Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-08-23
2001-07-31
Nguyen, Anhtuan T. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S195000, C604S128000
Reexamination Certificate
active
06267748
ABSTRACT:
The present invention relates to an automatic needle-retracting needle-holder and syringe.
After use, syringes can be dangerous for several reasons. There is a risk of getting hurt by the needle itself, and there is a risk of contagion of serious diseases as AIDS. For this reason the need of preventing re-use of syringes is widely recognized.
There are several types single-use syringes in the market nowadays. And there are numerous known implementations of such syringes.
U.S. Pat. No. 5,122,118 shows an automatic needle retracting syringe that includes a barrel having a needle end, a plunger end, a bore, and a plunger at the plunger end. A needle gasket is slidably mounted within the bore to define a near region and a far region. A hollow needle is mounted to the needle gasket. A path through the needle gasket connects the near region to the needle. A coil spring biases the needle gasket from an extended position to a retracted position, the needle fully housed within the barrel at the latter. The extended position is maintained by a retaining capsule wedged between a narrowed bore portion and the needle gasket. This retaining gasket is a gelatin that weakens upon contact with the liquid injectant so that after the liquid injectant contacts the retaining capsule for a period of time, the spring breaks the capsule causing the needle gasket to be moved back to the retracted position, thus retracting the needle back into the barrel.
This device implies use of a gelatin that will dissolve or lose strength upon contact with the injection. A relatively high amount of gelatin is needed to form a channel capsule for housing the needle, and this and the characteristics of the material make it difficult to guarantee that it will work. Use of gelatin makes production critical and difficult. The device has one lower part that has to be placed inside the barrel, this makes it impossible to use the device together with a standard syringe, where the barrel's cross section is reduced in the end facing the needle to permit fitting of a needle holder. The spring used to withdraw the needle has to be fairly strong and this raises the cost of the syringe. The device is complicated and has many different parts, this raises too the production costs. On the other side, once the needle is retracted in the syringe, it is retained in the barrel zone, and the plunger is thus at least in part pressed out of the barrel. This is not satisfactory because it is possible to reach inside the barrel and retrieve the needle. In this case, the aim of the device is not reached. Besides, it requires high precision under production, among others to secure that the space between the barrel and the plunger is sealed. This sealing will, on the other hand, lead to humidity problems when the water does not manage to get into the sealed side channels.
U.S. Pat. No. 5,049,133 shows a safety-syringe providing a needle with a hollow core having a spring coiled around the needle. The spring is capable of expanding to retract the needle into the body of the syringe. A pressure hinge is provided with a plurality of teeth-shaped triggers for retaining the needle in a position for use and for preventing the piston from moving after use.
This is again a device that cannot be used together with standard syringes available in the market. In this device one has to be sure that the teeth-shaped triggers do not move under pressure from the injection, high precision production is therefore required. The dimensions of the device make it possible to use force and to remove the piston from the plunger, thus making possible to retrieve and reuse the needle.
U.S. Pat. No. 5,188,614 shows a protective device for use with a hypodermic syringe. The protective device comprises a hollow cylindrical casino defining a forward end wall having an opening therein, a rearward open end and an angular gripping flange adjacent the rearward end. The casing is adapted to be disposed about the syringe such that the syringe is reciprocally translatable therein with the syringe needle projecting through the opening in the forward end wall of the casing and the angular gripping flange axially spaced from the syringe flange. A dual component foaming agent is disposed in the casing adjacent the forward end wall thereof which, when the components thereof are mixed together activate to form an expanding and hardening plastic foam. Upon pressing the syringe into the casing subsequent to the ejection of fluid from the syringe, the foaming agents are activated and the expanding foam forces the syringe and syringe needle rearwardly within the casing and passes about the needle and through the forward end of the casing and hardens, thereby encapsulating the used needle within the casing and foam.
The main disadvantage of this device is that it is possible to remove the casing rapidly before the foaming agent has acted and thus retrieve the needle. The device is complicated and has many details that lead to high production costs. The two component material has besides a limited storage time, this due to the limited dimensions of the device.
WO-A 9 205 813 describes a safety syringe with retractable needle. Biasing means is attached to the syringe's barrel for biasing the needle towards a hollow plunger, and means is provided for releasing the needle into the hollow plunger by applying additional forward pressure upon the plunger after the plunger is fully extended into the barrel. The plunger comprises a cutting tip generally configured as a cylindrical knife, that cuts through a retainer arid releases a spring that forces the needle into the hollow plunger.
This mechanism requires applying additional pressure upon the barrel after the injection fluid has been taken out. If a person wants to reuse the syringe, it is sufficient to refrain from pushing the plunger further, and the needle will not be released into the plunger. This known syringe does thus not assure automatic withdrawing of the needle.
The above mentioned devices are not satisfactory because they permit easy retrieval of the needle. Besides, some are not meant for use with standard syringes. This means that use of these known devices supposes replacement of all the standardized syringes in the market by new ones, leading to high marketing costs and, what is more important, difficulties and delays in making the product available for the public. A product that protects the population must be as easy available as possible. The known devices consist in general of several small parts that have to be produced and put together with high precision, this leads to high production costs and therefore high retailing prices.
It is an object of the present invention to provide a needle holder for use together with a standardized syringe and where the retraction mechanism is housed in the needle holder.
It is a further object of the present invention to provide a needle holder that accommodates a channel needle after retraction.
It is another object of the present invention to provide a syringe equipped with a needle holder and a retractable needle, where retraction of the needle happens automatically after injection of the contents.
This objects are achieved according to the invention by a needle holder and a syringe as described in the attached patent claims.
The needle holder according to the invention is provided with an expandable element and with retention means for the expandable element so that contact of the expandable element with an injection causes expansion of the expandable element and as a consequence retraction of the needle into the needle holder.
In one preferred embodiment of the invention the expandable element comprises a spring, and the retention means comprise a stopper firmly connected to the needle, releasable connected to the needle holder by means of a connecting element and whose function is to retain the spring in compression. Upon contact with the injection, the stopper will loosen from the needle holder, and the springs will expand retracting the needle inside the needle holder. I
Gulliksen Morten
Kristiansen Helge
Nguyen Anhtuan T.
Syringus AB
Thissell Jeremy
Young & Thompson
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