Patent Publication Number: US-2017370501-A1

Title: Flexible duct for convective device

Description:
TECHNICAL FIELD 
     The present disclosure is related to convective systems and components to be used in a convective system for warming or cooling. 
     SUMMARY 
     At least some aspects of the present disclosure feature a flexible duct for a convective device, comprising: an inflatable tubular structure in generally a tube shape when inflated comprising a flexible material. The tubular structure has a first longitudinal edge and a second longitudinal edge opposing to the first longitudinal edge. The an air-guide device includes a plurality of air-guide elements disposed in a pattern on the tubular structure, where the air-guide device is configured to direct flow of inflation medium when the tubular structure is bent. 
     At least some aspects of the present disclosure feature a convective system, comprising: a convective device comprising a pneumatic structure and an opening, a disposable duct and a nozzle configured to connect to the disposable duct. The disposable duct includes an inflatable tubular structure in generally a tube shape when inflated comprising a flexible material and an air-guide device disposed in the tubular structure. The opening of the convective device is configured to receive the nozzle. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, explain the advantages and principles of the invention. In the drawings, 
         FIG. 1A  illustrates one embodiment of a flexible duct; 
         FIG. 1B  illustrates a perspective view of the flexible duct illustrated in  FIG. 1A  when inflated and bent; 
         FIG. 2A  illustrates one example of a flexible duct; 
         FIG. 2B  illustrates the flexible duct illustrated in  FIG. 2A  bent at an air-guide element; 
         FIG. 2C  illustrates another example of flexible duct; 
         FIG. 2D  illustrates a perspective view of the flexible duct illustrated in  FIG. 2C  being inflated and bent; 
         FIGS. 2E-2G  illustrate some example constructions of flexible hose; 
         FIG. 3A  shows an example of a convective device with an integrated flexible duct; 
         FIG. 3B  shows the convective device illustrated in  FIG. 3A  with the flexible duct partially detached; 
         FIG. 3C  shows the convective device illustrated in  FIG. 3A  being inflated using the flexible duct connecting to a hose; 
         FIGS. 4A-4H  illustrate some examples of air-guide elements; 
         FIG. 5A  illustrates a perspective view of one embodiment of a hose clamp; 
         FIG. 5B  illustrates a side view of the hose clamp illustrated in  FIG. 5A ; 
         FIG. 5C  illustrates a front view of another embodiment of a hose clamp; 
         FIG. 6A  is a flattened view of a hose clamp toward the inner surface of an encircling element; 
         FIG. 6B  is a perspective view of the hose clamp illustrated in  FIG. 6A ; 
         FIG. 6C  is a side view of the hose clamp illustrated in  FIG. 6A ; 
         FIGS. 6D-6G  illustrate some example configurations of engaging components; 
         FIGS. 7A-7N  illustrate some examples of nozzle configurations; and 
         FIGS. 8A, 8B, and 8C  illustrate an example of a convective system using a flexible duct. 
     
    
    
     In the drawings, like reference numerals indicate like elements. While the above-identified drawing, which may not be drawn to scale, sets forth various embodiments of the present disclosure, other embodiments are also contemplated, as noted in the Detailed Description. In all cases, this disclosure describes the presently disclosed disclosure by way of representation of exemplary embodiments and not by express limitations. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this disclosure. 
     DETAILED DESCRIPTION 
     Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. 
     As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     Convective devices generally refer to a device distributing matter in gas state. For example, convective devices can receive a stream of pressurized, warmed air, inflate in response to the pressurized air, distribute the warmed air within a pneumatic structure, and emit the warmed air onto a body to accomplish such objectives as increasing comfort, reducing shivering, and treating or preventing hypothermia. In some embodiments, a convective device is a tubular convective device made from blown film. In such embodiments, the convective device does not use seals to form the pneumatic structure. In some cases, the convective device includes a homogeneous material to form the pneumatic structure. In some cases, at least part of the convective device has apertures of various shapes allowing pressured fluid to go through. In some embodiments, multiple tubular convective devices with or without tear perforations are formed in a roll. 
     In some embodiments, a convective device has a pneumatic structure that is formed by two layers, each layer including one or more sheets, and at least one of the layers is air permeable that allows air distribution. In some cases, the two layers are formed by the same sheet(s). As used herein, “inflatable” refers to a structure which increases in volume when air or other gas is supplied at a pressure greater than atmospheric pressure to the interior of the structure. Typically these structures inflate at relatively low pressures such as pressures less than 100 mmHg, preferably at pressures less than 50 mmHg, more preferably at pressures less than 25 mmHg. In some cases, the volume of the inflatable section can increase by greater than 100%. 
     At least some embodiments of the present disclosure direct to a flexible duct to be used with a convective device. In some cases, the flexible duct is integrated with the convective device, which can be used as a blanket or inserted into a gown. In some cases, the flexible duct is disposable, where the duct is made of disposable materials, for example, non-woven materials, blown film, or the like. In some embodiments, the flexible duct includes air-guide device(s) to direct air when the duct is bent. Typically, the pneumatic structure of the duct is kinked or pinched off proximate to the bending area where the duct is bent. In some cases, the flexible duct further includes an air-guide device, which may include one or more air-guide elements, adapted to direct inflation medium to reduce pressure drop of the inflation medium at the bending area. For example, the flexible duct can include an air-guide device to help form one or more crease(s) when it is inflated, proximate to the air-guide device. In some embodiments, the air-guide device includes air-guide elements disposed in the pneumatic structure of the convective device. As used herein, “in” is used to describe a spatial relationship of generally in the structure including at the edge of the structure. 
     At least some embodiments of the present disclosure direct to a convective device having a partially detachable access duct. In some cases, the access duct allows easy connection with a hose connecting to an inflation medium source. In some embodiments, the access duct is integrated with the convective device, for example, using the same layer(s) of materials the convective device. In some embodiments, the convective device includes a separation device disposed at an edge of the access duct to partially detach the access duct from the convective device. 
       FIG. 1A  illustrates one embodiment of a flexible duct  100 . The flexible duct  100  includes an inflatable tubular structure  105  in generally a tube shape when inflated. The flexible duct is made of a flexible material  107 . In some embodiments, the tubular structure  105  comprising a first longitudinal edge  110  and a second longitudinal edge  120  opposing to the first longitudinal edge  110 . In some cases, an air-guide device  130  includes a plurality of air-guide elements disposed in a pattern on the tubular structure  105 , where the air-guide device  130  is configured to direct flow of inflation medium when the tubular structure is bent. In the example illustrated, the air-guide element is a staked seal. In some cases, an air-guide element can be in any closed shape, for example, such as a circle, an oval, a square, a rectangle, a polygon, or the like. In some cases, an air-guide element can be a small seal in any shape, for example, such as a line, a curve, or the like. As used herein, a small seal refers to a seal having a length or diameter relative small, for example, less than two inches (5.08 cm). In some cases, the plurality of air-guide elements can be disposed with equal spacing. In some cases, at least some of the plurality of air-guide elements are disposed no more than one inch (2.54 cm) from one of the longitudinal edges. In some cases, at least some of the plurality of air-guide elements are disposed no more than two inches (5.08 cm) from one of the longitudinal edges. In some embodiments, the flexible duct  100 A can include two layers of flexible materials when it is uninflated, where each layer can use a same or different material(s). 
     In some embodiments, the air-guide device  130  includes a first set of air-guide elements  131  disposed proximate to the first longitudinal edge  110  and a second set of air-guide elements  132  disposed proximate to the second longitudinal edge  120 . In some cases, the first set of air-guide elements  131  are disposed generally equal spacing along the first longitudinal edge  110  and/or the second set of air-guide elements  132  are disposed generally equal spacing along the direction of the second longitudinal edge  120 . In one embodiment, the first set of air-guide elements  131  and the second set of air-guide elements  132  are disposed in a staggered pattern. 
       FIG. 1B  illustrates a perspective view of the flexible duct  100  when inflated and bent. In some cases, the air-guide device  130  help form creases  135  proximate to the air-guide device  130  when the duct  100  is inflated and bent. In the case illustrated, creases  135  are formed between the first set of air-guide elements  131  and the second set of air-guide elements  132 . A distribution of the air-guide elements may create a distribution of creases and further allow more bending areas, such that the duct becomes flexible to bend. 
       FIG. 2A  illustrates one example of a flexible duct  200 A. The flexible duct  200 A has a first edge  220 A, a second edge  230 A, an inflatable channel  245 A, and an air-guide device  212 A including one or more air-guide elements  210 A configured to direct flow of inflation medium when the flexible duct is inflated and bent. In some cases, the air-guide element  210 A is disposed proximate to the first edge  220 A and/or the second edge  230 A.  FIG. 2B  illustrates the flexible duct  200 A bent at one of the air-guide elements  210 A, where the flexible duct  200 A is separated into a first portion  241 A and a second portion  242 A separated at the bending location. In some cases, the air-guide element  210 A is disposed in the inflatable channel  245 A connecting the first portion  241 A and the second portion  242 A. In some cases, the air-guide element  210 A is configured to facilitate forming creases, for example,  215 A, at the edge of the air-guide element  210 A when the flexible duct  210 A is inflated and bent. In some cases, the air-guide element  210 A including a guiding seal extending from an edge of the tubular flexible duct toward the tube structure. 
       FIG. 2C  illustrates a close-up view of a portion of one example of flexible duct  200 C. The flexible duct  200 C, as illustrated, may use a non-woven material. The duct  200 C includes a plurality of pleats  230 C facilitating bending.  FIG. 2D  illustrates a perspective view of the flexible duct  200 C being inflated and bent. In some embodiments, the duct includes the z-fold pleat configuration of the duct material. The pleats are welded on each side to constrain their shape during inflation and movement. Once the pleats are formed, the edges ( 210 C,  220 C) along the longitudinal axis  240 C of the duct  200 C are welded or heat-sealed to hold the pleats  230 C in place. One or more heat seals may be formed in the direction of the longitudinal axis  240 C of the duct  200 C between the two edges of the duct  200 C. 
       FIGS. 2E-2G  illustrate some example constructions of flexible hoses.  FIG. 2E  illustrates a convective device  200 E made from blown film, where there are no seals at the edges. An air-guide device including a plurality of air-guide elements  210 E are disposed along the edges of the duct  200 E. The blown film can be made from suitable flexible polymer materials, for example, polyethylene, polyester, polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polyamide (PA), or the like. The blown film is typically made from a homogeneous material. 
       FIG. 2F  illustrates a flexible duct  200 F including two layers  220 F and  222 F, and the two layers  220 F and  222 F are sealed at longitudinal edges  240 F to form a pneumatic structure. In some cases, the flexible duct  200 F includes an air-guide device (not illustrated).  FIG. 2G  illustrates a flexible duct  200 G includes one layer of material  220 G that is sealed at its longitudinal edge  240 G. Typically, the one or more layers of the duct are made from flexible materials. In some cases, the flexible duct  200 G includes an air-guide device (not illustrated). 
     In some implementations, the flexible duct may be integrated with a convective device. In some embodiments, a layer of a convective device may include one or more sheet of materials. In some cases, a layer of a convective device may include an underside sheet formed from a flexible, fibrous, preferably non-woven structure composed of polymeric materials capable of bonding to an upper side sheet of a heat-sealable polymeric material. For example, the underside sheet may be a non-woven, hydroentangled polyester material and the upper side layer may include a polyolefin such as a polypropylene film which is extrusion-coated, thermally laminated, or adhesively laminated onto the polyester layer. Alternatively, the underside sheet may comprise a non-woven, paper-based material to which the upper side layer, including either a polyethylene, polyester, or polypropylene film, has been glue laminated. In one embodiment, the upper side and underside sheets can be made with a stratum of absorbent tissue paper prelaminated with a layer of heat-sealable plastic. In some cases, both the first layer and the second layer can include a same polymer material. 
     In some embodiments, one or two layers of a flexible duct are made from a polyolefin non-woven extrusion coated, each with a coating of polypropylene on one side. In some other embodiments, the one or more layers can be poly lactic acid spunbond with polyolefin based extrusion coat. In some cases, when the convective device is assembled, the polypropylene-coated side of the first layer is sealed to the polypropylene-coated side of the second layer at the periphery, and at the one or more locations to form the construction. The sealing process can use various techniques, for example, ultrasonic welding, radio frequency welding, heat sealing, or the like. Alternatively, the first layer and second layer may each include a laminate of polypropylene and polyolefin web. 
     In some cases, a flexible duct can be used with a convective device. In some other cases, a flexible duct can be integrated with a convective device. Flexible ducts can be shipped in flat packages.  FIG. 3A  shows an example of a convective device  300  with an integrated flexible duct  330 ;  FIG. 3B  shows the convective device  300  with the flexible duct partially detached; and  FIG. 3C  shows the convective device  300  being inflated using the flexible duct connecting to a hose. The convective device  300  includes a pneumatic structure  310  formed by one or more layers  305 . The pneumatic structure  310  may be formed by the one or more layers  305  sealed around a periphery by a periphery seal  306 . In some cases, the convective device  300  may include continuous or discontinuous seals  308 , which defines air channels. 
     The convective device may include a separation device  335  disposed on a side of the partially detachable access duct  330 . In some embodiments, the separation device  335  includes a separation element  336  and a seal  337  surrounding the separation element  336 . In some cases, the separation element  336  includes, for example, at least one of a line of weakness, perforation, slit, or the like. The access duct  330  can use any configurations of flexible ducts described in the present disclosure. For example, the access duct  330  may include an air-guide device, where the air-guide device is configured to direct flow of inflation medium when the access duct is bent. As another example, the access duct may include an air-guide device, where the air-guide device includes a plurality of air-guide elements disposed proximate to one or both longitudinal edges of the access duct. The partially detachable access duct  330  is configured to receive a hose  350 , as illustrated in  FIG. 3C  in connection with an inflation medium source (not illustrated). A hose clamp  360  may be used to maintain the connection of the access duct  330  and the hose  350 . The hose clamp  360  is discussed in further details below. The partially detachable access duct  330  is in fluid connection with the pneumatic structure  310 . 
       FIGS. 4A-4H  illustrate some examples of air-guide devices/air-guide elements.  FIG. 4A  illustrates an air-guide device or air-guide element  400 A including two guiding seals  402 A and  404 A, where both seals are extending from a periphery seal  410 A.  FIG. 4B  illustrates an air-guide device or air-guide element  400 B including one guiding seal  402 B extending from a periphery seal  410 B.  FIG. 4C  illustrates an air-guide device or air-guide element  400 C including a continuous seal  402 C, in a curve shape, starting from a first position  411 C on a periphery seal  410 C and ending at a second position  412 C on the periphery seal  410 C different from the first position  411 C. When the convective device is inflated, the air-guide device  400 C can facilitate forming a number of creases proximate to the air-guide device  400 C in the convective device where the convective device is bent.  FIG. 4D  illustrates an air-guide device or air-guide element  400 D including a continuous seal  402 D starting from a first position  411 D on a periphery seal  410 D and ending at a second position  412 D on the periphery seal  410 D different from the first position  411 D. 
       FIG. 4E  illustrates an air-guide device or air-guide element  400 E including three guiding seals  402 E extending from a periphery seal  410 E.  FIG. 4F  illustrates an air-guide device or air-guide element  400 F including one seal  402 F disposed proximate to but not touching a periphery seal  410 F.  FIG. 4G  illustrates an air-guide device or air-guide element  400 G including one continuous seal  402 G in a closed shape or a closed shape seal  402 G disposed proximate to but not touching a periphery seal  410 G. The seal  402 G can be in any closed shapes, for example, such as circle, oval, square, rectangle, polygon, or the like. In some cases, the seal  402 G is no more than one inch (2.54 cm) from the periphery seal  410 G. In some cases, the seal  402 G is no more than two inches (5.08 cm) from the periphery seal  410 G. 
       FIG. 4H  illustrates an example of air-guide device  400 H that is an integrated part of or proximate to a periphery seal  410 H. The air-guide device  400 H includes a zigzag portion  402 H between first and second portions of the pneumatic structure as illustrated in  FIGS. 1A, 2A and 3A , for example, such that the zigzag portion  402 H is adapted to facilitate the generation of a number of distributed creases  15 , and direct inflation medium to reduce pressure drop of the inflation medium at the bending area when the configurable convective device is inflated and at least one of the first portion and the second portion are rearranged such that the air channel between the two portions is bent. In some cases, the zigzag portion  402 H is integrated with the periphery seal  410 H. In some cases, the entire periphery seal can be zigzagged. In some cases, the zigzag portion  402 H is in a wavy shape. In some cases, the zigzag portion is a in a curve shape, square saw-tooth, triangular saw-tooth, or similar shape, or combination of shapes. 
     In some cases of using a flexible duct or partially detached access duct, a hose clamp may be used to maintain adequate air-tight connection between a hose connecting to an inflation medium source and the flexible duct or access duct.  FIG. 5A  illustrates a perspective view of one embodiment of a hose clamp  500 ; and  FIG. 5B  illustrates a side view of the hose clamp  500 . In the embodiment illustrated, the hose clamp  500  includes an encircling element  510 , an optional grabbing component  520  extending from the encircling element, and an optional engaging component  530  disposed on or integrated with the encircling element. The encircling element  510  includes having an inner surface  512  and an opposing outer surface  514 . In some cases, the central angle  550  of the encircling element  510  is greater than 180 degree. In some cases, the central angle  550  of the encircling element  510  is smaller than 360 degree. 
     In some embodiments, the engaging component  530  includes a plurality of engaging elements  535 . In some implementations, the engaging component  530  includes a pattern of engaging elements  535 , for example, a pattern of a line, a pattern of a wave, a pattern of higher density proximate to the end, or the like. The encircling element  510  has a first end  541 , a second end  542 , and a middle portion  545 . In some cases, the encircling element  510  can be semi-rigid or rigid. The encircling element  510  can include materials, for example, polycarbonate, polyethylene, nylon, acrylonitrile butadiene styrene (ABS), polypropylene, polyvinyl chloride (PVC), and/or the like. In some cases, the grabbing component  520  and the engaging component  530  can include the same materials as the encircling element  510 . In some other cases, the grabbing component  520  and the engaging component  530  can include different materials as the encircling element  510 . In some cases, the engaging component can have a material the same as or different from the material used for the encircling element  510 . In some cases, the engaging component  530  can use soft materials, for example, urethane, thermoplastic materials, thermoplastic elastomers (TPE), or the like. The engaging elements  535  can have any shapes, for example, cylinder, half sphere, prism, hexagonal prism, trapezoidal prism, cube, cuboid, cone, pyramid, or the like. 
       FIG. 5C  illustrates a front view of another embodiment of a hose clamp  500 C. The hose clamp  500 C includes an encircling element  510 , an optional grabbing component  520 C extending from the encircling element, and an optional engaging component  530  disposed on or integrated with the encircling element. Components with same labels can have same or similar configurations, compositions, functionality and/or relationships as the corresponding components in  FIGS. 5A and 5B . In the embodiment illustrated, the grabbing component  520 C includes two elements  521  and  522 . 
       FIG. 6A  is a flattened view of a hose clamp  600  toward the inner surface of an encircling element;  FIG. 6B  is a perspective view of the hose clamp  600 ; and  FIG. 6C  is a side view of the hose clamp  600 . The hose clamp  600  includes an encircling element  610 , an optional grabbing component  630  and an optional engaging component  620 A. The encircling element  610  has a first end  612 , a second end  614 , and a middle portion  616 . The engaging component  620 A can include one or more sets of engaging elements  625 . In one embodiment, the engaging component  620 A includes a set of engaging elements  622  disposed proximate to the first end  612  of the encircling element  610 . In the example illustrated in  6 A, the set of engaging elements  622  includes multiple engaging elements  625  (with three illustrated) disposed in a line, where the engaging elements  625  are disposed in a line slanted from the first end  612 . In some embodiments, the engaging component  620 A includes a set of engaging elements  624  disposed proximate to the second end  614  of the encircling element  610 . In the example illustrated in  FIG. 6A , the set of engaging elements  624  includes multiple engaging elements  625  disposed in a line, where the engaging elements  625  are disposed in a line slanted from the second end  614 . In some embodiments, the engaging component  620 A includes a set of engaging elements  626  disposed in the middle portion  616 . In some cases, the set of engaging elements  626  includes at least three engaging elements  625  disposed in a line. 
       FIGS. 6D-6G  illustrate some example configurations of engaging components.  FIG. 6D  illustrates an engaging component  620 D includes three elongated engaging elements  622 D,  624 D, and  626 D that are generally parallel with each other and extend proximate the first end  612  to the second end  614 .  FIG. 6E  illustrates an engaging component  620 E includes three sets of engaging elements ( 622 E,  624 E, and  626 E). The set of engaging element  622 E is proximate to the first end  612  and is in a line. The set of engaging element  624 E is proximate to the second end  614  and is generally in a line. The set of engaging element  626 E is proximate to the center portion  616  and is generally parallel to either end. 
       FIG. 6F  illustrates an engaging component  620 F including three engaging elements ( 622 F,  624 F, and  626 F). The engaging element  622 F is disposed proximate to the first end  612 , the engaging element  624 F is disposed proximate to the second end  614 , and the engaging element  626 F is disposed at the center portion  616 . The three engaging elements  622 F,  624 F, and  626 F, as illustrated, may be disposed at locations with different distances to the edges of the encircling element  610 .  FIG. 6G  illustrates an engaging component  620 G including multiple engaging elements  625 . In one embodiment, the engaging elements  625  can be disposed discontinuously across the encircling element  610  from the first end  612  to the second end  614 . 
     In some embodiments, a convective system includes an inflation medium source, a convective device, and a hose connecting the inflation medium source and the convective device. The convective device includes a pneumatic structure and an opening into the pneumatic structure. The hose includes a nozzle to insert to the opening of the convective device. The convective device can use any embodiments of convective device described herein.  FIGS. 7A-7N  illustrate some examples of nozzle configurations.  FIG. 7A  illustrates a side view of a nozzle  1300 A; and  FIG. 7B  illustrates a perspective view of the nozzle  1300 A facing the end of the nozzle. In the embodiment illustrated, the nozzle  1300 A is generally in a J-shape. The nozzle  1300 A includes a first end  1310 A and a second end  1320 A. In addition, the cross section of the first end  1310 A is elliptical. In some embodiments, the cross section of the second end  1320 A is generally circular. In some cases, the nozzle  1330 A may include a hindrance device (not shown), for example, a raised-up, to fix connection between the nozzle and the convective device. The hook portion proximate to the first end  1310 A can have various angles from the support portion proximate to the second end  1320 A, for example, 0-90 degree, and various lengths. 
       FIG. 7C  illustrates a side view of a nozzle  1320 C;  FIG. 7D  illustrates another side view of the nozzle  1320 C; and  FIG. 7E  illustrates a perspective view of the nozzle  1300 C facing one end of the nozzle. The nozzle  1300 C includes a main body  1305 C, a first end  1310 C and a second end  1320 C, where the first end  1310 C is to be inserted into the opening of the convective device. In some cases, the nozzle main body  1305 C includes one or more vents (not shown) allowing air to go through. The nozzle  1300 C includes a hindrance device  1330 C disposed on the nozzle. In some cases, the hindrance device  1330 C is configured to prevent the nozzle from over insertion. In some configurations, the hindrance device  1330 C is disposed on a portion or all of the circumference of the nozzle  1300 C. 
     In some embodiments, the hindrance device  1330 C comprises a softer material than the material of the nozzle. In some cases, the hindrance device  1330 C may include soft or rigid thermoplastic elastomers such as polyesters, polyurethanes, polyamides, or polyolefin blends; or thermoset elastomers such as natural and synthetic rubbers such as latex, nitrile, millable polyurethane, silicone, butyl and neoprene. In the example illustrated, the hindrance device  1330 C is disposed along the circumference of the nozzle  1300 C. In some embodiments, the nozzle  1300 C includes a piercing device  1340 C disposed on the nozzle  1300 C. In this example, the piercing device  1340 C comprises a plurality of piercing elements  1345 C, where each piercing element  1345 C is a protruded from the nozzle main body  1305 C. In some cases, the piercing element  1345 C has a slope in cross-sectional view with a lower protrusion closer to the first end  1310 C and a higher protrusion farther from the first end  1310 C. In some cases, the piercing device  1340 C is configured to facilitate insertion and/or prevent the hose from slipping from the opening of the convective device. In some cases, the piercing device  1340 C is disposed closer to the first end  1310 C than the hindrance device  1330 C. In some cases, at least one of the piercing elements  1345 C is in the shape of trapezoidal prism. In some cases, at least one of the piercing elements  1345 C is in the shape of triangular prism. In some configurations, the nozzle  1300 C includes a protrusion portion  1315 C at the first end  1310 C. 
       FIG. 7F  illustrates a perspective view of a nozzle  1320 F from one end;  FIG. 7G  illustrates a side view of the nozzle  1320 F; and  FIG. 7H  illustrates another side view of the nozzle  1300 F. The nozzle  1300 F includes a main body  1305 F, a first end  1310 F and a second end  1320 F, where the first end  1310 F is to be inserted into the opening of the convective device. The hose includes a hindrance device  1330 F disposed on the nozzle. In some cases, the hindrance device  1330 F is configured to prevent the nozzle from over insertion. In some configurations, the hindrance device  1330 F is disposed on a portion of a circumference of the nozzle  1300 F. In the example illustrated, the hindrance device  1330 F includes a plurality of hindrance elements  1335 F disposed in a pattern on the nozzle  1300 F. In some implementations, a cross section of each of the hindrance elements  1335 F is generally triangular. In some configurations, the nozzle  1300 F includes a protrusion portion  1315 F at the first end  1310 F. 
       FIG. 7I  illustrates a side view of a nozzle  1320 I;  FIG. 7J  illustrates another side view of the nozzle  1320 I; and  FIG. 7K  illustrates a perspective view of the nozzle  1300 I facing one end of the nozzle. The nozzle  1300 I includes a main body  1305 I, a first end  1310 I and a second end  1320 I, where the first end  1310 I is to be inserted into the opening of the convective device. In some cases, the nozzle main body  1305 I includes one or more vents (not shown) allowing air to go through. In some cases, the nozzle main body  1305 I has an angle  1303 I between the two portions of the main body. The nozzle  1300 I includes a hindrance device  1330 I integrated with the nozzle main body, for example, by having a recess portion  1335 I. In some cases, the hindrance device  1330 I is configured to prevent the nozzle from over insertion. In some configurations, the hindrance device  1330 I is integrated with a portion or all of the circumference of the nozzle  1300 I, where the recess  1335 I extends a portion or all of the circumference of the nozzle  1300 I. 
     In some embodiments, the nozzle  1300 I includes a piercing device  1340 I disposed on the nozzle  1300 I. In this example, the piercing device  1340 I comprises a plurality of piercing elements  1345 I, where the piercing element  1345 I is a protruded from the nozzle main body  1305 I. In some cases, the piercing element  1345 I has a slope in cross-sectional view with a lower protrusion closer to the first end  1310 I and a higher protrusion farther from the first end  1310 I. In some cases, the piercing device  1340 I, maybe together with the recess portion  1335 I, is configured to facilitate insertion and/or prevent the hose from slipping from the opening of the convective device. In some cases, the piercing device  1340 I is disposed closer to the first end  1310 I than the hindrance device  1330 I. In some cases, a piercing element  1345 I is in the shape of trapezoidal prism. In some cases, a piercing element  1345 I is in the shape of triangular prism. 
       FIG. 7L  illustrates a side view of a nozzle  1320 L;  FIG. 7M  illustrates another side view of the nozzle  1320 L; and  FIG. 7N  illustrates a perspective view of the nozzle  1300 L facing one end of the nozzle. The nozzle  1300 L includes a main body  1305 L, a first end  1310 L and a second end  1320 L, where the first end  1310 L is to be inserted into the opening of the convective device. In some cases, the nozzle main body  1305 L includes one or more vents (not shown) allowing air to go through. In some cases, the nozzle main body  1305 L has an angle  1303 L between the two portions of the main body. The nozzle  1300 L includes a hindrance device  1330 L protruded from the nozzle main body  1305 L. In some cases, the nozzle  1300 L includes a recess portion adjacent to the hindrance device  1330 L. In some cases, the hindrance device  1330 L is configured to prevent the nozzle from over insertion. In some configurations, the hindrance device  1330 L is disposed on a portion or all of the circumference of the nozzle  1300 L, where the recess  1335 L extends a portion or all of the circumference of the nozzle  1300 L. 
     In some embodiments, the hindrance device  1330 L comprises a softer material than the material of the nozzle. In some cases, the hindrance device  1330 L may include soft or rigid thermoplastic elastomers such as polyesters, polyurethanes, polyamides, or polyolefin blends; or thermoset elastomers such as natural and synthetic rubbers such as latex, nitrite, millable polyurethane, silicone, butyl and neoprene. In the example illustrated, the hindrance device  1330 L is disposed along the circumference of the nozzle main body  1305 L. In some embodiments, the nozzle  1300 L includes a piercing device  1340 L disposed on the nozzle  1300 L. In this example, the piercing device  1340 L comprises one or more piercing elements  1345 L, where the piercing element  1345 L is a protruded from the nozzle main body  1305 L. In some cases, the piercing element  1345 L has a slope in cross-sectional view with a lower protrusion closer to the first end  1310 L and a higher protrusion farther from the first end  1310 L. In some cases, the piercing device  1340 L is configured to facilitate insertion and/or prevent the hose from slipping from the opening of the convective device. In some cases, the piercing device  1340 L is disposed closer to the first end  1310 L than the hindrance device  1330 L. In some cases, a piercing element  1345 L is in the shape of trapezoidal prism. In some cases, a piercing element  1345 L is in the shape of triangular prism. 
       FIGS. 8A, 8B, and 8C  illustrate an example of a convective system  800  using a flexible duct. 
     The convective system includes a flexible duct  810 , which is connected to a nozzle  820  at one end. In some cases, the nozzle  820  may include a hindrance device  825  to prevent over insertion of the nozzle.  FIG. 8B  illustrates the flexible duct  810  connecting to an inflation medium source  840  via a nozzle  830 . In this example, the flexible duct  810  is connected to the nozzle  830  with a hose clamp  835 . The flexible duct, nozzle, and hose clamp may use any configuration of flexible ducts, nozzles, and hose clamps described in the present disclosure.  FIG. 8C  illustrates the flexible duct  810  is connected to a convective device  850  via an opening  855  in the convective device  850 . The nozzle  820  is inserted into the opening  855 . 
     Exemplary Embodiments 
     Item A1. A flexible duct for a convective device, comprising: 
     an inflatable tubular structure in generally a tube shape when inflated comprising a flexible material, the tubular structure having a first longitudinal edge and a second longitudinal edge opposing to the first longitudinal edge; and 
     an air-guide device comprising a plurality of air-guide elements disposed in a pattern on the tubular structure, wherein the air-guide device is configured to direct flow of inflation medium when the tubular structure is bent. 
     Item A2. The flexible duct of Item A1, wherein the air-guide device comprises staked seals. 
     Item A3. The flexible duct of Item A1 or A2, wherein the air-guide device comprises a first set of air-guide elements disposed proximate to the first longitudinal edge. 
     Item A4. The flexible duct of Item A3, wherein the first set of air-guide elements are disposed generally equal spacing along the first longitudinal edge. 
     Item A5. The flexible duct of Item A3, wherein the air-guide device further comprises a second set of air-guide elements disposed proximate to the second longitudinal edge. 
     Item A6. The flexible duct of Item A5, wherein the first set of air-guide elements are disposed generally equal spacing along the first longitudinal edge and the second set of air-guide elements are disposed generally equal spacing along the second longitudinal edge. 
     Item A7. The flexible duct of any one of Item A1-A6, wherein the first set of air-guide elements and the second set of air-guide elements are disposed in a staggered pattern. 
     Item A8. The flexible duct of any one of Item A1-A7, wherein the tubular structure comprises two flexible layers sealed along the first and the second longitudinal edges. 
     Item A9. The flexible duct of any one of Item A1-A8, wherein the tubular structure comprises one flexible layer sealed along the first longitudinal edge. 
     Item A10. The flexible duct of any one of Item A1-A9, wherein the flexible duct is disposable. 
     Item A11. A convective system, comprising: 
     a convective device comprising a pneumatic structure and an opening, 
     a disposable duct comprising:
         an inflatable tubular structure in generally a tube shape when inflated comprising a flexible material, and   an air-guide device disposed in the tubular structure, and       

     a nozzle configured to connect to the disposable duct, 
     wherein the opening is configured to receive the nozzle. 
     Item A12. The convective system of Item A11, wherein the air-guide device comprises a plurality of air-guide elements disposed in a pattern on the tubular structure, wherein the air-guide device is configured to direct flow of inflation medium when the tubular structure is bent. 
     Item A13. The convective system of Item A11 or A12, wherein the air-guide device comprises staked seals. 
     Item A14. The convective system of any one of Item A11-A13, wherein the air-guide device comprises a first set of air-guide elements disposed proximate to a first longitudinal edge of the inflatable tubular structure. 
     Item A15. The convective system of Item A14, wherein the first set of air-guide elements are disposed generally equal spacing along the first longitudinal edge. 
     Item A16. The convective system of Item A14, wherein the air-guide device further comprises a second set of air-guide elements disposed proximate to a second longitudinal edge of the inflatable tubular structure opposing to the first longitudinal edge. 
     Item A17. The convective system of Item A16, wherein the first set of air-guide elements are disposed generally equal spacing along the first longitudinal edge and the second set of air-guide elements are disposed generally equal spacing along the second longitudinal edge. 
     Item A18. The convective system of Item A17, wherein the first set of air-guide elements and the second set of air-guide elements are disposed in a staggered pattern. 
     Item A19. The convective system of any one of Item A11-A18, wherein the tubular structure comprises a blown film. 
     Item A20. The convective system of any one of Item A11-A20, wherein the tubular structure comprises one flexible layer sealed along the first longitudinal edge. 
     Item A21. The convective system of any one of Item A11-A20, wherein the flexible duct is disposable. 
     Item B1. A convective device, comprising: 
     a pneumatic structure formed by one or more layers, 
     a partially detachable access duct configured to receive a hose in connection with an inflation medium source, the partially detachable access duct in fluid connection with the pneumatic structure, and a separation device disposed on a side of the partially detachable access duct. 
     Item B2. The convective device of Item B1, wherein the separation device comprises a separation element and a seal surrounding the separation element. 
     Item B3. The convective device of Item B1 or B2, wherein the separation element comprises at least one of a line of weakness, perforation, and slit. 
     Item B4. The convective device of any one of Item B1-B3, wherein the access duct comprises an air-guide device disposed in the access duct, wherein the air-guide device is configured to direct flow of inflation medium when the access duct is bent. 
     Item B5. The convective device of Item B4, wherein the air-guide device comprises a plurality of staked seals. 
     Item B6. The convective device of Item B5, wherein at least part of the staked seals are disposed proximate to a longitudinal edge of the access duct. 
     Item B7. The convective device of Item B6, wherein at least part of the staked seals are disposed generally equal spacing along the longitudinal edge. 
     Item B8. A convective system, comprising: 
     a convective device, comprising:
         a pneumatic structure formed by one or more layers,   a partially detachable access duct configured to receive a hose in connection with an inflation medium source, the partially detachable access duct in fluid connection with the pneumatic structure, and       

     a separation device disposed on a side of the partially detachable access duct. 
     Item B9. The convective system of Item B8, wherein the separation device comprises a separation element and a seal surrounding the separation element. 
     Item B10. The convective system of Item B8 or B9, wherein the separation element comprises at least one of a line of weakness, perforation, and slit. 
     Item B11. The convective system of any one of Item B8-B10, wherein the access duct comprises an air-guide device disposed in the access duct, wherein the air-guide device is configured to direct flow of inflation medium when the access duct is bent. 
     Item B12. The convective system of Item B11, wherein the air-guide device comprises a plurality of staked seals. 
     Item B13. The convective system of Item B12, wherein at least part of the staked seals are disposed proximate to a longitudinal edge of the access duct. 
     Item B14. The convective system of Item B13, wherein at least part of the staked seals are disposed generally equal spacing along the longitudinal edge. 
     Item B15. The convective system of any one of Item B8-B14, further comprising: 
     a hose configured to connect to a inflation medium source; 
     a hose clamp, comprising:
         an encircling element, and   a grabbing component extending from the encircling element;       

     wherein the hose is configured to connect to the access duct, wherein the hose clamp is configured to use at the connection of the access duct and the hose. 
     Item B16. The convective system of Item B15, wherein the encircling element has a first end and a second end, and wherein the engaging component comprises a first set of engaging elements disposed proximate to the first end. 
     Item B17. The convective system of Item B16, wherein the engaging component further comprises a second set of engaging elements disposed proximate to the second end. 
     The present invention should not be considered limited to the particular examples and embodiments described above, as such embodiments are described in detail to facilitate explanation of various aspects of the invention. Rather the present invention should be understood to cover all aspects of the invention, including various modifications, equivalent processes, and alternative devices falling within the spirit and scope of the invention as defined by the appended claims and their equivalents.