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

Abstract

An endotracheal or tracheostomy tube with a cuff assembly includes a cuff pressure regulator and a leak detection system. Pressure sensors monitor and measure tracheal wall pressure and pressure in the cuff assembly. An abnormal reading from the pressure sensors can initiate a cuff pressure adjustment process. The leak detection system detects air leaks in the seal between the cuff assembly and the tracheal wall. An odor film with a predetermined odor is positioned on a lower portion of the cuff assembly, distal to the seal of the tracheal wall. When the predetermined odor is detected in the air in the trachea proximal to the cuff assembly, an air leak is indicated. An air circulation device creates a flow of air into the trachea so that a fresh batch of air can be sampled and tested. Detection of an air leak can initiate a cuff pressure adjustment process.

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 issued 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 tubes, and more particularly to pressure management and air leak detection systems and methods for inflatable cuff assemblies implemented on endotracheal tubes 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. Mechanically ventilated patients experience an altered physiologic environment: reduced ability to clear oral and nasal secretions, decreased tracheobronchial mucociliary clearance, increased accumulation of secretions in the lungs and bronchi, a diminished cough reflex, and an increased likelihood of gastric reflux. The combined effect of these factors predisposes mechanically ventilated patients to ventilator-associated pneumonia (VAP), a lung infection that typically develops after 48 hours of mechanical ventilation.

[0005] Respiratory tubes in mechanical ventilation include endotracheal tubes (ETTs) or tracheostomy tubes that include an inflatable cuff. The inflatable cuff provides a seal between the respiratory tube and the tracheal wall to help prevent leakage of secretions into the lungs and bronchi. In ventilated patients, the accumulation of secretions above the inflatable cuff is a normal physiological phenomenon. The source of the secretions is the oral cavity, nasal sinuses, and stomach ("orogastric secretions"). It is known that under normal conditions, the oral cavity and sinuses produce up to 3 liters of secretions per day. Again, this does not include gastric reflux, which can be a significant factor. While a healthy person can eliminate and / or control such secretions, a ventilated patient cannot. Instead, in a ventilated patient, secretions can accumulate above the inflatable cuff and / or leak into the trachea around the inflatable cuff.

[0006] The problem of secretions accumulating above the cuff is that the secretions harbor microorganisms, including bacteria and fungi. Because the secretions are heavily contaminated, they should be kept away from the body's sterile organs. The lungs are one of those sterile organs. Thus, it becomes imperative for the treating physician to make every effort to keep the secretions out of the patient's lungs.

[0007] The inflatable cuff can be a powerful suction barrier. When inflated, the inflatable cuff, which is located at the distal end of the respiratory tube, is believed to circumferentially contact the tracheal wall, resulting in a complete seal. Unfortunately, it is known that the inflatable cuff does not provide an effective seal, primarily due to wrinkles or folds being formed by the oversized cuff, as described below. This observation is corroborated by a study that shows that about 10% of mechanically ventilated patients develop ventilator-associated pneumonia (VAP), and the mortality rate for VAP is estimated to be 13%. Moreover, patients with VAP face longer hospital stays and incur higher healthcare costs than similar morbid patients without VAP. Given that in the United States, about 750,000 patients require ventilation each year, the human and financial costs of VAP are enormous.

[0008] Maintaining the cuff pressure within the recommended range is believed to be a key factor in patient care, reducing tracheal injury, and preventing ventilator-associated pneumonia. The ultimate goal of monitoring the 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] There are several cuff pressure management systems on the market today. However, the cuff pressure management systems have not shown a clinically meaningful benefit compared to the incidence of ventilator-associated pneumonia (VAP) and patient outcome metrics. Therefore, there is a need for improved cuff pressure management systems and methods to help reduce the incidence of VAP and improve patient outcomes. SUMMARY

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

[0011] In another aspect, a medical system includes an airway cannula configured for implantation within a trachea and a cuff assembly on a distal portion of the airway cannula. The medical system also includes at least one odoriferous material positioned on a distal side of the cuff assembly or on a portion of the airway cannula distal relative to the cuff assembly, wherein the at least one odoriferous material includes at least one predetermined odor. An air intake opening is formed in an outer wall of the airway cannula proximal relative to the cuff assembly, and an aspiration 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 cannula configured for implantation within a trachea and a cuff assembly on a distal portion of the airway cannula, wherein the cuff assembly includes an inner cuff positioned adjacent to the airway cannula and an outer bladder positioned adjacent to the inner cuff. At least one odoriferous material is positioned on a lower aspect of the inner cuff or on a portion of the airway cannula distal relative to the cuff assembly, wherein the at least one odoriferous material includes at least one predetermined odor. At least one odor detector is configured to detect the at least one predetermined odor in air over the cuff from the trachea.

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

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

[0015] In one or more of the above aspects, a pressure regulator system is configured to adjust pressure in the 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 alert on the user interface, wherein the alert comprises one or more of: an audible alert or a visual alert. The pressure regulator is further configured to adjust the pressure in the 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 an interior of the at least one inflatable sleeve. The first inflation lumen further includes a second proximal end fluidly coupled to the first air pump and the first release valve to add or remove air in the at least one inflatable sleeve.

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

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

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

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

[0022] In one or more of the above aspects, the inner sleeve is inflated at a first pressure range, and the outer bladder is configured to be inflated at 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, 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 odor in the at least one inflatable sleeve is released in a detectable amount 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 over the sleeve from the trachea.

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

[0027] In one or more of the above aspects, the pressure adjuster 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 exerted by the sleeve assembly. The pressure adjuster adjusts the pressure of the sleeve assembly in response to the tracheal wall pressure.

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

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

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

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

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

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

[0035] Figure 5 A schematic block diagram of an embodiment of a pressure sensor for a dual sleeve assembly in an airway cannula is illustrated.

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

[0037] Figure 7 A flowchart of an embodiment of one or more methods for monitoring and controlling the pressure of a sleeve assembly by an adjuster system is illustrated.

[0038] Figure 8A And Figure 8B A flowchart of an embodiment of a method for determining an operating pressure of a sleeve assembly is illustrated.

[0039] Figure 9 A schematic block diagram of an embodiment of a user interface for a pressure adjuster system is illustrated.

[0040] Figure 10A schematic block diagram illustrating an embodiment of a pressure regulator system.

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

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

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

[0044] Implementations will now be described in detail with reference to the drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the aspects described herein. However, it will be apparent to one skilled in the art that the aspects described herein can be practiced without some or all of these specific details. In other instances, well known process steps have been

[0045] Current pressure management systems require manual monitoring and adjustment of cuff pressure for endotracheal tubes or tracheostomy tubes. This manual adjustment is impractical and unreliable and requires valuable time from hospital personnel. 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] Further, current pressure management systems tend to fail due to their inability to detect leaks around the inflatable cuff. Ultimately, whether a patient will experience VAP depends on the overflow of oronasal 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 can accurately determine air leaks in the seal formed by the inflatable cuff against the tracheal wall.

[0047] Another key reason for current pressure management systems to fail is because they are unable to accurately determine the pressure exerted by the cuff on the tracheal wall (tracheal wall pressure). Current pressure management systems only measure the pressure within the cuff (intra-cuff pressure). But intra-cuff pressure has a small effect on tracheal wall pressure. The safe level of cuff inflation is proportional to tracheal wall pressure, not intra-cuff pressure. It is not ideal to care for intubated patients without knowing this important information. The current practice of adjusting cuff pressure based on an arbitrary target level (the CDC recommended 25 cm H2O level) represents a complete disregard for what is critically important to the safety and well-being of the patient. This application also describes a novel and innovative pressure management system and method that accurately determines tracheal wall pressure and improves patient outcomes.

[0048] SUMMARY

[0049] Described herein is a pressure management system that has the effective means to monitor tracheal wall pressure by utilizing an inter-cuff pressure sensor fixed at the interface between the inner cuff and outer bladder of a dual cuff assembly. The pressure management system performs a pressure check at predetermined intervals and adjusts the cuff volume to achieve a predetermined pressure in the cuff assembly. Also described herein is a leak detection system 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 the odor to escape from the plastic film and flow into the air of the trachea in the vicinity of the cuff assembly. An odor detector is configured to sample the air in the vicinity of the cuff assembly. When the odor detector detects the odor, an alarm is generated. The pressure management system receives input 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 input from the pressure sensor and the odor detector.

[0050] Embodiments of airway intubation with dual cuff assembly

[0051] Airway intubation tubes including tracheal tubes or endotracheal tubes or other medical tubes having inflatable cuff assemblies are now described in more detail. In one embodiment, the inflatable cuff assembly includes a dual cuff. Unlike previously known inflatable cuffs, the dual 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 relatively inelastic material that is stiffer. Due to its inherent stiffness, higher pressure levels (50 cm H20 to 100 cm H20) are required to inflate the LVHP cuff. As a result, the LVHP cuff creates excessive pressure on the tracheal mucosa even when inflated to the minimum pressure to form a seal with the tracheal wall. This high pressure leads to an unacceptably high incidence of tracheal ischemia and necrosis, for example, 5% to 20% incidence. Despite this, one key advantage of the LVHP cuff when inflated is the relative absence of folds or wrinkles, resulting in excellent tracheal sealing. LVHP cuffs were first used in the mid-1960s but have now been widely replaced by HVLP cuffs.

[0052] HVLP cuffs are 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 diameter of the trachea 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 pathway for orogastric secretions to pass through the HVLP cuff, ultimately leading to microaspiration and lung infection.

[0053] When examining the effects of cuff pressure on the trachea, it is important to remember that the tracheal wall mucosal capillary perfusion pressure in humans is in the range of 22 to 32 mm Hg, and tracheal mucosal blood flow can be compromised at applied pressures above 30 cm H20 (22 mm Hg), with blood flow to certain sections completely occluded at 50 cm H20 (37 mm Hg). Thus, it is clear that there is only a small overlap between the safe pressure range and the complication pressure range. In fact, the window of effectiveness and safety is very narrow, or even nonexistent.

[0054] The pressure required for a typical HVLP cuff to achieve reasonable distention with an acceptable number of folds or wrinkles is about 32 cm H2O. Guidelines established by various medical associations and organizations recommend maintaining the pressure of the HVLP cuff in the range of 20 cm H2O to 30 cm H2O to avoid occluding tracheal mucosal blood flow. Unfortunately, studies have shown that micro-aspiration of the HVLP cuff occurs even at pressures as high as 60 cm H2O, which indicates that wrinkles persist in the cuff even at higher pressures, allowing secretions to pass through. Thus, even though HVLP cuffs exhibit superiority 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 goal of an inflatable cuff that provides maximum airway seal and causes minimal damage to the airway is simple and straightforward, it has been a challenge to successfully achieve these goals. This failure has continued despite different modifications and improvements to the material, shape, and volumetric configuration. Thus, there is a need for an improved cuff system that helps reduce micro-aspiration and infection of the lungs by maintaining a good seal with the tracheal wall, but without unduly damaging the tracheal wall.

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

[0057] Figures 1 to 3 An 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 A perspective view of a tracheostomy tube 100 is illustrated, and Figure 1 Different cross-sectional views of the tracheostomy tube 100 shown in FIG. 1 are illustrated. Although a tracheostomy tube 100 is illustrated in this example, the leak detection system and method described herein can be implemented with an endotracheal tube or other medical device having an inflatable cuff or other type of airtight seal. In this example, the tracheostomy tube 100 includes an outer tube 102 and an inner tube 150, where the inner tube 150 is located inside the outer tube 102. The outer tube 102 and the inner tube 150 can include a soft polyvinyl chloride (PVC) material.

[0058] The outer sleeve 102 includes a proximal section 112, a curved midsection 114, and a distal section 116. The proximal section 112 of the outer sleeve 102 includes a circumferentially extending flange 108 or plate and includes two slits 118a, 118b on opposite sides. A cotton bandage or strap is secured in the slits 118a, 118b of the flange 108 to secure the tracheostomy tube 100 to the patient's neck. The proximal section 112 also includes a hub 110 extending proximally upward from the flange 108. An inner sleeve 150 is inserted through a proximal opening in the hub 110. The proximal opening 152 of the inner sleeve 150 is configured for connection to a ventilator via tubing or a hose.

[0059] The outer sleeve 102 of the tracheostomy tube 100 includes a curved intermediate section 114 and a distal section 116 that are configured and dimensioned for implantation within a patient's trachea. The intermediate section 114 is curved such that the proximal section 112 is angled to the distal section 116 at an angle of between about 80 degrees and about 90 degrees. The distal section 116 includes a cuff 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 end 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 surrounds and is positioned adjacent to an 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 patient's trachea, the outer surface of the outer balloon 122 contacts the tracheal wall and forms a seal.

[0061] The inner sleeve 124 and the outer bladder 122 may be cylindrical or annular. Figure 1 As shown, when inflated, the outer balloon 122 is a torus-shaped ring with a circular cross-section. The inner cuff 124 has a cylindrical shape with an arcuate outer surface that forms a ring around the tracheostomy tube 100. In this example, the length of the inner cuff ranges from 10 mm to 20 mm, and the length of the outer cuff ranges from 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 adhesive and / or tape. These specifications are exemplary, and the inner balloon 124 and / or outer cuff 122 may have alternative shapes, sizes, and attachment mechanisms.

[0062] The inner cuff 124 and the outer bladder 122 are configured for different operating pressures, so the tracheostomy tube 100 includes means for inflating the inner cuff 124 and the outer bladder 122 to different pressures. In one example, a first inflation line 106a is positioned in a first channel 200 shown. Figure 2 The first channel 200 is formed between an inner wall and an outer wall of the outer cannula 102. The first channel 200 extends from a proximal side of the flange 108 (e.g., at the hub 110) to at least the cuff assembly 120 on the front side of the outer cannula 102. A distal end 206 of the inflation line 106a extends through an opening 204 in the outer wall of the outer cannula 102 and into the inner cuff 124. The inflation line 106a forms a gas-tight fluid connection for inflating and deflating the inner cuff 124.

[0063] A second inflation line 106b is positioned in a second channel 300 shown. Figure 3 The second channel 300 is formed between an inner wall 302b and an outer wall 302a on the front side of the outer cannula 102. The second channel 300 extends from a proximal side of the flange 108 to at least the cuff assembly 120 at the hub 110 of the outer cannula 102. The second inflation line 106b is positioned inside the second channel 300. A distal end of the inflation line 106b extends into the outer bladder 122 through a sealed opening 304 in the outer wall 302a of the outer cannula 102. The inflation line 106b thus forms a gas-tight fluid connection for inflating and deflating the outer bladder 122.

[0064] In this implementation, two channels 200, 300 are formed in the front wall of the outer cannula 102 for holding the inflation lines 106a, 106b. In another implementation, the two channels 200, 300 can be formed in the side walls of the outer cannula 102. In yet another implementation, a single channel can accommodate both inflation lines 106a, 106b. In yet another implementation, the channels 200, 300 can be formed between the inner cannula 150 and the outer cannula 102, e.g., 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, e.g., the inflation lines 106a, 106b, the outer bladder 122 and the inner cuff 124 can be inflated to and maintained at different pressures. In an implementation, the inner cuff 124 is a low pressure inflatable cuff and is configured to operate in a low pressure range of 10 cm H2O to 20 cm H2O. In contrast, the outer inflatable bladder 122 is configured to be inflated to a higher pressure range of 50 cm H2O to 150 cm H2O. Thus, the inner cuff 124 operates in a pressure range that is lower than the pressure range of the outer bladder 122.

[0066] Furthermore, the inner sleeve 124 comprises a relatively elastic material, and the outer bladder 122 comprises a relatively inelastic material, e.g., 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 comprise 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 comprise 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, for example, when positioned in a patient's trachea and pressurized to an inflated state, the first inner cuff 124 behaves as a high-pressure, low-pressure, low-pressure (HVLP) cuff, while the second outer balloon 122 behaves as a low-pressure, low-pressure, high-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] Furthermore, due to its operation at high pressures, the outer balloon 122 in its inflated 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, 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 cuff assembly 120, cuff assembly 120 leverages the advantages found in both cuff types: an excellent tracheal seal and increased safety for the trachea. Cuff system 120 is characterized by an excellent seal to the tracheal wall while minimizing tracheal trauma. Thus, 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 cannula 100 in FIG. 1 further illustrates the suction channel 136 and the tubing 134 coupled to the suction channel 136. The air intake opening 130 is shown as being located at the posterior side of the airway cannula, but can also be located at the anterior side of the cuff assembly 120 or otherwise at the proximal side thereof. In this example, the stopper 210 is positioned in the suction channel 136 at a location that is distal relative to the air intake opening 130. The stopper 210 is sized to occlude the suction channel 136 and provide a seal to the suction channel 136 to prevent air or fluid flow to the distal end 126 of the airway cannula 100.

[0071] Embodiments of a leak detection system

[0072] In embodiments, 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 an odor-impregnated plastic film 128 or other material, such as Figures 1 to 3 shown positioned on the distal end 126 of the tracheostomy tube 100, for example on the distal side of the seal with the tracheal wall. In this example, the odor film 128 comprises a strip fixed circumferentially around the anterior portion of the inner cuff 124.

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

[0074] The one or more predetermined odorants are impregnated into one or more plastic polymers and made into a film. The one or more plastic polymers can comprise polyethylene, polypropylene, polystyrene, cellulose derivatives, and acrylonitrile-butadiene-styrene. The one or more plastic polymers are formulated such that the impregnated odorants are 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 with a seal, an air-tight packaging 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, such that it does not significantly alter the elastic properties of the inner cuff 124. The odor film 128 is preferably harmless to the human body and resistant to degradation and fluids. The odor film 128 can be fixed with an adhesive and / or with heat or by other means. Although a plastic polymer film embedded with odorants is described herein, any other type of odorant material that includes a slow-evaporating odorant that can be detected by an odor detector can be used.

[0075] The odor film 128 can be secured to the front of the inner cuff 124 as shown, or can alternatively be positioned on the front of the outer bladder 122, so long as the odor film 128 is under the seal formed between the cuff assembly 120 and the tracheal wall. In another example, the odor film 128 can be positioned on the distal end 126 of the tracheostomy tube 100, preferably proximate or adjacent to the cuff assembly 120. The odor film 128 is preferably not positioned proximate the distal opening 138 of the airway tube 100, where it can be unnecessarily exposed to inhaled and exhaled air, thereby potentially evaporating the odor from the film 128 too quickly. By placing the odor film 128 away from the air flow, for example on the back side of the cuff assembly 120, or adjacent to or just distal to the cuff assembly 120, the odor on the odor film 128 can last 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, for example above the seal with the tracheal wall. The air intake opening 130 fluidly connects the cuff-above air in the trachea to the suction channel 136 (see Figure 2 and Figure 3 ). A stop 140 is located in the suction channel 136 distally relative to the opening 310 to prevent air from flowing into the suction channel 136 from the distal side of the cuff 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 conduit 134 at the hub 110. An air pump is fluidly attached to the opposite end of the air conduit 134, such that the air pump is fluidly coupled to the air intake 130. The air conduit 134 or the air pump also includes a valve that fluidly couples the odor detector to the cuff-above air flowing through the air conduit 134.

[0077] When the tracheostomy tube 100 is positioned in the patient and the cuff assembly 120 is inflated, a gas-tight seal should be formed between the cuff assembly 120 and the tracheal wall to prevent fluid and / or secretions from leaking into the trachea. When the gas-tight seal is not formed, air flows from the odor film 128, through the seal, and into the air intake 130. The odor-laden air then flows through the suction channel 136 to the air conduit 134 and to the odor detector. The odor detector can thus detect the odor and generate an alert that the seal is compromised, as described in greater detail herein.

[0078] Figure 4AA schematic block diagram illustrating an embodiment of an odor probe system 400 is shown. The system 400 includes one or more odor probes 410 and a vacuum pump 420. In one embodiment, the odor probe 410 is an electronic device that includes 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 film 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 a polymer in the transducer contacts the predetermined odorant, it expands, thereby changing its electrical resistance. This change in the electrical resistance of the polymer is measured, and from the measurement, the presence of the predetermined odorant is determined.

[0079] The vacuum pump 420 in the odor probe system functions as a low pressure vacuum to draw the over-cuff air from the air tube. The vacuum pump 420 or air conduit 134 includes valves and ports to provide a sample of the over-cuff area to the odor probe. The over-cuff air in the air tube needs to be cycled and replaced before the next test to determine if odoriferous air is still leaking from the air tube wall seal. Otherwise, after the seal is improved and becomes airtight, the air pump can provide odoriferous air from a previous test that remains in the air tube to the odor probe 410. The odor probe 410 will then detect the odor and generate an alarm, even though the seal is now airtight. To prevent this repeated sampling of the same air, the vacuum pump 420 draws air from the air tube for a predetermined period of time. This period of time of drawing removes the previously sampled air from the air tube and helps to draw a fresh batch of air into the air tube. After the predetermined period of drawing, the air vacuum 420 provides an air sample to the odor probe 410 where the presence of the predetermined odor is tested. When the odor probe 410 detects the predetermined odor, it then generates an alarm. The alarm can include, for example, an audible warning and / or a visual alarm on a display, among others.

[0080] A filter 430 can also be used to filter the air sample from the suction channel 136 and / or conduit 134. The air sample can include secretions and other fluids that accumulate in the over-cuff area, particularly on the proximal side of the cuff assembly 120. The air sample in the suction channel 136 and conduit 134 can therefore also include such fluids. The filter 430 is configured to remove the secretions or other fluids from the air sample with little or no removal of any predetermined odor in the air sample. In embodiments, the suctioning and filtering of air and secretions from the over-cuff area can be performed at periodic intervals, even without odor probe testing being performed. This periodic suctioning of fluids in the over-cuff area helps to prevent the buildup of secretions that can lead to leaks into the lungs.

[0081] Figure 4BA perspective view of an embodiment of the filter 430 and vacuum pump 420 is illustrated. In this example, the filter 430 is a liquid collection canister coupled to the suction channel 136 by the tubing 134. Air over 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 odor remain on 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 shut-off valve to prevent overflow.

[0082] While a liquid collection canister is described herein, other types of air filters can also be implemented. For example, a coalescing filter that uses a filter media to remove liquid droplets and other particulates from the air can 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 can also be attached to the tubing 134 to remove secretions or other fluids that accumulate on the proximal side of the cuff assembly 120 when air testing is not being performed. Suction of the secretions can occur at periodic intervals and can be done manually or automatically.

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

[0085] Embodiments of a pressure adjustment 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, an endotracheal tube, or other airway tube) including a cuff assembly 120 is illustrated. In embodiments, the cuff assembly 120 includes at least one intra-cuff pressure sensor 510a associated with the inner cuff 124 and at least one intra-cuff pressure sensor 510b associated with the outer bladder 122. The intra-cuff pressure sensor 510a is positioned 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, e.g., as an indicator balloon, to measure the air pressure within the inner cuff 124. The intra-cuff pressure sensor 510b is positioned 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) can be positioned at the proximal end of the inflation line 106b, e.g., at an indicator balloon, to measure the air pressure within the outer bladder 122.

[0087] In embodiments, one or more pressure sensors 530a-530b can be positioned on the outer surface of the outer bladder 122 to measure the pressure or force applied by the cuff assembly 120 to the tracheal wall ("tracheal pressure"). However, these sensors 530a-530b can cause damage to the tracheal wall when pressed against it. Therefore, alternatively or additionally, one or more inter-cuff pressure sensors 520a-520b can be positioned between the outer bladder 122 and the inner cuff 124 to measure the tracheal pressure. As the force of the inner cuff 124 acts radially on the outer bladder 122, the inter-cuff pressure sensors 520a-520b ultimately measure the force applied by the cuff assembly 120 on the tracheal wall. As such, the inter-cuff pressure sensors 520a-520b measure the tracheal pressure, e.g., 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 can comprise thin film pressure sensors with force sensitive resistors that change resistance based on the applied force. The pressure sensors 510a-510b can comprise resistive or capacitive air pressure transducers. Additional pressure sensor devices can be positioned within the inflation lines 106a-106b to measure the intra-cuff pressure, or 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 can each comprise a wireless transmitter to transmit the pressure measurements to the pressure adjustment system. For example, the wireless transmitter can comprise 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 sensors can comprise a wired transmitter to transmit the pressure measurements.

[0089] The benefits and risks of the cuff assembly 120 depend on maintaining a predetermined pressure range in the cuff assembly 120, rather than the airway tube itself. For example, over-inflation of the cuff assembly 120 can result in tracheal mucosa damage, leading to ischemic injury and vocal cord nerve damage. This damage is due to the constant pressure of the cuff exerting the pressure that prevents blood flow to the tracheal mucosa. This loss of blood flow can result in tissue necrosis. Additionally, damage can also occur due to the repeated abrasion of the cuff moving over the tracheal wall. When the cuff is under-inflated and the tracheal seal is insufficient, the patient can not receive enough oxygen. Additionally, the patient has an increased likelihood of developing pneumonia due to aspiration of oral gastric contents. Therefore, maintaining the pressure of the cuff assembly 120 of the airway tube 100 is a critical part of patient care, reducing tracheal damage, and preventing ventilator-associated pneumonia (VAP).

[0090] Currently, several types of automatic cuff pressure regulators are available. These current devices monitor the intracuff pressure within a single cuff. However, a closer examination reveals major deficiencies in this approach. The intracuff pressure does not reflect the exact pressure exerted on 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 An exemplary embodiment of a schematic block diagram 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 uses measurements of tracheal wall pressure and leak detection to inflate and regulate pressure within the cuff assembly 120, for example, when the airway tube 100 is implanted into 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 that store 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 comprises at least one processing circuit, such as a microprocessor, microcontroller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and / or any device that manipulates signals (analog and / or digital) based on hard coding of the circuitry and / or operational instructions. The memory device 610 includes a non-transitory memory device and can be internal or external memory and can be a single memory device or multiple memory devices. The memory device 610 can be read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, 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, touchscreen, mouse, touchpad, meter, switch, or other I / O device.

[0093] In use, the pressure settings of the cuff assembly 120 are determined. The pressure controller 606 can use default pressure settings or receive pressure settings from a user. Different pressure settings are used for the inner cuff 124 and the outer bladder 122. For example, the pressure setting for the inner cuff can be a pressure in the range of 10 cm H20 to 20 cm H20 (plus or minus 2 cm H20). In contrast, the pressure setting for the outer inflatable bladder can be a pressure in the range of 50 cm H20 to 150 cm H20 (plus or minus 2 cm H20). Thus, the inner cuff 124 operates at a lower range of operating pressures than the outer bladder 122. The pressure controller 606 also determines the frequency at which to measure and adjust the pressure of the cuff assembly 120, for example, by user input or default settings.

[0094] The pneumatic system 620 has a first pneumatic path for the outer bladder 122 that includes, for example, a first air pump 622a and a release valve 624a that is fluidly coupled to the outer bladder 122 by the inflation line 106b. The pneumatic system 620 also includes a different second pneumatic path for the inner cuff 124 that includes a second air pump 622b and a release valve 624b that is fluidly coupled to the inner cuff 124 by, for example, the 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 independently and separately fluidly increase or decrease the pressure in the inner cuff 124 and the outer bladder 122.

[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 can include one or more cuff- in pressure sensor devices 510a-510b located within the inflated inner cuff 124 and outer bladder 122 and / or located on the inflation lines 106a-106b leading to the cuff assembly 120 that indicate the pressure within the cuff. For example, the cuff-in pressure sensor devices 510a-510b measure the internal air pressure of the inner cuff 124 and the outer bladder 122 and communicate the measurements to the pressure controller 606. In addition, one or more inter-cuff pressure sensor devices 520a-520b measure the 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 the tracheal wall pressure. The pressure controller 606 can also receive input from one or more odor detectors 410. Additional pressure sensor devices can also be implemented. The pressure sensor devices generate pressure measurements and communicate them to the pressure controller 606, for example, through wired leads and / or wireless transmitters.

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

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

[0098] Figure 7 A flowchart illustrating an embodiment of one or more methods 700 for monitoring and controlling the pressure of the cuff assembly 120, for example, by the regulator system 600 is shown. 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 can be 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 can control the release valve 624b to release air from the inner cuff 124. Since tracheal mucosal blood flow can be compromised at applied pressures higher than 30 cm H2O (22 mm Hg), the regulator system 600 can reduce the pressure of at least the inner cuff 124 when the measured tracheal pressure exceeds 30 cm H2O (22 mm Hg).

[0099] When the tracheal pressure is below the predetermined pressure range, at step 706, the regulator system 600 increases the pressure in at least the inner sleeve 124. For example, the regulator system 600 can control the air pump 622b to pump air into the inner sleeve 124. In addition, the pressure of the outer bladder 122 can also be adjusted. These steps can 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, using these pressure measurements, the regulator system 600 determines whether the pressure of the outer bladder 122 is within a predetermined pressure range. For example, the pressure measurements can be from one or more pressure sensor devices 510b located within the outer bladder 122, or from an indicator cuff for the outer bladder 122, or from the 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 can 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 can have a predetermined pressure range of 50 cm H20 to 150 cm H20.

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

[0102] The pressure of the inner cuff 124 and the outer bladder 122 of the cuff assembly 120 is thus controlled separately using separate pneumatic paths (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 the outer bladder 122 to adjust the tracheal pressure.

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

[0104] The procedure 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 can include a pressure range of 8 to 12 cm H2O or about 10 cm H2O. The initial pressure level of the outer bladder 122 can include a pressure range of 35 to 45 cm H2O, or about 40 cm H2O. The initial pressure levels can be set by default or can 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 from an average, mean, or maximum of measurements from the intercuff 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 a 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, that the current airway tube (e.g., endotracheal or tracheostomy tube) be replaced with an airway tube having a larger outer diameter. When the airway tube is replaced, the procedure 800 begins again at 802.

[0106] When the tracheal wall pressure is below 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 area above the cuff of the trachea. The air exhaust system of the airway 100 (e.g., the opening 130, the suction channel 136, and the tracheal tube 134) is connected to the low pressure vacuum pump 420 to provide good circulation in the area above the cuff. The air above the cuff 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, it 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 cm H20. After the pressure in the inner cuff 124 is incrementally increased, it is determined at 818 whether the pressure in the inner cuff is greater than 25 cm H20, e.g., the maximum inner cuff pressure. When it is 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, then an alarm is generated at 822. The alarm can indicate that the maximum tracheal pressure has been exceeded and / or can indicate, for example, that the current airway tube (e.g., endotracheal or tracheostomy tube) be 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 the air leak test can be repeated until the pressure in the inner cuff 124 is greater than the maximum inner cuff pressure (e.g., 25 cm H20) or the tracheal wall pressure exceeds the maximum tracheal pressure (e.g., 25 cm H20). When no leak is detected at 824, then the pressure of the cuff assembly 120 is maintained and monitored at 826. 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.

[0109] When a leak is still detected at 824 and the incrementally increased pressure of the inner cuff 124 exceeds the maximum inner cuff pressure at 818, then the process proceeds to Figure 8BStep 830, as indicated by arrow A. At step 830, the pressure in the outer cuff 122 is adjusted. For example, the pressure within the outer cuff can be increased in increments of 2 to 3 cm H20. After the pressure of the outer cuff 122 is increased in increments, it is determined at 832 whether the pressure in the outer cuff 122 is greater than the maximum outer cuff pressure, for example 60 cm H20. When the outer cuff 122 is greater than the maximum outer cuff pressure at 832, then an alarm is generated at 834. The alarm can indicate that the leak detection has exceeded the maximum outer cuff pressure, and / or can indicate that the current airway tube (e.g., endotracheal or tracheostomy tube) be replaced with an airway tube having a larger outer diameter, for example. When the airway tube 100 is replaced, the process 800 begins again at 802.

[0110] When the pressure in the outer cuff 122 is not greater than the maximum outer cuff pressure at 832, the pressure within the inner cuff is adjusted to a lower pressure, for example an initial pressure of 10 cm H20, 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, then an alarm is generated at 840. The alarm can indicate that the maximum tracheal pressure has been exceeded and / or can indicate that the current airway tube (e.g., endotracheal or tracheostomy tube) be replaced with an airway tube having a larger outer diameter, for example. 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 cuff 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 Figure 8A Step 810 in FIG. 8, as indicated by arrow C. Periodic air leak tests are 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 cuff 122 and the initial pressure of the inner cuff 124, then the process continues to Figure 8A Step 816 in FIG. 8, 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 inner cuff pressure is reached at 818. When the maximum inner cuff pressure is reached at 818, the process again continues to 830 and the pressure in the outer cuff 122 is increased to a higher pressure. When no air leak is detected at 824 or 844, the pressure of the inner cuff and the outer cuff are below their respective maximums, and the tracheal wall pressure is below the maximum, 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 this process 800, the tracheal wall pressure does not exceed a maximum pressure, for example, within the range of 20 to 25 cm HO. If the tracheal wall pressure exceeds the maximum pressure required to achieve an airtight cuff inflation, the airway tube size is adjusted, for example, by increasing the size to the next larger 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. Thus, 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. This process helps reduce microaspirations and infections in the lungs by achieving and maintaining a good seal with the tracheal wall without excessively damaging the tracheal wall.

[0114] Figure 9 A schematic block diagram of an embodiment of a user interface 900 for the 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 can be an interactive touch screen. The display 902 includes one or more icons or data displays, such as a display of the current tracheal wall pressure 904 and a warning / alarm 906. The display 902 also includes a display of cuff pressure 908, such as a set or target pressure 910 and a current pressure 912 for the inner cuff 124 and outer bladder 122. The display 902 can 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 can 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 touchpad, 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 the pressure regulator 600. A deflate button / icon 940 activates deflation of the cuff assembly 120, for example, to remove the airway tube 100 from the patient.

[0116] The automatic mode button / icon 942 can be activated to start the automatic mode. In the automatic mode, the pressure regulator 600 automatically inflates the cuff assembly to the default setting and performs Figures 8A to 8BOne or more of the processes described in the foregoing are used to determine the optimal operating pressure of the sleeve assembly 120 in the absence of a leak. After inflation, in the automatic mode, in addition to the leak detection test at predetermined intervals, the pressure regulator 600 also performs automatic sleeve pressure measurement and pressure adjustment of the sleeve assembly 120. The predetermined interval can default to 30 minutes, manually set between 5 minutes and 4 hours.

[0117] The user interface 900 also includes a manual mode button / icon 944 for initiating the manual mode. In the manual mode, default settings can be entered, such as a default pressure setting for the sleeve assembly 120, a maximum pressure setting for the sleeve assembly and / or tracheal wall pressure, an interval between leak detection tests, an interval between pressure measurements, etc. In the manual mode, a "initial pressure setting" button / icon can be manually activated to inflate the sleeve assembly 120 to the default settings and perform a leak detection test. Figures 8A to 8B One or more of the processes described in the foregoing are used to determine the optimal operating pressure of the sleeve assembly 120 in the absence of a leak. After inflation, in the automatic mode, in addition to the leak detection test at predetermined intervals, the pressure regulator 600 also performs automatic sleeve pressure measurement and pressure adjustment of the sleeve assembly 120. The predetermined interval can default to 30 minutes, manually set between 5 minutes and 4 hours.

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

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

[0120] While the sleeve assembly 120 is described as including an inner sleeve 124 and an outer cuff 122, the pressure adjustment system 600 and method described herein can also be implemented with a single inflatable sleeve. Figure 11 A schematic block diagram of an embodiment of a leak detection and pressure adjustment system for a single sleeve assembly is illustrated. In this example, the sleeve assembly includes a single inflatable sleeve 1100 that surrounds the airway tube 100. One or more in-sleeve sensors 1102 are positioned to measure air pressure within the sleeve 1100, for example, positioned within the sleeve 1100 and / or positioned in an indicator bulb of an inflation line connected to the sleeve 1100. One or more pressure sensors 1104 can be externally coupled to the sleeve 1100 to measure force applied to the tracheal wall. One or more pressure sensors 1106 positioned between the sleeve 1100 and the airway tube 100 can also be used to measure tracheal wall pressure. Pressure measurements from the pressure sensors 1102, 1104, 1106 can be periodically transmitted to the pressure controller 606 using wired or wireless transmitters 614.

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

[0122] The airway cannula 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 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 measurements to the pressure controller 606.

[0123] The pressure controller 606 can control the vacuum pump 420 and odor detectors 410, and / or a separate processor device 1122 along 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 can also include a user interface 1126 and a transmitter 1128.

[0124] Figure 12 An illustrative flowchart of an embodiment of a method 1200 for leak detection of a tracheal seal formed by a cuff assembly 120 in an airway cannula 100 is illustrated. The cuff assembly 120 can include a single inflatable cuff 1100 or dual cuffs 122, 124. The method 1200 can be performed by a separate leak detection system 1120 or by the pressure controller 606 that controls the cuff assembly 120. At 1202, a command to initiate a leak detection test is obtained. The command can be generated automatically at preset time intervals or entered manually.

[0125] The vacuum pump 420 is initiated at 1204 for a predetermined period of time to obtain an air sample at 1206 from the trachea proximally relative to the cuff assembly. 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 detectors 410 are exposed to the air sample and determine whether an odor is detected at 1208. When no odor is detected at 1208, the leak detection system 1120 returns to step 1202 to await 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 cuff assembly 120, pressure regulator system 600, and leak detection system 1120 improve protection and safety for intubated patients. The cuff assembly 120 and pressure regulator system 600 maintain an improved seal with the tracheal wall, which reduces leakage of secretions and infection of the lungs without unduly damaging the tracheal wall. Automatic pressure measurement and regulation also help to save time for caregivers. The leak detection system 1120 provides early warning of possible problems with the seal formed by the cuff assembly 120 against the tracheal wall. Intervention can then be provided earlier to help prevent leakage of secretions 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 "operatively" or "configurably" means that an element includes one or more of circuitry, instructions, modules, data, inputs, outputs, etc. to perform one or more of the described or necessary respective functions, and can also include an inferred coupling with one or more other items to perform the described or necessary respective functions. As can also be used herein, the terms "coupled," "coupled to," "connected to," and / or "connected" or "interconnected" include direct connection or link between nodes / devices and / or indirect connection between nodes / devices via intermediate items. As can further be used herein, an inferred connection (i.e., where one element is connected to another element by inference) includes both direct and indirect connections between two items in the same manner as "connected to." As used herein, the terms "substantially" and "approximately" provide an industry-acceptable tolerance for the relative between their respective terms and / or items.

[0128] Note that aspects of the disclosure can be described herein in terms of processes that are depicted as schematic diagrams, flowcharts, flow diagrams, block / functional diagrams, or block diagrams. Although the flowcharts can describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations can be re-arranged. A process is terminated when its operations are completed. A process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

[0129] The various features of the disclosure described herein can be implemented in different systems and devices without departing from the disclosure. It should be noted that the foregoing aspects of the disclosure are merely examples and are not to be construed as limiting of the disclosure. The description of aspects of the disclosure is intended to be illustrative, and not to limit the scope of the claims. As such, the present disclosure is readily applicable to other types of apparatuses, and many alternatives, modifications, and variations will be apparent to those of ordinary skill in the art.

[0130] In the foregoing specification, certain representative aspects are described. However, the disclosure can be practiced without incorporating certain aspects described. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Modifications and changes can be made with respect to the above description and illustrations, and still be within the scope and spirit of the application accordingly. The scope of the application should, therefore, be determined not with reference to the above description and illustrations, but instead should be determined with reference to the appended claims along with their full scope of equivalents. For example, the components and / or elements described in any apparatus claims can be assembled or otherwise operably disposed in any arrangement and are therefore not limited to the specific configurations described in the claims.

[0131] Moreover, some benefits, other advantages, and solutions to problems have been described with regard to the particular embodiments; however, the benefit, advantage, solution to problem, or any element that causes any particular benefit, advantage, or solution, not to be desirably implemented, or causes it to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

[0132] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other similar term are intended to be open-ended. The term "comprises" and / or "comprising," when used in a description of a process, method, composition of matter, and / or article of manufacture, is / are not intended to exclude the addition of another integer / step / element / component / feature to what is described by the scope of the claim / s. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0133] In addition, reference to an element in the singular is not intended to mean "one and only one", unless specifically so stated, but rather "one or more". Unless specifically stated otherwise, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase "means for."

Claims

1. A medical device, comprising: an airway tube configured for implantation within 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 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 sampled from the trachea on a proximal side of the cuff assembly.

2. The medical device according to claim 1, wherein The airway cannula further comprises: 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 system is configured to adjust pressure in the at least one inflatable cuff of the cuff assembly in response to the at least one odor detector.

5. The medical device according to claim 4, wherein The pressure regulator system is configured to: determining that the at least one odor detector has detected a leak around the sleeve assembly; wherein said at least one odor detector comprises a chemical and / or electronic sensor configured to detect said predetermined odor; 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 has 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 system is configured to: Based on the at least one 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 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, 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 within 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 the proximal end of the airway tube; and At least one odor detector is configured to detect the at least one predetermined odor in the air above the cuff from the trachea.

15. The medical system according to claim 14, wherein: The at least one odor detector comprises a chemical and / or electronic sensor configured to detect the at least one predetermined odor in the air above the cuff from the trachea.

16. The medical system of claim 14, 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 14, wherein: The medical system further comprises: A pressure regulator system 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 according to 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 system 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 within the trachea; a cuff assembly on a distal portion of the airway tube, wherein the cuff assembly comprises an inner cuff positioned adjacent the airway tube and an outer bladder positioned adjacent the inner cuff; at least one scented 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 scented material comprises at least one predetermined scent; 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 system is configured to adjust the pressure of the inner sleeve and / or the outer bladder in response to the at least one odor detector detecting the at least one predetermined odor.

21. The medical system of claim 19, wherein: The at least one odor detector comprises a chemical and / or electronic sensor.

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