Surgery – Respiratory method or device – Means for supplying respiratory gas under positive pressure
Reexamination Certificate
1999-07-30
2001-09-04
Dawson, Glenn K. (Department: 3761)
Surgery
Respiratory method or device
Means for supplying respiratory gas under positive pressure
C128S205140, C128S205150, C128S205160, C128S205170, C128S204280, C128S203280
Reexamination Certificate
active
06283121
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved hand-operated or manual pump for fluid. This invention also relates to an improved Ambu bag which can be operated by a single person for a long time.
2. Prior Art
A popular conventional hand-operated pump comprises a cylindrical bellows body formed of a flexible plastic or rubber material, which may be made thick and resilient so as to assist to restore its expanded or original configuration after the bellows body is manually pressed from both sides with two hands and contracted along its axis to discharge fluid. When the resilience of the bellows body is insufficient, the manual pump requires considerable manual assistance to return to its expanded state to charge fluid. When the resilience of the bellows body is excessive, the manual pump requires its operator to exert considerable energy to contract the bellows body.
Another conventional manual pump utilizes repulsion means such as a coil spring installed within its cylindrical bellows body so that the coil spring may assist the bellows body to restore its expanded configuration after the bellows body is contracted. Such a spring-assisted manual pump is disclosed in Japanese Utility Model Application Laid-Open Publication No. 48-96503, which requires use of both hands of an operator.
Japanese Utility Model Application Laid-Open Publication No. 55-60481 discloses a vacuum packer including a spring-assisted manual pump comprising a curved base having air charge and discharge means and a plastic bellows pump cylinder body. This device also requires use of both hands.
All those manual pumps not only require use of both hands of an operator but also keep occupying both hands, preventing the operator from doing anything else while operating the manual pumps.
When such a pump mechanism is incorporated into an Ambu bag, properly holding a facemask of the Ambu bag on a patient while concurrently activating the Ambu bag is virtually impossible for a single operator since both hands of the operator are kept on the bag. Such an Ambu bag requires at least two persons for a practical medical operation.
Another conventional Ambu bag is shown in
FIG. 5
, indicated by “
70
”, comprising a rugby ball-like bag or chamber
80
and a facemask device
40
connected to the chamber
80
in fluid communication. The bag
70
is generally made of a “thick” and resilient rubber material to provide quick recovery of shape of the bag after its deformation with a hand or hands. Although it may be possible to activate the pump chamber
80
with a single hand, it is very energy consuming or fatiguing to keep activating or repeatedly squeeze such a thick bag for a long time with a single hand as will be readily understood by medical practitioners. The operator will frequently have to switch hands or use both hands, or another person must take over the operation. Thus, it usually requires at least two medical persons to apply an Ambu bag on a patent for a long time, one squeezing the bag and the other applying a facemask.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a manual pump which can be easily operated with a single hand with minimum energy.
It is another object of the present invention to provide an Ambu bag incorporation such a manual pump.
It is another object of the present invention to provide such a manual pump or Ambu bag which can be held contracted for compact storage and easy transportation.
Other objects of the present invention will become apparent to people skilled in the art from the descriptions hereunder.
A manual pump of the present invention comprises a pair of side plates arranged a distance apart, generally in parallel, a pump chamber provided between these side plates, an axial shaft provided through the pump chamber, a pair of handle bars arranged a distance apart, generally in parallel, and firmly secured to edge portions of the side plates respectively, and spring means generally provided in and through the pump chamber.
The pair of side plates are preferably circular disks made of a light material such as a rigid plastic or aluminum material. Other materials such as wood may be equally utilized. The diameter and thickness of the side plates can be appropriately selected so as to serve purposes of use. Each side plate may be provided with a center hole of an appropriate size to receive an end portion of the axial shaft airtight.
The pump chamber is a space provided between the side plates, which is enclosed with a flexible cylindrical wall of an appropriate thickness whose round edges are secured airtight to the circumferential edges of the side plates, respectively, with appropriate securing means. The material for the flexible cylindrical wall may be vinyl chloride, polyethylene, nylon, or synthetic or natural rubber. It is advantageous that the cylindrical wall possesses a degree of resilience to assist in restoration of shape. Other flexible materials may be utilized as well.
The axial shaft is generally a round rod. The axial shaft will retain the side plates always in alignment while the side plates relatively rotate about the axial shaft and the distance between the side plates changes. The end portions of the axial shaft may be respectively received in the center holes of the side plates slidably in all directions but held airtight with the center holes with seal means such as O-rings. Alternatively, one of those end portions may be firmly fixed in the corresponding center hole. Still alternatively, an end of the axial shaft may be firmly secured directly on a side plate (having no center hole). In both cases, only the other unfixed end portion of the axial shaft can slide freely relative to the corresponding center hole (while being held airtight). The axial shaft may be made of a rigid plastic material such as hard-type polyethylene, nylon, or polyacetal. Other appropriate rigid materials may be equally used.
The pair of handle bars are firmly secured respectively to edge portions of the side plates, keeping an appropriate distance apart, generally in parallel, such that the handle bars can be comfortably grabbed with a single hand and clutched towards each other. As the handle bars approach each other, the side plates are turned relative to each other about the axial shaft, twisting the flexible cylindrical wall to reduce the volume of the pump chamber, discharging air or liquid from the pump chamber. As the handle bars return to their normal position with assistance from spring means (to be further described later) and possibly from the resilience of the cylindrical wall, the pump chamber restores its normal shape, charging fluid into the pump chamber. Preferably, each handle bar may comprise a bar portion which extends at a right angle with its corresponding side plate towards the other, and in parallel with the cylindrical wall, both bar portions extending in opposite directions.
As described earlier, the spring means assists restoration of shape of the pump chamber. The spring means is preferably a coil spring provided through the pump chamber and around the axial shaft with both ends of the coil spring secured internally to the side plates, respectively. Alternatively, one or both of the ends of the coil spring or spring means may be unsecured.
To function as a pump, it is required to further provide suction or charge means and expelling or discharge means. The charge means and the discharge means are internally provided with one-way valve means. Advantageously, the manual pump of the present invention is provided with a plurality of the charge holes or pipes such that air or liquid may be sucked into the pump chamber efficiently, which assists to promote speed of shape restoration. Alternatively, a single sufficiently large-sized charge hole may suffice. Such charge holes or pipes may be provided on one of the side plates or on both side plates. The discharge means is generally a single hole or pipe provided on one of the side plates.
It is important to note that handle bar c
Dawson Glenn K.
Fukutomi Healthscience & Service Co.
Patel Mital
Wells, St. John, Roberts Gregory & Matkin P.S.
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