fig1 shows a first embodiment of the voice prosthesis in accordance with the invention . the main part of the voice prosthesis is the tube - shaped metal part 1 , here bent into an l shape . at its end lying next to the tracheal end when in situ , the metal part exhibits an open , funnel - shaped expansion 2 . this open , funnel - shaped expansion 2 is , in the embodiment shown , covered by an element 3 that produces an audible tone when air is blown against it , or in the present case , by a membrane 4 . this membrane 4 grips the rim 5 of the funnel - shaped expansion 2 from the back . in this way , an exceptionally stable locating of the membrane 4 over the funnel - shaped expansion 2 is achieved . in the embodiment shown , the back side of the membrane is formed with more of a hose - shaped extension , and has at its distal end a ring - shaped flange 30 . between this flange 30 and the back side 31 of the funnel - shaped expansion 2 , the walls of the trachea and the esophagus ( not shown , but possibly sewn together ) come together in a sealing position . the membrane part including the membrane 4 with its hose - shaped extension and the protruding flange 30 is made of silicone rubber . the shore hardness of this material lies in the range of about 30 to 70 . a higher shore hardness allows the membrane 4 to generate a higher tone , a lower shore hardness a lower tone , when the membrane has air blown against it from the trachea . for tone generation , there is placed in membrane 4 at least one slit 6 through which air can flow into the tube - shaped metal part 1 . the funnel - shaped expansion 2 is dimensioned in such a way that the membrane 4 does not touch the floor 7 of the expansion 2 , even when the membrane vibrates with maximum oscillation amplitude . in addition , the voice prosthesis represented in fig1 has an additional element 3 that can vibrate and produce an audible tone , namely a metal voice plate 8 anchored in the free lumen of the tube - shaped metal part 1 . this voice plate 8 is configured in almost an l shape , with a long leg that can vibrate in the lumen of the metal part 1 , and with a short leg that is anchored in the wall 1 &# 39 ; of the metal part 1 , for example in a slot that has been provided therein . at the esophageal end , the voice prosthesis is provided with a protective device 9 that prevents food particles and saliva from entering the voice prosthesis . in the present case , the tube - shaped metal part 1 is provided with a one - way valve 9 &# 39 ;, which comprises a plastic tube 14 that is pushed over the tube - shaped metal part 1 . it lies close to the wall 1 &# 39 ; of the tube - shaped metal part 1 ; this cannot be seen clearly in fig1 due to representation limitations . this plastic tube has a longitudinal slit 15 in its esophageal end . when air flows from the trachea to the esophagus , the longitudinal slit spreads and allows air to flow into the pharyngeal area of the patient . if the air flow is interrupted , for instance when the patient stops speaking , the longitudinal slit closes due to the material &# 39 ; s inherent resilient forces , and effectively prevents the entry of food particles or saliva into the voice prosthesis . the represented voice prosthesis also has as an additional protective means on the tracheal end , a protective device in the form of a one - way ball valve 18 . this valve comprises a ball 19 positioned in the tube - shaped metal part 1 in such a way that it can move freely between a limit stop 20 and a valve seat 21 . this limit stop 20 can be a metal strip or wire seated in the wall 1 &# 39 ; of the tube - shaped metal part 1 . in either case , it offers only slight resistance to the flow of air . the limit stop 20 limits the movement of the ball 19 in the direction away from the funnel - shaped expansion 2 . in the mouth area of the open lumen of the tube - shaped metal part 1 , in the funnel - shaped expansion 2 , a valve seat is formed that prevents any further movement towards the left of the drawing . when the patient begins to speak , the ball 19 is forced from the represented position at the valve seat 21 towards the limit stop 20 , and air can flow through the tube - shaped metal part 1 , causing the membrane 4 and the voice plate 8 to vibrate , and , as the slit 15 of the flutter valve opens , flow from the trachea into the esophagus . the vibrations arriving at the pharyngeal area are then subject to articulation by the patient . fig2 shows a second embodiment . at this point , note should be taken of the differences versus the voice prosthesis shown in fig1 . the anchoring location for the voice plate 8 is different from that shown in fig1 . basically , the anchoring location for the voice plate is unimportant . what is relevant , however , is that the long , vibrating leg have enough room to carry out maximum amplitude vibrations . primarily , it is the protective device 9 on the esophageal end that most differs from what is shown in fig1 . here , the tube - shaped metal part 1 is closed at its front opening . in its place , side openings 16 are provided in the side wall 1 &# 39 ;; these openings are protected against the entry of food particles and saliva by an overhanging protective hood 17 . the protective hood 17 can be an integral component of the tube - shaped metal part 1 . however , it can also be made of silicone and be bonded to the metal part 1 . in fig3 an embodiment is shown that , in contrast to those of fig1 and 2 , has no additional protective device on the tracheal end . instead , the voice plate 8 is anchored at this location . the protective device 9 on the esophageal end also differs from the embodiments explained above . here , the tube - shaped metal part 1 is again closed at the esophageal end . openings 11 in the side wall 1 &# 39 ; are provided as air entry openings . a ball 10 of a one - way valve 9 &# 34 ; is situated in the interior of the tube - shaped metal part 1 . the arrangement is such that when the patient begins to speak , the ball 10 is lifted by the flow of air to the extent that a passage is opened between the funnel - shaped expansion 2 and the openings 11 . the openings 11 are shielded by protective flaps 13 that are made of an elastic material and are bonded , for example , to the metal part 1 above the openings 11 . fig4 illustrates another embodiment , which only has available a single element 3 that can vibrate and produce an audible tone , namely via the membrane 4 which grips the rim 5 of the funnel - shaped expansion 2 from behind . here , as protective device 9 on the esophageal end , a one - way valve 9 &# 39 ; is provided , which is formed from a plastic tube 14 that is pushed over the tube - shaped metal part 1 and that has -- as already shown in fig1 -- a longitudinal slit 15 . the manners of functioning are the same . in contrast to the embodiment of fig1 the plastic tube 14 is lengthened and has as integral components flanges 30 and 31 , between which the tracheal and esophageal walls ( not shown ) come together in a sealing position . fig5 shows a further embodiment of the voice prosthesis . the tube - shaped metal part 1 again forms the main part , with a protective device 9 at the esophageal end that has 10 already been explained by means of the embodiment in fig2 . as the tone - generating element 3 , a membrane 4 is used that grips the rim 5 of the funnel - shaped expansion 2 of the tube - shaped metal part 1 from behind and covers the funnel - shaped expansion . the membrane 4 is an integral component of a long , narrow , tube - shaped capping piece 22 , which in its tube - shaped section contains a one - way ball valve 18 as an additional protective device on the tracheal end . the movable ball 24 , that is a part of this valve , is limited in its movement towards the funnel - shaped expansion 2 by a limit stop 25 that crosses the tube section . this limit stop is formed like limit stop 20 , as explained by means of fig1 and 2 . the ball 24 is limited in its movement towards the air entry opening 26 by a ball valve seat 27 , which is formed in the air entry opening 26 in the mouth area of the lumen of the tube section . the trachea and esophagus walls ( not shown ) are brought together between sections 32 and 33 , which act as flanges . fig6 shows a final embodiment , again with a tone - generating element 3 , namely a membrane 4 that is stretched over the funnel - shaped expansion 2 and grips the expansion &# 39 ; s rim from behind . the protective device 9 and one - way valve 9 &# 34 ; on the esophageal end correspond with the ones already described by means of fig . 3 . in contrast with the previously described embodiments , in the present case a sleeve - like tube piece 34 , preferably made of silicone , is pushed over the tube - shaped metal part 1 up to the funnel - shaped expansion 2 . part 34 has without more specific designation , the flanges between which the trachea and esophagus walls ( not shown ) are placed . finally , three views of membranes 4 &# 39 ;, 4 &# 34 ;, and 4 &# 39 ;&# 34 ; are shown in fig7 . membrane 4 &# 39 ; as shown in fig7 a has two slits 6 &# 39 ; the membrane 4 &# 34 ; shown in 7b has only one slit 6 &# 34 ;, which has in its center a hole - like expansion 35 . membrane 4 &# 39 ;&# 34 ; as shown in fig7 c has instead only one slit 6 &# 39 ;&# 34 ;. various parameters such as the pitch of the tone can be adjusted by varying the numbers and / or arrangements of slits . the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and , accordingly , reference should be made to the appended claims , rather than to the foregoing specification as indicating the scope of the invention .
a voice prosthesis is provided for use in a shunt between the trachea and the esophagus of a laryngectomized patient . the voice prosthesis has a tube - shaped metal part with a funnel - shaped expansion that opens towards its tracheal end . within the path of the stream of air from the trachea to the esophagus there is provided at least one element that is caused to vibrate by the stream of air passing through the prosthesis , thereby producing an audible tone . with this prosthesis , a laryngectomized patient can produce a much more natural sounding voice than has previously been the case .