Patent Publication Number: US-7210176-B2

Title: Patient transfer device having inclined upper surface

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority of U.S. Provisional Application No. 60/612,805, filed Sep. 24, 2004, entitled “Patient Transfer Mattress Having Inclined Surface”, and U.S. Provisional Application No. 60/548,901, filed Mar. 24, 2004, entitled “Active Head/Neck Positioning Device for Intubation”, each incorporated herein by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates to a patient transfer device. More particularly, the present invention relates to a patient transfer mattress with an inclined surface, which may be useful for supporting obese patients in a more upright posture to ease the burden of breathing or to facilitate patient intubation regardless of patient weight. 
   BACKGROUND OF THE INVENTION 
   Patient transfer mattresses have an inflatable plenum and discharge air through a plurality of holes in a bottom sheet to create a cushion of air beneath the mattress. The air cushion lifts and facilitates movement of the mattress with respect to a bed or other support surface. Some contemporary examples of patient transfer mattresses are disclosed in U.S. Pat. No. 5,067,189 (Weedling et al), reissued as U.S. Pat. No. Re. 35,299, and U.S. Pat. No. 5,561,873 (Weedling). 
   Patients, particularly those that are morbidly obese, often have coexisting physical conditions that make it unhealthy for the patient to lay in a flat supine condition for extended lengths of time. Obesity can contribute to respiratory difficulty as the lungs are compressed by the heavy chest wall making it difficult for the lungs to lift and expand to inhale. This breathing difficulty can aggravate other conditions such as Chronic Obstructive Pulmonary Disease (COPD) and Congestive Heart Failure (CHF). 
   For these reasons obese patients, particularly those with COPD or CHF, can have a stressful time while lying flat during diagnostic procedures or while being transferred from one rest surface to another. Arterial blood gas levels for obese patients maintained in a supine condition can increase to a level that impairs proper circulation of oxygen. For patients with CHF, the heart may not be able to adequately pump blood throughout the body, and blood may accumulate in the lungs, causing shortness of breath, fatigue, and edema of the extremities. When the lungs become congested with fluid, the resulting shortness of breath frequently causes CHF patients to experience sleep interruptions. 
   Patient treatment often requires endotracheal intubation. Direct visualization of the larynx using a rigid laryngoscope constitutes the primary procedure of achieving endotracheal intubation, and the procedure is called laryngoscopy. Successful laryngoscopy is contingent upon alignment of the oral, pharyngeal and laryngeal axes. In this position, sometimes referred to as the “sniffing position”, the patient&#39;s head is slightly extended and the occiput is elevated. Placing a patient in the proper intubation position by manual manipulation is somewhat difficult, however, and the difficulty increases when the patient is obese. 
   Consequently, others have developed body support devices to facilitate endotracheal intubation. U.S. Pat. No. 4,259,757 (Watson) discloses a cushion that can be used to position a patient&#39;s head and neck to facilitate endotracheal intubation. The cushion, however, supports only the head and neck and does not support the torso of the patient to provide a full support system for achieving the sniffing position. U.S. Pat. No. 5,528,783 discloses a wedge-shaped head and torso support including an inflatable bladder. The bladder is adjustable to provide for partial inflation as well as full inflation. The support includes only one bladder and, therefore, is incapable of providing elevation of the head independently from that of the torso. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the invention, a patient transfer device includes an inflatable transfer mattress having a top sheet and a bottom sheet. The bottom sheet includes holes to create a cushion of air beneath the mattress. The top sheet is inclined from an intermediate lengthwise position upward toward the head end of the mattress, such that the head and upper torso of a supported patient are raised above the legs and lower torso. 
   In one embodiment, the inflatable transfer mattress includes a plurality of relatively narrow chambers in an intermediate portion of the mattress to provide increased strength and stability in the intermediate portion for supporting a patient on the mattress in an inclined condition. Preferably, the relatively narrow chambers extend transversely with respect to the mattress. 
   In another embodiment, the transfer mattress includes a leg separator located in a foot portion of the top sheet of the mattress. The leg separator is preferably tapered to widen toward an end of the mattress. Preferably, the leg separator includes at least one inflatable chamber having at least one inlet port for inflation of the chamber. The leg separator may include a plurality of chambers separated from each other by baffle walls. 
   In another embodiment, the transfer mattress includes a pump mounted to the mattress and connected to at least one inlet port of the mattress. The pump may be connected to one or more inlet ports of the mattress by a hose. Alternatively, the pump may be mounted directly to an inlet port. 
   According to another aspect of the invention, a patient transfer device includes a torso and head support. The torso support has an inflatable chamber, and the head support is located on an upper surface of the torso support and also has an inflatable chamber. The upper surface of the torso support is inclined upward with respect to an underlying support surface when the torso support chamber is inflated such that a patient&#39;s upper torso is elevated with respect to the patient&#39;s legs and feet. The head support chamber defines an interior that is separated from an interior of the torso support chamber to provide for independent inflation of the respective chambers. 
   In one embodiment, the patient transfer device includes an inlet tube connected to each of the support chambers for delivering pressurized air to inflate the associated chamber. The patient transfer device also includes a distribution manifold operably connected to a source of pressurized air and first and second valves, each connected to one of the inlet tubes, for controlled delivery of pressurized air to the associated chamber. Preferably, the valves are electrically controlled valves. The patient transfer device further includes a controller connected to the distribution manifold and adapted to control the operation of the valves for independent inflation of the torso support chamber and the head support chamber. 
   In another embodiment, the patient transfer device also includes exhaust tubes connected to each of the torso support chamber and the head support chamber for discharging air from the associated chamber. The distribution manifold includes third and fourth valves connected to the exhaust tubes for controlled deflation of the associated chamber. 
   In another embodiment, the patient transfer device includes a control system including a control unit connected to the distribution manifold for controlling the operation of the valves. According to one preferred embodiment, the control unit is adapted for mounting to a laryngoscope for actuation of the valves by a user&#39;s thumb to align the three axes to the sniffing position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a patient transfer device according to the present invention. 
       FIG. 2  is a perspective view of a patient transfer device according to a second embodiment of the invention. 
       FIG. 3  is a perspective view of a patient transfer device according to a third embodiment of the invention. 
       FIG. 4  is a perspective view of a patient transfer device according to a fourth embodiment of the invention. 
       FIG. 5  is a perspective view of a patient transfer device according to a fifth embodiment of the invention, shown with a head support pillow in a deflated condition. 
       FIG. 6  is a partial side elevation view of the patient transfer device of  FIG. 5 , shown with the head support pillow in an inflated condition. 
       FIG. 7  is a perspective view of a patient transfer device according to a sixth embodiment of the invention. 
       FIG. 8  is a partial perspective view of the inflatable head/torso support attachment of the patient transfer device of  FIG. 7  including an inflation control system providing independent inflation of the head and torso bladders. 
       FIG. 9  is a side elevation view of a patient having head and torso supported such that the oral, pharyngeal and laryngeal axes are substantially aligned to facilitate endotracheal intubation. 
   

   DESCRIPTION OF THE INVENTION 
   Referring to the drawings, where like numerals identify like elements, there is shown in  FIG. 1  a patient transfer device of the type having an inflatable mattress  10 . As will be described in greater detail below, the patient transfer device provides an inclined surface for supporting a patient&#39;s head and torso in an elevated condition with respect to the patient&#39;s lower torso and legs. Support in this manner is desirable for obese patients, particular for obese patients having coexisting conditions such as Chronic Obstructive Pulmonary Disease (COPD) and Congestive Heart Failure (CHF). 
   The inflatable transfer mattress  10  includes a top sheet  12 , a bottom sheet  14  and side panels  16 . The bottom sheet  14  includes a plurality of openings for discharging air from the mattress  10  to create an air cushion beneath the mattress to facilitate sliding of the mattress  10  along an underlying support surface. The transfer mattress  10  may include looped handles  18  secured to the sides of the mattress  10  to facilitate application of a pulling force to guide the movement of mattress. 
   The transfer mattress  10  may also include looped pull straps  19  secured to each of the looped handles  18 . The looped pull straps  19  are elongated to allow a caregiver to grasp and pull at a distance from the mattress  10 . This situation could present itself, for example, when it is desired to transfer a patient from a first support surface to a second surface located between the caregiver and the first support surface. The elongated looped pull straps  19  allow the caregiver to apply a pulling force to the mattress while the caregiver&#39;s back is in a substantially upright condition to reduce the likelihood of back injury. The transfer mattress  10  may also include patient restraint straps  20  for securing a patient to the mattress. 
   The patient transfer mattress  10  preferably includes longitudinally extending side air chambers  22  and transverse chambers  24  extending between the side chambers  22 . Some suitable constructions for the side air chambers  22  and transverse chambers  24  of mattress  10  are described in U.S. Pat. No. 5,067,189 (Weedling), reissued as U.S. Pat. No. RE 35,299, and U.S. Pat. No. 5,561,873. 
   The patient transfer mattress  10  includes a head portion  26  at one end, a foot portion  28  at an opposite end, and an intermediate portion  30  located between the head and foot portions  26 ,  28 . The head portion  26  of the transfer mattress  10  includes expansion panels  32  located between the top and bottom sheets  12 ,  14  and connected to the side panels  16 . As shown in  FIG. 1 , the inclusion of the expansion panels  32  results in elevation of the top sheet  12  in the head portion  26  of the mattress  10  above the rest of the top sheet  12  when the transfer mattress  10  is inflated. As shown, the expansion panels  32  are dimensioned such that the top sheet  12  is inclined at a substantially uniform rate throughout a majority of the head portion  26 . Preferably, the angle of inclination, Θ, of top sheet  12  in the head portion  26  with respect to the rest of the top sheet  12  is between approximately 30 degrees and approximately 40 degrees when fully inflated and not loaded by a patient. The invention, however, is not limited to any particular angle of inclination. 
   The inclination elevates the head and upper torso of a supported patient above the patient&#39;s lower torso and legs. Supporting an obese patient in a more upright position facilitates circulation and respiration, both at rest and lateral transfer. 
   The transfer mattress  10  includes an air inlet hose  31  for supplying air to the interior to inflate the mattress. The inclined head portion  26  of transfer mattress  10  may have an interior chamber that communicates with the interior of the remainder of the transfer mattress  10 . Constructed in this manner, the entire transfer mattress  10 , including the inclined head portion  26 , would be inflated in common from the same source of air via the air inlet hose  31 . Alternatively, the inclined surface of the head portion  26  of patient transfer mattress  10  may define a torso support chamber that is isolated from the remainder of the transfer mattress. Arranged in this manner, the torso support chamber could receive a static supply of air through an inlet valve for optional inflation of the torso support chamber when desired. Such an arrangement provides the option of supporting a patient in a substantially supine condition or in a more upright position. 
     FIG. 2  shows a second embodiment of a patient transfer device according to the invention in the form of a patient transfer mattress  33 . Similar to patient transfer mattress  10  of  FIG. 1 , the patient transfer mattress  33  includes top and bottom sheets  12 ,  14 , side panels  16 , looped handles  18  and patient restraint straps  20 . Also similar to transfer mattress  10 , the mattress  33  includes expansion panels  32  in a head portion  26  of the mattress  33  resulting in elevation of the head portion  26  above the rest of the top sheet  12  when the transfer mattress  33  is inflated. 
   The inclination of the top sheet  12  and elevation of the patient&#39;s upper torso will tend to distribute a larger percentage of the patient&#39;s weight to the intermediate portion  30  of the transfer mattress  33  than when the patient is supine. To compensate for this increased weight, the intermediate portion  30  of transfer mattress  33  includes transverse chambers  34  that are narrower in width than the transverse chambers  24  included in other parts of the mattress  33 . As a result, the density of the transverse chambers  34  (i.e., the number of chambers per unit area) is increased in the intermediate portion  30  such that the weight that each chamber  34  must bear is reduced in comparison to that required if the relatively wider transverse chambers  24  were used. Preferably, the transverse chambers  34  of the intermediate portion  30  of mattress  33  open directly into the longitudinal side chambers  22  of transfer mattress  33 . Although it is preferred that the narrowed chambers of the intermediate portion  30  extend transversely, it is not required. 
   Referring to  FIG. 3 , there is illustrated a patient transfer device according to a third embodiment of the invention in the form of a transfer mattress  36 . The transfer mattress  36  includes a top sheet  12 , a bottom sheet  14 , side panels  16  and expansion panels  32  similar to those of transfer mattresses  10  and  33  such that the top sheet  12  is inclined in the head portion  26  of transfer mattress  36 . Also similar to patient transfer mattress  33 , the transfer mattress  36  includes relatively narrow transverse chambers  34  in the intermediate portion  30  of the mattress  36  for increased support and stability in the intermediate portion  30 . 
   Transfer mattress  36  also includes a cluster of inflatable chambers  38  secured to the top sheet  12  in the foot portion  28  of mattress  36 . The cluster of chambers  38 , when inflated, creates a tapered formation that increases in width towards end  40  of mattress  36 . This tapering formation acts like a wedge tending to maintain separation between the legs of a patient supported on the mattress  36 . For obese patients, leg separation promotes circulation and preserves skin integrity. Preferably, the chambers  38  are separated from each other by baffle walls  42  for increased strength of the cluster. Accordingly, each of the chambers  38  of the leg separating cluster includes at least one inlet port  44  for inflation. It should be understood that it not necessary that the inflatable leg separator include a cluster of multiple chambers. The leg separator could include a single chamber forming the wedge-like configuration shown. It is also not a requirement that the leg separator be inflatable. The leg separator could, alternatively, comprise a material such as foam secured to the top sheet  12  of mattress  36 . 
   The transfer mattress  36  preferably includes a top sheet  12  inclined in the head portion  26  of mattress  36  and narrow transverse chambers  34  in the intermediate portion  30 . The invention, however, is not limited to this construction. The leg separator described in the preceding paragraph could be included on any transfer mattress having substantially uniform transverse chambers  24  throughout the mattress, or on a transfer mattress having a top sheet that is not inclined in the head portion. 
     FIG. 4  shows a patient transfer device according to a fourth embodiment of the invention in the form of an air transfer mattress  46 . Similar to transfer mattresses  10  and  33 , the transfer mattress  46  preferably includes a top sheet  12  that is inclined in a head portion  26 . It is also preferable that the transfer mattress  46  includes an intermediate portion  30  having relatively narrow transverse chambers  34 , like transfer mattresses  33  and  36 , and a leg separator formed by a cluster of chambers  38 , like transfer mattress  36 . 
   As shown in  FIGS. 1 through 3 , each of transfer mattresses  10 ,  33 , and  36 , includes an inlet hose  31  for supplying air from an air source to inflate the transfer mattress. Transfer mattress  46  includes an inflator  48  mounted directly to the transfer mattress for inflating the mattress. The inflator  48  is preferably mounted to the foot portion  28  of transfer mattress  46  adjacent to the mattress end  40 . The inflator  48  includes a pair of hoses  50  connected to inlet ports located on opposite sides of the mattress  46  adjacent end  40 . The inflator  48  includes a power cord  52  adapted for engagement with an electrical socket. Alternatively, the inflator  48  could include its own battery source for power. It is not required that inflator  48  include a pair of inlet hoses  50  and could, instead, have only one hose. Alternatively, the transfer mattress  46  could include a single inlet port to which the inflator is directly connected, thereby eliminating the need for a hose to interconnect the inflator and the inlet port. Although the inflator  48  is shown mounted to the foot portion  28  of mattress  46 , it should be understood that the inflator could conceivably be mounted to the mattress  46  at another location. 
   The transfer mattress  46  preferably includes a top sheet  12  inclined in the head portion  26 , narrow transverse chambers  34  in the intermediate portion  30 , an inflator  48 , and a leg separator in the foot portion  28 . The invention, however, is not limited to this construction. It is conceivable, for example, that the inflator  48  described in the preceding paragraph could be used with any transfer mattress, including those which do not include a leg separator, or which have substantially uniform transverse chambers  24  throughout, or a transfer mattress having a top sheet that is not inclined in the head portion. 
     FIGS. 5 and 6  show a patient transfer device according to a fifth embodiment of the invention in the form of a transfer mattress  54 . Similar to transfer mattress  10  of  FIG. 1 , transfer mattress  54  includes top and bottom sheets  12 ,  14 , side panels  16 , looped handles  18  and patient restraint straps  20 . Also similar to transfer mattress  10 , the transfer mattress  54  has expansion panels  32  in a head portion  26  of the mattress providing an inflatable torso support chamber  56  for inclining the top sheet  12  in the head portion  26 . Similar to mattress  10 , the inflatable torso support chamber  56  could be separated from the main plenum defined by the remainder of the mattress  54  for separate inflation by its own air supply. Alternatively, the inflatable torso support chamber  56  could communicate with the main plenum for common air supply. 
   The transfer mattress  54  further includes a head support chamber  58  connected to the top sheet  12  in the head portion  26 . The head support chamber  58  of mattress  54  preferably communicates with the torso support chamber  56  for inflating the head support chamber  58  with air from the torso support chamber  56 . The head support chamber  58  is shown in  FIG. 5  in a deflated condition. Straps  60  secured to opposite sides of the head support chamber  58  are releasably attached to tabs  62  mounted to the top sheet  12  to maintain the head support chamber  58  in the deflated condition. The straps  60  and tabs  62  preferably carry hook and loop fastener material to provide for the desired releasable attachment. However, any suitable fastening means such as snaps, for example, could be used instead. 
   Referring to  FIG. 6 , the straps  60  have been released from the tabs  62  to permit air from the torso support chamber  56  to inflate the head support chamber  58 . The inflation of the head support chamber  58  provides for the support of a patient&#39;s head in an elevated condition, with the chin pivoted slightly toward the chest. As shown in  FIG. 6 , the torso and head support chambers  56 ,  58  preferably include valves  64 ,  66  for controlling the inflation pressure in the respective chambers. The inclusion of separate torso and head chambers  56 ,  58 , and independent control over the amount of inflation of the respective chambers, provides for independent elevation adjustment of a patient&#39;s torso and head to facilitate an endotracheal intubation of the patient, as described in greater detail below. 
     FIGS. 7 and 8  show a patient transfer device according to a sixth embodiment of the invention in the form of an inflatable transfer mattress  68  and an inflatable torso and head support as an accessory  70  that can be attached to the transfer mattress  68 . The inflatable transfer mattress, in conventional fashion, includes a top sheet  71  providing for substantially supine support of a patient. As shown in  FIG. 7 , the inflatable transfer mattress  68  and the torso and head support accessory  70  include fasteners  72  for releasable attachment of the torso and head support accessory  70  to the transfer mattress  68 . The releasable attachment of the torso and head support accessory  70  provides for use of the underlying mattress  68  with or without torso and head elevation. 
   The torso and head support accessory  70  includes an inflatable torso chamber  74  and an inflatable head pillow  76  located on an upper surface of the torso chamber  74 . The torso and head support accessory  70  also includes a foot end portion  78  connected to the torso chamber  74 . As shown in  FIG. 7 , the torso chamber  74  and foot end portion  78  are preferably dimensioned such that the torso and head support accessory  70  covers substantially all of the upper surface of the underlying inflatable mattress  68 . 
   As shown in  FIG. 7 , the torso chamber  74  is wedge-shaped when inflated such that the upper surface is inclined to elevate a patient&#39;s upper torso with respect to the patient&#39;s lower torso and legs. The foot end portion  78  of the torso and head support  70  is not inflatable. Inflation of the foot end portion  78  is not necessary as the underlying transfer mattress  68  provides the necessary support to transfer a patient. 
   Referring to  FIG. 8 , the torso chamber  74  and head pillow  76  of the torso and head support accessory  70  are shown in greater detail. The head pillow  76  includes an inflatable chamber  80  defining an interior that is separated from an interior of the torso chamber  74  to provide for separate inflation of the torso chamber  74  and head pillow  76 . The head pillow  76  also includes a cushion  82 , preferably made from foam material, located above the inflatable chamber  80 . The cushion  82  includes a concavely curved upper surface. The head pillow  76  also includes a cover  84  enclosing the chamber  80  and cushion  82 . The cover  84  includes a concavely curved upper surface corresponding to the upper surface of the cushion  82 . The cover  84  also includes accordion-like formations at a lower end of the cover  84  to provide for expansion and collapse of the cover  84  depending on whether the enclosed chamber  80  is inflated or deflated. 
   As shown in  FIG. 8 , the torso and head support accessory  70  includes a first pair of tubes  86 ,  88  connected to the chamber  80  of the head pillow  76  and a second pair of tubes  90 ,  92  connected to the torso chamber  74 . This arrangement provides for independent inflation of the torso chamber  74  and head pillow  76  from air supplied by a source of pressurized air, preferably a compressor  94 . In each of the tube pairs, one of the tubes provides for inlet of air to the associated chamber while the other provides for discharge of air from the chamber. The torso and head support accessory  70  also has an inflation control system  96  including an air distribution manifold  98  for controlling inlet and discharge of air to the torso chamber  74  and head pillow  76 . As described below in greater detail, the inflation control system  96  is capable of making very fine adjustments in the amount of inflation in either or both of the torso chamber  74  and the head pillow chamber  80 . 
   The air distribution manifold  98  includes four valves  100  each connected to one of the tube  86 ,  88 ,  90 ,  92 . The valves  100  control the inflow of air to, or the exhaust of air from, the respective chambers  74 ,  80  and are preferably electrically controlled valves. Electrically controlled valves for controlling air flow are well known and no further description is necessary. The air distribution manifold  98  is connected to the compressor  94  by a line  102  to deliver compressed air from the compressor  94  to the air distribution manifold  98 . Preferably, the line  102  is also configured to carry electrical power supply to the distribution manifold  98  for powering the electrically operated valves  100  of the distribution manifold  98 . 
   The inflation control system  96  also includes a control unit  104  connected to the air distribution manifold  98  by a cord  106  for controlling the operation of the valves  100 . The control unit  104  is shown mounted to the end of an intubation handle  108  adapted for grasped receipt by a user&#39;s hand. Arranged in this manner, the control unit  104  can be actuated by an intubator&#39;s thumb allowing the intubator to make fine-tuned adjustments to the inflation of the torso/head chambers  74 ,  80  without having to look away from the patient. As shown, the control unit  104  includes four thumbswitches  110  arranged in a circular array for separate actuation of the four valves  100 . Although the above-described handle mounted arrangement desirably facilitates an intubation procedure, the present invention is not limited to any particular control configuration and could vary from that shown. 
   It should be readily understood that any combination of head support position and torso support position can be achieved because of the independent control of the chambers  74 ,  80  that is provided by the inflation control system  96 . According to a preferred method of controlling the torso and head support  70  for intubation, a patient is positioned on the patient transfer device with the torso and head support accessory  70  attached to the transfer mattress  68 . Each of the torso and head chambers  74 ,  80  is then fully inflated using the control unit  104  to elevate the patient&#39;s upper torso and rotate his head slightly forward with respect to his torso. Next, the head chamber  80  is partially deflated until the three axes line up to place the patient in the above-described “sniffing position”. As shown in  FIG. 9 , the oral, pharyngeal and laryngeal axes (respectively, OA, PA, LA) are placed in substantial alignment with the patient supported in this position. In many instances, the fully-inflated torso chamber  74  will be adequate. However, deflation of both chambers  74 ,  80  to a partially-inflated condition may be necessary to properly position a given patient for intubation. Moreover, it should be understood that for certain patients a full inflation of both chambers  74 ,  80  may result in sufficient alignment between the three axes OA, PA, LA for successful intubation to occur. 
   The foregoing describes the invention in terms of embodiments preferred by the inventor for which an enabling description was available, notwithstanding that insubstantial modifications of the invention, including those not presently foreseen, may nonetheless represent equivalents thereto.