Abstract:
A laryngoscopes blade of the disposable variety for use with a Fiber Optic Green System Handle having a blade portion made from stainless steel and a heel portion made from thermoplastic resin.

Description:
FIELD OF THE INVENTION 
   This invention relates to Laryngoscope blades generally and more particularly to single use laryngoscopes blades of the disposable variety for use with a Fiber Optic Green System Handle. 
   DESCRIPTION OF THE PRIOR ART 
   Laryngoscope blades of the Green System type are used to examine and visualize a patients upper airway and aid in the placement of a tracheal tube during intubations, and also during resuscitations. Multiple use or reusable laryngoscope blades are well known in the industry but present at least a two fold problem, namely: 1) studies have shown that as many as sixteen percent of the laryngoscope blades that had been cleaned were still contaminated and 2) re-cleaning reusable blades can currently cost from $3.25–$5.00 depending on geographic labor costs. Prior art disposable laryngoscope blades have not been well received in hospitals in the United States as they all are constructed primarily from plastic and tend to twist and flex during use and some have even broken in use. 
   SUMMARY OF THE INVENTION 
   The object of this invention was to develop a disposable single use laryngoscope blade for use in a handle-blade world-wide system in conjunction with a Fiber Optic Green System Handle that would be acceptable for every surgical procedure and everyday usage in the hospital, as well as in the field, and at a price that was cost effective. To that end, a device that is the subject of this invention achieves the following: 1) a stainless steel blade that won&#39;t flex or break during use; 2) has traditional profiles and sizes and therefore suitable for use on all patients; 3) cost effective to the hospital when compared to cleaning costs; 4) sterile with no more cleaning or contamination problems. To that end, the blade spatulas are made from type 304 austenitic stainless steel in accordance with the ISO/DIS 7153/3, standard recommended by ASTM (American society for testing metals) which is highly recommended for surgical/medical instruments. The ball plungers which acts as a locking aid, and their springs and covers are also made from type 304 stainless steel. The heel of the blade (also referred to as the foot of the blade) is made from Dupont&#39;s Delrin (R) 900P NC 010, a low viscosity acetal resin, a thermoplastic polymer material which is a resin for molding in multi cavity molds and thin sections that are difficult to fill, has good chemical resistance to some alkalies and some acids, has improved thermal stability and is stable during the Gamma sterilization process. To insure that the device is not reused in a hospital environment where sterilization is normally performed by steam autoclaving, the resin material selected will not accept steam autoclaving. The light carrier is made from cast acrylic rods cut and bent in the desired shape and acts as a light carrier from the lamp in the handle to the distal tip of the blade for visualization of the larynx during intubation, while the light carrier fastener is made from polypropylene material and is immune to stress cracking. These disposable blades are used to examine and visualize a patients upper airway and aid in placement of a tracheal tube during intubations. The conventional Fiber Optic Green System handle suitable for use with this blade is mechanically attached to the blade in the conventional manner and light is transmitted from a source in the handle to the distal tip of the blade through the light carrying rod. 
   In accordance with IAEA (International Atomic Energy Agency) recommended standards, these blades, after the final manufacturing steps have been completed, are packed in sterilized pouches made from material which is stable during gamma ray sterilization, such as Tyvec, and sterilized by gamma ray sterilization processing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a laryngoscope blade mounted on its cooperating handle with the handle and the heel of the blade shown in section; 
       FIG. 2  is an enlarged fragmentary view of a portion of the device shown in  FIG. 1 ; 
       FIG. 3  is a sectional view taken along the lines  3 — 3  in  FIG. 2 ; 
       FIG. 4  is a side elevational view of the plastic part of the heel portion of the device of  FIG. 1   
       FIG. 5  is a left side view of the heel portion shown in  FIG. 4 ; 
       FIG. 6  is a right side view of the heel portion shown in  FIG. 4 ; 
       FIG. 7  is a cross sectional view of the heel portion shown in  FIG. 4 ; 
       FIG. 8  is a bottom view of the heel portion shown in  FIG. 4 ; 
       FIG. 9  is a bottom view of the heel portion shown in  FIG. 4 ; and 
       FIG. 10  is an exploded view of the blade portion of the assembly shown in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings a laryngoscope blade-handle assembly is shown generally at  10  and includes a blade portion  12  and a handle portion  14 . The handle is of the conventional type referred to as a Fiber Optic Green System Handle which is reusable and includes a gripable housing  15  in which is a source of electrical power in the form of a battery  16 , a source of light in the form of a bulb  18  actuated upon its depression and contact with a conductor  20  and a securable mounting end  22  at the upper end thereof surrounding the bulb  18 . The mounting end  22  has a slot  23  formed therein traversed by a cross pin  24  and a pair of laterally spaced and opposed detents (not shown), one on each lateral side of the slot  23 . 
   The blade portion  12  includes a conventionally flanged blade  26  and a heel portion  28 . The blade  26  is made from type 304 austenitic stainless steel and, with reference to  FIG. 10 , has an attaching proximal end  27 , a distal end  29 , a pair of securing cross holes  30  and  31  formed laterally in the attaching end  27  and an elongated opening  32  formed intermediate the opposed ends of the blade  26 . The opening  32  is formed so as to snugly receive an acrylic light carrier  34  having an elongated rod shape in the conventional light carrier configuration. The light carrier  34  is bent to fit and extends from the distal end  29  of the blade  26  to the bottom  39  of the heel portion  28  and its proximal end  35  at the heel end is bent downwardly and extends into an annular polypropylene fastener  36  and fittingly and securely received therein. The fastener, in turn, is securely received in a vertically extending slot-like opening  38  formed in the side of the heel portion  28  and extending from the bottom  39  to the top of the heel portion so that the carrier  34  extends from the bottom  39  of the heel portion to the distal end  29  of the blade  26 . 
   The heel portion  28  has an inclined slot  40  formed laterally across the right end thereof, which slot receives the cross pin  24  of the handle  14  when assembled thereon. A spring loaded poppet  42  received in an opening  44 , formed in the heel portion  28  and open to the slot  40 , which poppet resiliently engages the top of the cross pin  24  to assist in holding the assembly together. A hole  45  is formed in the lower part of slot  40  which is slightly larger than the hole  44 , to provide access for the spring loaded poppet  42  so that it can be inserted therethrough and into the opening  44 . A pair of spring loaded poppets  46  and  48 , carried by the heel portion  28  in a cross hole  47 , and extending in lateral opposition to engage mating detents (not shown) in the slot  23  of the mating end  22  of the handle  14  to resiliently assist in holding the assembly together. The poppets  42 ,  46  and  48 , along with their springs and mounting sleeves are made from the same type 304 stainless steel as the blade. 
   The blade  26  of the blade portion  12  can be made from sheet stock material which is first sheared to size, blanked and bent, and holes drilled for molding of the blade  26  of the blade portion  12  can be precision cast out of type 304 austenitic steel and requires no machining. After forming the blade  26 , it is merely polished, ultrasonically cleaned and then sand blasted before the heel is molded thereon in an insert molding process in which low viscosity acetal resin plastic, such as Delrin®) 900P, flows into the holes  30  and  31  in the blade  26  to thus form a blade portion assembly which will not separate; the blade  26  being securely and fittingly received in a space  26 A in the heel portion, shown in  FIGS. 5 ,  6 ,  7  and  8  which space is formed intimately around the blade during the molding process. After molding, the heel portion  28  is merely deburred, the light carrier installed, the poppets  42 ,  46  and  48 , along with their springs and stainless steel mounting devices are installed in the heel portion, the blade portion wrapped and then sterilized by gamma ray sterilization to complete the manufacturing process. 
   The blade portions  12  are contemplated to be supplied in the well known conventional sizes of Macintosh: sizes 2, 3 and 4; Miller: sizes 0, 1, 2, and 3; and special types of pediatric blades. 
   While only a single embodiment of this invention has been shown and described, it is apparent that changes can be made therein without departing from the scope of this invention as claimed in the following claims.