MULTISHOT SIDEARM INJECTION DEVICE
The present invention relates to a multishot sidearm injection device having a main body, and a needleless injector for introducing a medical solution into the main body, and a valve for controlling flow of the medical solution into the main body. When the device is actuated, pressure is applied to the valve body to force it open and to permit a medical solution to be introduced into the delivery tube of the main body. The loss of the pressure or removal of an injection syringe will permit the valve to close so that no air is introduced into the delivery tube. An important characteristic of the present invention is, thus, its ability to prevent embolisms caused by introduction of air into the delivery tube. Another very important characteristic of the present invention consists in that it also provides for drawing of a blood sample, if it is needed, from the patient without an extra needle insertion.
Figure 1 shows a conventional device in which a typical injection needle is connected to a dropper by a flexible rubber tube 10. A conventional Y-shaped injection element is illustrated in Figure 2. It includes a main tube 11 and a branch tube 12 disposed at an angle to - and in communication with - the main tube 11. The branch tube 12 is sealed by a rubber plug 13. The main tube 11 is coupled to a delivery tube at each end. When a patient receiving a dropping injection is to be supplied with another medical solution, the common way is to introduce the solution directly into the rubber tube 10 or
the branch tube 12 via the rubber cork 13. Thereby the necessity of subjecting the patient to another needle insertion is avoided. However, these prior art injection devices have the following disadvantages:
A nurse has to hold the injection syringe in one hand and force the pointed needle thereof into the rubber tube 10 or the plug 13 held in the other hand. This increases the possibility that the needle can accidently puncture the skin of the hand of the nurse, creating a serious danger of infection, especially when the stick is in contact with the blood of a patient who suffers from a contagious disease such as AIDS. Therefore, the prior art injection syringes are not safe enough, especially in a time when AIDS threatens innocent people because of an accidental puncture.
The repeated piercing of the pointed needle into the rubber tube 10 or the rubber plug 13 will produce tiny rubber debris which can enter the injection delivery tube, thereby constituting a danger to the patient.
There are miniature holes produced in the rubber tube 10 or the rubber plug 13 as a result of repeated piercings by the pointed needles, permitting air to enter the delivery tube, thus increasing the risk of embolisms. Further, there are situations when drawing of a blood sample from a patient is
needed. This would require an additional needle insertion into a blood vessel of the patient.
It is a primary object of the present invention to provide a safe multishot injection device using a needleless injector to introduce a medical solution into the delivery tube of a syringe device without risk of puncturing the skin of the device user.
Another object of the present invention is to provide a multishot injection device using a needleless injector which is able to introduce a medical solution into the delivery tube via a valve-controlled injection tube, so that no portion of the device is pierced, thus preventing the formation of embolisms which is caused by air which is introduced into the delivery tube through pierced holes when conventional devices are used. Yet, another object of the present invention is to enable drawing of a blood sample from a patient with the needleless injector, without an extra needle insertion to a patient. The present invention prevents additional painful needle sticks and provides for saving of needles.
A further object of the invention is to enable delivery to a patient a piggy-back (secondary) solution without constant participation of a nurse.
The present invention will now be described by way of example with reference to the accompanying drawings, wherein
Figure 1 is a schematic view of a prior art injection assembly for use with a dropper;
Figure 2 is a sectional view showing a prior art Y-shaped injection syringe element;
Figure 3 is an exploded view of a needleless injector according to the present invention;
Figure 4 is a perspective view of the needleless injector shown in Figure 3 in an assembled condition thereof;
Figure 5 is a sectional view of the needleless injector shown in Figure.4;
Figure 6 is a schematic view of the needleless injector device according to the present invention with a piggy-back for feeding a solution into the delivery tube and connected to a dropper system; and
Figure 7 is a sectional view similar to that of
Figure 5 showing the device according to the present invention connected to a needleless syringe.
Referring now to Figures 3, 4, and 5, the device of the present invention comprises a main body 21, an extension sidearm 22 and a valve body 23 having a slotted cap 224 formed integrally therewith on the end of the valve body 23. The device is preferably made of a transparent thermoplastic material of sufficient clarity and strength to permit visual observation of the internal fluid flow. The valve body 23 is preferably made of resilient silicone. The main body 21 has a tubular opening 211 extending therethrough, and a laterally extending through-hole 212, which is in communication with the opening 211 of the main body 21, and is formed for receiving the extension sidearm 22.
The extension sidearm 22 is tubular and has a tapered bore 221. The valve body 23 as well as the slotted cap 224 are cylindrical. The valve body 23 with the cap 224 has such a shape that when the valve body 23 is laterally displaced in the through-hole 22, a medical solution can pass from the bore 221 of the tubular sidearm 22 via the slot 232 of the cap 224 into the opening 211. The regular or primary solution flows in the opening 211 around the valve body 23.
Referring to Figures 4 and 5, to assemble the device, the extension sidearm 22 is inserted into the through-hole 212 of the main body 21 after the cylindrical valve body 23 having the slotted cap 224 is laterally positioned in the main body 21. The narrow tapered end of the sidearm 22 abuts the shoulder 225 of the cylindrical valve body 23, with the cap 224 extending into the bore 221 of the sidearm 22.
Due to resiliency of the valve body 23, the shoulder 225 firmly abuts the inner end surface of the sidearm 22 so that no air can flow into the main body.
As shown in Figure 6, the present invention is adapted to be connected to a dropper by a closure piercing device 30, so that the primary solution can flow into a chamber 31A, which is coupled to a volume control 32 with a delivery tube 33 extending therefrom. The bottom end of the delivery tube 33 is connected to the device 20 (where the needleless injector of the present invention is located) , and another delivery tube 33A is coupled to an injection needle at the end of the dropper system. A piggy-back solution may be delivered through the inventive injector. The piggy-back 3IB is coupled to another volume control 32A, with a delivery tube 33B extending therefrom to the inventive injector. The delivery tube 33B is provided at its
end remote from the volume control 32A with a connector, e.g., a Luer-lock connector, for the connection with the sidearm 22 of the inventive injector.
As shown in Figure 7, if another medical solution is to be added to the dropper system, a needleless syringe 40 (which has withdrawn the solution from a medical container) is used to introduce a solution into the dropper system. A protruding end 41 of the syringe 40 is inserted into the bore 221 of the sidearm 22 with the slotted cup 224 extending into the bore 221. Due to the tapered shape of the bore 221, the air in the bore 221 can be expelled therefrom, when the protruding end 41 of the syringe 40 is inserted into the bore 221, through a clearance between the wall of the bore 221 and the outer surface of the end 41. Thus, no air will be pumped into the delivery tube during the injection of the medical solution from the syringe 40, eliminating a cause of embolisms in the blood vessels of a patient. When a piggy-back is used, instead of the syringe 40, a connector having the same shape is used.
When the syringe 40 is used to deliver a medical solution into the main body, the protruding end 41, when the syringe 40 is connected with the sidearm 22 , will force the valve body 23 to open to permit the solution to flow into the delivery tube 33 from the bore 41A via the slot 232 of the slot
of the cap 224, as shown by an arrow in Fig. 7. When a piggy¬ back is used, the solution flows into the main body 21 under force of gravity. When the pressure is lost or the syringe is removed, the deformed valve body 23 will return to its original shape so that the shoulder 225 of the valve body 23 again abut the end surface of the sidearm 22, preventing air from entering into the delivery tube. Therefore, no matter how many times the device is used, no air can enter the dropper system. As shown in Figure 7, the syringe 40 or the piggy-back connector can be provided with a Luer lock 42 to firmly secure syringe 40 or the piggy-back solution connector to the lugs 222 of the extension sidearm 22.
It can be readily seen that the present invention has the following advantages:
The use of the inventive device with a needleless injector to introduce a medical solution into a patient can effectively protect the nursing personnel from being accidentally injured by needles, so that the nursing personnel is free from the risk of infection resulting from needle punctures of the skin.
The use of the needleless injection effectively avoids repeated piercing of the delivery tube thereby minimizing the
danger of embolisms resulting from the introduction of air into the dropper system.
No rubber debris is produced due to piercing of the dropper tube or the plug, which might have entered into the patient body with the solution.
The injection syringe can be firmly retained in place due to the additional threads on the protruding end of the syringe which is retained by the lugs on the extension sidearm.
Further, the syringe 40, after a solution is delivered to a patient, can be used for drawing a blood sample from the patient. Thus, the present invention permits to draw a blood sample from a patient without additional needle sticks.