US 3918317 A
An apparatus for artificial respiration includes a frame, an air delivery device, a rotatable drive and a power transmission system including a four part linkage. The linkage includes a first joint which is rigidly supported but adjustable and lockable relative to the frame. A second joint of the linkage engages the drive and is freely movable thereby. A guide mechanism engages and guides movement of a third joint of the linkage and a fourth joint of the linkage connects to the air delivery device. The guide mechanism provides a guide path for the third joint and is adjustable and lockable with respect to the frame for relocating such guide path.
Claims available in
Description (OCR text may contain errors)
United States Patent 1191 Claussen Nov. 11, 1975 APPARATUS FOR ARTIFICIAL RESPIRATION  Inventor:
 Assignee: Georg Kinzler, Munich, Germany  Filed: Nov. 6, 1973  Appl. No.: 413,347
Uwe Claussen, Munich, Gennany  Foreign Application Priority Data Nov. 8, 1972 Germany 2254634  US. Cl. 74/4'69; 74/51; 92/132; 92/134; 92/137; 128/1456; 417/472  Int. Cl. F16H 21/42  Field of Search 74/469, 48, 51; 128/1456, 128/145.7, 188; 417/472; 92/13, 13.2, 13.4, 13.7
Primary Examiner-Samuel Scott Assistant Examir'zer-F. D. Shoemaker Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn  ABSTRACT An apparatus for artificial respiration includes a frame, an air delivery device, a rotatable drive and a power transmission system including a four part linkage. The linkage includes a first joint which is rigidly supported but adjustable and lockable relative to the frame. A second joint of the linkage engages the drive and is freely movable thereby. A guide mechanism engages and guides movement of a third joint of the linkage and a fourth joint of the linkage connects to the air delivery device. The guide mechanism provides a guide path for the third joint and is adjustable and lockable with respect to the frame for relocating such guide path.
17 Claims, 21 Drawing Figures US. Patent Nov. 11, 1975 Sheet 1 of5 3,918,317
US. Patent Nov. 11, 1975 Sheet 2 of5 3,918,317
US. Patent Nov.11, 1975 Sheet30f5 3,918,317
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Sheet 4 of 5 3,918,317
U.S. Patent Nov. 11, 1975 U.S. Patent Nov. 11,1975 SheetS 0f5 3,918,317
APPARATUS FOR ARTIFICIAL RESPIRATION The invention relates to an apparatus for artificial respiration comprising a rigid frame in which a movable part of a breathing air delivery apparatus can be driven intermittently by a drive via an adjustable an flexible power transmission arrangement.
Such apparatus is used for the artificial respiration of persons whose respiratory organs are wholly or partially, and permanently or temporarily paralyzed.
With this apparatus it is necessary for the quantity of air per breath, the breathing frequency and the breathltime ratio, i.e., the time ratio between the inhalation and exhalation times, to be variable so that the apparatus may be adapted to suit each individual patient. Thus, for example, babies only require air quantities of less than cm" for each breath, but lift frequencies of up to 80 lifts per minute, whereas adults require up to 1 litre of air per breath with a lift frequency of up to 12 lifts per minute.
An artificial respirator having an independently variable pumping frequency and volume as well as a variable ratio between inhalation and exhalation is already known from German Offenlegungsschrift No. 1,962,302. In this apparatus the piston of a piston pump in the cylinder is intermittently moved back and forth under the influence of a rotating drive shaft and with the aid of a system of levers and two joints which are vertically slidable parallel to one another, the sliding and locking of the two slidable joints on guide rods provided for this purpose enabling the relative times of the reciprocating motion to be varied by means of the first joint and the relative lift of the piston pump during its reciprocating motion to be limited by means of the second joint.
However, the known apparatus is not without disadvantages. Whenever the two joints are to be adjusted, the pivotable sleeves each forming part of the joints must, when released with their fixtures, slide along the guide rods for a suitable distance and then be secured in their new positions by means of clamping screws. As an increasing number of unskilled workers have to be used in the nursing profession, there is the danger that the adjustment of the joints may be incorrectly effected and that these joints may be insufficiently locked or secured to prevent adjustment during operation, which can result in serious damage to the patient. Furthermore, a number of slidably interlocking components are used in the known apparatus to convert the rotary motion of the drive shaft into the translational movement of the piston rod, which, in the event of inadequate lubrication or as a result of inaccuracies during manufacture, can lead to sudden jamming and resultant .stopping of the respirator with serious consequences for the patient.
Apart from these disadvantages relating to reliable operation, it must be considered a disadvantage that the known apparatus can only be transported with difficulty owing to its construction and dimensions, thereby rendering its use more difficult in rescue vehicles or at different places inside a hospital. When electrically operated, the apparatus also requires a high feed rate as a result of its mass to be moved so that it is unsuitable for battery-operated use, for example under-the seat of an invalid chair.
The problem underlying the invention is therefore to provide a transportable artificial respirator which has only a low power requirement, is absolutely reliable in operation and which moreover should be lightweight so that it can be quickly conveyed by one person.
This problem is solved in accordance with the invention in that a four-part linkage with parallel revolving 'a'xles'is arranged in the power transmission system, in which-linkage a first joint is rigidly secured, but is adjustable and lockable with its fixture relative to the frame, a second joint in which the drive engages is arranged so as to be freely slidable and a third and fourth joint are provided, the latter two each being guided on a guide mechanism having a defined guide path, but being adjustable and lockable relative to the frame.
To adapt to individual adjusting requirements, it has proved advantageous, according to an embodiment of the apparatus of the invention, for the first joint to be slidable in a substantially straight line, sliding along a guide path extending substantially perpendicular to the direction of movement of the movable part of the air delivery device being particularly preferred, and moreover for the third joint to be slidable along a guide path extending substantially parallel to the direction of movement of that movable part of the air delivery apparatus.
For trouble-free operation it proved to be advantageous that all the guide paths of the apparatus according to the invention have a constant radius and that furthermore the guide paths are adjustable and lockable along paths of circular arc form relative to the frame.
In accordance with another embodiment of the invention it is provided that all the auxiliary devices used to move the first and third joints can be locked.
Apractical embodiment of the invention is illustrated in the drawings and described in more detail below.
FIG. 1 showsa'side view of the apparatus according to the invention looking on to the power transmission system provided between the drive and the air delivery apparatus,
. FIG. 2a is a schematic representation of the parts of the power transmission system which are moved during each pumping operation, with a predetermined breathltime ratio arid'pump lift and in a selected operative position,
FIGS. 2b and 2c are diagrams showing the transmission ratios between the driving and driven sides of the respirator occurring in the event of a predetermined setting of the breath/time ratio and pump lift according to FIG. 2a,
.FIGS. 3a and 31 are schematic representations showing the position of each transmission element upon maximum opening of the bellows, and
FIGS. 4a to 4i.are schematic representations showing the position of'each transmission element when the bellows are closed.
As can be seen in FIG. 1, the apparatus 1 consists essentially of a housing 2 with a support frame 3, mounted therein and attached to the outer components, a pump bellows 4 with a pivotable part 5 and a four-part linkage connecting the latter to a driving shaft 6 of a drive (not shown), preferably in the form of an electromotor, and comprising levers (or more precisely, links) 7, 8, 9, l0 and joints 11, 12, l3, 14 as well as a connecting link 15 which connects the driven joint 12 to a rotating crank arm 16 nonrotatably secured to the driving shaft 6. Also mounted in the housing 2 are all-the systems (not shown) for producing and monitoring the breathing air mixture, for example, for humidifying or heating the breathing air.
The joint 11 is rigidly mounted, but can be adjusted relative to the frame 3 by means of a lever 18 which is pivotable about an axle l7 and on the free end ofwhich the joint 11 is supported. If the free end of the lever 18 is pivoted, the joint 11 moves in a circular are defined by the length of the lever 18 between the pivot axle l7 and a pivot axle 19. A rod 20 extending from outside into the housing is provided for pivoting and locking the lever 18, its lower end comprising a threaded section 21 which engages with a correspondingly toothed section 22 on the end of the lever 18 facing the former. The worm drive 21, 22 can be operated with the aid of a control knob 23 attached to the upper end of the rod 20.
A lever 7 is connected to the joint 11 by means of the pivot axle 19, its other end being connected to a pivot axle 24 of the joint 12. Also connected to the axle 24 is a connecting link 15, the other end of which supports a pivot axle 25 connected to the rotating crank arm 16. The joint 12 is driven by means of the members 15 and 16. Also connected to the axle 24 is the first end of the lever 8, its other end being pivotally connected to a revolving axle 26 of the joint 13. This joint 13 is guided on a guide mechanism having .a defined path of movement, but being adjustable and lockable relative to the frame, said guide mechanism essentially comprising a lever 27 and a lever 29. The lower end of the lever 27 is connected to the revolving axle 26 and its upper end to a pivot axle 28 which is arranged at the upper end ofa lever 29 pivotable about an axle 30. If the lever 29 is pivoted about the axle 30, the pivot axle 28 moves in a circular arc with the radius of the length of the lever 29 between the axles 30 and 28. Displacement of the revolving axle 26 and therefore of the joint 13 in a circular arc defined as a radius by the lever 27 is also effected with the displacement of the axle 28.
A thread 32, arranged at the lower end of a rod 31 extending from outside into the housing and meshing with a toothed section 33 on the lower part of the lever 29, serves to pivot the lever 29 about the axle 30. The worm drive 32, 33 can be actuated and therefore the lever 29 and axle 28 pivoted with the aid of a knob 34 attached to the upper end of the rod 31 on the outside of the housing. One end of the link 9 is also pivotally connected to the revolving axle 26 of the joint 13, its other end being arranged on the pivot axle 35 of the joint 14. The joint 14 is also guided on a guide mechanism having a defined path of movement, but being adjustable and lockable relative to the frame, because the path of movement of the joint 14 which is adjusted during operation automatically results from, respectively, the position of the pivot axle 26, the length of the link 9 and the length of the part between the pivot axle 35 and a pivot axle 36, thereby defining the radius of the circular arc paths described by the joint 14.
One end of the lever is flexibly connected to the pivot axle 35 of the joint 14, its other end being attached to the part 5 of the bellows 4 pivotable about the axle 36. An outlet 37 for the breathing air delivered to the bellows is arranged at the end of the bellows lying opposite the part 5.
FIG. 2a shows the parts of the apparatus which are set into motion upon each revolution of the driving shaft 6 to perform a pumping cycle of the bellows section 5. This representation does not show the adjustability of the apparatus, since it is based on an already effected adjustment of the breath/time ratio and pump lift. Driven by the rotating crank arm 16 nonrotatably mounted on the shaft 6 and by the connecting link 15 pivotably connected to the arm 16 on the revolving axle 25, the joint 12 which is associated with the revolving axle 24 executes a reciprocating movement with every revolution of the crank arm 16, which movement is transmitted to the revolving axle 35, rigidly connected to the bellows section 5, via the lever 8, the revolving axle 26 of the joint 13 and the lever 9. FIG. 2a also shows the pivoting of the bellows section 5 about the axle 36 which can be achieved upon a full revolution of the driving shaft 6 and with the breathing time ratio and pump lift at a predetermined setting. The diagrams in FIGS. 2!) and 20 show the transmission ratios between the driving and driven sides of the apparatus occurring upon adjustment of the apparatus forming the basis of FIG. 2a.
The variable adjustment of the pump lift which can be achieved by the sliding of the joint 13 by means of the lever 29 being pivoted, and the variable setting of the breathing time ratio which can be effected by sliding the joint 11 with the aid of the lever 18 can be seen in FIGS. 3a to 4i.
In this connection FIGS. 3a to 3! illustrate the positions of the respective transmission elements upon maximum opening of the bellows, and FIGS. 4a to 4i the positions of the transmission elements when the bellows are closed. The transmission elements 18 and 29 which are adjustable, but lockable after adjustment is effected are shown by broken lines so as to be better distinguished from the constantly movable transmission elements. For the sake of clarity transmission elements which actually overlap in the illustrated operating conditions have been shown as extending parallel to one another (for example, the elements 15 and 16 in FIG. 3a and the elements 27 and 29 in FIG. 4a). In both FIGS. 3a to 31' and FIGS. 4a to 41' the ratios between different pump lifts are shown from left to right and different breathing time ratios (breathing irregularity) from top to bottom. The illustrations reproducing the positions of transmission elements in the case of maximum, medium and minimum lifts or irregularities clearly show that the pump lift and breathing time ratio (irregularity) may be adjusted independently of one another with the respirator according to the invention.
The variable adjustment of the pump lift is effected by pivoting the lever 29 about the axle 30 with the aid of the worm drive 32, 33 which can be operated by the knob 34. If the lever 29 is pivoted about the axle 30, the pivot axle 28 mounted on the other end of the lever 29 describes a circular arc in a direction substantially parallel to the direction of movement of the movable bellows section 5. Since the joint 13 and its axle 26 are connected to the pivot axle 28 by the lever 27, the pivoting of the axle 28 results in movement of the joint 13 in a circular arc relative to the frame, the radius of the circular are being defined by the free length of the lever 27 between the axles 28 and 26.
As can be seen in FIGS. 3a to 31', the pump lift, i.e. the inclination of the bellows section 5 towards the vertical, is at its maximum when the lever 29 is in the position of maximum pivoting to the left (FIGS. 3a to 30) where the pivot axle 28 mounted on the free end of the lever 29 has its minimum spacing from the driving shaft 6. The position of the lever 29 is illustrated in FIG. 1. If the axle 28 is pivoted out of its position described above in the direction of the bellows section 5, a me- ,5 dium lift is obtained according to, FIGS. 3d to-3f and,
\ upon further pivoting in the direction of thebellows, a
minimum lift as shown in FIGS. 3g to 31'.
The variable setting of the breathing time ratio or irregularity is effected by pivoting the lever 18 about the axle 17 with the aid of the worm drive 21, 22 operated by the knob 23. If the lever 18 is pivoted about the axle 17, the joint 11 and its axle l9 movein a path of circular arc form in a substantially perpendicular direction relative to the frame. As can be seen particularly in.
causes minimum irregularity as shown in FIGS. 30, 3f 20 and 31', in which case the inhalation and exhalation times are of equal length in practice. The lowest position of the lever 18 which causes minimum irregularity inthe pumping action is shown in FIG. '1. I
' FIGS. 3a to 41' clearly show that the pump lift and breathing time ratio may be independently adjusted by corresponding pivoting'of the elements-29 and 18, respectively, in which case it is of particular importance that some transmission elements, such as certain levers and certain axles or joints, overlap in given operating conditions. As already-mentioned, the overlapping of variouslevers was illustrated in FIGS. 3a to 4'! by showing corresponding levers extending parallel to one another. In order toshow the overlapping of 'various joints clearly in the said figures,theoverlappedjoint or axle has therelevant referencenu'r'neral' in brackets.
. Thus FIGS. 4a. to 41' show that the transmission elements 7 and 18 as well as 27 and 29 and the axles 24 and 17 as well as 26 and 30 overlap-when the bellows are closed. When considering the said figures, it should therefore always be noted that the axles l7 and 30 are rigid (fixedly located with respect to frame 3), whereas the axles 24 and 26 are movable.
The independent setting of irregularity (breathing time ratio) and pump lift is described below with the aid of two examples:
1. As mentioned above, the levers 27 and 29 overlap when the bellows are closed. If the lever 29 determining the pump lift is then adjusted, only the lever 27 is moved by the permanently movable transmission elements. If the apparatus is set in operation again after pivoting of the lever 29, only a different pump lift is apparent and not a changed breathing time ratio.
2. As also described above, the levers 7 and 18 also overlap when the bellows are closed. If the lever 18 which determines the breathing time ratio is then pivoted, only the lever 7 is moved by the permanently movable transmission elements. If, after pivoting of the lever 18, the apparatus is set in operation again, only a different breathing time ratio is apparent, and not a different pump lift.
In the embodiment shown in FIG. 1, the levers l8 and 29 are arrested by the worm drives 21, 22 and 32, 33 which, in design, are self-locking and free of 'play. To eliminate the possibility of the selected apparatus setting being adjusted by unauthorized persons, manual controls, for example knobs, can also be provided directly on the adjusting levers l8 and 29, to be used only for adjustment, while the locking action'is-effecte dby means of wing nuts and bolts which move slidably through slots provided in the frame 3. The levers l8 and 29. can be clamped on the frame with the aid of these wing nuts and bolts. However, such a solution would have the disadvantage that the front wall of the housing would have-to .be previously removed. The worm drives are therefore preferred where no unauthorized adjustment of the apparatus is likely, whereas in a case where unauthorized adjustment cannot be excluded, adjustment in thehousingwould appear to be advantageous. I I claim:
1. Apparatus for artificial respiration comprising a rigid frame, a breathing air delivery'apparatus having a movable part, a drive, an adjustable and flexible power transmission system interconnecting and arranged for intermittently driving said movable 'part from said drive, said transmission system including a fourpartlinkage having plural joints with parallel pivot axes, said linkageincorpo'rating a'first said joint which is rigidly mounted,.but adjustable-and lockable, relative to the frame, a second said joint engaged by the drive and freely movable thereby, a guide mechanism having a defined path of movement, but being adjustable and lockable, relative to the frame and third and fourth said joints guided on the guide mechanism, the interconnection of said transmission system to said movable part including said fourth joint. V
1 2. Apparatus as claimed in claim I, in which the path of adjustment, relative to the frame, of the first joint is arcuate. a
3.- Apparatus as claimed in claim 1, wherein the guide mechanism has a guide path of constant radius, said third joint being constrainedtomovement along said guide path by said guide mechanism.
'4. Apparatus as claimed in claim 3,in which the guide mechanism provides a plurality of guide paths alternatively selectable by said adjustment and locking thereof relative tothe'frame, said guide paths being of circular arc form.
5. Apparatus as claimed in claim 1, in which the driven second joint is guided along a guide path defined by said drive and the portion of said linkage coupling .said first and second joints.
6. Apparatus as claimed in claim 2, in which a tangent to said arcuate path of adjustment of the first joint is substantially perpendicularly intersected by a tangent to the direction of movement of the movable part of the air delivery apparatus.
7. Apparatus as claimed in claim 3, in which said guide path, along which the third joint is movable, has a tangent which extends substantially parallel to a tangent to the direction of movement of the movable part of the breathing air delivery apparatus.
8. Apparatus as.claimed in claim 1, in which the mounting of said first joint comprises a lever pivotable about an axis fixed with respect to the frame for adjustably moving the first joint, the first joint defining a pivot axis on the free end of said lever.
9. Apparatus as claimed in claim 8, including means for locking said lever at a desired position within its pivoting range.
10. Apparatus as claimed in claim 1, in which said guide mechanism comprises a lever pivotable about a pivot, the location of which pivot is adjustable and lockable relative to the frame, the third joint defining a pivot axis on the free end of said lever and thereby movable through an arc of radius centered on said pivot of said lever.
11. Apparatus as claimed in claim 10, in which said guide mechanism includes a further lever having a free end carrying said pivot, which further lever is pivotable about an axis fixed with respect to the frame, said further lever being lockable against pivoting about said fixed axis.
12. Apparatus as claimed in claim 10, in which said movable part of said apparatus is pivoted with respect to said frame and connected to said fourth joint, the fourth joint being movable in a circular arc of radius determined by the separation between the pivot axis of the movable part and the connection between the fourth joint and movable part.
13. Apparatus as claimed in claim 12, including a lever member fixed to said movable part and pivotally connected to the fourth joint.
I 14. Apparatus as claimed in claim 1, in which said drive includes a connecting element and a rotatably driven crank, wherein one end of the connecting element is pivotably connected to the second joint, its other end being connected to the free end of said rotating crank.
15. Apparatus as claimed in claim 1, in which said linkage includes first, second and third links respectively connecting said first, second, third and fourth joints in series for relative pivotal movement thereon, said apparatus including a first adjustable lever pivoted at one end of said frame and carrying said first joint on its free end, first adjustment and locking means connected to said first adjustable lever and actuable for alternatively pivotally relocating said first adjustable lever and first joint and locking same in fixed location with respect to said frame, whereby to adjust the breathing time ratio of the apparatus, said drive including a rotatable shaft, a crank arm fixed to the shaft, and a connecting link pivotally interconnecting the free end of said crank arm with said second joint, said guide mechanism including a second adjustable lever pivoted at one end on said frame, a guide lever pivotally interconnecting the free end of said second adjustable lever with said third joint, and further adjustment and locking means connected to said second adjustable lever and actuable for alternatively pivotally relocating same and locking same is fixed location with respect to said frame, whereby to adjust the amplitude of movement of said movable part independently of adjustment of said breathing time ratio.
16. Apparatus as claimed in claim 15, in which said links define adjacent oppositely opening angles, variable during operation. at said second and third joints, the path of said second joint lying adjacent said pivoted one end of said first adjustable lever, the path of said third joint lying adjacent said pivoted one end of said second adjustable lever.
17. In a respiration apparatus having a frame, a drive stationarily positioned with respect to said frame, an adjustable transmission incorporating a linkage, a bellows pump including a movable part driveable through said adjustable transmission, said linkage having an end member hinged to said movable member, wherein the pump lift of the pump is changeable by adjusting the linkage, the improvement comprising:
a first joint at the start of said linkage and means normally supporting same stationarily, but for alternative positional adjustment and securement, relative to said frame;
a second joint adjacent said first joint and a link member interconnecting said first and second joints, said second joint being coupled to said drive;
a third joint interposed in said linkage between the second joint and said end member;
guide means alternatively adjustable and securable with respect to said frame and a guide member carried by said guide means and guiding motion of said third joint, the distances between all adjacent joints being nonchangeable.