Patent Publication Number: US-2023149120-A1

Title: Negative Pressure Respiratory Treatment Hood System

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This United States non-provisional patent application claims priority to U.S. provisional patent application Ser. 63/001,897, filed Mar. 30, 2020, for all purposes. The disclosure of that provisional patent application is incorporated herein by reference, to the extent not inconsistent with this disclosure. 
    
    
     BACKGROUND FIELD OF THE INVENTION 
     This invention relates to apparatus used in connection with medical procedures. While not confined to use with any single treatment, by way of example this invention relates to apparatus and methods used in connection with the treatment of patients which have highly contagious diseases. 
     It is known that in the process of treating such patients, including but not limited to intubations, frequently the patients expel contaminated aerosols or otherwise emit germs. Such aerosols, when carrying highly contagious and potentially very dangerous viruses such as that known as COVID-19, create a very dangerous situation for the health care professionals carrying out treatment. Even though the health care professionals use personal protective equipment, known by the acronym PPE, they remain at risk for contracting serious illnesses. 
     It is therefore desired to have an apparatus which reduces the exposure of the health care professionals to potentially dangerous aerosols, germs, etc. emitted by the patient during treatment. Current apparatus and methods all exhibit various limitations, giving rise to a desire for an improved apparatus and method that addresses these issues. 
     SUMMARY OF THE INVENTION 
     The negative pressure respiratory treatment hood system embodying the principles of the present invention comprises a rigid, generally box-shaped hood with walls and a size and shape designed to receive to receive the head, neck and a portion of the shoulders of a patient to be intubated or otherwise treated. The hood has an opening in the front wall. The patient would typically be on his/her back on a table, face up, and the hood is placed in position over the patient&#39;s body, or the patient is moved into position within the hood. A hinged door may be attached to the hood, usually near an upper edge of the opening in the front wall, and movable between a first, open position, to permit placement of the hood around the patient; and a second, closed position rotated down toward the patient&#39;s body and latched in place. If provided, the door preferably has a cut-out shape to fit the general shape of the patient&#39;s body, with a shroud, preferably of an elastic material, to fit tightly around the body and provide a seal. The shroud is fastened tightly in place to seal around the patient&#39;s body by cleats or similar fasteners, fastening it to the hood. 
     A plurality of access openings are provided in the walls of the hood to permit access to the interior of the hood, and thus the patient, by healthcare workers. Each opening comprises an elastic material forming a shroud or cuff, having a hole therein. When the health care worker&#39;s hand and arm are inserted through the hole (which stretches to the extent needed to accommodate the arm), the elastic material cuff seals tightly around the arms of the health care worker. It can be understood that medical equipment could also be inserted through the holes in the elastic material and sealed therein, as well. Flaps, which may be of a pliable material, seal against the holes when not being used by the worker, to enable the pressure seal to be maintained. 
     A negative pressure fitting or connection is fixed to the hood for connection to the hospital suction source, to create a negative pressure environment within the hood. A portable negative pressure pump mount permits the hood to be used for negative pressure transportation of the patient. 
     Overall, the sealed hood permits creation of a sealed, negative pressure environment around a patient&#39;s head and upper body, while still enabling health care personnel to work within the hood via openings in the elastic material in the access openings. Any pathogens emitted from the patient are pulled into the hospital suction and the healthcare workers are isolated from same. It is understood that the apparatus creates what is essentially a loose seal about the patient, which permits some air to enter the interior of the hood in response to the negative pressure, but which stops air flow out of the hood. 
     In addition to intubation procedures, the apparatus may be used for other medical respiratory treatment, for example long term intensive care unit (ICU) patients, thereby saving PPE and preventing spread of contaminants. Sealed side port holes may be provided for ventilator and feeding tube passage. It is understood that the scope of the invention comprises any medical treatment which can be accomplished by use of the system. 
     Contoured edges are provided as necessary to avoid sharp edges and pressure hot spots for the patient. 
     The hood, at least portions thereof, is advantageously formed from clear materials, including but not limited to plastic, for example PETG (polyethylene terephthalate glycol), which can be shaped as desired. This permits viewing of the patient under the hood. Preferably, the hood is of unitary construction with rounded surfaces, particularly on the inner surfaces joining the sides and top, eliminating sharp corners of plexiglass hoods which are difficult to clean and disinfect. The rounded surfaces of the instant hood are much easier to clean and disinfect. The hood can be shaped in the form by methods known in the art. 
     Preferably, the system comprises controls and instrumentation to monitor air flow into and out of the hood interior, and to monitor the pressure differential between the interior of the hood and the ambient surroundings. A loss of the pressure seal, hence creation of a possibility of pathogens flowing from the interior of the hood, may give rise to an alarm based on either or both of pressure and airflow readings. 
     Preferably, a plurality of pathogen-killing lights, such as ultraviolet-C (UV-C) lights, are mounted on or around the hood, with the light directed inside the hood, to kill pathogens such as virus, including but not limited to COVID-19 virus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view one embodiment of the negative pressure respiratory treatment hood system (at times referred to as the “hood”), showing a patient in position and a health care worker in an exemplary position with hands and arms inserted into the interior of the hood for carrying out a procedure on the patient. 
         FIG.  2    is a perspective view of the hood. 
         FIG.  3    is a side view of the hood, namely the front side away from the door (rear wall). 
         FIG.  4    is a side view of the hood (side wall). 
         FIG.  5    is a side view of the hood, showing the door side (front wall). 
         FIG.  6    is a perspective view of an embodiment of the hood  20  without the attached door, and showing the hood shroud in partial view. Various other elements of the system are omitted from  FIG.  6   , for clarity. 
     
    
    
     DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT(S) 
     While various negative pressure respiratory treatment hoods can embody the principles of the present invention, with reference to the drawings some of the presently preferred embodiments can be described. It is understood that certain of the elements are not shown in all of the drawings, for clarity. 
     The negative pressure respiratory treatment hood system  10  embodying the principles of the present invention comprises a generally box-shaped rigid hood  20  with an opening  22  in a front wall  24  to receive the head, and preferably at least a portion of the neck and shoulders, of a patient to be treated, for example intubated. At least portions of hood  20  are made of a material which is sufficiently transparent that the patient within the hood can be viewed therein, therefore permits the health care personnel to see into the interior of hood  20 , so as to enable treatment of the patient; as noted below, in a preferred embodiment hood  20  is formed from a substantially transparent material, for example only a clear plastic, as described in more detail below. The patient would typically be on his/her back on a table, face up, and hood  20  is placed in position over the patient&#39;s body. In a presently preferred embodiment, a hinged door  26  is attached to an upper edge of opening  22  and movable between a first, open position (as can be seen in  FIG.  4   ), to permit easier placement of hood  20  around the patient; and a second, closed position, as in  FIGS.  1  &amp;  2   , rotated down toward or around the patient&#39;s body. However, it is understood that door  26  may or may not be provided. If provided, door  26  preferably has a cut-out shape, preferably to fit the general shape of the patient&#39;s body, as can be seen in  FIGS.  2  and  5   , with a shroud  28  (shown in  FIGS.  1 ,  2 ,  4  and  5   ) to fit tightly around the patient&#39;s body and provide a seal. Shroud  28  may be made from an elastic material such as rubber or the like. Shroud  28  may be held tightly in place by fasteners, such as cleats  48  or similar means. Latches  46  may be provided to hold door  26  in the closed position. 
     One or more access openings  30  are provided in the walls of hood  20  to permit access to the interior of hood  20 , and thus the patient, by healthcare workers, as can be seen in  FIG.  1   . It is understood that any number of access openings  30  may be provided, in order to efficiently access the patient and/or manipulate instruments within hood  20 . Each access opening  30  is covered by an elastic material  32 , for example a highly stretchable rubber shroud or cuff, having an opening  34  therein. Opening  34  is preferably small in diameter (relative to the diameter of access opening  30 ) and centrally positioned in elastic material  32 . The health care worker inserts his or her hand, then arm, through opening  34 , into the interior of hood  20 , with elastic material  32  sealing tightly around the arm and maintaining the negative pressure seal. Flaps  36  are shown in  FIG.  3   , are preferably provided over each of openings  34 , and cover openings  34  when not in active use, thereby maintaining the negative pressure seal within hood  20 . It is understood that flaps  36  essentially work as check valves. In a preferred embodiment, flaps  36  may be made of a flexible or pliable sheet of material, which in a first position are covering openings  34 , and can be simply bent back out of the way to permit access through openings  34 . 
     A connection  38 , namely a negative pressure fitting, shown in  FIGS.  1 - 4   , is fixed to the hood for connection to the hospital suction or vacuum source  40 , to create a negative pressure environment within the hood. In addition, a portable negative pressure pump  44  can be attached to permit movement of the patient while maintaining the negative pressure environment. 
     In a presently preferred embodiment, measurement and instrumentation devices are provided to monitor both air flow rate into and out of the interior of hood  20 , and to monitor a pressure differential between the interior of hood  20  and ambient pressure outside of hood  20 . Alarms are provided to signal undesired flow and/or pressure differential conditions. The measurement, instrumentation and alarms are represented schematically as element  50  in the drawings. 
     A bottom seal  52  can be added to the bottom surface of hood  20 , and a door seal  54  can be added between door  26  and hood  20 . 
       FIG.  3    is a view from the direction of the position of the health care worker in  FIG.  1   . 
       FIG.  4    is a side view, showing door  26  and attached shroud  28  in a first, closed position and in a second, partially opened position, as noted. 
       FIG.  5    is a view of the system looking into opening  22 , with door  26  in a closed position and shroud  28  in a flattened position. 
       FIG.  6    is a perspective view of an embodiment of hood  20  without door  26 , and showing shroud  28  in partial view. Various other elements of the system are omitted from  FIG.  6   , for clarity. 
     Overall, the system  10  permits creation of a sealed, negative pressure environment around a patient&#39;s head and upper body, while still enabling health care personnel to work within the hood via the rubber shrouds in the access openings. It is to be understood that the sealed, negative pressure environment may be regarded as a “loosely sealed” environment, as air may flow into the interior of the hood in response to the negative pressure (vacuum) created therein, but air and any pathogens carried therein would not leave the interior of the hood. Any pathogens emitted from the patient are pulled into the hospital suction and the healthcare workers are isolated from same. 
     Preferably, a plurality of pathogen-killing lights, such as ultraviolet-C (UV-C) lights  42  are mounted on or around the hood, with the light directed inside the hood, to kill pathogens such as virus, including but not limited to COVID-19 virus. UV-C lights (emitting light with a wavelength generally between 200 and 280 nm) have been shown to have effective germicidal properties. It is understood that other pathogen-killing lights may be used. 
     A Method of Use of the System 
     An exemplary method of use of system  10 , to create a negative pressure environment around the head of a human medical patient and carrying out a medical procedure within said negative pressure environment, may comprise the steps of:
         a) positioning the human medical patient upon a table;   b) placing a rigid hood over the medical patient so as to receive the medical patient&#39;s head within an interior space of the rigid hood, at least a portion of said hood being sufficiently transparent that the medical patient within said hood can be viewed inside the hood, the rigid hood comprising walls and comprising an opening in a front wall with the medical patient&#39;s body extending through said opening;   c) draping a shroud over the patient&#39;s body and securing the shroud to the hood, the shroud creating at least a partial pressure seal around the patient&#39;s body; and   d) connecting a negative pressure source to said interior of said hood and creating a negative pressure environment inside the hood.       

     Commonly, a method of use would also include the step of:
         e) accessing the medical patient within the hood and performing a desired medical procedure on the patient, the access being through one or more access openings in the walls of the hood, each of the one or more access openings covered by an elastic material having an opening, the elastic material and the opening therein permitting access to the medical patient while maintaining a negative pressure environment within the hood, the hood comprising a flap which bears against the opening in the elastic material and forms a pressure seal against same, the flap being movable to permit access through the opening in the elastic material.       

     Materials and Fabrication 
     Hood  20  is advantageously formed from a clear or largely clear material, which may be a plastic, such as PETG (polyethylene terephthalate glycol), which can be shaped within a hemispherical form, and forms a rigid hood  20 . It is understood that any other material of sufficient transparency may be used to fabricate hood  20 . Preferably, hood  20  is of unitary construction with rounded surfaces, particularly on the inner surfaces joining the sides and top, eliminating sharp interior corners which are difficult to clean and disinfect. The rounded surfaces of the hood  20  are much easier to clean and disinfect. Hood  20  can be shaped in the form by methods known in the art. The elastic material (for example, rubber or the like) shrouds and access opening material may be of materials known in the medical arts. It is understood that materials and methods of fabrication may be altered as desired. 
     Contoured edges are provided as necessary to avoid sharp edges and pressure hot spots for the patient. 
     CONCLUSION 
     While the preceding description contains many specificities, it is to be understood that same are presented only to describe some of the presently preferred embodiments of the invention, and not by way of limitation. Changes can be made to various aspects of the invention, without departing from the scope thereof. 
     Therefore, the scope of the invention is to be determined not by the illustrative examples set forth above, but by the appended claims and their legal equivalents.