System and method for detecting air leak from visceral pleura of the lung

Abstract

A system for detecting an air leak in the lung parenchyma and / or airway may have a heater configured to vaporize at least one fluid into an aerosol. A conduit system may include a conduit portion configured to be received in a user's airway. A motive flow source is connected to the conduit system for inducing a flow of the aerosol into the conduit portion. A controller is configured for operating the heater to generate the aerosol, and for controlling the motive flow source to induce the flow of the aerosol into the conduit portion at a flow rate of a given level. A method for detecting an air leak in the lung parenchyma and / or airway is also provided.

Description

SYSTEM AND METHOD FOR DETECTING AIR LEAK FROM VISCERAL PLEURA OF THE LUNGCROSS-REFERENCE TO RELATED APPLICATIONThe present application claims the priority of United States Patent Application No. 63 / 669,454, filed on July 10, 2024 and incorporated herein by reference.TECHNICAL FIELD

[0001] The application relates to air leak detection from the visceral pleura of the lung.BACKGROUND

[0002] Pulmonary air leaks may be difficult to detect intraoperatively.

[0003] Various intraoperative techniques can be used to locate pulmonary air leaks. One of these is the immersion test, which involves bathing the lungs in a sterile solution and observing the formation of bubbles while ventilating the lungs, indicating the presence of an air leak. Often surgeons do not perform the immersion test because of time requirements. Moreover, in the immersion test, it may be difficult to localise the bubbles’ origin, specifically on the posterior aspect of the lung, and lung manipulations may be required to see the leak etc.

[0004] Another technique for air leak detection involves the use of a surfactant, such as a Yang bubble solution, applied onto the surface of the lungs while ventilating the lungs. Because of the use of a surfactant, the lung is not immersed, resulting in a simplification over the immersion test. However, this technique may not be optimal to detect leaks in the posterior part of the lungs.

[0005] Consequently, it would be desirable to address the need for intraoperative detection of pulmonary air leak. The method and system associated with air leak detection should be able to effectively identify different types of leaks, at body temperature, in conditions of reduced visibility (such as during minimally invasive thoracic surgery), without imposing significant constraints on the surgeon and with few or no side effects for the patient.SUMMARY

[0006] In one aspect, there is provided a system for detecting a leak in a lung comprising: a unit configured to vaporize at least one fluid into an aerosol; a conduit system including a conduit portion configured to be received in a user’s airway; a motive flow source connected to the conduit system for inducing a flow of the aerosol into the conduit portion; and a controller configured for operating the heater to generate the aerosol, and for controlling the motive flow source to induce the flow of the aerosol into the conduit portion at a flow rate of a given level to generate a leak through the lung.

[0007] Further in accordance with the aspect, for instance, the motive flow source includes a pump.

[0008] Still further in accordance with the aspect, for instance, the motive flow source includes a valve operable by the controller to achieve the given flow rate.

[0009] Still further in accordance with the aspect, for instance, the motive flow source is controlled to induce a flow ranging from 0.1 l / min-10.0 l / min, inclusively.

[0010] Still further in accordance with the aspect, for instance, a source of fluid is included.

[0011] Still further in accordance with the aspect, for instance, the fluid is a mixture of water and glycerine.

[0012] Still further in accordance with the aspect, for instance, the heater includes at least one resistive coil.

[0013] Still further in accordance with the aspect, for instance, the at least one resistive coil as a resistance ranging from 0.05 ohm to 5 ohm, inclusively.

[0014] Still further in accordance with the aspect, for instance, at least one pressure sensor may communicate with the controller and configured to measure a pressure in the conduit system.

[0015] Still further in accordance with the aspect, for instance, a pressure relief valve may be in the conduit system.

[0016] Still further in accordance with the aspect, for instance, a user interface may be provided for adjusting the flow rate to the given level.

[0017] Still further in accordance with the aspect, for instance, the controller includes a current sensor and a transistor configured to perform a feedback loop.

[0018] Still further in accordance with the aspect, for instance, an imaging device may be inserted in a pleural cavity for imaging a surface of the lung to visually detect aerosol leaking through the lung.

[0019] Still further in accordance with the aspect, for instance, the imaging device is one of an endoscope, a laparoscope and a thoracoscope.

[0020] Still further in accordance with the aspect, for instance, a light source may be provided and configured to be inserted into the pleural cavity to illuminate the aerosol leaking.

[0021] Still further in accordance with the aspect, for instance, the light source has an elongated body connected to an elongated body of the imaging device.

[0022] Still further in accordance with the aspect, for instance, the light source has a plurality of light emitting devices.

[0023] Still further in accordance with the aspect, for instance, the light source has an L-shaped end, with the plurality of light emitting devices oriented toward a capturing portion of the imaging device.

[0024] Still further in accordance with the aspect, for instance, the conduit portion is a tracheal conduit portion configured to be received in a user’s trachea.

[0025] In accordance with another aspect, there is provided a method for detecting a leak in a lung comprising: vaporizing at least one fluid into an aerosol; inducing a flow of the aerosol into a conduit system at a flow rate of a given level; directing the aerosol into the lungs via the conduit system; and imaging a leak of the aerosol from one of the lungs from a point of view in a pleural cavity.

[0026] Further in accordance with the other aspect, for instance, vaporizing the at least one fluid includes vaporizing a solution of water and glycerine.

[0027] Still further in accordance with the other aspect, for instance, vaporizing the at least one fluid includes powering a resistive coil.

[0028] Still further in accordance with the other aspect, for instance, an intrapulmonary pressure may be monitored during at least part of the method.

[0029] Still further in accordance with the other aspect, for instance, inducing the flow of aerosol includes inducing the flow at a flow rate ranging from 0.1 l / min- 10.0 l / min, inclusively.

[0030] Still further in accordance with the other aspect, for instance, pressure may be relieved from the conduit system when a pressure is above a given threshold.

[0031] Still further in accordance with the other aspect, for instance, imaging the leak is achieved laparoscopically.

[0032] Still further in accordance with the other aspect, for instance, the method is performed in an automated manner.

[0033] Still further in accordance with the other aspect, for instance, light may be emitted in the pleural cavity to emphasize the leak of the aerosol.

[0034] Still further in accordance with the other aspect, for instance, emitting light in the pleural cavity includes emitting light from a point of view different from that of the imaging.

[0035] Still further in accordance with the other aspect, for instance, emitting light from the point of view different from that of the imaging includes backlighting the leak of the aerosol relative to the imaging.DESCRIPTION OF THE DRAWINGS

[0036] Reference is now made to the accompanying figures in which:

[0037] Fig. 1 is a block diagram of a system for detecting lung puncture in accordance with the present disclosure;

[0038] Fig. 2 is a block diagram of the system of Fig. 1 , according to a variant of the present disclosure;

[0039] Fig. 3 is a block diagram of a controller and related components, according to a variant of the present disclosure;

[0040] Fig. 4 is a perspective view of an exemplary assembly of an imaging device and of light source according to a variant of the present disclosure; and

[0041] Fig. 5 is a flow chart of a method for detecting lung puncture in accordance with another embodiment of the present disclosure.DETAILED DESCRIPTION

[0042] Referring to the drawings and more particularly to Fig. 1 , a system for detecting lung pleural air leakage is generally shown at 10, in accordance with the present disclosure. For simplicity, it will be referred to as system 10. As a possibility, the system 10 is used intraoperatively, such as during a surgical procedure that may be associated with the lungs or with the thorax, for example to treat a pathology. It is also considered to use the system 10 as part of an independent air leak detection procedure, i.e., not in combination with another surgical procedure. The detection of air leak in lungs (i.e., in the lung parenchyma) using the system 10 may be said to be minimally invasive. It may optionally be achieved using thoracoscopy as the imaging modality, thereby limiting the size of incisions in soft tissue to image the lungs. Moreover, by using standard equipment for minimally invasive thoracic surgery — laparoscope / thoracoscope / endoscope — , the system 10 and method described below may be readily achieved without additional imaging equipment such as MRI, near infrared imaging or cat-scans.

[0043] The system 10 may include various combinations of components, that may be referred to as an aerosol creating unit 20 (which may be a heating unit 20) and is illustrated in Fig. 1 as “vaporizer”, a conduit system 30, a motive flow source 40, and a controller 50. The system 10 may also include a fluid source A, various valves, sensors, and like control components, for the system 10 to be operated in accordance with the present disclosure. The system 10 may also include or be used with an imaging device, such as a laparoscope / thoracoscope / endoscope 60, for imaging a surface of the lung to visually detect the aerosol leaking through the lung, after or while the aerosol is generated by the system 10. Moreover, a light source 70 may optionally be present, and may be used as to visually emphasize the presence of an aerosol. In a variant, as discussed below, the light source 70 is positioned relative to a point of view of the imaging device 60 to create some backlighting. In a variant, the imaging device 60 includes a camera, or othertraditional imaging system, as opposed to a specialized imaging system such as radiography.

[0044] The aerosol creating unit 20 is configured to vaporize one or more fluids into an aerosol. The one or more fluids may be in the form of a solution, specifically selected to be vaporized into a dense and visually contrasting aerosol. By aerosol, the present disclosure refers to a suspension of droplets of the fluid in a flow of air or other gas. In a variant, the fluid from the fluid source A is a solution of water, and glycerine, as an example of a solution that may be vaporized into a suitably detectable aerosol - as other substances may be used. Glycerine aerosol is known to flow in the lung with limited condensing and / or depositing. This is merely an example, as other substances may be used for the aerosol, such as propylene glycol, a mixture of propylene glycol / glycerine, triacetin, polyethylene glycol or medium chain triglycerides. Considering that the aerosol is injected in the airway and lungs of the user, a biocompatible liquid must be used.

[0045] The aerosol creating unit 20, also referred to as a heater, a vaporizer, an atomizer, may be embodied by one or more coils 21 (e.g., Figs. 2 and 3), if embodied as a heating unit. The coil(s) 21 is a resistive coil that may have a resistance ranging from 0.05 ohm to 5 ohm, inclusively, though the resistance may have other values. As a general non-limitative observation, the lower the resistance of the coil 21 , the more it may heat up and produce a vapour of suitable density for visual detection. As an alternative, the aerosol creating unit 20 may be a vaporizer or a nebulizer solution. The aerosol creating unit 20 is selected to produce the densest vapour to enhance visual contrast during a visual detection. In an embodiment, merely given as an example, as numerous other types of coils may be used, the heating coil(s) 21 is(are) 0.15 Q coils, an example of which is the coil FL1- D, by FreeMax, Shenzen, China.

[0046] Referring to Figs. 1 and 2, the conduit system 30 is illustrated schematically, and allows fluid flow between the various components of the system 10, such as between the aerosol creating unit 20 and the motive flow source 40. For example, the conduit system 30 may include pipes, tubes, tubing, flexible or rigid. The conduit system 30 may include a conduit portion 31 configured to be received in a user’s airway. For example, the conduit portion 31 is tracheal conduit portion that ispositioned into the trachea for the aerosol to be injected into the lungs. In a variant, the conduit portion 31 may not go as deep in the user’s respiratory system.

[0047] One or more pressure sensors 32 may be in the conduit system 30 and may be controlled and may communicate with the controller 50, though optionally present. The pressure sensor 32 is configured to measure a pressure in the conduit system 30. In Fig. 2, it is observed that the pressure sensor 32 is near the conduit portion 31 and in fluid communication with it, for pressure readings to be representative of the pressure of the aerosol delivered to the lungs, and / or of intrapulmonary pressure. One or more pressure sensors may be located elsewhere in the system 10.

[0048] As a safety component, a pressure relief valve 33 may also be in the conduit system 30, though optional. In Fig. 2, it is observed that the pressure relief valve 33 is near the conduit portion 31 and in fluid communication with it, to ensure that the pressure in the system 10 remains within a given threshold, thus avoiding an excessive pressure build-up in the lungs. In Fig. 2, the components 31 , 32 and 33 are schematically shown as being in parallel but other arrangements are possible.

[0049] The motive flow source 40 is optionally present, and may be connected to the conduit system 30 and is tasked with inducing a flow of the aerosol into the conduit portion 31 for delivery onto the airways. In a variant, the motive flow source 40 includes a pump 41 (Fig. 2). The pump 41 may be electrically powered, and is one example among others of a device that can be used to introduce a flow of gas. Other examples may include a ventilator, a blower, a fan, a compressor, and passive units such as a compressed gas tank. In a variant, given merely as a non- exhaustive example, the pump 41 is a Jecod PA-35, Jebao, Zhongshan, China, that generates a relatively low air flow, that may emulate the volumetric flow of human respiration, within a given pressure range. Accordingly, the pump 41 , or equivalent device, is preferably selected to preserve a relatively high density of vapour, while avoiding inflation of the lungs that may be too rapid. Indeed, the motive flow source 40 may be operated to slowly fill the lungs with gas, as the leaks may be more readily detected when the pleural cavity has clearance, i.e., when the lungs are not or not fully inflated. In a variant, the vaporizer 20 may be a pressure vessel for the nebulizer solution, and hence the motive flow source 40 may be the vaporizer 20 itself, and not a separate one as discussed above.

[0050] As shown in Fig. 2, the motive flow source 40 may optionally include a valve 42 operable by the controller 50. The valve 42 may for example be a solenoid valve that is modulated or otherwise controlled to contribute to maintaining a flow of gas within a given interval. The given level may be a range, such a 0.1. l / min-10.0 l / min, inclusively, as an example among others. The given level may be similar to the normal air intake of a human during normal breathing cycles.

[0051] In a variant, the relative positioning of the components is as shown in Fig. 2, with the motive flow source 40 being upstream and the aerosol creating unit 20 being between the motive flow source 40 and the conduit portion 31 , with a remainder of the conduit system 30 enabling a flow of gas between the various components.

[0052] Referring to Figs. 1 and 3, the controller 50 is configured for operating the aerosol creating unit 20 to generate the aerosol, and for controlling the motive flow source 40 to induce the flow of the aerosol into the tracheal conduit portion 31 at the flow rate of the given level. The controller 50 may include one or more processors or processing units 50A, and a non-transitory computer-readable memory 50B communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for operating the system 10 in the manner described herein. The controller 50 may therefore be connected to various components of the system, including the pressure sensor(s) 32, the valve 42, the aerosol creating unit 20 and the pump 41 , as the controller 50 may be tasked with operating the system 10 within strict parameters. The parameters may be set in factory calibration or may be adjustable by a user of the system 10. Therefore, as shown in Fig. 3, the system 10 may have a user interface 50A, that may be used for various tasks, such as for adjusting the flow rate to the given level. The interface 50A may be integrated into the system, or in a tablet, phone, smart device or laptop. The controller 50 may also control the operation of various active components of the system 10, such as by controlling the power feed to the heating unit 20 and the speed of the pump 41. As shown in Fig. 3, the controller 50 may be employed with some electronic components, such as a current sensor 51 and a transistor 52, to ensure the operation of the system 10. For example, the controller 50 may use the current sensor 51 and the transistor 52, to perform a feedback loop (e.g., such as a PID (proportional-integral-derivative) loop). Fig. 3 also shows a power supply and transformer. The current may be adjusted at the power supply, whether manually orby the controller 50, in an effort to operate the system 10 within the parameters described herein.

[0053] The controller 50 is tasked with operating the system 10 so as to be within threshold of intrapulmonary pressures. Moreover, lung temperature is taken into consideration in the generation of the aerosol, but, as the system 10 is used in vivo, the lungs are usually around 37 C. The powering of the aerosol creating unit 20 is also controlled by the controller 50, as the temperature of the aerosol creating unit 20 is instrumental in achieving a suitable density. The dense aerosol can be detected through a defect in the lung parenchyma and / or airway in spite of a lung not fully being inflated. Thus, the system 10 may monitor lung pressure according to the flow delivered by the motive flow source 40 (e.g., pump 41 ), depending on what the lung can withstand. In a variant, the less the lung is inflated (i.e., the intrapulmonary pressure is low), the easier it may be to see the aerosol escaping from a puncture, with more space in the pleural cavity for the imaging device such as the laparoscope / thoracoscope / endoscope 60 to observe leaking aerosol. The system 10 may be said to be easy to use, fast, and may be operable with non and / or non-fully inflated lungs.

[0054] Referring to Fig. 4, an exemplary arrangement of imaging device 60 and light source 70 is illustrated. Both the imaging device 60 and the light source 70 have an elongated body, respectively shown as 60A and 70A, to facilitate minimally invasive insertion of the assembly in the thoracic cavity (or more particularly, the pleural cavity), to observe the lungs. In a variant, the elongated bodies 60A and 70A may be flexible and shapeable, may be connected to one another, for concurrent movement into position relative to the lungs. For example, clips 80 may optionally be present to connected the bodies 60A and 70A to one another. In a variant, a sheath, tape, etc, may be used, and may have a smoother profile than the clips 80. The imaging device 60 may have a lens 61A at the tip of the elongated body 60A such that a point of view of the imaging device 60 is axially forward relative to a longitudinal axis of the elongated body 60A. The lens may provide a suitable field of view angle. Other options are possible.

[0055] In a variant, the imaging device 60 and the light source 70 are separated, and have separate entry points. The imaging device 60 and the light source 70 may both be endoscope-like device to be minimally invasive. As an alternative, a staticlight source may be positioned into the thoracic cavity, such as onto the lung. In another variant, the light source 70 may be on a trocar for a zenithal lighting.

[0056] The light source 70 may have one or more light emitting devices 71. In Fig. 4, an array of light emitting devices is shown. For example, the light emitting devices may be light emitting diodes (LEDs). The light source 70 may be arranged for its end portion to have an L-shape, as illustrated. The bending radius of the L- shape could be changed by selectively pulling cables attached to the light source with a handle, as one possible approach to shape the light source 70. The L-shape is such that the light emitting device(s) may face toward the capturing portion (e.g., lens) of the imaging device 60. Other shapes are possible, with an option being a straight shape with light emitting device(s) emitting light toward the capturing portion. In the variant of Fig. 4, a distance between the light emitting devices of the light source 70 and the capturing portion of the imaging device 60 may be between 2.0 cm to 8.0 cm. Other values are possible. The imaging device 60 may have the capacity to emit light itself, as the pleural cavity may be insufficiently lit for a leak of aerosol to be seen. If present, the light source 70 separate from the imaging device 60 may provide additional lighting, such as from a different point of view than that of the imaging device 60. This may include backlighting.

[0057] The system 10 may thus be generally described as being a system for detecting a leak in a lung comprising: a heater configured to vaporize at least one fluid into an aerosol; a conduit system including a conduit portion configured to be received in a user’s airway; a motive flow source connected to the conduit system for inducing a flow of the aerosol into the conduit portion; and a controller configured for operating the heater to generate the aerosol as well as for controlling the motive flow source to induce the flow of the aerosol into the conduit portion at a flow rate of a given level.

[0058] Now that the system 10 has been described, a method for detecting a leak in a lung is described, and is generally shown as 100 in Fig. 5. The method 100 may or may not be performed by the system 10. In a variant, all steps of the method 100 are performed by the system 10 in an automated manner — though this is optional.

[0059] According to 101 , at least one fluid is vaporized into an aerosol. Vaporizing the at least one fluid may include vaporizing a solution of water and glycerine, but other solutions can be vaporized. Vaporizing the at least one fluid may includepowering a resistive coil. The resistive coil is powered to achieved a given level of aerosol density.

[0060] According to 102, a flow of the aerosol is induced into a conduit system at a flow rate of a given level. Inducing the flow of aerosol may include inducing the flow at a flow rate ranging from 0.1 l / min-10.0 l / min, inclusively. This may be done by controlling a pump and / or a valve.

[0061] According to 103, the aerosol is directed into the lungs via the conduit system. The aerosol may be directed into the lungs at the flow rate of the given level.

[0062] According to 104, a leak of the aerosol from one of the lungs is imaged. The imaging may be done from a point of view in a pleural cavity. Imaging the leak may be achieved laparoscopically / thoracoscopically.

[0063] During the method 100, or at any point thereof, an intrapulmonary pressure may be monitored. The method 100 may be achieved without fully inflating the lungs.

[0064] During the method, pressure of the aerosol may be relieved from the conduit system when a pressure is above a given threshold.

[0065] The method 100 may thus generally be described as a method for detecting a leak in a lung comprising: vaporizing at least one fluid into an aerosol; inducing a flow of the aerosol into a conduit system at a flow rate of a given level; directing the aerosol into the lungs via the conduit system; and imaging a leak of the aerosol from one of the lungs from a point of view in a pleural cavity.

[0066] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.

Claims

CLAIMS1 . A system for detecting a leak in a lung comprising: a unit configured to vaporize at least one fluid into an aerosol; a conduit system including a conduit portion configured to be received in a user’s airway; a motive flow source connected to the conduit system for inducing a flow of the aerosol into the conduit portion; and a controller configured for operating the heater to generate the aerosol, and for controlling the motive flow source to induce the flow of the aerosol into the conduit portion at a flow rate of a given level to generate a leak through the lung.

2. The system according to claim 1 , wherein the motive flow source includes a pump.

3. The system according to claim 2, wherein the motive flow source includes a valve operable by the controller to achieve the given flow rate.

4. The system according to claim 3, wherein the motive flow source is controlled to induce a flow ranging from 0.1 l / min-10.0 l / min, inclusively.

5. The system according to any one of claims 1 to 4, further including a source of fluid.

6. The system according to claim 5, wherein the fluid is a mixture of water and glycerine.

7. The system according to any one of claims 1 to 6, wherein the heater includes at least one resistive coil.

8. The system according to claim 7, wherein the at least one resistive coil as a resistance ranging from 0.05 ohm to 5 ohm, inclusively.

9. The system according to any one of claims 1 to 8, further including at least one pressure sensor communicating with the controller and configured to measure a pressure in the conduit system.

10. The system according to any one of claims 1 to 9, further including a pressure relief valve in the conduit system.

11. The system according to any one of claims 1 to 10, further including a user interface for adjusting the flow rate to the given level.

12. The system according to any one of claims 1 to 11 , wherein the controller includes a current sensor and a transistor configured to perform a feedback loop.

13. The system according to any one of claims 1 to 12, including an imaging device configured to be inserted in a pleural cavity for imaging a surface of the lung to visually detect aerosol leaking through the lung.

14. The system according to claim 14, wherein the imaging device is one of an endoscope, a laparoscope and a thoracoscope.

15. The system according to claim 13 or claim 14, including a light source configured to be inserted into the pleural cavity to illuminate the aerosol leaking.

16. The system according to claim 15, wherein the light source has an elongated body connected to an elongated body of the imaging device.

17. The system according to claim 16, wherein the light source has a plurality of light emitting devices.

18. The system according to claim 17, wherein the light source has an L-shaped end, with the plurality of light emitting devices oriented toward a capturing portion of the imaging device.

19. The system according to any one of claims 1 to 18, wherein the conduit portion is a tracheal conduit portion configured to be received in a user’s trachea.

20. A method for detecting a leak in a lung comprising: vaporizing at least one fluid into an aerosol; inducing a flow of the aerosol into a conduit system at a flow rate of a given level; directing the aerosol into the lungs via the conduit system; and imaging a leak of the aerosol from one of the lungs from a point of view in a pleural cavity.

21. The method according to claim 20, wherein vaporizing the at least one fluid includes vaporizing a solution of water and glycerine.

22. The method according to any one of claims 20 and 21 , wherein vaporizing the at least one fluid includes powering a resistive coil.

23. The method according to any one of claims 20 to 22, including monitoring an intrapulmonary pressure during at least part of the method.

24. The method according to any one of claims 20 to 23, wherein inducing the flow of aerosol includes inducing the flow at a flow rate ranging from 0.1 l / min- 10.0 l / min, inclusively.

25. The method according to any one of claims 20 to 24, including relieving pressure from the conduit system when a pressure is above a given threshold.

26. The method according to any one of claims 20 to 25, wherein imaging the leak is achieved laparoscopically.

27. The method according to any one of claims 20 to 26, wherein the method is performed in an automated manner.

28. The method according to any one of claims 20 to 27, including emitting light in the pleural cavity to emphasize the leak of the aerosol.

29. The method according to claim 28, wherein emitting light in the pleural cavity includes emitting light from a point of view different from that of the imaging.

30. The method according to claim 29, wherein emitting light from the point of view different from that of the imaging includes backlighting the leak of the aerosol relative to the imaging.

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