Systems and methods for endobronchial diagnostics
Methods and systems for accessing and diagnosing diseased lung compartments are disclosed. Methods may comprise introducing a diagnostic catheter with an occluding member at its distal end into a lung segment; inflating the occluding member to isolate the lung compartment; and performing a diagnostic procedure with the catheter. The proximal end of the diagnostic catheter is configured to be attached to a console. Methods may also include allowing air to enter the lung compartment through the passage in the catheter while the patient is inhaling and blocking air from being expelled from the lung compartment through the catheter passage while the patient is exhaling 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 proximal-to-distal direction is allowed and flow in a distal-to-proximal direction is inhibited or prevented.
1 . A method of assessing functionality of a lung compartment in a patient, the 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 lung compartment is provided only through a passage of the catheter when the occluding member is expanded;
allowing air to enter the lung compartment through the passage in the catheter while the patient is inhaling;
blocking air from being expelled from the lung compartment through the passage in the catheter while the patient is exhaling by using a solenoid valve adapted to be disposed within or in-line with the passage of the catheter so that flow in a proximal-to-distal direction is allowed and flow in a distal-to-proximal direction is inhibited or prevented, wherein a control unit is coupled to the solenoid valve and configured to close the solenoid valve during exhalation and open the solenoid valve during inhalation;
measuring a baseline flow into the lung compartment via one or more flow sensors communicatively coupled to the control unit while the patient is inhaling before actuation of the solenoid valve;
measuring flow into the lung compartment via the one or more flow sensors communicatively coupled to the control unit while the patient is inhaling after actuating of the solenoid valve; and
determining a degree of collateral ventilation present in the lung compartment based at least in part on a difference between the baseline flow and the measured flow into the lung compartment while the patient is inhaling without ventilation assistance, wherein the degree of collateral ventilation present is correlated to the difference between the baseline flow and the measured flow.
2 . The method of claim 1 , wherein determining whether collateral ventilation is present in the lung compartment comprises determining that no collateral ventilation is present if flow into the lung compartment decreases below a threshold value.
3 . The method of claim 1 , wherein determining whether collateral ventilation is present in the lung compartment comprises determining that collateral ventilation is present if flow into the lung compartment remains above a threshold value.
4 . The method of claim 1 , wherein the distal end of the catheter is sealed in the airway by inflating the occluding member with a pressure between 5 and 20 psi.
5 . The method of claim 1 , further comprising measuring pressure within the lung compartment.
6 . The method of claim 5 , wherein determining whether collateral ventilation is present in the lung compartment is further based on the measured pressure.
7 . The method of claim 6 , wherein determining whether collateral ventilation is present in the lung compartment comprises calculating a value of collateral resistance.
8 . The method of claim 7 , further comprising determining a degree of collateral ventilation based on the calculated value of collateral resistance.
9 . Apparatus for assessing functionality of a lung compartment in a patient, the apparatus comprising:
a catheter having a distal end and a passage;
an occluding member for sealing the distal end of the catheter in an airway feeding the lung compartment, the occluding member being adapted to be expanded in an airway which feeds the lung compartment such that access to the lung compartment is provided only through the passage of the catheter when the occluding member is expanded;
a control unit coupled to a solenoid valve;
the solenoid valve adapted to be disposed within or in-line with the passage of the catheter so that flow in a proximal-to-distal direction is allowed and flow in a distal-to-proximal direction is inhibited or prevented, the control unit configured to close the solenoid valve during exhalation and open the solenoid valve during inhalation thereby allowing air to enter the lung compartment through the passage in the catheter while the patient is inhaling and blocking air from being expelled from the lung compartment through the passage in the catheter while the patient is exhaling;
one or more flow sensors communicatively coupled to the control unit for measuring a baseline flow into the lung compartment while the patient is inhaling before actuation of the solenoid valve and measuring flow into the lung compartment while the patient is inhaling after actuation of the solenoid valve; and
determining means for determining a degree of collateral ventilation present in the lung compartment based at least in part on a difference between the baseline flow and the measured flow into the lung compartment while the patient is inhaling without ventilation assistance, wherein the degree of collateral ventilation present is correlated to the difference between the baseline flow and the measured flow.
10 . The apparatus of claim 9 , wherein the determining means is configured to determine that no collateral ventilation is present if flow into the lung compartment decreases below a threshold value.
11 . The apparatus of claim 9 , wherein the determining means is configured to determine that collateral ventilation is present if flow into the lung compartment remains above a threshold value.
12 . The apparatus of claim 9 , wherein the distal end of the catheter is sealed in the airway by inflating the occluding member with a pressure between 5 and 20 psi.
13 . The apparatus of claim 9 , wherein the one or more flow sensors are further configured to measure pressure within the lung compartment, and wherein the determining means is further configured to determine whether collateral ventilation is present in the lung compartment based on the measured pressure.
14 . The apparatus of claim 13 , wherein the determining means is configured to determine whether collateral ventilation is present in the lung compartment by calculating a value of collateral resistance.
15 . The apparatus of claim 14 , wherein the determining means is further configured to determine a degree of collateral ventilation based on the calculated value of collateral resistance.
16 . The method of claim 1 , wherein the degree of collateral ventilation present is inversely correlated to the difference between the baseline flow and the measured flow.
17 . The apparatus of claim 9 , wherein the degree of collateral ventilation present is inversely correlated to the difference between the baseline flow and the measured flow.