be expanded in an airway which feeds the lung compartment such that access to the compartment is provided only through a passage of the catheter when the occluding member is expanded;
blocking air from entering the lung compartment through the catheter passage while the patient is inhaling by using a one-way flow element adapted to be disposed within or in-line with the passage of the catheter so that flow in a distal-to-proximal direction is allowed and flow in a proximal-to-distal direction is inhibited or prevented;
measuring air flow or accumulation from the catheter over time using a flow-measurement device connectable to the catheter; and
detecting collateral ventilation based on the measured air flow or accumulation from the catheter over time.
2. A method as in claim 1 , wherein the flow-measurement device comprises a slack collection bag.
3. A method for evaluating a lung compartment comprising:
sealing a distal end of a catheter in an airway feeding the lung compartment by using an occluding member that is adapted to be expanded in an airway which feeds the lung compartment such that access to the compartment is provided only through a passage of the catheter when the occluding member is expanded;
blocking air from entering the lung compartment through the catheter passage while the patient is inhaling by using a one-way flow element adapted to be disposed within or in-line with the passage of the catheter so that flow in a distal-to-proximal direction is allowed and flow in a proximal-to-distal direction is inhibited or prevented;
measuring pressure within the lung compartment; and
detecting collateral ventilation based upon the measured pressure.
4. The method as in claim 3 , wherein detecting collateral ventilation comprises calculating a degree of hyperinflation of the target lung compartment.
5. The method as in claim 3 , wherein detecting collateral ventilation comprises calculating a state of compliance of the target lung compartment.
6. The method as in claim 3 , wherein detecting collateral ventilation comprises calculating collateral resistance of the target lung compartment.
7. The method as in claim 3 , wherein a plurality of measurements of pressure are generated over a predetermined time period.
8. The method as in claim 3 , further comprising injecting a compound into the lung compartment to block collateral flow channels.