Systems and methods for pressure management and air leak detection of inflatable sleeve in medical devices

Abstract

An endotracheal tube or tracheostomy tube with a sleeve assembly includes a sleeve pressure adjuster and a leak detection system. A pressure sensor monitors and measures tracheal wall pressure and pressure in the sleeve assembly. Abnormal readings from the pressure sensor may initiate a sleeve pressure adjustment process. A leak detection system detects air leaks in a seal between the sleeve assembly and the tracheal wall. An odor film having a predetermined odor is positioned on the lower portion of the sleeve assembly on the sealed distal side of the tracheal wall. An air leak is indicated when a predetermined odor is detected in the air in the trachea proximal to the sleeve assembly. The air circulation device generates air flow entering the air pipe, so that a new batch of air can be sampled and tested. A sleeve pressure regulation process may be initiated when an air leak is detected.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 18 / 103,641, filed on January 31, 2023, entitled “System and Method for Pressure Management and Air Leak Detection of an Inflatable Cuff in a Medical Device,” which is a continuation-in-part application under 35 U.S.C. §120 of application No. 17 / 902,691, filed on September 2, 2022, which is incorporated herein by reference in its entirety. Application No. 17 / 902,691, as a continuation-in-part application under 35 U.S.C. §120, claims priority to application No. 17 / 848,273, filed on June 23, 2022 (now granted as U.S. Patent No. 11,602,605), which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to systems and methods for tracheostomy tubes and / or endotracheal cannulas, and more particularly to pressure management and air leak detection systems and methods for inflatable cuff assemblies implemented on endotracheal cannulas and / or tracheostomy tubes. Background Art

[0004] Mechanical ventilation (MV) is a life support measure in which a patient is intubated with a breathing tube and receives oxygen and air delivered by a machine through the breathing tube. The physiologic environment of a mechanically ventilated patient is altered: reduced ability to clear oral and nasal secretions, decreased tracheobronchial mucociliary clearance, increased accumulation of secretions in the lungs and bronchi, reduced cough reflex, and increased likelihood of gastric reflux. The combined effect of these factors is to predispose mechanically ventilated patients to ventilator-associated pneumonia (VAP), a lung infection that typically develops after 48 hours of mechanical ventilation.

[0005] The breathing tube in mechanical ventilation includes an endotracheal tube (ETT) or tracheostomy tube containing an inflatable cuff. The inflatable cuff provides a seal between the breathing tube and the tracheal wall to help prevent secretions from leaking into the lungs and bronchi. In ventilated patients, the accumulation of secretions above the inflatable cuff is a normal physiological phenomenon. The sources of secretions are the mouth, sinuses, and stomach ("orogastric secretions"). It is known that under normal conditions, the mouth and sinuses produce up to 3 liters of secretions per day. Again, this does not include gastric reflux, which may be an important factor. Although healthy people can eliminate and / or control such secretions, ventilated patients cannot. In contrast, in ventilated patients, secretions may accumulate above the inflatable cuff and / or leak around the inflatable cuff into the trachea.

[0006] The problem with the accumulation of secretions above the cuff is that the secretions are loaded with microorganisms, including bacteria and fungi. Because secretions are highly contaminated, they should be kept away from the sterile organs of the human body. The lungs are one of those sterile organs. Therefore, it becomes essential for the treating physician to do their best to keep the secretions out of the patient's lungs.

[0007] An inflatable cuff can be a powerful suction-blocking mechanism. When inflated, the inflatable cuff located at the distal end of the breathing tube is thought to contact the tracheal wall circumferentially, resulting in a complete seal. Unfortunately, inflatable cuffs are known to fail to provide an effective seal, primarily due to wrinkles or folds formed by an oversized cuff as described below. This observation corroborates a study that showed that approximately 10% of mechanically ventilated patients develop ventilator-associated pneumonia (VAP), and the mortality rate of VAP is estimated to be 13%. In addition, patients with VAP face longer hospital stays and incur higher health care costs than similarly ill patients without VAP. Considering that approximately 750,000 patients require ventilation each year in the United States, the human and financial costs of VAP are enormous.

[0008] Maintaining cuff pressure within the recommended range is considered a critical factor in patient care, reducing tracheal injury, and preventing ventilator-associated pneumonia. The ultimate goal of monitoring cuff pressure is to obtain a pressure that is high enough to maintain a good seal between the trachea and the cuff to prevent leakage of secretions, but low enough to avoid compromising tracheal blood flow.

[0009] Today, several cuff pressure management systems are available on the market. However, cuff pressure management systems have not demonstrated clinically meaningful benefits in terms of ventilator-associated pneumonia (VAP) rates and patient outcome measures. Therefore, improved cuff pressure management systems and approaches are needed to help reduce VAP rates and improve patient outcomes. Summary of the invention

[0010] In one aspect, a medical device includes an airway tube configured for implantation in a trachea and a cuff assembly implemented on a distal portion of the airway tube, wherein the cuff assembly includes at least one inflatable cuff. At least one odorous material is positioned on a distal side of the cuff assembly or on a portion of the airway tube that is distal to the cuff assembly. At least one odor detector is configured to detect a predetermined odor of the odorous material from air, wherein the air is sampled from the trachea on a proximal side of the cuff assembly.

[0011] In another aspect, a medical system includes an airway cannula configured for implantation in a trachea and a cuff assembly on a distal portion of the airway cannula. The medical system also includes at least one odorous material positioned on a distal side of the cuff assembly or on a portion of the airway cannula distal to the cuff assembly, wherein the at least one odorous material includes at least one predetermined odor. An air intake opening proximal to the cuff assembly is formed in an outer wall of the airway cannula, and a suction channel extends from the air intake opening to a proximal end of the airway cannula.

[0012] In another aspect, a medical system includes an airway tube configured for implantation in a trachea and a cuff assembly on a distal portion of the airway tube, wherein the cuff assembly includes an inner cuff positioned adjacent the airway tube and an outer bladder positioned adjacent the inner cuff. At least one odorous material is positioned on an underside of the inner cuff or on a portion of the airway tube distal to the cuff assembly, wherein the at least one odorous material includes at least one predetermined odor. At least one odor detector is configured to detect at least one predetermined odor in the air above the cuff from the trachea.

[0013] In one or more of the above aspects, the airway tube includes an air intake opening formed in an outer wall of the airway tube proximally relative to the cuff assembly, and a suction channel extending from the air intake opening to a proximal end of the airway tube.

[0014] In one or more of the above aspects, a vacuum pump is fluidly coupled to the suction channel at the proximal end of the airway tube, wherein the vacuum pump draws air from the trachea through the air intake opening and the suction channel. A filter may be used to remove fluid from the air prior to testing by the at least one odor detector.

[0015] In one or more of the above aspects, the pressure regulator system is configured to adjust the pressure in at least one inflatable cuff of the cuff assembly in response to the odor detector.

[0016] In one or more of the above aspects, the pressure regulator is configured to determine that the odor detector has detected a leak in the seal around the sleeve assembly and generate an alarm on the user interface, wherein the alarm includes one or more of the following: an audible alarm or a visual alarm. The pressure regulator is also configured to adjust the pressure in at least one inflatable sleeve of the sleeve assembly in response to the detected leak.

[0017] In one or more of the above aspects, the first inflation lumen includes a first distal end coupled to the interior of the at least one inflatable cuff. The first inflation lumen also includes a second proximal end fluidly coupled to a first air pump and a first release valve to add or remove air in the at least one inflatable cuff.

[0018] In one or more of the above aspects, the pressure sensor device measures tracheal wall pressure exerted by the cuff assembly.

[0019] In one or more of the above aspects, a pressure regulator adjusts pressure in at least one inflatable cuff of the cuff assembly in response to the detected leak and tracheal wall pressure.

[0020] In one or more of the above aspects, the at least one inflatable cuff is an inner cuff positioned adjacent the airway tube, and the cuff assembly further includes an inflatable outer bladder positioned adjacent an outer surface of the inner cuff.

[0021] In one or more of the above aspects, a pressure sensor device configured to measure tracheal wall pressure is positioned between the inner cuff and the outer balloon.

[0022] In one or more of the above aspects, the inner cuff is inflated within a first pressure range and the outer bladder is configured to be inflated within a second pressure range, wherein the first pressure range is lower than the second pressure range.

[0023] In one or more of the above aspects, the at least one odoriferous material comprises a polymer film embedded with an odorant, wherein the odor embedded film is non-degradable, is waterproof, and does not alter the elasticity of the at least one inflatable sleeve.

[0024] In one or more of the above aspects, the predetermined scent in the at least one inflatable sleeve is released in detectable amounts over a period of 2 to 3 months.

[0025] In one or more of the above aspects, the at least one odor detector is configured to detect the at least one predetermined odor in the air above the cuff from the trachea.

[0026] In one or more of the above aspects, the user interface issues an audible or visual alarm when the at least one odor detector detects the at least one predetermined odor in the air above the sleeve.

[0027] In one or more of the above aspects, the pressure regulator is configured to adjust the pressure of the sleeve assembly when the at least one odor detector detects the at least one predetermined odor in the air above the sleeve.

[0028] In one or more of the above aspects, the pressure sensor device measures tracheal wall pressure applied by the cuff assembly.The pressure regulator adjusts the pressure of the cuff assembly in response to the tracheal wall pressure.

[0029] In one or more of the above aspects, the pressure regulator adjusts the pressure of the inner cuff and / or the outer bladder in response to the odor detector detecting at least one predetermined odor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A perspective view of an embodiment of an airway tube with leak detection is illustrated.

[0031] Figure 2 A cross-sectional view of an embodiment of an airway tube with leak detection is illustrated.

[0032] Figure 3 Another cross-sectional view of an exemplary embodiment of an airway tube with leak detection is illustrated.

[0033] Figure 4A A schematic block diagram illustrating an embodiment of a scent detector system is illustrated.

[0034] Figure 4B A perspective view illustrating an embodiment of a filter and a vacuum pump in an odor detector system.

[0035] Figure 5 A schematic block diagram illustrating an embodiment of a pressure sensor for a double cuff assembly in an airway tube is illustrated.

[0036] Figure 6 A schematic block diagram of an exemplary embodiment of a pressure regulator and control system for a cuff assembly is illustrated.

[0037] Figure 7 A flow chart illustrating an embodiment of one or more methods for monitoring and controlling pressure of a cuff assembly by a regulator system.

[0038] Fig. 8A and Figure 8B A flow chart illustrating an embodiment of a method for determining an operating pressure of a cuff assembly.

[0039] Fig. 9 A schematic block diagram illustrating an embodiment of a user interface for a pressure regulator system.

[0040] Fig.10A schematic block diagram of an embodiment of a pressure regulator system is illustrated.

[0041] Fig.11 A schematic block diagram illustrating an embodiment of a leak detection and pressure regulation system for a single cuff assembly is illustrated.

[0042] Fig.12 A schematic flow chart illustrating an embodiment of a method for leak detection of an tracheal seal formed by a cuff assembly in an airway tube. DETAILED DESCRIPTION

[0043] The wording "exemplary" or "embodiment" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or aspect described herein as "exemplary" or "embodiment" is not necessarily to be construed as preferred or advantageous over other aspects of the invention. Likewise, the wording "aspects" does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation.

[0044] Embodiments will now be described in detail with reference to the accompanying drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the aspects described herein. However, those skilled in the art will appreciate that these and other aspects may be practiced without some or all of these specific details. In addition, in order not to obscure the various aspects of the present disclosure, well-known steps in the methods of the process may be omitted from the flowcharts presented herein. Similarly, well-known components in the device may be omitted from the drawings and descriptions thereof presented herein to avoid confusing the various aspects of the present invention.

[0045] Current pressure management systems require manual monitoring and adjustment of the cuff pressure for an endotracheal cannula or tracheostomy tube. Such manual adjustment is impractical and unreliable, and requires hospital personnel to spend valuable time. The present application describes a novel and innovative pressure management system that continuously receives and processes inputs from relevant sources and seamlessly and automatically adjusts the pressure in the inflatable cuff. This automatic system reduces the work of hospital personnel and helps protect patients from tracheal injury and ventilator-associated pneumonia.

[0046] Furthermore, current pressure management systems tend to malfunction due to their inability to detect leaks around the inflatable cuff. Ultimately, whether a patient will experience VAP depends on the spillage of oral and nasal secretions into the lungs, which depends on the presence of a gap between the cuff and the tracheal wall. The presence of a gap between the cuff and the tracheal wall can be detected by measuring air leaks in the seal. The present application describes a new and innovative pressure management system and method that is able to accurately determine air leaks in the seal formed by an inflatable cuff against the tracheal wall.

[0047] Another key reason for the failure of current pressure management systems is due to their inability to accurately determine the pressure that the cuff applies to the tracheal wall (tracheal wall pressure). Current pressure management systems only measure the pressure within the cuff (intra-cuff pressure). But the intra-cuff pressure has little effect on the tracheal wall pressure. The safe level of cuff inflation level is proportional to the tracheal wall pressure, not to the intra-cuff pressure. Caring for intubated patients without knowing this important information is less than ideal. The current practice of adjusting cuff pressure based on an arbitrary target level (the 25 cm H2O level recommended by the CDC) represents a complete disregard of what is critical to patient safety and health. The present application also describes a novel and innovative pressure management system and method that accurately determines tracheal wall pressure and improves patient outcomes.

[0048] Overview

[0049] A pressure management system is described herein having an effective means for monitoring tracheal wall pressure by utilizing an inter-cuff pressure sensor fixed at the interface between the inner cuff and the outer bladder of a double cuff assembly. The pressure management system performs pressure checks at predetermined intervals and adjusts the cuff volume to achieve a predetermined pressure in the cuff assembly. A leak detection system is also described herein that detects air leaks in the seal between the tracheal wall and the cuff assembly. A strip of plastic film or other material impregnated with an odorant is fixed to the lower portion of the cuff assembly, below the seal with the tracheal wall. In this configuration, air leaks in the seal cause odors to escape from the plastic film and flow into the air of the trachea near the cuff assembly. The odor detector is configured to sample the air near the cuff assembly. When the odor detector detects an odor, an alarm is generated. The pressure management system receives inputs from the odor detector as well as the pressure sensor. The pressure management system automatically adjusts the pressure in the cuff assembly and generates an alarm in response to inputs from the pressure sensor and the odor detector.

[0050] Embodiments of airway tubes with double cuff assemblies

[0051] An airway cannula including a tracheostomy tube or endotracheal cannula or other medical tube with an inflatable cuff assembly is now described in more detail. In one embodiment, the inflatable cuff assembly includes a double cuff. Unlike previously known inflatable cuffs, the double cuff assembly described herein includes at least two independently controlled inflatable cuffs. Currently, there are two main types of cuffs: low volume high pressure (LVHP) cuffs and high volume low pressure (HVLP) cuffs. The first type of LVHP cuff is made of a harder, relatively inelastic material. Due to its inherent stiffness, a higher pressure level (50cm H2O to 100cm H2O) is required to fill the LVHP cuff. Therefore, the LVHP cuff generates excessive pressure on the tracheal mucosa, even when inflated to a minimum pressure to form a seal with the tracheal wall. This high pressure leads to an unacceptably high incidence of tracheal ischemia and necrosis, such as an incidence of 5% to 20%. Nevertheless, a key advantage of the LVHP cuff when filled is the relative absence of wrinkles or wrinkles, thereby obtaining an excellent tracheal seal. The LVHP cuff was first used in the mid-1960s but has been widely replaced by the HVLP cuff.

[0052] The HVLP cuff is composed of a more elastic and compliant material that inflates at lower pressures. To compensate for the lower pressure characteristics and form a seal against the tracheal wall, the diameter of the HVLP cuff is typically 1.5 to 2 times the tracheal diameter when fully inflated. However, the increased volume of the HVLP cuff requires a significant amount of cuff material, which increases the bulk of the HVLP cuff, making intubation more difficult. In addition, the excess material has a tendency to form wrinkles or folds due to "incomplete inflation." These wrinkles or folds often create a path for orogastric secretions to pass through the HVLP cuff, ultimately leading to microaspiration and lung infection.

[0053] In examining the effects of cuff pressure on the trachea, it is important to remember that the capillary perfusion pressure of the human tracheal wall mucosa ranges from 22 to 32 mmHg and that tracheal mucosal blood flow may be compromised at applied pressures above 30 cm H2O (22 mmHg), with blood flow to some segments completely blocked at 50 cm H2O (37 mmHg). Therefore, it is clear that there is only a small overlap between the safe pressure range and the complication pressure range. In practice, the window of effectiveness and safety is very narrow or even nonexistent.

[0054] The pressure required to achieve reasonable inflation of a typical HVLP cuff with an acceptable number of wrinkles or folds is approximately 32 cm H2O. Guidelines developed by various medical societies and organizations recommend that HVLP cuff pressures be maintained in the range of 20 cm H2O to 30 cm H2O to avoid obstruction of tracheal mucosal blood flow. Unfortunately, studies have shown that microsuction of HVLP cuffs occurs even at pressures as high as 60 cm H2O, indicating that wrinkles persist in the cuff even at higher pressures, allowing secretions to pass through. Therefore, even though HVLP cuffs appear superior due to their ability to create a seal at lower pressure levels and avoid tracheal wall necrosis, they are still far from ideal.

[0055] While the primary goals of an inflatable cuff that provides maximum airway seal with minimal damage to the airway are simple and straightforward, successfully achieving these goals has been a challenge. This failure continues despite various modifications and improvements to materials, shapes, and volume structures. Therefore, there is a need for an improved cuff system that helps reduce lung microaspiration and infection by maintaining a good seal with the tracheal wall, but does not unduly damage the tracheal wall.

[0056] In the embodiments described herein, a high pressure outer balloon is attached to the outer surface of the inner cuff. The inner cuff is coupled to the distal end of an endotracheal cannula or tracheostomy tube. The inner cuff is a low pressure inflatable cuff and is configured to operate within a low pressure range of 10 cm H2O to 20 cm H2O. In contrast, the outer balloon is configured to be inflated to a high pressure range of 50 cm H2O to 150 cm H2O. Thus, the inner cuff operates within a pressure range lower than the pressure range of the outer balloon.

[0057] Figures 1 to 3 One embodiment of a tracheostomy tube 100 with leak detection is illustrated. Figure 1 A perspective view of a tracheostomy tube 100 is illustrated, and Figures 2 to 3 Illustrated Figure 1 . Although the tracheostomy tube 100 is illustrated in this example, the leak detection systems and methods described herein can be implemented using an endotracheal tube or other medical device with an inflatable cuff or other type of airtight seal. In this example, the tracheostomy tube 100 includes an outer sleeve 102 and an inner sleeve 150, wherein the inner sleeve 150 is located inside the outer sleeve 102. The outer sleeve 102 and the inner sleeve 150 may include a soft polyvinyl chloride (PVC) material.

[0058] The outer sleeve 102 includes a proximal section 112, a curved middle section 114 and a distal section 116. The proximal section 112 of the outer sleeve 102 includes a flange 108 or plate extending outwardly along the circumference and includes two slits 118a, 118b on opposite sides. A cotton bandage or strap is fixed in the slits 118a, 118b of the flange 108 to keep the tracheostomy tube 100 on the patient's neck. The proximal section 112 also includes a hub 110 extending upwardly from the flange 108 proximally. The inner sleeve 150 is inserted through the proximal opening in the hub 110. The proximal side opening 152 of the inner sleeve 150 is configured to be connected to a ventilator by a tube or hose.

[0059] The outer sleeve 102 of the tracheostomy tube 100 includes a curved middle section 114 and a distal section 116, which are configured and sized to be implanted in the trachea of ​​a patient. The middle section 114 is curved so that the proximal section 112 is at an angle of between about 80 degrees and about 90 degrees to the distal section 116. The distal section 116 includes a sleeve assembly 120, a distal end 126, and a main distal opening 138.

[0060] The tracheostomy tube 100 includes a novel dual cuff assembly 120 disposed at the distal section 116. The cuff assembly 120 includes at least two independently controlled inflatable cuffs, a first inner cuff and a second outer balloon 122. The first inner cuff 124 surrounds and is adjacent to the outer sleeve 102 and is configured to expand radially outward from the tracheostomy tube 100. The second outer balloon 122 is positioned around and adjacent to the outer surface of the inner balloon 124 such that at least a portion of the inner balloon 124 is located between the outer balloon 122 and the tracheostomy tube 100. The outer balloon 122 is configured to expand radially outward from the inner cuff 124 such that when implanted in the trachea of ​​a patient, the outer surface of the outer balloon 122 contacts the tracheal wall and forms a seal.

[0061] The inner sleeve 124 and the outer bag 122 can be cylindrical or annular. Figure 1 As shown, when inflated, the outer balloon 122 is a ring with a torus shape having a circular cross-section. The inner cuff 124 has a cylindrical shape with an arched outer surface that forms a ring around the tracheostomy tube 100. In this example, the length of the inner cuff is in the range of 10 mm to 20 mm, and the length of the outer cuff is in the range of 5 mm to 9 mm. The outer balloon 122 is bonded to the inner cuff 124 without being constrained to the outer sleeve 102 of the tracheostomy tube 100. The inner cuff 124 is attached to the outer sleeve 102 by an adhesive and / or a strap. These specifications are exemplary, and the inner balloon 124 and / or the outer cuff 122 may have alternative shapes, sizes, and attachment means.

[0062] The inner cuff 124 and the outer balloon 122 are configured for different operating pressures, and thus the tracheostomy tube 100 includes means for inflating the inner cuff 124 and the outer balloon 122 to different pressures. Figure 2 102. The first passage 200 is formed between the inner and outer walls of the outer sleeve 102. The first passage 200 extends from the proximal side of the flange 108 (e.g., at the hub 110) to at least the sleeve assembly 120 on the front side of the outer sleeve 102. The distal end 206 of the inflation line 106a extends through the opening 204 in the outer wall of the outer sleeve 102 and into the inner sleeve 124. The inflation line 106a forms an airtight fluid connection for inflating and deflating the inner sleeve 124.

[0063] The second inflation line 106b is located at Figure 3 102. The second passage 300 is formed between the inner wall 302b and the outer wall 302a on the front side of the outer sleeve 102. The second passage 300 extends from the proximal side of the flange 108 to at least the sleeve assembly 120 at the hub 110 of the outer sleeve 102. The second inflation line 106b is located inside the second passage 300. The distal end of the inflation line 106b extends into the outer bag 122 through the sealed opening 304 in the outer wall 302a of the outer sleeve 102. The inflation line 106b thus forms an airtight fluid connection for inflating and deflating the outer bag 122.

[0064] In this embodiment, two channels 200, 300 for holding the inflation lines 106a, 106b are formed in the front wall of the outer sleeve 102. In another embodiment, the two channels 200, 300 can be formed in the side wall of the outer sleeve 102. In yet another embodiment, a single channel can accommodate both inflation lines 106a, 106b. In yet another embodiment, the channels 200, 300 can be formed between the inner sleeve 150 and the outer sleeve 102, for example, on the front side of the tracheostomy tube 100. Other implementations can also be used to position the inflation lines 106a, 106b from the proximal side of the flange 108 to the cuff assembly 120 of the tracheostomy tube 100.

[0065] Due to the separate means for inflation, such as inflation lines 106a, 106b, the outer bag 122 and the inner cuff 124 can be inflated to and maintained at different pressures. In an embodiment, the inner cuff 124 is a low-pressure inflatable cuff and is configured to operate in a low pressure range of 10cm H2O to 20cm H2O. In contrast, the outer inflation bag 122 is configured to be inflated to a higher pressure range of 50cm H2O to 150cm H2O. Therefore, the inner cuff 124 operates in a pressure range lower than the pressure range of the outer bag 122.

[0066] In addition, the inner sleeve 124 includes a relatively elastic material and the outer bladder 122 includes a relatively inelastic material, for example, the material of the outer bladder 122 is less elastic than the material of the inner sleeve 124. For example, the relatively elastic material of the inner sleeve 124 may include one or more of the following: rubber, silicone, latex, polyvinyl chloride (PVC), neoprene, polyisoprene, or polyurethane (PU). The relatively inelastic material of the outer bladder 122 may include one or more of the following: polyethylene terephthalate (PETP), low density polyethylene (LDPE), polyvinyl chloride (PVC), silicone, neoprene, polyisoprene, or polyurethane (PU).

[0067] In use, e.g., when positioned in the trachea of ​​a patient and pressurized to an inflated state, the first inner cuff 124 behaves as an HVLP-type cuff, while the second outer balloon 122 behaves as an LVHP-type cuff. The more compliant inner cuff 124 is able to regulate the pressure exerted on the tracheal wall by the higher pressurized outer balloon 122 ("tracheal pressure"). In other words, the lower pressure, more resilient inner cuff 124 is configured to absorb excess pressure that may otherwise be exerted on the tracheal wall by the outer balloon 122. For example, due to the greater compliance and resiliency of the inner cuff 124, the cuff assembly 120 exerts a lower total pressure / force on the tracheal wall, e.g., lower than the outer balloon pressure. The force of the inner cuff 124 acts radially on the outer balloon 122 and therefore represents the force ultimately exerted on the trachea as the tracheal pressure. Thus, the radial force generated by the inner cuff 124 and acting on the outer balloon 122 is the tracheal pressure. For example, when the outer balloon pressure is greater than the intra-cuff pressure, and the outer balloon 122 is inflated so that the outer surface contacts the trachea, the intra-cuff pressure is the same as the tracheal wall pressure.

[0068] In addition, due to its operation at high pressures, the outer balloon 122 in the expanded state forms a relatively smooth surface with fewer folds or wrinkles, for example, compared to an LVHP cuff. This reduction in wrinkles reduces the risk of leaks and creates a more uniform tracheal seal.

[0069] Thus, the cuff assembly 120 utilizes a novel system to titrate tracheal pressure, thereby reducing tracheal complications. By combining the characteristics of HVLP and LVHP cuffs into the cuff assembly 120, the cuff assembly 120 utilizes the advantages found in both types of cuffs: excellent tracheal seal, greater safety to the trachea. The cuff system 120 is characterized by an excellent seal to the tracheal wall with reduced tracheal trauma. Thus, the cuff assembly 120 helps protect the lungs from contamination with orogastric contents or blood without causing undue damage to the tracheal wall.

[0070] Figure 2The cross section of the airway tube 100 in FIG. 1 also illustrates a suction channel 136 and a conduit 134 coupled to the suction channel 136. The air intake opening 130 is shown as being located on the rear side of the airway tube, but may also be located on the front side of the cuff assembly 120 or otherwise on the proximal side thereof. In this example, a stopper 210 is positioned in the suction channel 136 at a position distal to the air intake opening 130. The stopper 210 is sized to block the suction channel 136 and provide a seal to the suction channel 136 to prevent air or fluid from flowing to the distal end 126 of the airway tube 100.

[0071] How Leak Detection Systems are Implemented

[0072] In an embodiment, the tracheostomy tube 100 further comprises a leak detection system that detects air leaks in the seal between the tracheal wall and the cuff assembly 120. The leak detection system comprises a plastic film 128 or other material impregnated with an odorant, such as Figures 1 to 3 As shown, it is positioned on the distal end 126 of the tracheostomy tube 100, for example, on the distal side that seals with the tracheal wall. In this example, the scent membrane 128 comprises a strip fixed circumferentially around the front of the inner sleeve 124.

[0073] The scent film 128 may include one or more types of scents - woody scents, fresh scents, herbal scents, floral scents, fruity scents, etc. The predetermined scents are preferably long-lasting, well-tolerated, pleasant and safe for people. In addition, the predetermined scents are configured to chemically interact with the chemical sensors of the scent detector.

[0074] The one or more predetermined odorants are impregnated into one or more plastic polymers and made into films. The one or more plastic polymers may include polyethylene, polypropylene, polystyrene, cellulose derivatives and acrylonitrile-butadiene-styrene. The one or more plastic polymers are formulated to allow the impregnated odorants to be slowly released in a detectable amount over a long period of time, for example, 2 to 3 months after opening. The film preferably has a long shelf life, for example, a sealed, airtight package that preserves the one or more predetermined odorants impregnated in the one or more plastic polymers until opening. The odor film 128 is preferably thin and flexible, for example, equal to or less than 1 mm, so that it does not significantly change the elastic properties of the inner sleeve 124. The odor film 128 is preferably harmless to the human body, and is resistant to degradation and fluid. The odor film 128 can be fixed with adhesive and / or with heat or by other means. Although the plastic polymer film embedded with an odorant is described herein, any other type of odorant material including a slowly evaporating odorant that can be detected by an odor detector can be used.

[0075] The scent membrane 128 may be secured to the front of the inner cuff 124 as shown, or may alternatively be positioned on the front of the outer balloon 122, as long as the scent membrane 128 is below the seal formed between the cuff assembly 120 and the tracheal wall. In another example, the scent membrane 128 may be positioned on the distal end 126 of the tracheostomy tube 100, preferably near or adjacent to the cuff assembly 120. The scent membrane 128 is preferably not positioned near the distal opening 138 of the airway tube 100, where it may be unnecessarily exposed to the inhaled and exhaled air, thereby evaporating the scent from the membrane 128 too quickly. By placing the scent membrane 128 away from the air flow, such as on the back side of the cuff assembly 120, or adjacent to the cuff assembly 120 or just distal to the cuff assembly 120, the scent on the scent membrane 128 may persist for a longer period of time.

[0076] To detect air leaks, an air intake opening 130 is formed in the outer wall of the airway tube 100 on the proximal side of the cuff assembly 120, e.g., above the seal with the tracheal wall. The air intake opening 130 fluidly connects the air above the cuff in the trachea to the suction channel 136 (see FIG. Figure 2 and Figure 3 ). The stopper 140 is located in the suction channel 136 at a distal position relative to the opening 310 to prevent air from flowing into the suction channel 136 from the distal side of the sleeve assembly 120. In another embodiment, the suction channel 136 terminates at the air intake opening 130. The proximal end of the suction channel 136 is connected to the air duct 134 at the hub 110. The air pump is fluidly attached to the opposite end of the air duct 134 so that the air pump is fluidly coupled to the air inlet 130. The air duct 134 or air pump also includes a valve that fluidly couples the odor detector to the air above the sleeve flowing through the air duct 134.

[0077] When the tracheostomy tube 100 is positioned in the patient and the sleeve assembly 120 is inflated, an airtight seal should be formed between the sleeve assembly 120 and the tracheal wall to prevent fluid and / or secretions from leaking into the trachea. When an airtight seal is not formed, air flows from the scent membrane 128, through the seal, and into the air inlet 130. The scented air then flows through the suction channel 136 to the air duct 134 and to the scent detector. The scent detector can therefore detect the odor and generate an alarm that the seal is compromised, as described in more detail herein.

[0078] Figure 4AA schematic block diagram of an embodiment of an odor detector system 400 is illustrated. The system 400 includes one or more odor detectors 410 and a vacuum pump 420. In one embodiment, the odor detector 410 is an electronic device including at least one receiver and at least one transducer. The receiver includes a compound designed to react with a chemical in a predetermined odorant in the odor membrane 128. The sensor then measures the chemical reaction to the predetermined odorant. The chemical reaction can increase or decrease the impedance of the receiver. For example, when the polymer in the transducer contacts the predetermined odorant, it expands, thereby changing its resistance. This change in the resistance of the polymer is measured, and the presence of the predetermined odorant is determined from the measurement results.

[0079] The vacuum pump 420 in the odor detector system acts as a low-pressure vacuum to draw air above the cuff from the trachea. The vacuum pump 420 or air duct 134 includes valves and ports to provide samples of the area above the cuff to the odor detector. Before the next test, the air above the cuff in the trachea needs to be circulated and replaced to determine whether the odorous air is still leaking from the tracheal wall seal. Otherwise, after the seal is improved and becomes airtight, the air pump can provide the odorous air remaining in the trachea from the previous test to the odor detector 410. Then, the odor detector 410 will detect the odor and generate an alarm, even if the seal is now airtight. In order to prevent this repeated sampling of the same air, the vacuum pump 420 draws air from the trachea for a predetermined period of time. This period of suction removes the previously sampled air from the trachea and helps to draw a new batch of air into the trachea. After the predetermined suction period, the air vacuum 420 provides an air sample to the odor detector 410, which tests the presence of a predetermined odor at the odor detector 410. When the odor detector 410 detects a predetermined odor, it then generates an alarm. For example, the alarm may include an audible warning and / or a visual alarm on a display, etc.

[0080] Filter 430 may also be used to filter the air sample from the suction channel 136 and / or the duct 134. The air sample may include secretions and other fluids that accumulate in the region above the sleeve, particularly on the proximal side of the sleeve assembly 120. Therefore, the air sample in the suction channel 136 and the duct 134 may also include such fluids. The filter 430 is configured to remove secretions or other fluids in the air sample, and little or no predetermined odor is removed in the air sample. In an embodiment, even when no odor detection test is performed, suction and filtering of air and secretions from the region above the sleeve may be performed at periodic intervals. This periodic suction of the fluid in the region above the sleeve helps prevent the accumulation of secretions that may cause leakage into the lungs.

[0081] Figure 4BA perspective view of an embodiment of a filter 430 and a vacuum pump 420 is illustrated. In this example, the filter 430 is a liquid collection canister coupled to the suction channel 136 via a conduit 134. Air above the cuff with secretions or other fluids enters the collection canister, and the liquid falls to the bottom of the canister due to its heavier weight. The air and any odors remain on the top of the canister. The suction vacuum siphons the air sample from the top of the canister and exposes the air sample to the odor detector. The collection canister can be equipped with an overflow shutoff valve to prevent overflow.

[0082] Although a liquid collection canister is described herein, other types of air filters may also be implemented. For example, a coalescing filter that uses a filter medium to remove droplets and other particles from the air may be implemented. In other examples, a demister or vapor removal filter provides an alternative to a coalescing filter.

[0083] In embodiments, a syringe or vacuum device may also be attached to tubing 134 to remove secretions or other fluids that accumulate on the proximal side of cuff assembly 120 when air testing is not being performed. Aspiration of secretions may occur at periodic intervals and may be done manually or automatically.

[0084] Although a tracheostomy tube 100 is described herein, the cuff assembly 120 may be implemented in conjunction with any suitable medical device including, but not limited to, an endotracheal cannula or other airway tube, a catheter, a stent, and / or a feeding tube.

[0085] Implementation of the pressure regulation system

[0086] Figure 5 A schematic block diagram of an embodiment of a pressure sensor for an airway tube 100 (e.g., a tracheostomy tube, endotracheal cannula, or other airway tube) including a cuff assembly 120 is illustrated. In an embodiment, the cuff assembly 120 includes at least one in-cuff pressure sensor 510a associated with the inner cuff 124 and at least one in-cuff pressure sensor 510b associated with the outer bladder 122. The in-cuff pressure sensor 510a is located within the inner cuff 124 and is configured to measure the air pressure within the inner cuff 124. Additionally or alternatively, a pressure sensor (not shown) can be positioned at the proximal end of the inflation line 106a, such as as part of an indicator bladder, to measure the air pressure within the inner cuff 124. The in-cuff pressure sensor 510b is located within the outer bladder 122 and is configured to measure the air pressure in the outer bladder 122. Additionally or alternatively, a pressure sensor (not shown) may be positioned at the proximal end of the inflation line 106 b , such as at the indicator balloon, to measure the air pressure within the outer balloon 122 .

[0087] In an embodiment, one or more pressure sensors 530a-530b may be positioned on the outer surface of the outer balloon 122 to measure the pressure or force applied by the cuff assembly 120 to the tracheal wall ("tracheal pressure"). However, these sensors 530a-530b may cause damage to the tracheal wall when pressed against the tracheal wall. Therefore, alternatively or additionally, one or more inter-cuff pressure sensors 520a-520b may be positioned between the outer balloon 122 and the inner cuff 124 to measure tracheal pressure. Since the force of the inner cuff 124 acts radially on the outer balloon 122, the inter-cuff pressure sensors 520a-520b ultimately measure the force applied by the cuff assembly 120 on the tracheal wall. In this way, the inter-cuff pressure sensors 520a-520b measure tracheal pressure, such as the pressure applied by the cuff assembly 120 on the tracheal wall. In one example, the tracheal wall pressure sensors 520a-520b and 530a-530b may include thin film pressure sensors with force sensitive resistors that change resistance based on the applied force. The pressure sensors 510a-510b may include resistive or capacitive air pressure transducers. Additional pressure sensor devices may be positioned within the indicator balloon of the inflation line 106a-106b to measure the intra-cuff pressure, or positioned within or at the tip of the airway tube 100 to measure the pressure of the oxygenated air delivered to the patient.

[0088] The pressure sensors may each include a wireless transmitter to transmit the pressure measurement results to the pressure regulation system. For example, the wireless transmitter may include a wireless transmitter such as a near field or radio frequency identification (RFID) transmitter or an Internet of Things (IoT) cellular type transmitter. Alternatively, the pressure sensor may include a wired transmitter to transmit the pressure measurement results.

[0089] The benefits and risks of the sleeve assembly 120 rely on maintaining a predetermined pressure range in the sleeve assembly 120, rather than the airway tube itself. For example, overinflation of the sleeve assembly 120 may cause damage to the tracheal mucosa, resulting in ischemic injury and vocal cord nerve damage. The damage is due to the constant pressure applied by the sleeve to prevent blood from flowing to the tracheal mucosa. This blood loss flow may cause tissue necrosis. In addition, damage may also occur due to repeated wear and tear of the sleeve moving on the tracheal wall. When the sleeve is under-inflated and the tracheal seal is not sufficient, the patient may not receive enough oxygen. In addition, the patient has an increased likelihood of pneumonia due to aspiration of orogastric contents. Therefore, maintaining the pressure of the sleeve assembly 120 of the airway tube 100 is a key part of patient care, reducing tracheal injury and preventing ventilator-associated pneumonia (VAP).

[0090] Currently, several types of automatic cuff pressure adjusters are available. These current devices monitor the intra-cuff pressure within a single cuff. However, a closer inspection reveals a major flaw in this approach. The intra-cuff pressure does not reflect the precise pressure applied to the tracheal wall, but only the air pressure within the inflated cuff. Ultimately, it is the tracheal wall pressure that determines the risks and benefits of the cuff. Therefore, there is a need for an improved system and method to monitor and adjust cuff pressure.

[0091] Figure 6 A schematic block diagram of an exemplary embodiment of a pressure regulator and control system ("regulator system") 600 for a cuff assembly 120 is illustrated. The regulator system 600 is in fluid communication with the cuff assembly 120 and, for example, inflates and regulates the pressure within the cuff assembly 120 using measurements of tracheal wall pressure and leak detection when the airway tube 100 is implanted in the trachea of ​​a patient. The regulator system 600 includes a pressure controller 606 and a pneumatic system 620. The pressure controller 606 includes a processor device 608 and a memory device 610. The memory device 610 includes one or more non-transitory processor-readable memories storing instructions that, when executed by the processor device 608 or other components of the regulator system 600, cause the regulator system 600 to perform one or more functions described herein. The processor device 608 includes at least one processing circuit, such as a microprocessor, a microcontroller, a digital signal processor, a microcomputer, a central processing unit, a field programmable gate array, a programmable logic device, a state machine, a logic circuit, an analog circuit, a digital circuit, and / or any device that manipulates signals (analog and / or digital) based on hard coding of circuits and / or operating instructions. The memory device 610 includes a non-transitory memory device and can be an internal memory or an external memory and can be a single memory device or a plurality of memory devices. The memory device 610 can be a read-only memory, a random access memory, a volatile memory, a non-volatile memory, a static memory, a dynamic memory, a flash memory, a cache memory, and / or any non-transitory memory device that stores digital information.

[0092] The pressure controller 606 can be co-located in the same physical device as the pneumatic system 620, or in separate devices or housings. The pressure controller 606 also includes a user interface 612. The user interface 612 generates user input and output (I / O) and includes one or more of a display, keyboard, touch screen, mouse, touch pad, gauges, switches, or other I / O devices.

[0093] In use, the pressure setting of the sleeve assembly 120 is determined. The pressure controller 606 can use a default pressure setting or a pressure setting received from a user. Different pressure settings are used for the inner sleeve 124 and the outer bladder 122. For example, the pressure setting of the inner sleeve can be a pressure in the range of 10cm H2O to 20cm H2O (plus or minus 2cm H2O). In contrast, the pressure setting for the external inflatable airbag can be a pressure in the range of 50cm H2O to 150cm H2O (plus or minus 2cm H2O). Therefore, the inner sleeve 124 operates in a pressure range that is lower than the operating pressure range of the outer bladder 122. The pressure controller 606 also determines the frequency of measuring and adjusting the pressure of the sleeve assembly 120, such as through user input or default settings.

[0094] The pneumatic system 620 has a first pneumatic path for the outer bladder 122, which includes, for example, a first air pump 622a and a release valve 624a, which is fluidly coupled to the outer bladder 122 via an inflation line 106b. The pneumatic system 620 also includes a different second pneumatic path for the inner cuff 124, which includes a second air pump 622b and a release valve 624b, which is fluidly coupled to the inner cuff 124 via, for example, an inflation line 106a. Although two air pumps 622a, 622b are described herein, a single air pump can supply pressurized air to the inner cuff 124 and the outer bladder 122, for example, using a valve or switch between the two fluid paths. Thus, the pneumatic system 620 includes separate pneumatic paths to fluidly increase or decrease the pressure in the inner cuff 124 and the outer bladder 122 independently and separately.

[0095] In operation, the pressure controller 606 receives pressure measurements from one or more pressure sensor devices to adjust the pressure of the cuff assembly 120. For example, the one or more pressure sensor devices may include one or more in-cuff pressure sensor devices 510a-510b located within the inflated inner cuff 124 and outer bladder 122 and / or within the indicator bladder of the inflation line 106a-106b leading to the bladder assembly 120. For example, the in-cuff pressure sensor devices 510a-510b measure the internal air pressure of the inner cuff 124 and outer bladder 122 and transmit the measurement results to the pressure controller 606. In addition, one or more inter-cuff pressure sensor devices 520a-520b measure tracheal wall pressure. One or more outer cuff assembly pressure sensor devices 530a-530b can be positioned on the outer surface of the outer bladder 106 to further measure tracheal wall pressure. The pressure controller 606 may also receive input from one or more odor detectors 410. Additional pressure sensor devices may also be implemented. The pressure sensor device generates pressure measurements and transmits them to the pressure controller 606, such as via wired conductors and / or a wireless transmitter.

[0096] The regulator system 600 includes a pressure feedback loop in which a pressure controller 606 controls a pneumatic system 620 to adjust the pressure for both the inner sleeve 124 and the outer bladder 122 in response to pressure measurements and / or an odor detector. The pressures of the inner sleeve 124 and the outer bladder 122 are monitored and controlled separately. The pressure controller 606 sends a signal to the pneumatic system 620 to add or release air to the outer bladder 122 and / or the inner sleeve 124. For example, to adjust the pressure in the outer bladder 122, the pressure controller 606 may send a signal to the air pump 622a to add air to the outer bladder 122, or to the release valve 624a to release air from the outer bladder 122. In another example, to adjust the pressure in the inner sleeve 124, the pressure controller 606 may send a signal to the air pump 622b to add air to the inner sleeve 124, or to the release valve 624b to release air from the inner sleeve 124.

[0097] The regulator system 600 monitors the pressure measurements from the pressure sensor and the alarms from the odor detector and automatically adjusts the pressure in the sleeve assembly 120 in response thereto. The pressure controller 606 may continuously monitor and adjust the pressure of the sleeve assembly 120, or may monitor and adjust the pressure at predetermined intervals. The regulator system 600 may also include visual and / or audible warnings in the event of unsafe pressure measurements.

[0098] Figure 7 A flow chart illustrating an embodiment of one or more methods 700 for monitoring and controlling the pressure of a cuff assembly 120, for example, by a regulator system 600. At step 702, one or more pressure measurements related to tracheal wall pressure are obtained by the regulator system 600 from one or more pressure sensor devices. At step 704, using these pressure measurements, the regulator system 600 determines whether the tracheal pressure (e.g., the pressure exerted on the tracheal wall by the cuff assembly 120) is within a predetermined pressure range. The pressure measurements may come from one or more inter-cuff pressure sensor devices 520a-520b between the inner cuff 124 and the outer bladder 122 and / or from one or more pressure sensors 530a-530b located on the outer surface of the outer bladder 122. When the tracheal pressure exceeds the predetermined pressure range, at step 706, the regulator system 600 reduces the pressure in at least the inner cuff 124. For example, the regulator system 600 may control the release valve 624b to release air from the inner cuff 124. Because tracheal mucosal blood flow may be compromised when applied pressure is above 30 cm H2O (22 mmHg), the regulator system 600 may reduce the pressure of at least the inner cuff 124 when the measured tracheal pressure exceeds 30 cm H2O (22 mmHg).

[0099] When the tracheal pressure is below the predetermined pressure range, the regulator system 600 increases the pressure in at least the inner cuff 124 at step 706. For example, the regulator system 600 may control the air pump 622b to pump air into the inner cuff 124. In addition, the pressure of the outer bladder 122 may also be adjusted. These steps may be performed at preset intervals or continuously.

[0100] At step 708, one or more pressure measurements related to the outer bladder pressure are obtained by the regulator system 600 from one or more pressure sensor devices. At step 710, the regulator system 600 determines whether the pressure of the outer bladder 122 is within a predetermined pressure range using these pressure measurements. For example, the pressure measurements may come from one or more pressure sensor devices 510b located within the outer bladder 122, or from an indicator air bag for the outer bladder 122, or from an inflation line 106b for the outer bladder 122. When the pressure of the outer bladder 122 is below or above the predetermined pressure range, at step 712, the regulator system 600 increases or decreases the pressure in the outer bladder 122. For example, the regulator system 600 may control the air pump 622a to pump air into the outer bladder 122 when the outer bladder pressure is below the predetermined pressure range, or control the release valve 624a to release air from the outer bladder 122 when the outer bladder pressure is above the predetermined pressure range. The outer bladder 122 may have a predetermined pressure range of 50 cm H2O to 150 cm H2O.

[0101] At step 714, one or more pressure measurements related to the pressure of the inner cuff 124 are obtained by the regulator system 600 from one or more pressure sensor devices. At step 716, using these pressure measurements, the regulator system 600 determines whether the pressure of the inner cuff 124 is within a predetermined pressure range. For example, the pressure measurements may come from one or more pressure sensor devices 510a located within the inner cuff 124 or at an indicator bladder for the inner cuff 124 or at an inflation line 106a for the inner cuff 124. When the pressure within the cuff is below or above the predetermined pressure range, at step 718, the regulator system 600 may increase or decrease the pressure in the inner cuff 124. For example, the regulator system 600 may control the air pump 622b to pump air into the inner cuff 124 when the pressure of the inner cuff 124 is below the predetermined pressure range, or control the release valve 624b to release air from the inner cuff 124 when the pressure of the inner cuff 124 is above the predetermined pressure range. In one example, the predetermined pressure range may be 10 cm H20 to 20 cm H20.

[0102] The pressure of the inner cuff 124 and outer bladder 122 of the cuff assembly 120 is thus controlled separately using separate pneumatic pathways (e.g., separate air pumps 622 and / or release valves 624 and separate inflation lines 106a-106b). The pressure of the less elastic outer bladder 122 is maintained at a higher pressure than the pressure of the more elastic inner cuff 124. Thus, the pressure controller 602 can independently adjust the pressure of the inner cuff 124 or outer bladder 122 to adjust the tracheal pressure.

[0103] FIG. 8A to FIG. 8B A schematic block diagram of an embodiment of a method 800 for determining an operating pressure of a cuff assembly 120 is illustrated. After implantation, a cuff-bladder pressure adjustment process can be performed to determine the operating pressure. Process 800 can also be performed in whole or in part after inflation in response to leak detection, out-of-range pressure measurements from the inner cuff 124, outer bladder 122, or tracheal wall pressure (e.g., from the intercuff sensors 520a-520b or outer cuff assembly sensors 530a-530b), or in response to a manual request.

[0104] The process 800 begins with the pressure regulator system 600 inflating or deflating the inner cuff 124 and the outer bladder 122 to respective initial pressure levels at 802. For example, the initial pressure level of the inner cuff 124 may include a pressure range of 8 to 12 cm H2O, or approximately 10 cm H2O. The initial pressure level of the outer bladder 122 may include a pressure range of 35 to 45 cm H2O, or approximately 40 cm H2O. The initial pressure levels may be set by default, or may be input by an operator through the user interface 612.

[0105] After the inner cuff 124 and the outer bladder 122 are at their respective initial pressure levels, the tracheal wall pressure is obtained at 804. The pressure regulator 600 can determine the tracheal wall pressure based on the average, mean, or maximum of the measurements from the inter-cuff pressure sensors 520a-520b and / or the pressure sensor devices 530a-530b on the outer surface of the cuff assembly 120. When the tracheal wall pressure is greater than the predetermined maximum tracheal pressure at 806, an alarm is generated at 808. The alarm can indicate that the maximum tracheal pressure has been exceeded and / or can indicate, for example, to replace the current airway tube (e.g., endotracheal or tracheostomy tube) with an airway tube having a larger outer diameter. When the airway tube is replaced, the process 800 starts again at 802.

[0106] When the tracheal wall pressure is lower than the predetermined maximum tracheal pressure at 806, an air leak test is performed at 810. The air leak test includes obtaining an air sample from the cuff-top region of the trachea. The air exhaust system (e.g., opening 130, suction channel 136, and airway cannula 134) of the airway 100 is connected to a low-pressure vacuum pump 420 to provide good circulation in the cuff-top region. The cuff-top air is sampled for the presence of one or more predetermined odorants. When no air leak is detected at 812, it indicates that the cuff assembly 120 has a good seal with the tracheal wall. The pressure of the cuff assembly 120 is then maintained and monitored at 814. The air leak test can be repeated periodically or on command to ensure that the cuff assembly 120 maintains a good seal with the tracheal wall.

[0107] When an air leak is detected at 812, this indicates that the cuff assembly 120 does not have a good seal with the tracheal wall. To obtain a better seal, the pressure in the inner cuff 124 is adjusted at 816. For example, the pressure in the inner cuff 124 can be increased in increments of 1 to 2 cmH2O. After the pressure of the inner cuff 124 is incrementally increased, it is determined at 818 whether the pressure in the inner cuff is greater than 25H2O, such as a maximum intra-cuff pressure. When not, it is determined at 820 whether the tracheal wall pressure is greater than the maximum tracheal wall pressure. When the tracheal wall pressure exceeds the maximum tracheal wall pressure at 820, an alarm is generated at 822. The alarm may indicate that the maximum tracheal pressure is exceeded and / or may indicate, for example, that the current airway tube (e.g., an endotracheal or tracheostomy tube) is replaced with an airway tube having a larger outer diameter. When the airway tube 100 is replaced, the process 800 begins again at 802.

[0108] When the tracheal wall pressure is below the maximum tracheal wall pressure at 820, another air leak test is performed at 824. These steps of increasing the pressure in the inner cuff 124 and performing an air leak test may be repeated until the pressure in the inner cuff 124 is greater than the maximum cuff intra-pressure (e.g., 25 cm H2O) or the tracheal wall pressure exceeds the maximum tracheal pressure (e.g., 25 cm H2O). When no leak is detected at 824, the pressure of the cuff assembly 120 is maintained and monitored at 826. The air leak test may be repeated periodically or on command to ensure that the cuff assembly 120 maintains a good seal with the tracheal wall.

[0109] When a leak is still detected at 824 and the incremented pressure of the inner cuff 124 exceeds the maximum cuff pressure at 818, the process proceeds to Figure 8BStep 830 is performed, as shown by arrow A. At step 830, the pressure in the outer balloon 122 is adjusted. For example, the pressure in the outer balloon can be increased in increments of 2 to 3 cm H2O. After the pressure of the outer balloon 122 is incrementally increased, it is determined at 832 whether the pressure in the outer balloon 122 is greater than the maximum outer balloon pressure, such as 60 cm H2O. When the outer balloon 122 is greater than the maximum outer balloon pressure at 832, an alarm is generated at 834. The alarm can indicate that the leak detection exceeds the maximum outer balloon pressure, and / or can indicate, for example, to replace the current airway tube (e.g., an endotracheal or tracheostomy tube) with an airway tube having a larger outer diameter. When the airway tube 100 is replaced, the process 800 starts again at 802.

[0110] When the pressure in the outer balloon 122 is not greater than the maximum outer balloon pressure at 832, the cuff pressure is adjusted to a lower pressure, such as an initial pressure of 10 cm H2O, at 836. At 838, it is determined whether the tracheal wall pressure is greater than the maximum tracheal wall pressure. When greater than the maximum tracheal wall pressure, an alarm is generated at 840. The alarm may indicate that the maximum tracheal pressure has been exceeded and / or may indicate, for example, that the current airway tube (e.g., an endotracheal or tracheostomy tube) is replaced with an airway tube having a larger outer diameter. When the airway tube 100 is replaced, the process 800 begins again at 802.

[0111] When the tracheal wall pressure is below the maximum pressure at 838, an air leak test is performed at 842. The air leak test determines whether a good seal is formed at the new increased pressure of the outer bladder 122 and the initial pressure of the inner cuff 124. When no leak is detected at 844, the pressure of the cuff assembly 120 is maintained and monitored at 846. The process continues to Fig. 8A 810 in step 810, as shown by arrow C. Periodic air leak testing is performed to ensure that the cuff assembly 120 maintains a good seal with the tracheal wall.

[0112] When a leak is detected at 844 at the new increased pressure of the outer bladder 122 and the initial pressure of the inner cuff 124, the process continues to Fig. 8A 816 in the process, as indicated by arrow B. The initial pressure of the inner cuff 124 is then increased until no leak is detected at 824 or the maximum intra-cuff pressure is reached at 818. When the maximum intra-cuff pressure is reached at 818, the process continues again to 830, and the pressure in the outer bladder 122 is increased to a higher pressure. When no air leak is detected at 824 or 844, the pressures of the inner cuff and outer bladder are below their respective maximum values, and the tracheal wall pressure is below the maximum value, the process 800 is complete.

[0113] In this process 800, the pressure in the inner cuff 124 is first increased within its operating range while maintaining the initial pressure of the outer cuff. If a leak is still detected, the outer cuff pressure is increased to a higher pressure and the inner cuff is reset to its initial pressure and increased within its operating range until no leak is detected. Throughout the process 800, the tracheal wall pressure does not exceed a maximum pressure, for example, within a range of 20 to 25 cm H2O. If the tracheal wall pressure exceeds the maximum pressure to achieve airtight cuff inflation, the size of the airway tube is adjusted, for example, the size is increased to a larger next size. When another airway tube is implanted in the patient, the entire process 800 is repeated to adjust the pressure in the cuff assembly 120. Therefore, the cuff assembly 120 and the regulator system 600 provide a process for determining and maintaining the optimal operating pressure of the cuff assembly 120 without leaks. The process helps to reduce microaspiration and infection of the lungs by obtaining and maintaining a good seal with the tracheal wall without excessively damaging the tracheal wall.

[0114] Fig. 9 A schematic block diagram of an embodiment of a user interface 900 for a pressure regulator system 600 is illustrated. The user interface 900 receives settings and commands from a user. In one example, the user interface 900 includes a display 902, which may be an interactive touch screen. The display 902 includes one or more icons or data displays, such as a display of a current tracheal wall pressure 904 and a warning / alarm 906. The display 902 also includes a display of a cuff pressure 908, such as a set or target pressure 910 and a current pressure 912 for the inner cuff 124 and the outer bladder 122. The display 902 may also include a display of leak detection 914, such as the time of the last test 916 and the results of the last test 918. Additional and / or alternative data may also be presented in the display 902.

[0115] The user interface 900 also includes one or more user input devices, such as a knob controller, a button, a touch pad, a switch, etc., to receive one or more commands from the user. Alternatively, the display 900 may include an interactive touch screen that displays one or more icons to receive user commands. For example, the user interface 900 includes a power button / icon 930 that activates power on of the pressure regulator 600. The deflation button / icon 940 activates deflation of the sleeve assembly 120, for example, for removing the airway tube 100 from the patient.

[0116] The automatic mode button / icon 942 can be activated to initiate the automatic mode. In the automatic mode, the pressure regulator 600 automatically inflates the cuff assembly to the default setting and performs FIG. 8A to FIG. 8B120 to determine the operating pressure in the absence of a leak detected in the cuff assembly 120. After inflation, in the automatic mode, in addition to leak detection testing at predetermined intervals, the pressure regulator 600 also performs automatic cuff pressure measurement and pressure regulation of the cuff assembly 120. The predetermined interval can be set to 30 minutes by default and manually set between 5 minutes and 4 hours.

[0117] The user interface 900 also includes a manual mode button / icon 944 for initiating a manual mode. In the manual mode, default settings may be entered, such as a default pressure setting for the cuff assembly 120, a maximum pressure setting for the cuff assembly and / or tracheal wall pressure, an interval between leak detection tests, an interval between pressure measurements, etc. In the manual mode, an "initial pressure setting" button / icon may be manually activated to inflate the cuff assembly 120 to the default setting and perform a FIG. 8A to FIG. 8B 946 to determine the optimal operating pressure of the cuff assembly 120 without leaks. After inflation, the cuff pressure measurement check can be manually activated, including manual pressure adjustment using arrow keys 946. The leak detection test can be manually initiated by activating the corresponding icon / button 948. The user interface 900 may include other commands and / or data for operating the pressure regulator 600.

[0118] Fig.10 A schematic block diagram of an embodiment of a pressure regulator system 600 is illustrated. In one example, the user interface 900 is included in a control module 1000, which may also include a pressure controller 606. The pneumatic system 620 may be in a separate housing as shown, or included with the control module 1000. When in a separate housing, the pneumatic system 620 and the pressure controller 606 may communicate using a wired or wireless transmitter.

[0119] The pneumatic system 620 includes a first output port 626a coupled to an extension tube 1002a for inflating the outer bladder 122 of the cuff assembly 120. The extension tube 1002a may include an air filter 1004a to filter any contaminants and is attached to the inflation line 106a of the airway tube 100. The inflation line 106a may include an indicator balloon 1010a, which serves as an indication of the air pressure in the outer bladder 122. The pneumatic system 620 includes a second output port 626b coupled to an extension tube 1002b for inflating the inner cuff 124 of the cuff assembly 120. The extension tube 1002b may include an air filter 1004b to filter any contaminants and is connected to the inflation line 106b of the airway tube 100. The inflation line 106b may also include an indicator balloon 1010b, which serves as an indication of the air pressure in the inner cuff 124. In addition to the inflation lines 106a-106b, additional manual inflation lines may be connected to the cuff assembly 120 for manually inflating the inner cuff 124 and outer balloon 122, for example, using a parenteral syringe.

[0120] Although the cuff assembly 120 is described as including an inner cuff 124 and an outer bladder 122, the pressure adjustment system 600 and methods described herein may also be implemented with a single inflatable cuff. Fig.11 A schematic block diagram of an embodiment of a leak detection and pressure adjustment system for a single cuff assembly is illustrated. In this example, the cuff assembly includes a single inflatable cuff 1100 surrounding an airway tube 100. One or more in-cuff sensors 1102 are positioned to measure air pressure within the cuff 1100, such as being positioned within the cuff 1100 and / or positioned in an indicator balloon of an inflation line connected to the cuff 1100. One or more pressure sensors 1104 may be externally coupled to the cuff 1100 to measure the force applied to the tracheal wall. Tracheal wall pressure may also be measured using one or more pressure sensors 1106 located between the cuff 1100 and the airway tube 100. Pressure measurements from the pressure sensors 1102, 1104, 1106 may be periodically transmitted to the pressure controller 606 using a wired or wireless transmitter 614.

[0121] The airway tube 100 and the sleeve 1100 may also include a leak detection system 1120. The leak detection system 1120 includes one or more scent membranes 128 located on the distal side of the sleeve 1100. The one or more scent membranes 128a may be positioned circumferentially around the distal side of the sleeve 1100. Additionally or alternatively, one or more scent membranes 128b may be positioned circumferentially around the airway tube 100. The scent membranes 128a-128b include embedded odorants that may be detected by one or more scent detectors 410.

[0122] The airway tube 100 also includes an air intake opening 130 formed in the outer wall that is fluidly connected to a suction channel 136. The suction channel 136 and the opening 130 are preferably located on the proximal side of the cuff assembly 120. An air conduit 134 is attached to the proximal end of the suction channel 136, and a vacuum pump 420 is attached to the air conduit 134. The vacuum pump 420 draws air from the trachea through the opening 130. The vacuum pump 420 obtains an air sample for one or more odor detectors 410. The odor detectors 410 transmit the measurements to the pressure controller 606.

[0123] The pressure controller 606 can control the vacuum pump 420 and the odor detector 410, and / or a separate processor device 1122 together with a memory device 1124 can control the leak detection system 1120. The memory device 1124 includes one or more non-transitory processor-readable memories that store instructions that, when executed by the processor device 1122 or other components of the leak detection system 1120, cause the leak detection system 1120 to perform one or more functions described herein. The leak detection system 1120 may also include a user interface 1126 and a transmitter 1128.

[0124] Fig.12 A schematic flow chart of an embodiment of a method 1200 for leak detection of an tracheal seal formed by a cuff assembly 120 in an airway tube 100 is illustrated. The cuff assembly 120 may include a single inflatable cuff 1100 or dual cuffs 122, 124. The method 1200 may be performed by a separate leak detection system 1120 or by a pressure controller 606 controlling the cuff assembly 120. At 1202, a command to initiate a leak detection test is obtained. The command may be automatically generated at a preset time interval or manually input.

[0125] The vacuum pump 420 is activated at 1204 for a predetermined period of time to obtain an air sample from the trachea proximally relative to the cuff assembly at 1206. The predetermined period of time is set so that the air above the cuff in the trachea is circulated and refreshed between tests. The odor detector 410 is exposed to the air sample and determines at 1208 whether an odor is detected. When no odor is detected at 1208, the leak detection system 1120 returns to step 1202 to wait for a command to perform another test. When an odor is detected at 1208, an alarm is generated at 1210. The alarm can be an audible warning and / or a visual display. The pressure in the cuff assembly 120 can then be adjusted and the leak detection process repeated.

[0126] The sleeve assembly 120, the pressure regulator system 600 and the leak detection system 1120 improve the protection and safety of intubated patients. The sleeve assembly 120 and the pressure regulator system 600 maintain an improved seal with the tracheal wall, which reduces the leakage of secretions and infection of the lungs without unduly damaging the tracheal wall. Automatic pressure measurement and regulation also help save caregivers' time. The leak detection system 1120 provides early warnings about possible problems with the seal formed by the sleeve assembly 120 against the tracheal wall. Intervention can then be provided earlier to help prevent secretions from leaking into the lungs. Additional or alternative advantages and improvements are possible in one or more embodiments described in the specification and / or claims.

[0127] As used herein, the term "operably" or "configurably" represents that an element includes one or more of a circuit, instruction, module, data, input, output, etc., to perform one or more of the described or necessary corresponding functions, and may also include an inference connection with one or more other items to perform the described or necessary corresponding functions. As may also be used herein, the term "connection", "connected to", "connected to" and / or "connection" or "interconnection" includes a direct connection or link between nodes / equipment and / or an indirect connection between nodes / equipment via an intermediate item. As may further be used herein, the inferred connection (that is, one of the elements is connected to another element by inference) includes a direct and indirect connection between two items in the same manner as "connected to". As used herein, the terms "substantially" and "approximately" provide an industrially acceptable tolerance for the relativity between its corresponding terms and / or items.

[0128] Note that various aspects of the present disclosure may be described herein as processes depicted as schematic diagrams, flow charts, flow diagrams, structure diagrams, or block diagrams. Although a flow chart may describe an operation as a sequential process, many operations may be performed in parallel or simultaneously. In addition, the order of the operations may be rearranged. When the operations of a process are completed, the process terminates. A process may correspond to a method, function, process, subroutine, subprogram, etc. When a process corresponds to a function, its termination corresponds to returning the function to a calling function or a main function.

[0129] The various features of the present disclosure described herein may be implemented in different systems and devices without departing from the present disclosure. It should be noted that the foregoing aspects of the present disclosure are merely examples and should not be construed as limiting the present disclosure. The description of the various aspects of the present disclosure is intended to be illustrative rather than limiting the scope of the claims. Similarly, the present invention may be easily applied to other types of devices, and many substitutions, modifications, and variations will be apparent to those skilled in the art.

[0130] In the foregoing description, certain representative aspects have been described with reference to specific embodiments. However, various modifications and changes may be made without departing from the scope of the invention as set forth in the claims. The description and drawings are illustrative rather than restrictive, and modifications are intended to be included within the scope of the invention. Therefore, the scope of the invention should be determined by the claims and their legal equivalents, rather than merely by the examples described. For example, the components and / or elements described in any device claim may be assembled or otherwise operably configured in various arrangements, and are therefore not limited to the specific configurations described in the claims.

[0131] Furthermore, certain benefits, other advantages, and solutions to problems have been described above with respect to particular embodiments; however, any benefit, advantage, solution to problems, or any element that may cause any particular benefit, advantage, or solution to occur or become more significant should not be construed as a critical, required, or essential feature or component of any or all the claims.

[0132] As used herein, the words "comprises," "comprising," "having," "containing," or any variation thereof, are intended to represent non-exclusive inclusion, such that a process, method, article, composition, or apparatus comprising a list of elements includes not only those elements listed, but may also include other elements not expressly listed or inherent to such processes, methods, articles, compositions, or apparatuses. Other combinations and / or modifications of the above-described structures, arrangements, applications, proportions, elements, materials, or components used in the practice of the present invention, except those not specifically described, may be varied or otherwise specifically adapted to specific environments, manufacturing specifications, design parameters, or other operating requirements without departing from the general principles of the present invention.

[0133] In addition, unless otherwise specified, referring to an element in the singular does not mean "one and only one", but rather "one or more". Unless otherwise explicitly stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure are known or will be known to those of ordinary skill in the art, and these equivalents are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. Under 35 U.S.C. §112(f), no claim element is intended to be interpreted as a "means plus function" type element unless the element is explicitly stated using the phrase "means for..." or, in the case of a method claim, the phrase "step for..." is used to state the element.

Claims

1. A medical device, comprising: an airway tube configured for implantation in the trachea; a cuff assembly implemented on a distal portion of the airway tube, wherein the cuff assembly includes at least one inflatable cuff; at least one odorous material positioned on a lower portion of the cuff assembly or positioned on the airway tube distally relative to the cuff assembly; and At least one odor detector is configured to detect a predetermined odor of the odorous material from air in response to a leak, wherein the air is sampled from the trachea on a proximal side of the cuff assembly.

2. The medical device according to claim 1, wherein: The airway cannula also includes: an air intake opening formed in an outer wall of the airway tube proximal to the cuff assembly; and A suction channel extends from the air intake opening to the proximal end of the airway tube.

3. The medical device according to claim 2, further comprising: a vacuum pump fluidly coupled to the suction channel at the proximal end of the airway tube, wherein the vacuum pump draws air from the trachea through the air intake opening and the suction channel; and A filter is configured to remove fluid from the air prior to testing by the at least one odor detector.

4. The medical device according to claim 1, further comprising: A pressure regulator is configured to adjust the pressure in the at least one inflatable cuff of the cuff assembly in response to the scent detector.

5. The medical device according to claim 4, wherein: The pressure regulator is constructed as follows: determining that the odor detector has detected a leak around the sleeve assembly; generating an alert on a user interface, wherein the alert comprises one or more of: an audible alert or a visual alert; and The pressure in the at least one inflatable cuff of the cuff assembly is adjusted in response to the detected leak.

6. The medical device according to claim 5, further comprising: A first inflation lumen having a first distal end coupled to an interior of the at least one inflatable cuff and a second proximal end fluidly coupled to a first air pump and a first release valve to add or remove air from the at least one inflatable cuff.

7. The medical device according to claim 4, further comprising: A pressure sensor device is configured to measure tracheal wall pressure exerted by the cuff assembly.

8. The medical device according to claim 7, wherein: The pressure regulator is constructed as follows: Based on the odor detector and the tracheal wall pressure, the pressure in the at least one inflatable cuff of the cuff assembly is adjusted in response to the detected leak.

9. The medical device according to claim 8, wherein: The at least one inflatable cuff is an inner cuff positioned adjacent to the airway tube; and Wherein, the sleeve assembly further includes an inflatable outer bladder positioned adjacent to the outer surface of the inner sleeve.

10. The medical device according to claim 9, wherein: The pressure sensor device configured to measure tracheal wall pressure is positioned between the inner cuff and the outer balloon.

11. The medical device according to claim 9, wherein: The inner cuff is configured to be inflated within a first pressure range, and wherein the outer bladder is configured to be inflated within a second pressure range, wherein the first pressure range is lower than the second pressure range.

12. The medical device according to claim 1, wherein: The at least one odorous material comprises an odorant embedded polymer film, wherein the odorant embedded polymer film is non-degradable, is waterproof, and does not alter the elasticity of the at least one inflatable sleeve.

13. The medical device according to claim 12, wherein: The predetermined scent in the at least one inflatable sleeve is released in detectable amounts over a period of 2 to 3 months.

14. A medical system, comprising: an airway tube configured for implantation in the trachea; a cuff assembly on a distal portion of the airway tube; at least one odorous material positioned on a distal side of the cuff assembly or on a portion of the airway tube distal to the cuff assembly, wherein the at least one odorous material comprises at least one predetermined odor; an air intake opening formed in an outer wall of the airway tube proximally relative to the cuff assembly; a suction channel extending from the air intake opening to a proximal end of the airway tube; and At least one odor detector is configured to detect the at least one predetermined odor.

15. The medical system of claim 14, wherein: The at least one odor detector is configured to detect the at least one predetermined odor in the air above the cuff from the trachea.

16. The medical system of claim 15, wherein: The medical system further comprises: A user interface is provided for providing an audible or visual alarm when the at least one odor detector detects the at least one predetermined odor in the air above the sleeve.

17. The medical system of claim 15, wherein: The medical system further comprises: A pressure regulator is configured to adjust the pressure of the sleeve assembly when the at least one odor detector detects the at least one predetermined odor in the air above the sleeve.

18. The medical system of claim 17, wherein: The medical system further comprises: a pressure sensor device configured to measure tracheal wall pressure exerted by the cuff assembly; and Wherein, the pressure regulator is further configured to adjust the pressure of the cuff assembly in response to the tracheal wall pressure.

19. A medical system, comprising: an airway tube configured for implantation in the trachea; a cuff assembly on a distal portion of the airway tube, wherein the cuff assembly includes an inner cuff positioned adjacent to the airway tube and an outer bladder positioned adjacent to the inner cuff; at least one odorous material positioned on a lower portion of the inner cuff or on a portion of the airway tube distal to the cuff assembly, wherein the at least one odorous material comprises at least one predetermined odor; and At least one odor detector is configured to detect at least one predetermined odor in the air above the cuff from the trachea.

20. The medical system of claim 19, further comprising: A pressure regulator is configured to adjust the pressure of the inner sleeve and / or the outer bladder in response to the odor detector detecting the at least one predetermined odor.

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