US 2351828 A
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Description (OCR text may contain errors)
June 2o, 1944. J; c. MARSH 2,351,828
SURGICAL PUMP Filed Jan. 8, 1942 P121. q V7.5
SM- @7m Patented June 20, 1944 f SURGICAL PUMP Jack C. Marsh, Pittsburgh, Pa., assignor to G. L. Meyers and G. H. Drumheller, Jr., both of Aspinwall, Pa.
Application January 8, 1942, Serial No. 425,999
' Claims. y (Cl. 103-148) This invention relates to continuous drip apparatus and it has particular relation to a surgical pump suitable for the gradual administration of liquid compositions in the treatment of ailments, such as peptic ulcer, or the removal of fluid from the tubular organs.
One of the objects of the invention isto provide a surgical pump in which the delivery rate of the liquid is positive and the rate accurately maintained.
Another object of the invention is to provide a surgical pump in which an automatically controlled unit regulates the ow of liquid to the patient. Other objects may be inferred from the nature of the invention.
I Heretofore the apparatus employed has depended on suction obtained by allowing water to flow from a bottle suspended above the patient through a tube to a bottle placed below the patient. When the rate of ow of water is 'changed the air pressure in the chamber also changes. As the air regulates the flow of liquid to the patient the rate of flow would necessarily fluctuate and which in an apparatus of this type cannot be adjusted accurately. Pumping apparatus have heretofore been employed to overcome the above objections but they have been unsatisfactory due either to lack of control of the suction formed in the operation of the apparatus or failure of accurately controlling the delivery rate of the pump, particularly in the smaller quantities, i. e. amounts of from ve to fteen drops a minute.
Inuthe use of a surgical pump constructed in accordance with my invention, the pump is positioned beside the patient. The pump is formed with a constant speed motor provided to drive a plurality of cam elements, which engage ngers adapted to contact a tube, the tube extending from a source of supply to a patient. A time control device connected to the motor through a microswitch is provided to regulate the action of the pump. The time control permits the pump to 'deliver a single stroke of the pump, five drops of fluid, after which the pump stops for a time. This stop or wait may be adjusted from less than a second to more than sixty seconds by means of a control knob operatively connected to the timer control. As soon as the pump has created a suction more than equal to a column of Water two feet six inches high, a vacuum control operatively connected to the tube shuts ofi the pump, while maintaining the vacuum. As soon as the vacuum is broken the pump is automatically turned on again and operates until such time as more than the designated acquired.
For a better understanding of the invention, referencemay now be had to the accompanying drawing forming a part of the specification in which:
Fig. l is a plan View of thel invention, with certain portions in section for the sake of clearness.
Fig. 2 is a diagrammatic view of an electrical circuit employed in the invention.
In practicing my invention, the fluid is placed in a container IIJ, at substantially the same level as the patient, with the tube I2, formed of rubber or other elastic material, extending from the container to the patient. A pumping apparatus I3, contained in a casing I4, having a bracket I5, formed with a member Il adapted to engage the tube I2, as indicated at I8, is provided to feed fluid to or from the patient as des-ired.
The pumping apparatus is provided with a plurality of cams 20, 2l, and 22 adapted to engage suction is lingers 23, 24, and respectively. Each of the fingers, formed with end members 2'I adapted to compress the tube I2, is provided with springs 28 positioned in openings 29 of a block 30. The
member 21 of the fingers 23 and 25 have edge portions which engage the tube I2. These fingers are provided to entrap thelud in the tube between the two points of engagement. The iinger 24 is provided to act as a piston, for forcing the liquid to the patient and is formed with the edge portion of the member 21 extending longitudinally of the tube I2. The springs maintain the fingers in contact with the cams. The cams are mounted on a shaft 32 supported in a housing 33, with the shaft being driven by a motor 34 through reduction gearing 35 integral with the motor.
A microswitch element 31 mounted on the housing 33 and actuated by the cam 2| is provided with a lead 39-connected to the motor 34 together with a lead 40 connected to a condenser 4I of a time control device 42. The time control 42 is also provided with a relay 43, having connected thereto a lead 44 extending to the motor and a vacuum or rectifier tube 43, having a lead 41 connected to one'side of the condenser 4I. Extending from the condenser to a time control dial 49 mounted on the casing I4 is a lead 59, operately connected to the condenser. Leads 5I and 52 extending from the control dial are connected to the relay 43 and to the vacuum tube'46 respectively. A toggle switch 54 mounted on the `casing I4 is provided with a lead 55, connected to connected to the vacuum or rectifier tube 46. A
resistance cord 59 is connected at one end to the lead 51 and at the other end to the relay 43. A switch B5, of a control device 56 is provided with a lead 61 connected to a vacuum or rectiiier tube 46, and alead 68 coimected to the relay 43. The switch 65 is provided with a contact element 15 normally held in engagement with bellows 1l, formed of rubber or other elastic material. Connected to the bellows on the side opposite the switch is a tube 13 connecting to the bellows and the tube l2, intermediate the lingers and the patient.
In operation, the cams 2U, 2l and 22 are driven by the motor 34, so that at least one finger is always compressing the tube l2; -for example, as shown in Fig. 1, with the finger closed against the tube. In starting the pump a suction is created by compressing and expanding the tube l2, for example when linger 214 compresses the tube. As the cams rotate, the finger V'24 moves back and finger 25 closes. When iinger 24 moves back, it releases the tube l2, which expands and fills from the supply container le. With finger 24 back and the outlet end closed by finger 25, the finger 23 moves forward closing the inlet end of the tube and remains in such position until linger 25 moves back from the tube, with finger 24 moving forward driving over the required amount of fluid. As one iinger is always closed, there is a closed system maintained at-all times. At the end of each stroke of the pump, the cam 2i actuates the switch 31 which stops the pump fer a time. This stop or wait can be adjusted from less than a second to'more than sixty seconds, depending on the dial setting 49, before making another stroke. The operation of the time control depends upon the principle that the time required to discharge an electrical condenser through a resistance depends upon the charging potential applied to the condenser. s
As soon as the pump has-created a suction more than equal to a column of water two feet six inches high, the vacuum control shuts ofi the motor. As shown in Fig. l, the Contact -element 13, of the switch 65, engages a side of the bellows 1l which normally maintain the switch in closed position. When more than the ldesired suction is exerted, the bellows contract, thus opening the switch and stopping motor, `while maintaining a vacuum. This is particularly important in the removal of fluidand gas Yfrom the duodenum. As soon as the vacuum is broken by the removal of the fluid and gas from the duodenum, the purnp is automatically started and operates until two feet six inches of negative pressure is again obtained.
From the foregoing description it is apparent that I have provided va surgical pump having electrically controlled means which .provides intermittent operation of the pump, together with a structure which permits wide variation .of the quantities of fluid delivered to or .removed from the patient. Moreover itis apparent thathave provided a structure that is simple in operation,
accurate in the function thereof and which, when once set, may be operated by a novice of the medical profession.
It is to be understood that the form of the invention herewith shown and described is merely illustrative of a preferred embodiment and that such changes as fall within the purview of one skilled in the art may be made without departing from the spirit of the invention and the scope of the appended claims.
l. A pumping apparatus for medical treatments lcomprising a constant speed motor, a plurality of cam elements operated by the motor, a plurality of nii-gers actuated by the cams, in a predetermined .sequence, an elastic tube adapted to be compressed by the fingers, an electrical time control for cont-rolling the action of the pump and means connected with the time control for regulating the delivery rate of the pump.
2. A pumping apparatus for medical treatments comprising a constant speed motor, a plurality of cam elements operated by the motor, a plurality of fingers actuated by the cams, in a predetermined sequence, an elastic tube adapted to be compressed by the ngers, an electricalvtime control for controlling the action of the pump, a switch element operatively connected with one of the cams, for actuating the time control and means connected to the time control for regulating said time'control.
3. A pumping apparatus for medical treatments comprising a constant speed motor, a plurality of cams operated by the motor, a plurality .of fingers actuated by the cams, in a predetermined sequence, an elastic tube adapted to be .compressed by the fingers, an electrical time control including a condenser for controlling the action of the pump, a switch element operatively `connected with one of the cams for actuating the time control and means connected with the .conf denser for regulating the time control.
4. A pumping apparatus for medical treatments comprising a constant speed motor, a plurality of cam elements operated by the motor, a plurality of lingers actuated by the cams, in apredetermined sequence, an elastic .tube .adapted ,to be compressed by the fingers, for creating ,a suction, means secured to the tube Yfor-stopping the pump upon creation -of a suction above a predetermined point, an electrical time control for controlling the intermittent operation of .the pump and means operatively connected `to the time control for regulating said time control.
5. A pumping apparatus 'for medical ,treatments comprising a constant .speed motor, a plurality of cam elements operated Vby the motor, a ,plurality of nngers actuated by the cams, in =a predetermined sequence, an elastic tube 4adapted to be compressed by the Vfingersfor creating ,a suction, a vacuum control element secured `to .the tube for stopping the pump .upon creation of .a suction above a predetermined point and v`electrical means for intermittently .operating `.the pump. f V