Patent Description:
A humidification apparatus is used to provide heated and humidified gases to a patient via a patient interface. Humidified medical gases protect the peritoneum from desiccation and inflammation caused by cold dry gases used during surgical procedures.

Pass-over humidification devices supply heated, humidified gases to a patient. Such a humidification system comprises a humidification apparatus, a humidification chamber, a tube system, and a patient interface. The humidification apparatus further comprises a heater plate that is configured to heat the humidification chamber. This causes vapour to form, which enters the gases flow, humidifying the medical gases. Humidification systems can have a large footprint and require large volumes of liquid for humidification to take place. Heat is applied to the heater plate of the humidification chamber to form vapour, meaning the heater plate is hot to touch.

Humidification systems for surgical applications may comprise a tube with a wicking or absorptive material positioned within the gas path. The wicking or absorptive material connects with an external liquid supply or reservoir. Heat is applied to the wicking material, releasing vapour into the tube. Different humidification systems hold liquid within compartments or reservoirs within the tube. Once heat is applied, vapour moves through a permeable membrane into the lumen of the tube.

An external liquid supply reduces the portability of the system, increases the number of set-up steps, and thus increases the overall complexity of the system. The system also requires a large portion of the limited space within a surgical theatre.

Liquid held in reservoirs within the tube increases the weight and reduces the flexibility of the tube, thereby making the tube difficult to manipulate within the surgical space.

<CIT> discloses an insufflation tube for use in laparoscopy, characterized in that in its interior a humidifying material is located in the immediate vicinity of which a heating element is positioned, the length of the tube being <NUM>-<NUM>. The heating element and the humidifying material occupy at least <NUM> of the tube and at least <NUM>% of the total tube length. The gas introduced during laparoscopy is heated and humidified by means of a humidifying agent inside the tube.

<CIT>, <CIT>, <CIT>, <CIT> and <CIT> are also disclosed.

A humidification system is disclosed that comprises a tube with an integrated liquid supply and heating mechanism to provide heated and humidified gases to a patient.

In an embodiment, the humidification system comprises a bead that is configured to absorb or hold a liquid. The bead is spirally wound with an outer layer to form a tube. The tube is pre-loaded such that sufficient liquid is stored within the bead. A heating mechanism is integral to the tube and supplies heat to the bead to release vapour and to increase the gases temperature to above ambient temperature. The outer layer provides a barrier to reduce or eliminate the likelihood of the generated vapour entering the atmosphere. Gases flowing through the tube are heated and humidified by the vapour that is released from the bead. Heat is also supplied to the gases by the heating mechanism. The heating mechanism is connected with an external power supply.

The tube comprises a small diameter and lightweight construction. Thus, the humidification system is easily integrated into a surgical environment. Liquid required for the surgical procedure is stored within the bead material. Flexibility of the tube is maintained when liquid is stored within the bead. The liquid is released as vapour upon application of heat. The bead is configured to provide structural support to the tube.

The humidification system comprises minimal set-up steps due to the integrated tube design. For example, there is no need for an external liquid reservoir to supply the system with sufficient liquid for the surgical procedure. Similarly, there is no need for a wick to convey liquid into the tube so that humidification can take place. The tube is not dependent on a specific orientation for functionality, which gives the medical practitioner more freedom to manipulate the system.

According to a first aspect of the present disclosure, a tube for delivering humidified gases is disclosed. The tube comprises a hydrophilic or hygroscopic material and a heating mechanism. The hydrophilic or hygroscopic material stores a liquid in the tube. The heating mechanism heats the liquid stored in the tube to produce vapour to humidify gases delivered by the tube. The tube is pre-loaded by storing liquid in the hydrophilic or hygroscopic material prior to use.

The hydrophilic or hygroscopic material may store sufficient liquid to produce a desired amount of humidity for an intended volume of gases delivered by the tube. The desired amount of humidity may be at least <NUM>% relative humidity. The desired amount of humidity may be at least <NUM>% relative humidity. The hydrophilic or hygroscopic material may be a thermoplastic polyurethane. The hydrophilic or hygroscopic material may be a nylon. The heating mechanism may be a heater wire. The heating mechanism may be integral to the tube. The heating mechanism may be positioned near the centre of the lumen. The heating mechanism may heat gases delivered by the tube.

The tube may comprise an outer layer and a bead of the hydrophilic or hygroscopic material spirally wrapped inside the outer layer. The bead may provide structural support to the outer layer. The outer layer may be spirally wound with the bead. The bead may be positioned internally to the outer layer. The outer layer may have low permeability to liquid, vapour, and/or gases. The outer layer may be a hydrophobic material. The outer layer may be impermeable to liquid, vapour, and gases. The outer layer may be a thermoplastic polyurethane. The heating mechanism may be positioned adjacent to the bead.

According to a second aspect of the present disclosure, a medical gases delivery system for providing heated and humidified gases to a patient during a medical procedure is disclosed. The medical gases delivery system comprises a gases source and a tube for delivering heated and humidified gases from the gases source to the patient. The tube comprises a hydrophilic or hygroscopic material and a heating mechanism. The hydrophilic or hygroscopic material stores liquid in the tube. The heating mechanism heats liquid stored in the tube to produce vapour to humidify gases delivered by the tube. The heating mechanism heats gases delivered by the tube. The tube is pre-loaded by storing liquid in the hydrophilic or hygroscopic material prior to use during the medical procedure.

The hydrophilic or hygroscopic material may store sufficient liquid to produce a desired amount of humidity for an intended volume of gases delivered by the tube. The desired amount of humidity may be at least <NUM>% relative humidity. The desired amount of humidity may be at least <NUM>% relative humidity. The intended volume of medical gases may be a volume sufficient for use during the surgical procedure. The hydrophilic or hygroscopic material may be a thermoplastic polyurethane. The hydrophilic or hygroscopic material may be a nylon. The heating mechanism may be a heater wire. The heating mechanism may be integral to the tube. The heating mechanism may be positioned near the centre of the lumen.

In some embodiments, an integrated tubular device for delivering humidified gases includes an elongate tubular body comprising an open proximal end, an open distal end, and a lumen therethrough; a material operably connected to an interior of the lumen and configured to reversibly store a volume of liquid in liquid form within the material and release the volume of liquid in vapour form when the material is heated; and a heating element operably connected to the elongate tubular body, the heating element configured to heat the material such that the volume of liquid transforms from a liquid form to the vapour form.

In some embodiments, the material comprises a hydrophilic or hygroscopic material. In some embodiments, the material comprises a hydrophilic material. In some embodiments, the material comprises a hygroscopic material. In some embodiments, the material is configured to absorb the volume of liquid. In some embodiments, the material is configured to wick the volume of liquid. In some embodiments, the material comprises the volume of liquid. In some embodiments, the volume of liquid is between about 10cc and about <NUM>,000cc. In some embodiments, the volume of liquid is between about 25cc and about 500cc. In some embodiments, the elongate tubular layer comprises an outer layer, wherein the outer layer is impermeable to liquid, vapour, or gases. In some embodiments, the heating element comprises a heater wire. In some embodiments, the heater wire is proximate the material. In some embodiments, the liquid comprises water.

In some embodiments, a method of delivering humidified gases to a target includes providing an integrated tubular device for delivering humidified gases, comprising: an elongate tubular body comprising an open proximal end, an open distal end, and a lumen therethrough; a material operably connected to an interior of the lumen and configured to reversibly store a volume of liquid in liquid form within the material and release the volume of liquid in vapour form when the material is heated; flowing gases from a gases source from the open proximal end of the elongate tubular body, through the lumen, and out the open distal end of the elongate tubular body; heating the material such that at least a fraction of the volume of liquid transforms from a liquid form to the vapor form to humidify the flowing gases; and flowing the humidified gases to the target.

In some embodiments, the method further comprises contacting the material with a source of the liquid to reversibly store the volume of liquid in liquid form within the material. In some embodiments, at least <NUM>% of the volume of liquid transforms from a liquid form to the vapour form to humidify the flowing gases. In some embodiments, wherein the target comprises an operative site of a patient. In some embodiments, the gases comprise carbon dioxide. In some embodiments, the liquid comprises water.

<FIG> illustrates a prior art humidification system <NUM> that is configured to deliver heated and humidified gases to a patient <NUM>. The humidification system <NUM> comprises a humidification apparatus <NUM>, a humidification chamber <NUM>, and a gases source <NUM>. In an embodiment, the gases source <NUM> is an insufflator. The humidification chamber <NUM> is configured to hold water. The humidification apparatus <NUM> comprises a heating mechanism configured to heat the water within the humidification chamber <NUM> to form water vapour. Gases from the gases source <NUM> are heated and humidified as they pass through the humidification chamber <NUM> and the conditioned gases are delivered to the patient <NUM>.

Gases as herein described refers to respiratory gases (for example, oxygen, air, nitrogen, carbon dioxide, or a combination of any of these), or surgical gases, (for example, carbon dioxide, nitrous, oxygen, air, helium, or a mixture of carbon dioxide with nitrous or oxygen). Other gases or combinations of gases also fall within the scope of the disclosed apparatus and systems.

<FIG> illustrates a prior art humidification system <NUM> that is configured to deliver heated and humidified gases to a patient <NUM>. The humidification system <NUM> comprises a tube humidifier <NUM>, a water channel <NUM>, a water supply <NUM>, and a gases source <NUM>. Gases from the gases source <NUM> are delivered to the patient <NUM> via the tube humidifier <NUM>. The tube humidifier <NUM> comprises a wicking membrane that wicks water via the water channel <NUM> from the water supply <NUM>. The water that has been wicked is heated using a heating mechanism, thereby causing evaporation of the water. The water vapour generated enters the lumen of the tube humidifier <NUM>, thereby causing the gases flowing therein to become humidified. The humidified gases are delivered to the patient <NUM>.

<FIG> illustrates an example embodiment of a tube humidifier <NUM> that is configured to deliver heated and humidified gases to a patient. The tube humidifier <NUM> can be configured to be a disposable component. The tube humidifier <NUM> comprises a single component to facilitate heating and humidifying gases. The tube humidifier <NUM> comprises an outer layer <NUM>, a bead <NUM>, and a heating mechanism <NUM>. The tube humidifier <NUM>, for example, the outer layer <NUM> of the tube humidifier <NUM>, defines a lumen <NUM> that is configured to provide a passageway through which gases are transported from the gases source to the patient. The outer layer <NUM> is configured to provide a barrier between the lumen <NUM> and the atmosphere. Thus, the outer layer <NUM> is configured to comprise a low permeability to gases, liquid, and vapour. Low permeability, as herein described refers to a material that provides at least a partial barrier to reduce or eliminate the likelihood of liquid, gases, and/or vapour reaching the atmosphere, such that sufficient gases move through the system to maintain the pneumoperitoneum of the patient.

In an embodiment, the outer layer <NUM> is made from materials from the class of thermoplastic polyurethanes. In an embodiment, the outer layer <NUM> comprises polyethylene. In an embodiment, the outer layer <NUM> comprises polyester. The scope of the disclosed apparatus and systems are in no way limited to the examples above, thus, any suitable or similar material could be used to form the outer layer <NUM>. The outer layer <NUM> provides a strong, tough, and flexible layer of the tube humidifier <NUM>. In an embodiment, the outer layer <NUM> is hydrophobic. In an embodiment, the outer layer <NUM> is not hydrophilic. In an embodiment, the outer layer <NUM> is configured to be non-permeable to gases, liquid, and vapour.

The bead <NUM> can be spirally wound, associated in a linear fashion, or otherwise operably connected with the outer layer <NUM> to form a tube. In an embodiment, the tube comprises an extruded or corrugated configuration. In an embodiment, the tube comprises an annular bead. In an embodiment, the bead <NUM> is inserted into the lumen <NUM> of the tube. The bead <NUM> can be pre-coiled prior to insertion into the lumen <NUM>. The bead <NUM> can be formed into a plurality of rings and inserted into the lumen <NUM>. In an embodiment, the outer layer <NUM> of the tube comprises multiple layers wherein the bead <NUM> is configured to be positioned between the layers. The bead <NUM> may be bonded to at least one of the layers or may be freely positioned within the layers. In a further embodiment, the bead <NUM> may be coupled with the outside of the tube. For example, the bead <NUM> may bond with the outside of the tube. In an additional example, the bead <NUM> may be pre-coiled such that it can be mechanically fitted to the outside or inside of the tube.

In the illustrated embodiment, the bead <NUM> comprises a hydrophilic or hygroscopic material. The bead <NUM> is configured to hold a liquid, for example, water, and/or a medicament. In some embodiments, the bead or other material is configured to hold a volume of liquid such that the volume of liquid does not substantially migrate out of the material until the material is heated as desired. A hygroscopic material can store liquid, such as water, in a liquid form. A hygroscopic material attracts and holds water molecules via adsorption. The material can be porous (like silica gel or zeolite) or can have surface features that increase the effective surface area of the material. A hydrophilic material can store liquid, such as water, in a liquid and/or vapour form. A hydrophilic material stores water via absorption. The material can be foamed or can include surface features to increase the effective surface area of the material.

Prior to use, the tube humidifier <NUM>, e.g., the bead <NUM>, is pre-loaded to facilitate the entry of liquid into the bead <NUM>. In an embodiment, the tube humidifier <NUM> is soaked prior to use. Thus, the tube humidifier <NUM> is preloaded with liquid and provided to the medical practitioner ready to use. This improves the usability of the tube humidifier <NUM> by reducing the number of set-up steps for the system. The quantity of liquid held within the bead <NUM> is sufficient to supply between <NUM>% to <NUM>% relative humidity during a surgical procedure. In an embodiment, the bead <NUM> is configured to hold enough liquid to supply humidity for a given volume of gases, in the range of <NUM>% to <NUM>%, <NUM>% to <NUM>%, <NUM>% to <NUM>%, or at least <NUM>% relative humidity during a surgical procedure. Sufficient liquid can be stored within the tube humidifier <NUM> to provide humidification for a range of volumes of gases required for different surgical procedures. For example, a range of tube humidifiers <NUM> can be configured to hold a range of quantities of liquid to provide humidification for different surgical procedures. In some embodiments, the relative humidity is delivered at or substantially at body temperature, e.g., about <NUM>. In some embodiments, the volume of liquid that can be reversibly stored by the material is between about 10cc and about <NUM>,000cc, between about 25cc and about 500cc, or between about 50cc and about 250cc in some embodiments.

The bead <NUM> can be made of materials chosen such that the bead <NUM> is strong and easy to process. In an embodiment, the bead <NUM> holds liquid using chemical properties such that liquid is stored within the bead <NUM>. Storage of liquid in this way also enables the bead <NUM> to remain lightweight and flexible. The bead <NUM> can contribute towards the overall strength and robustness of the tube humidifier <NUM>. In an embodiment, the bead <NUM> provides a structural component to the tube humidifier <NUM>.

In an embodiment, the tube comprises a bead <NUM> and a reinforcing component. In such an embodiment, the bead <NUM> may not provide a structural component to the tube humidifier <NUM>. The reinforcing component can comprise a metal or plastic material. The reinforcing component can comprise, for example, a reinforcing rib and can be positioned within the tube humidifier <NUM>. In an embodiment, the tube humidifier <NUM> comprises the reinforcing component integrally within the outer layer <NUM> of the tube humidifier <NUM>. In a further embodiment, the reinforcing component is positioned externally to the tube humidifier <NUM>. In a further embodiment, a heating mechanism <NUM>, discussed in further detail below, comprises the reinforcing component. For example, but without limitation, the heating mechanism <NUM> may comprise a steel heater wire.

In an embodiment, the materials of the bead <NUM> are chosen from the class of thermoplastic polyurethanes. In an embodiment, the materials of the bead <NUM> are chosen from the class of nylons. In a further embodiment, the bead <NUM> comprises polyester. In a further embodiment, the bead <NUM> comprises polyether. The scope of the disclosed apparatus and systems is in no way limited to the examples above; thus, any suitable or similar material could be used to form the bead <NUM>.

In an embodiment, materials are chosen that facilitate bonding between the outer layer <NUM> and the bead <NUM>. In an embodiment, the materials are chosen such that bonding does not occur, or is less likely to occur, between the outer layer <NUM> and the bead <NUM>. An additional component, for example, an adhesive, a weld, or a mechanical coupling mechanism, may facilitate coupling between the outer layer <NUM> and the bead <NUM>. In an embodiment, the bead <NUM> may be positioned freely within the lumen <NUM> of the tube humidifier <NUM>. In an embodiment, the outer layer <NUM> may comprise a preformed film. In a further embodiment, the bead <NUM> is configured to be contained within space that is created by a coaxial tube arrangement. The coaxial tube arrangement comprises an inner tube comprising a gases permeable material and an outer tube comprising a low permeability or gases impermeable material. In an embodiment, the bead <NUM> bonds to the inner tube. In an embodiment, the bead <NUM> bonds to the outer tube. In an embodiment, the bead <NUM> lies freely between the inner tube and the outer tube.

In an embodiment, the bead <NUM> comprises a circular shape. The bead <NUM> can have a diameter of approximately <NUM>. In an embodiment, the bead <NUM> comprises a triangular, square, elliptical or other customised shape. A different diameter of the bead <NUM> falls within the scope of the disclosed apparatus and systems. Characteristics of the bead <NUM> can be chosen to optimise performance. In an embodiment, the characteristics can be chosen to meet the requirements of different surgical procedures.

In an embodiment, the diameter of the bead <NUM> is chosen to optimise absorption or total absorbed liquid volume of the bead <NUM>. For example, increasing the diameter of the bead <NUM> may increase the absorption level of the bead <NUM> for a given material. Similarly, the diameter of the bead <NUM> is chosen to optimise desorption or the total amount of liquid volume that is released from the bead <NUM> under given conditions. For example, increasing the diameter of the bead <NUM> may increase the desorption level of the bead <NUM> under given conditions. The given conditions may comprise, for example, an application of heat to the bead <NUM>.

In an embodiment, the length of the tube is chosen to meet the requirements of different surgical procedures. For example, the tube can be <NUM> in length. Altering the length of the tube, for example, to <NUM> or <NUM> in length, or to other lengths as specified by the surgical procedure, falls within the scope of the disclosed apparatus and systems.

Altering the surface area of the bead <NUM> may alter the rate of absorption for a given material. Altering the surface area of the bead <NUM> may also alter the rate of desorption and thus the rate at which liquid is released from the bead <NUM>.

Altering the pitch of the bead <NUM> may alter the volume of liquid that is absorbed by the bead <NUM> for a given length of tube. For example, for a given material a tighter pitch facilitates a greater quantity of liquid being stored within the bead <NUM> as compared with the volume of liquid stored within a bead comprising a larger pitch. Therefore, the pitch can be optimised to control the volume of liquid stored within the bead <NUM>.

Altering the material of the bead <NUM> can alter the performance, for example, absorption capacity, rate of absorption, and/or rate of desorption. In an embodiment, materials can be chosen to optimise the absorption capacity of the bead <NUM>. In an embodiment, materials can be chosen to optimise the rate of absorption or the rate of desorption of the bead <NUM>.

In an embodiment, liquid is trapped in a pocket <NUM> that forms near the bonding location between the bead <NUM> and the outer layer <NUM>. The shape of the bead <NUM> can be chosen to determine the angle between the bead <NUM> and the outer layer <NUM>, which can be chosen to optimise the volume of liquid trapped therein. The trapped liquid is vaporised upon application of heat by the heating mechanism <NUM>. Altering the shape of the bead <NUM> can affect liquid movement within the bead <NUM>. In the illustrated example embodiment of <FIG>, a bead <NUM> comprises a square base <NUM> and a concave top <NUM>, herein referred to as a cup shape. The cup shape is configured to trap liquid. <FIG> illustrate embodiments of beads <NUM>', <NUM>" that increase the surface area of the beads <NUM>', <NUM>" relative to bead <NUM> to improve, e.g., increase, the rate of absorption and the rate of desorption. Increasing the surface area increases the time that gases contact the bead <NUM>', <NUM>", thereby increasing the humidification of the gases as they pass through the tube humidifier <NUM>. The embodiments shown in <FIG> are examples only and other shapes and configurations also fall within the scope of the disclosed apparatus and systems.

In the illustrated embodiment, the bead <NUM> comprises a non-foamed material. In an embodiment, the bead <NUM> comprises a foamed material. A foamed material facilitates increased liquid absorption and increased surface area for moisture and heat transfer within the tube humidifier <NUM>. The foamed material creates voids within which the liquid is held in addition to the liquid held within the material. Thus, the material has an increased liquid uptake compared with a non-foamed material. The material remains breathable such that the liquid is easily released from the voids. A foamed material may be used in procedures requiring a large amount of relative humidity, for example, due to usage of a large volume of gases. The foamed material is configured to be pre-loaded with liquid prior to use. In an embodiment, the foamed material is soaked to take up liquid prior to use. In an embodiment, the foamed material is injected with liquid prior to use.

Heat is applied to the bead <NUM> to heat the gases to a temperature that is greater than the ambient temperature and to release liquid stored within the bead <NUM>. Released vapour enters the lumen <NUM> and humidifies the gases flowing through the tube humidifier <NUM>. Release of vapour into the lumen <NUM> is controlled by the amount of heat supplied to the bead <NUM>. A heating mechanism <NUM> is located near the bead <NUM> and acts to apply heat to the bead <NUM>. In an embodiment, the heating mechanism <NUM> is integral with the bead <NUM>. In an embodiment, the heating mechanism <NUM> is adjacent the bead <NUM>. In a further embodiment, the heating mechanism <NUM> is positioned within the lumen <NUM> of the tube. In an embodiment in which the outer layer <NUM> comprises multiple layers, the heating mechanism <NUM> can be positioned between layers. In an embodiment, the heating mechanism <NUM> can be positioned external to (e.g., wrapped around an outer surface of) the outer layer <NUM>; in such an embodiment, the heating mechanism <NUM> can be insulated.

In an embodiment, the tube comprises a dry section and a humidifying section. For example, the humidifying section comprises a bead <NUM> to humidify the gases. The dry section comprises a non-humidifying section. Thus, gases move through the dry section, into the humidifying section, where they are humidified prior to delivery to the patient. The humidifying section comprises the heating mechanism <NUM>. In an embodiment, the dry section comprises the heating mechanism <NUM> to heat the gases prior to entry into the humidifying section. This may improve the desorption rate of vapour from the bead <NUM>. In an embodiment, the dry section is an unheated section. In an embodiment, the gases move through the humidifying section, into the dry section, and to the patient. Thus, the humidifying section and the dry section may comprise the heating mechanism <NUM> such that heated humidified gases are provided to the patient. Heating within the dry section causes a decrease in the relative humidity of the gases, which reduces the likelihood of condensate formation as the gases reach the patient. Thus, heating within the dry section of the tube may improve control of the temperature drop between the heated tube and the patient to reduce the condensate formed within the system. In a further alternative embodiment, multiple dry and humidifying sections are interspersed along the length of the tube. In an embodiment, multiple heating wires allow for customised heating solutions. For example, low or no heating can be applied in parts of the tube and increased heating can be applied in other parts of the tube.

In the illustrated embodiment of <FIG>, the heating mechanism <NUM> comprises a heater wire. In an embodiment, multiple heater wires are used, for example, two heater wires. The heater wires may be coated prior to being positioned near the bead <NUM>. The diameter and material of the heater wires affects the resistance of the heater wires. In the illustrated embodiment, the diameter of the heater wires is <NUM>. The diameter can be chosen to optimise the resistance of the heater wires and to affect the power delivered to the system. Thus, a range of different diameters and materials fall within the scope of the disclosed apparatus and systems.

The heating mechanism <NUM> can be integrated into the tube. The pitch of the heating mechanism <NUM> affects the distribution of heat produced. For example, a smaller pitch causes a more equal distribution of heat within the tube compared to a larger pitch. The pitch is optimised to provide sufficient heat and relative humidity to the gas for for a given procedure. In an embodiment, the heating mechanism <NUM> is incorporated within the bead <NUM>. In an embodiment, the heating mechanism <NUM> is positioned on the inner surface of the bead <NUM>. This reduces the surface temperature of the tube humidifier <NUM>. Thus, the tube humidifier <NUM> is more comfortable to the touch. In an embodiment, the surface temperature of the tube humidifier <NUM> is configured to fall within acceptable limits as specified by Medical Design Standard IEC60601. A power supply (discussed below) supplies power to the heating mechanism <NUM>.

The power supply delivers power to the heating mechanism <NUM>, which is integrated with the tube humidifier <NUM>. In some embodiments, a control system is configured to control the power, and subsequently heat, delivered to the tube humidifier <NUM>, causing the gases to be heated to above ambient temperature and humidity to be released from the bead <NUM>. The amount of heat delivered is determined based on the power supplied to the system. This enables the control system to make an estimation of the humidity being received by the patient. In an embodiment, the control system supplies differential heating to the system to control or adjust the temperature and humidity of the gases that are delivered to the patient.

The control system is configured to initiate a warm up mode. The warm up mode is configured to last for the duration of the warm up of other surgical instruments, such as, for example, a scope warmer or a cannula. The warm up mode can be controlled such that the dew point temperature of the gases within the tube humidifier <NUM> exceeds the temperature of the surgical instruments, thus reducing condensate formation. In the illustrated embodiment, no additional sensors or other form of feedback are required. In an embodiment, sensors such as a humidity sensor, temperature sensor, flow sensor, and/or pressure sensor could be used to control the system.

In an embodiment, the control system and the power supply are integrated into a single component. The single component may be integrated into the tube humidifier <NUM> or may be an external component. In an embodiment, the control system and the power supply comprise individual or separated components. In a further embodiment, the control system is integrated into a gases source. In a further embodiment, the control system is integrated into a connector. In a further embodiment, the control system is integrated into the tube humidifier <NUM>.

<FIG> illustrate various configurations for the tube humidifier <NUM>. In the embodiment of <FIG>, the heating mechanism <NUM> is a heater wire disposed within and surrounded by the bead <NUM>. In the illustrated embodiment, the bead <NUM> is positioned adjacent and/or attached to the outer layer <NUM> and is spirally wound or formed in rings disposed within the outer layer <NUM>. <FIG> illustrates a configuration in which the material of the bead <NUM> is foamed as described herein, which can advantageously increase the storage capacity of the bead <NUM> and/or allow for quicker pre-loading (absorption or adsorption) of the bead <NUM>. In some embodiments, for example as shown in <FIG>, diameters of the tube (e.g., of the outer layer <NUM>) and/or the bead <NUM> can be increased relative to other configurations to increase the storage capacity of the bead <NUM> and/or strength of the tube. In some embodiments, a diameter of the bead <NUM> can be approximately <NUM>. In some embodiments, a diameter of the tube can be approximately <NUM>. <FIG> illustrates a configuration similar to that of <FIG> in which the bead <NUM> is formed of a different material, e.g., Estane, which may increase the storage capacity of the bead <NUM> compared to the material of the bead <NUM> of <FIG>, which may be, for example, Arnitel. In some embodiments, for example as shown in <FIG>, a reinforcing wire <NUM> can be disposed within and surrounded by the bead <NUM> to help strengthen the tube. In some embodiments, the reinforcing wire <NUM> is made of stainless steel. <FIG> illustrate an example configuration similar to that of <FIG>; however, in the configuration of <FIG>, the bead <NUM> is separated from the outer layer <NUM> by a layer of liquid <NUM>. In some embodiments, the layer of liquid <NUM> can act as a reservoir to store additional liquid that can permeate into the bead <NUM> as the liquid pre-stored in the bead <NUM> is vaporized in use. In some embodiments, the separation of the bead <NUM> from the outer layer <NUM> allows for easier manufacturing and assembly. For example, the bead <NUM> and the outer layer <NUM> can be extruded or otherwise formed independently from one another and then assembled together, for example, by coiling the bead <NUM> and inserting the bead <NUM> into the outer layer <NUM>. The bead <NUM> can be soaked with liquid before or after insertion into the outer layer <NUM>. Other configurations and materials for the bead <NUM> and/or heater wire <NUM> are also possible.

<FIG> illustrate example embodiments of systems incorporating a tube humidifier, which can include some or all of the features of the tube humidifier <NUM> described herein and shown in <FIG>.

<FIG> illustrates an example embodiment of a humidification system <NUM> that delivers gases to a patient <NUM>. The humidification system <NUM> comprises a tube humidifier <NUM> according to the present disclosure, a gases source <NUM>, a power supply <NUM>, a first connector <NUM>, and a second connector <NUM> connecting with a patient interface <NUM>. The tube humidifier includes a heating mechanism as described herein, for example, heating mechanism <NUM>. The humidification system <NUM> can also include a filter <NUM>. The power supply <NUM> is configured to supply power to the heating mechanism within the tube humidifier <NUM>. The first connector <NUM> enables an electrical connection to be formed between the power supply <NUM> and the heating mechanism. The power supply <NUM> is located externally to the tube humidifier <NUM>. The power supply <NUM> is configured to be a reusable component. A cable connects the power supply <NUM> to the first connector <NUM>.

In the illustrated embodiment, the tube humidifier <NUM> connects directly to the gases source <NUM> via the first connector <NUM>, thereby forming a pneumatic connection. An electrical connection is formed between the power supply <NUM> and the tube humidifier <NUM> through the first connector <NUM>. In an embodiment, the power supply <NUM> couples with the tube humidifier <NUM> at any point along the length of the tube humidifier <NUM>. In such an embodiment, an additional connector can form an electrical connection between the power supply <NUM> and the tube humidifier <NUM>. The power supply <NUM> is a compact unit that is easily integrated into the medical environment.

<FIG> illustrates an example embodiment of a humidification system <NUM> that delivers heated and humidified gases to a patient <NUM>. The humidification system <NUM> comprises a tube humidifier <NUM> according to the present disclosure, a gases supply <NUM>, a power supply <NUM>, a first connector <NUM>, and a second connector <NUM> connecting with a patient interface <NUM>. The tube humidifier includes a heating mechanism as described herein, for example, heating mechanism <NUM>. The humidification system <NUM> can also include a filter <NUM>. The power supply <NUM> is configured to supply power to the heating mechanism within the tube humidifier <NUM>. In the illustrated embodiment, the power supply <NUM> is integrated with the gases source <NUM>. The power supply <NUM> is configured to be a reusable component. The first connector <NUM> enables an electrical and pneumatic connection between the gases source <NUM> and the tube humidifier <NUM>.

The tube humidifier <NUM>, <NUM>, <NUM> thus has improved ease of use over the humidification systems <NUM>, <NUM> disclosed above and illustrated in <FIG>. The tube humidifier <NUM>, <NUM>, <NUM> has a similar footprint to a conventional tube set, while providing humidified gases to the patient. Use of a small diameter tube, for example, a tube with a diameter of approximately <NUM>, reduces the footprint of the tube humidifier <NUM>, <NUM>, <NUM>. In an embodiment, the diameter of the tube can be chosen to maintain sufficient compressible volume within the system. In an embodiment, the tube humidifier <NUM>, <NUM>, <NUM> comprises a different diameter tube. Selecting the desired diameter alters the footprint of the tube humidifier <NUM>, <NUM>, <NUM> as appropriate. The length of the tube should be sufficient for use in the surgical environment. In an embodiment, the length is approximately <NUM>. In an embodiment, the length is approximately <NUM>. Longer or shorter tubes also fall within the scope of the disclosed apparatus and systems.

<FIG> illustrates an example embodiment of a humidification system <NUM> that delivers heated and humidified gases to a patient <NUM>. The humidification system <NUM> comprises a tube humidifier <NUM> according to the present disclosure, a gases source <NUM>, a power supply <NUM>, a first connector <NUM>, and a second connector <NUM> that connects with a patient interface <NUM>. The tube humidifier includes a heating mechanism as described herein, for example, heating mechanism <NUM>. The humidification system can also include a filter <NUM>. The power supply <NUM> is integrated into the tube humidifier <NUM>. The power supply <NUM> comprises, for example, a battery source. In an embodiment, the power supply <NUM> is a disposable product. In an embodiment, the power supply <NUM> is removably coupled to the tube humidifier <NUM>. Thus, the power supply <NUM> can be a reusable product. The battery source is replaceable following a surgical procedure.

In the illustrated embodiment, the power supply <NUM> connects via connector <NUM> to the gases source <NUM>. The electrical connection between the power supply <NUM> and the tube humidifier <NUM> can be formed via the connector <NUM>. A pneumatic connection is formed between the tube humidifier <NUM> and a gases source <NUM> using the connector <NUM>. In an embodiment, the power supply <NUM> is located on an external surface of the tube humidifier <NUM>. The power supply <NUM> forms an electrical connection between an additional connector connected with the cable of the power supply <NUM> and a junction on the external surface of the tube humidifier <NUM>.

In an embodiment, the tube humidifier <NUM>, <NUM>, <NUM>, <NUM> may comprise an integrated sensing system for improved control. In an additional embodiment, two sensor wires are incorporated with the heating mechanism <NUM>. The sensing system may comprise an end of hose sensor. In an embodiment, sensor probes provide an indication of the gases characteristics. Characteristics such as humidity, temperature, flow, and/or pressure could be sensed using the sensing system.

In an embodiment, alternative power supplies, such as batteries or standard electrical systems, can be used to supply power to the tube humidifier <NUM> , <NUM>, <NUM>, <NUM>. In an embodiment, the power supply comprises an indication of liquid using visual cues, for example, light emitting diodes, warning lights, or a colour change. The visual cues can be achieved by electromechanical, mechanical or chemical mechanisms. By way of example only, silica is red when dry and turns blue when saturated by a liquid, such as, water. In an embodiment, the visual cues are displayed on the first connector <NUM>, <NUM>, <NUM>, or the second connector <NUM>, <NUM>, <NUM>, as discussed, or on an outer surface of the tube humidifier <NUM>, <NUM>, <NUM>, <NUM>.

In an embodiment, the heating mechanism <NUM> comprises alternative mechanisms, for example, exothermic reactions, induction heating or electromagnetic heating.

In an embodiment, for example as shown in <FIG>, a tube humidifier <NUM> may comprise an outer layer <NUM> that comprises multiple layers to improve insulation. In an embodiment, the multiple layers may comprise spaces between them, for example, comprising air, to further improve the insulation properties.

In an embodiment, for example as shown in <FIG>, a tube humidifier <NUM> comprises an outer layer <NUM> that comprises a hollow tube <NUM> that is spirally wound defining a lumen <NUM> of a larger tube. In an embodiment, the hollow tube <NUM> is wound with a bead <NUM> to form a larger tube. The hollow tube <NUM> provides properties such as insulation and flexibility to the larger tube. The bead <NUM> provides a structural component to the larger tube. In an embodiment, the hollow tube <NUM> provides a structural component and the bead <NUM> provides insulation and flexibility to the larger tube. In an embodiment, a heating mechanism <NUM> is integral to the tube. In an embodiment, the heating mechanism <NUM> is incorporated within the hollow tube <NUM>. In an embodiment, the heating mechanism <NUM> is incorporated within the bead <NUM>.

<FIG> illustrate an embodiment of a tube humidifier <NUM> that comprises a heating mechanism, such as one or more heater wires <NUM>, insulated in and surrounded by one or more layers of a hydrophilic or hygroscopic material <NUM>. In some embodiments, the material <NUM> can be Arnitel (a thermoplastic co-polyester). In some embodiments, the material <NUM> can be Estane (a thermoplastic polyurethane). The tube humidifier <NUM> comprises an outer layer <NUM> that defines a lumen <NUM> through which gases flow during use. The outer layer <NUM> can be similar to (e.g., be made of the same or similar materials, have the same or a similar structure, etc.) other outer layers as described herein. For example, the outer layer <NUM> can be non-permeable or have a low permeability to gases (e.g., surgical gases), liquids, and/or vapour.

The layer of material <NUM> holds a liquid, such as water and/or a medicament. The material <NUM> can store and hold the liquid, such as water or saline, via a chemical bond. For example, due to the polarity of water, water can chemically bond to the material. In use, heat from the heater wire <NUM> causes the liquid to vaporize and be released from the material <NUM> (or causes a vapour stored in the material <NUM> to be released) into the lumen <NUM> where the vapour mixes with and humidifies gases flowing through the lumen <NUM> to the patient. The material <NUM> can be permeable to the vapour in all directions. In other words, the material can release the liquid in the form of vapour in all directions and is not orientation dependent. This allows for gases passing over or by any portion of the material <NUM> to be humidified. The release of liquid from the material <NUM> can be dependent on a temperature and/or concentration gradient between the material <NUM> and the surrounding environment. In some such embodiments, a heater wire <NUM> may not be needed to drive release of liquid from the material <NUM>. In some embodiments, the amount of liquid released (in the form of vapour) and/or the rate of liquid released during the procedure can be controlled by controlling the power to the heater wire <NUM>. The heater wire <NUM> may be the only heating mechanism in a humidification system including the tube humidifier <NUM>. The heater wire <NUM> can therefore affect or control the temperature and/or humidity of gases delivered to the patient. The relative humidity and efficiency of such a humidification system is therefore a function of the tube humidifier <NUM> geometry (e.g., the surface area of the material <NUM> exposed to the gases flowing through the tube humidifier <NUM>), the contact time between the gases and the hydrophilic material, the temperature of the gases, and/or the energy supplied by the heater wire <NUM>.

The material <NUM> can be pre-soaked or pre-loaded with the liquid. The material <NUM> can be pre-soaked with a known quantity of liquid, which may be a quantity of liquid calculated or determined to be needed during a particular laparoscopic procedure of a particular duration. A humidification system incorporating the tube humidifier <NUM> therefore need not include a separate, external liquid reservoir or delivery system and as such the reversible liquid reservoir can advantageously be integrated within the tube itself. The user may not need to input liquid into the system before or during the procedure. Properties such as the diameter of the layer of material <NUM> and/or the amount of the material <NUM> present can be adjusted to adjust the quantity of liquid that can be stored in the layer of material <NUM>. Adjusting the diameter or amount of material <NUM> may alter the amount of liquid that can be held by the material <NUM>, but may affect the inner diameter of the tube humidifier <NUM> or the space available for gases to flow within the lumen <NUM>, which may in turn affect resistance to gases flow within the tube humidifier <NUM>. For example, increasing the diameter of the layer of material <NUM> for an outer layer <NUM> having a given diameter can decrease the space available for gases flow between the layer of material <NUM> and the outer layer <NUM>, which can increase resistance to gas flow within the tube humidifier <NUM>, but allows the material <NUM> to hold more liquid. Thus, a trade-off exists between the quantity of liquid held by the material <NUM> and the resistance to flow. If desired, a diameter or length of the tube humidifier <NUM> can be altered to balance these effects.

In some embodiments, the layer of material <NUM> and/or heater wire <NUM> can extend along an entire length of the tube humidifier <NUM> from an insufflator to the patient. In other embodiments, the layer of material <NUM> and/or heater wire <NUM> maybe extend along only part or parts of the length of the tube humidifier <NUM>. The layer of material <NUM> and heater wire <NUM> can be free floating within the outer layer <NUM>. In some embodiments, the layer of material <NUM> and/or heater wire <NUM> can be secured at a connector between the tube humidifier <NUM> and the insufflator, a connector between the tube humidifier <NUM> and the patient, and/or at one or more points along the tube humidifier <NUM>, for example, to maintain the layer of material <NUM> and/or heater wire <NUM> generally in a centre of tube humidifier <NUM>.

In some embodiments, the heater wire <NUM> (or heater wires <NUM> if the tube humidifier <NUM> includes multiple heater wires <NUM>) extends longitudinally within the layer of material <NUM> and the tube. In other embodiments, the heater wire <NUM> (or wires) extends within the layer of material <NUM> and the tube in a spiral configuration. In some embodiments, both the heater wire <NUM> and the surrounding layer of material <NUM> can extend along the tube in a spiral configuration. A spiral configuration can increase the surface area exposed to surgical gases flowing through the tube. In some embodiments, instead of or in addition to a heater wire within the layer of material <NUM>, a heating mechanism, such as a heater wire, can be embedded within the outer layer <NUM>, disposed on or wrapped around an inner or outer surface of the outer layer <NUM>, or disposed within the lumen <NUM> outside of the layer of material <NUM>.

The layer of material <NUM> can be made of various materials, such as those described herein with respect to bead <NUM>. The rate of liquid uptake by the layer of material <NUM> during loading is dependent on, for example, the amount of surface contact of the material <NUM> to the liquid, the temperature of the liquid (e.g., hot water is generally taken up faster than cold water), and/or the time of exposure of the material <NUM> to the liquid. If desired or required, the material can be selected to increase the amount of water held by the layer of material <NUM>. However, increasing the amount of water held may increase the weight of the tube humidifier <NUM> due to the increased weight of the additional water and because a greater amount and therefore weight of material is generally needed to hold a greater amount of water. A given material may be able to hold only a small percentage of its weight in water. Therefore, to increase the amount of water held, a relatively large increase in material weight may be required. In some embodiments, the layer of material <NUM> can be rechargeable, for example, by re-soaking the layer of material <NUM> in the liquid.

In some embodiments, the layer of material <NUM> can have cavities or channels within the material. Such cavities or channels can increase the liquid-storage capacity of the layer of material <NUM>. The cavities or channels can be pre-loaded with liquid. In some embodiments, the cavities or channels can be rechargeable, for example, during use or between uses. Smaller cavities or channels may have an increased resistance to loading and storing liquid, whereas larger cavities or channels may have a decreased resistance to loading and storing liquid. In some embodiments, the layer of material <NUM> has multiple cavities or channels. In some embodiments, the tube humidifier <NUM> includes multiple layers of material <NUM>. Each layer may include one or more cavities or channels. In some embodiments having multiple layers of material <NUM>, each layer may include, e.g., surround, a heater wire <NUM>. In other embodiments, multiple layers may surround a single heater wire <NUM>.

According to the present invention, the tube humidifier <NUM> includes one or more layers of a hydrophilic or hygroscopic material <NUM> surrounding a central liquid reservoir or channel <NUM>, with a heating mechanism, such as one or more heater wires <NUM>, disposed in the layer(s) of material <NUM>, for example as shown in <FIG>. Such an arrangement may allow for quicker manufacturing as the central liquid channel <NUM> may be able to be filled more quickly than the material <NUM> can be pre-soaked. Liquid can permeate the material <NUM> from the channel <NUM>. The heater wires <NUM> can extend longitudinally within the material <NUM>, can extend in a spiral along a length of the material <NUM>, or be arranged in other configurations. <FIG> illustrates an alternative arrangement of the present invention in which the layer(s) of material <NUM> surrounds two liquid reservoirs or channels 1046a, 1046b and the heating mechanism, such as one or more heater wires <NUM>, is positioned in a central reinforcing strut portion or the material <NUM>. Such an arrangement can advantageously help liquid from the liquid reservoirs 1046a, 1046b permeate the material <NUM> more quickly.

In some embodiments, the tube humidifier <NUM> includes a wick in contact with the layer of material <NUM>. In some embodiments, the wick can be at least partially placed within a channel in the layer of material <NUM>. The wick can allow for transfer of liquid from a reservoir (e.g., channel <NUM> shown in <FIG> or a separate reservoir used to load the material <NUM>) to the hydrophilic material, for example, before use, for recharging, and/or during use. The use of a wick and reservoir can increase the overall liquid storage and release capacity of the layer of material <NUM> during use.

The tube humidifier <NUM> can be incorporated into humidification systems such as those described herein. Such systems can include a control system, which may be external to the tube humidifier <NUM>. Such systems can include a power source external to the tube humidifier <NUM> for supplying power to the heater wire <NUM> and/or to the control system.

The tube humidifier <NUM>, and other tube humidifiers described herein and according to the present disclosure, can advantageously allow for a humidification system with a smaller footprint and fewer set-up steps than prior art systems.

Although reference has been made throughout this specification regarding surgical procedures, such as open or laparoscopic surgery, the disclosed apparatus and systems can be applied to different medical fields, for example, respiratory assistance systems.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the apparatus and systems of the disclosure and without diminishing its attendant advantages. For instance, various components may be repositioned as desired. It is therefore intended that such changes and modifications be included within the scope of the apparatus and systems of the disclosure. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present apparatus and systems of the disclosure. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow.

Wherein the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

The apparatus and system of the disclosure may also be said broadly to include the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Claim 1:
A tube humidifier (<NUM>) for delivering humidified gases, comprising:
one or more layers of hydrophilic or hygroscopic material (<NUM>) configured to hold a liquid;
an outer layer (<NUM>) defining a lumen (<NUM>) through which the gases flow;
a heating mechanism in the one or more layers of hydrophilic or hygroscopic material (<NUM>), wherein the heating mechanism is configured to cause the liquid to vaporise and be released from the one or more layers of hydrophilic or hygroscopic material (<NUM>) into the lumen (<NUM>),
wherein the one or more layers of hydrophilic or hygroscopic material (<NUM>) are generally in a centre of the tube humidifier (<NUM>),
characterized in that
the one or more layers of hydrophilic or hygroscopic material (<NUM>) surround a liquid reservoir or channel (<NUM>, 1046a, 1046b).