MULTIFUNCTIONAL RETRACTABLE NEEDLE TYPE GENERAL PURPOSE DISABLING SYRINGE HAVING ENHANCED SAFETY FEATURES AND
RELATED METHOD OF OPERATION 5
This invention relates generally to syringes for medical and general purpose usage and more particularly to such syringes having a retractable needle and other related and novel features. These features are directed to the safety to humans during syringe use and were heretofore unavailable in the art of medical instrumentation. These safety features have been conceived and developed to maximize the safety of the syringe user and those around him and to minimize all human exposure to the needle of the syringe when the syringe is in use. These features include the ability to completely disable the syringe after use and thereby totally prevent the possibility that the syringe be retrofitted.
As a result of recent increases in certain contagious diseases such as the Acquired Immune Deficiency Syn- 25 drome (AIDS), the number of cases reported where a human being has been inadvertently pricked with the needle of a syringe is growing at an alarming rate. With the current increase in these infectious diseases which may be transmitted by a contaminated syringe, this fact ^0 has caused a great concern in the medical community and other related professions not only for the health and welfare of nurses, physicians, and patients alike, but also a concern for the health and welfare of people within the illegal drug community. 35
Most standard types of syringes are designed so that the needle portion of the syringe is permanently in place in an extended position at the end of the syringe and there protected by a cap which is to be removed at the time the syringe is used either in the home or in hospital 40 applications. However, an obvious disadvantage with this type of syringe construction and design (which may indeed represent the lowest cost of syringe construction) is that during the syringe handling and use by the hospital personnel and patients alike there is a relatively 45 high degree of needle exposure to humans per unit of time that the syringe is in actual handling or use. In addition, these fixed-needle types of syringes have been known to cause needle puncture through a wall of a protective cap being replaced thereon and stick the 50 person handling the syringe.
To reduce this human exposure time to the exposed needle, certain types of retractable-needle type syringes have been developed wherein mechanisms are provided within the syringe for withdrawing the needle to a 55 protected and shielded position within the housing of the syringe after the syringe is actually used for giving an injection to a patient. Examples of such a retractableneedle type syringe are disclosed in U.S. Pat. No. 4,790,822 issued to Haining and in U.S. Pat. No. 60 4,838,869 issued to Allard, both incorporated herein by reference. However, these retractable-needle types of syringes have nevertheless failed to provide a minimum of human exposure to the needle of the syringe per unit of time when the syringe is in actual use. Furthermore, 65 these retractable-needle type syringes have not been designed such that the syringe is disabled after use. This of course leaves open the possibility that the syringe
may be retrofitted and subsequently used in such a manner to transmit an infectious disease.
Thus, these prior art devices do not minimize as completely as possible all kinds of accidental needle contacts by humans and the possible contamination of and disease contraction to a human who is inadvertently pricked by an exposed needle. With the current unfortunate increase of many contagious and infectious diseases, the desirability of reducing to an absolute minimum this quotient of human exposure-to-needle time per unit of time when a syringe is being handled and operated while simultaneously providing a totally disabling capability to the syringe is manifest.
DISCLOSURE OF INVENTION AND BRIEF DESCRIPTION THEREOF
The general purpose and principal object of the present invention is to provide a new and improved retractable-needle type of syringe whose needle exposure time per unit of time that the syringe is in actual use has been minimized with respect to any known retractable-needle type syringes of the prior art.
Another object of this invention is to provide a new and improved retractable-needle type syringe of the type described which may be rendered completely inoperative after a single injection, thereby completely eliminating the possibility of undesirable retrofitting and secondary use of the syringe for the injection of illegal drugs and the like.
Another object of this invention is to provide a new and improved retractable-needle type syringe of the type described which may be operated to provide the multiple functions of needle extension and retraction, syringe filling of fluid and ejection of fluid therefrom, and thereafter to totally disable the syringe and thus prevent the possibility of any secondary use.
Another object of this invention is to allow the syringe user to totally disable the syringe after use with a release-and-press motion of a user's thumb, thereby enabling the user's other hand to be totally removed from the syringe and "out of harm's way".
Another object of this invention is to provide a new and improved retractable-needle type syringe of the type described which is rigid and durable in construction and reliable in operation.
A novel feature of this invention is the provision of a syringe wherein the needle thereof is maintained in a retracted and totally shielded and protected position prior to the time the syringe is to be used.
Another feature of this invention is a provision of a new and improved syringe of the type described in which the above described multiple functions of needle manipulation and fluid control are performed using a novel mechanical system including certain individual parts which provide multiple functions during the five function operation of the syringe to be described in further detail below.
Another feature of this invention is the provision of a novel method of syringe operation which has now been made available in accordance with the teachings of the present invention, and by the use of a single hand of an operator to disable the syringe. This method of operation relies upon the novel co-action and cooperation of certain mechanical components which are mechanically coupled and linked within the syringe housing to thereby enable series of syringe operations to be carried out in a predetermined sequence. The syringe may then be disabled with a single release and press motion of a