JP2647132B2 - Cannula insertion device with safety retraction needle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to medical devices, and more particularly to an apparatus for inserting a cannula, such as a venous cannula, into a patient's body.

As is well known, intravenous and intraarterial vessels and other endogenous catheters have a myriad of vital medical uses. It is also known in the medical community that severe problems have evolved in connection with all such devices.

The problem arises from the ongoing presence of terrible and now incurable diseases such as acquired immunodeficiency syndrome ("AIDS") and hepatitis, transmitted by the exchange of bodily substances between people. It is. These conditions have led medical institutions to dedicate disposable needles for injection and catheter or cannulation.

However, a severe danger remains for the healthcare professional in carelessly touching the needle tip after withdrawal from an infected patient. Medical needles are specifically designed and manufactured to be extremely sharp and to pierce skin and flesh with only slight pressure.

As a result, what would otherwise be insignificant or abrasions and pricks can and do cause severe illness or even death for many medical professionals. Needless to say, healthcare professionals are well aware of this danger and take considerable precautions to avoid such careless stings. Thus, this danger has dropped to a very small value on a “probability” basis. Nevertheless, stabs are sometimes unavoidable because the risks at stake for doctors, nurses and technicians on the ground are so widespread. As a practical matter, it is virtually impossible for such individuals to reduce the incidence of accidental stings, for example, less than once a year, or perhaps once every few years.

Of course, not all such stings will result in needle contamination by patients with infectious and fatal diseases.
Nevertheless, there are enough medical personnel and enough patients to die of a significant number of medical personnel in these contingencies-and of course more people are seriously ill.

In discussing this problem, needles of the type used with syringes are usually prominent. Although the term "subcutaneous" has changed somewhat from its current use in the medical world, the present inventors refer to needles used with syringes to give injections for clarity and simplicity "subcutaneous needles". To Needle used to draw blood I will call it. By this terminology, we intend to clearly distinguish all such needles from cannulated, ie, needles used in the field of the present invention.

Subcutaneous and Are often discussed because they are used prominently and in large quantities. But interestingly, subcutaneous and The actual manual operation involved in using is relatively convenient to avoid stab accidents.

More specifically, after withdrawing the hypodermic needle from the patient,
Some people are using the needle (eg, intramuscular injection)
In, both hands can be used for proper processing of the needle. Under normal circumstances he or she can quickly wrap it up and discard it before paying attention to the patient.

In many other situations (eg, intravenous injection), a person using a hypodermic needle is almost always free with one hand to at least hold the needle until the needle can be properly covered. Also, in certain situations where more dexterity is needed (eg blood sampling) The person using the can usually find at least one second or so to temporarily place the needle out of the way until safe treatment has time.

(It will be understood that our discussion here is directed to the relatively low risk of injection or blood collection procedures when contrasted with the cannulation procedure. Once properly shielded, the hypodermic needle is not necessarily said to be safe, i.e., of course, there remains some possibility of inadvertent opening and many other types of accidents.) Injection and There is an exception to the above general claim that is less dangerous than the cannulation procedure. That is, there are learning situations, emergencies, and situations where normal operations are complicated by the patient's mental or physical state. But these are probably subcutaneous and Only between 10% and 20% of all use cases.

The procedure of inserting a vein or other cannula is not very convenient for avoiding accidental stings. For example, when a cannula is placed in a patient's blood vessel, the cannula potentially creates an open path for transporting the patient's blood out of the body.

Therefore, the patient's blood vessels must be tightly closed until and while this pathway is typically connected to a mating tube that is pressurized with the fluid to be injected into the patient's body. No. In practice, a physician, nurse or technician will usually occlude a blood vessel by manually pressing it outside the patient's body, just at the tip of the cannula.

This pressure is maintained continuously until the tube is attached to the cannula. As you can see from this,
Before the clinician's hands are free, there is an intermediate time during which the hands are not free.

In some cases, the needle used to mount the cannula is hollow and the tube may be temporarily connected to the back of the needle. However, this is in fact only a temporary relief, since eventually the tube has to be removed from the needle, the needle has to be removed from the patient and the tube has to be reconnected to the cannula.

Also, in some cases, the user of the needle can place a tray (tray) for temporarily placing the opened needle close to the patient's arm without moving it. However, this option is not always available,
In any case, the use of such a tray is a dangerous proposal in itself.

As a result, clinicians who frequently activate venous tubes and the like typically become skilled at obscuring the needle with one hand. Historically, this has been the least problematic solution to a continuing problem.

Nevertheless, it is a very poor solution. It is a type of measure that will fall, sooner or later, precisely, leading to accidental scratches and stabs, and thus statistically severe illness and death.

FIG. 16 shows a device that is generally representative of a modern, commercially available standard cannulation kit. A familiar term for such conventional devices in the healthcare industry is "IV insertion set"-the initial of the word "intravenous".

The needle is stainless steel and is sharp and sharp at its front end, which is the left end in FIG. The needle shank is permanently secured within the front end of the molded plastic cylinder, with the sharp end of the needle projecting forward from the cylinder as shown. The cylinder may typically be made of polycarbonate.

It is preferred, but not necessary, that the needle be hollow for reasons that will become apparent hereinafter. The inventor is not familiar with the manufacturing details of these articles, but believes that the needle may be secured to the cylinder by a press or shrink fit or by molding a plastic cylinder into place on the needle. It is.

A separate catheter assembly or "cannula" fits very tightly, but removably, on the forward projection of the needle. The tapered front of the cannula slides with the needle through the patient's skin and flesh.

The posterior or hub of the cannula is radially enlarged to define a very slightly tapered posterior container for a standard diameter tube such as an intravenous supply tube. The cannula, or at least the portion of the needle that fits snugly over the shank, is made of a biologically inert but extremely slippery material such as that sold under the well-known trade name "Teflon". The hub is typically made of high molecular weight polypropylene or the like.

In use, the needle and cannula are both inserted into the patient's blood vessels-or possibly into a body cavity or abscess, or wherever fluid communication is to be established. As mentioned above, the clinician who subsequently uses the device applies pressure to the exterior of the patient's body, usually just in front of the needle tip to prevent blood bleeding.

The clinician then withdraws the needle and leaves the cannula in place in the body. Finally, fluid communication is completed by inserting a standard diameter tube into the container at the rear end of the cannula.

In a typical cannulated set, the back of the cylinder is formed very much like the back end of the cannula, taking into account differences in the material properties of the cylinder and the cannula. This molding allows the attachment of the standard tubing to a cylinder rather than a cannula.

In use, if it is not necessary or desirable to leave only the cannula in the patient's body with the tubular portion attached-or if it is not desirable to do so immediately, intravenously via a steel needle And so on. This is why the needle is advantageously hollow.

A separate safety cover (not shown) is typically provided in place on each insert set. This separate safety cover securely grips the cylinder and completely covers the needle, prevents accidental sticks and prevents accidental contamination of the needle with materials in the environment prior to use.

In order to use the insert set, this safety cover must be completely removed and set aside.

As already outlined, our focus is now on the possibility that the needle, when used, can be contaminated by substances in the patient. Thus, the safety cover should be re-covered over the sharp end of the needle to prevent accidental stabs and, in particular, to prevent contact of non-patients with possible contaminants on the needle.

This is where the prior art cannot be effective. This is because the process of reapplying the safety cover is susceptible to the dangers described above. To the inventor's knowledge, the medical product market lacks instruments or devices aimed at solving this problem.

The closest safety devices that may also be suitable for weighing are actually in a different field, namely the field of hypodermic needles. The device is an IC
From U Medical Co., Ltd. “ICU High Risk Nee
A special form of hypodermic needle marketed under the trade name "dle".

This ICU device has a sliding jacket carried on the shaft of the hypodermic needle itself. After use, the jacket is advanced over the needle tip.

This device undoubtedly serves a useful purpose, and of course we criticize what is clearly the only commercial endeavor directed to a problem slightly similar to the problem of interest. Is not what you want. On the other hand, the device has limitations that must be explicitly mentioned.

First, the ICU High Risk Needle is offered as a special item at a special price for use only with patients known to be "high risk" patients . Not all patients with transmissible fatal diseases are known to be at high risk.

Secondly, it is believed that the jacket may inadvertently apply lateral forces with the leverage sufficient to pop the needle. Attached in the middle of the needle. If that happens before the mantle is fully advanced, the chance of accidental stabbing can be substantial.

Third, having the jacket lock in place when advancing-or, if at all, locking it tight enough to withstand normal vibrations in the workplace is an issue with this product. It is not clear from the instructions for use. Without such features, the device would only seem to provide very limited protection.

Finally, as already suggested, this ICU product is neither designed nor provided for cannula insertion. It would require considerable modification for such use.

Numerous patents have been issued for devices that shield medical needles, but they are virtually all subcutaneous or belongs to. Only one of these patents mentions a needle used in installing an intravenous cannula. It was Janin on June 3, 1986.
U.S. Pat. No. 4,592,744 to Sea Jaguar et al. The introductory part of the Jaguar patent mentions for example:

"Needle retraction means, particularly a safety venipuncture device having a hypodermic needle having a retractable needle, having a retractable needle And an intravenous injection device having a retractable needle. However, once past the introductory part of the patent, Jaguar et al. Is squeezed. They have never mentioned the possibility of applying the invention to an intravenous device.

In other words, the Jaguar patent indicates that it encompasses disclosure within the field of the present invention, but that does not appear to be the case. The Jaguar disclosure does not include any specific disclosure directed to safely inserting a cannula into a patient.

Jaguar et al. Illustrate and illustrate a device that facilitates retraction of a hypodermic needle into a physician-protected enclosure. They also Other devices are also shown and described which facilitate retraction of the same into a similar enclosure. With any of these devices, the retraction procedure is relatively cumbersome.

In a subcutaneous device, the needle is mounted by a relatively tight press fit on the front end of a syringe that fits within the handle. The needle also extends through a hole in the front of the handle in a relatively loose press fit.

After use, the syringe must be withdrawn completely from the rear end of the handle, and the needle must be moved backward from the front end press fit with the handle into the cavity in the handle. The needle is then carried in a flange that is too wide to escape from the rear end of the handle, thus withdrawing from a tight fit with the front end of the syringe. The needle is thus captured in the handle.

In, the blood collection container is initially enclosed in an outer housing and / or handle during use. The rear end of the needle penetrates the elastic stopper on the container in a tight friction fit.

Thereafter, the needle is removed from the front end of the handle using the container as a tool. The container stopper is then withdrawn from the back end of the needle, which allows the container containing the blood sample to be removed from the handle. As the container is withdrawn, the needle is captured in the handle by its flange.

Thus, the two forms of the Jaguar invention described above require the user to actually pull the needle back all the way through the hole in the handle. This movement must then be continued until the needle is completely within the handle cavity.

About 1 inch long (2.54 cm), as you will soon see
It is difficult to perform this operation using only one hand in the case of a needle exceeding. This difficulty is compounded if the operation is performed with only a part of the user's attention, as is common.

In most cases, the necessary manual operations must involve several movements one after the other. What is required is a complex movement, each step of which is typically of relatively large amplitude in comparison to the length of the needle and the size of the user's hand.

As a matter of biochemistry, the need for such large-amplitude and complex movements is inherently disadvantageous for a clear, secure and therefore safe retreat. This is especially true for medical personnel under complex circumstances.

Jaguar invention subcutaneous and Other factors specific to the procedure make the procedure more cumbersome and difficult. First, for the Jaguar hypodermic needle, proper retraction depends on maintaining a design relationship between the two friction levels. These relationships are too easily subverted.

For example, they go beyond the knowledge of the person using the device,
May be disturbed by temperature changes during storage. They can also be disturbed by the leakage of coagulable or sticky substances, such as blood and sancalose solutions, into the exposed seam between the handle and the needle flange through the large opening in the back of the handle.

And the necessary frictional relationship can also be disturbed by the imperfect insertion of the syringe tip into its mating receptacle at the rear of the needle flange. The procedure is often performed by the on-site medical technician, rather than by the manufacturer, and may at least in principle damage any of the friction fit surfaces.

In such a situation, the syringe can be withdrawn from the needle flange before retracting the needle-without leaving the proper means for retraction.

Jaguar's For, the arrangement for retraction is even more disadvantageous for reliable operation.

The flange must actually be removed before pulling it back into the handle.

In any case, it is not suggested how the Jaguar invention would be configured or function for use in a cannula insertion device. As mentioned above, it is a field of the present invention.

Some other prior art describes devices for automatic or semi-automatic re-sheathing of hypodermic syringes. However, they do not even mention the possibility of using an intravenous cannula.

Haller, U.S. Pat. No. 4,026,287, is one of these relatively superior. Since it at least specifies that the used needle be retracted integrally into the cavity of the sturdy structure. However, Haller's device requires that the syringe plunger be threaded into the back of the needle flange after use, breaking the fragile seal around the flange and then retracting the needle.

The Haller patent also does not protect against inadvertent insertion of a fingertip into a syringe barrel. It is no easy matter that Haller's syringe plunger can only be held in place by a detent at the rear of the barrel.

Thus, the Harrah patent plunger is prone to dangerous re-advancing of the needle if the syringe accidentally shakes past the detent. In addition, most of the devices of the Haller patent and other devices discussed below, in that the jacket configuration after use is at least as long-or even longer-as the initial or pre-use configuration. Disadvantageous.

Devices to be discarded, especially those that are dangerous to pry open, should not protrude too much and should not have a multi-stage structure. Such a configuration can lead to breakage and potentially serious accidents.

(Additionally, in this context, the name of the Harrah patent invention is somewhat misleading; its name is "Syringe with retractable cannula"-but her term "cannula" is intrinsic. Mitchell's U.S. Pat. No. 4,631,057 also provides access to the fingertip through the unsealed front end of the jacket, rather than pointing to the catheter cannula but to the front of the syringe body.) It is something to leave. Mitchell's device, together with Haller's device, shares the undesired sensitivity to shaking the device out of its safe detent and, in addition, a similar undesirable overhang after use.

Other patented devices with similar weaknesses to shaking out of detent and similar protruding configuration after action, but with at least better front shielding against fingertip insertion U.S. Pat. Nos. 4,573,976 (Sampson), 4,643,199 (Jennings, Jr., etc.) and 4,643,200 (Jennings, Jr.).

It is US Pat. No. 4,425,120 to Sampson et al. Which is worth mentioning by providing more aggressive resistance to vibration expulsion from the needle retracted position. The device suffers from its better safety lock at the complexity required to be manually operated in use.

Similar observations apply to Leeson's U.S. Pat.No. 3,890,971, which has a relatively compact and stable configuration after use, but relatively complex mechanisms and large amplitude motion to perform re-shedding. It is provided at a price.

Numerous devices have also been patented for simply providing a visual shield or occlusion of a hypodermic syringe. Among these are U.S. Pat. Nos. 2,876,770 (white), 2,674,246 (via) and 3,134,380 (armao). Such a device is actually counterproductive for the purposes here, since it effectively masks the presence of needles that are dangerously sharp and may become contaminated.

The prior art has therefore failed to provide a safety device suitable for use under modern conditions in the field of the present invention-intrinsic medical cannulation. No conventional device adequately protects people from contact with device parts that were inside the patient. In particular, no conventional device provides the necessary secure and easy operation essential to the effectiveness of such protection.

The present invention is a safety device used in inserting a cannula into a patient. It also subsequently helps to protect medical personnel, waste handlers and other people who may have accidental contact with the used equipment. This device protects all such individuals from contact with parts of the device that were in the patient.

The device of the present invention includes a needle for piercing the patient and for guiding and carrying the cannula into place within the patient. The needle has a shaft with at least one sharp end.

The present invention also has a hollow handle adapted to encapsulate at least the sharp end of the needle. The handle is particularly adapted to enclose sharp edges so that it cannot be reached by the fingers of people.

In addition, the invention includes some means for securing the needle shaft to the handle with the sharp end protruding from the handle. For the generality of the description, we will refer to these means as "sticking means".

The present invention further includes some means for releasing the anchoring means and retracting the sharp end of the needle into the handle. For generality, we will call these means "release and retraction means". Retraction of the needle by these means is substantially permanent.

The release and retraction means of the present invention can be manually actuated by a simple integral movement. By "simple integral" movement, we mean a non-complex movement, i.e., one that involves a single step of travel or movement in only one direction.

The amplitude of this movement is substantially shorter than the length of the needle. Alternatively, it may be said to be generally small compared to the size of the user's finger or hand.

The above is a description of the present invention in its most general form. However, as will be appreciated, there are additional features that the inventor wishes to incorporate into the present invention to specifically optimize the efficacy of the present invention.

Such desirable and preferred features include a hole defined in the handle that is small compared to the fingers of the people to be protected, but large enough to pass the needle. Another preferred feature is a trigger mechanism operable from outside the handle and forming part of the release and retraction means.

The release and retraction means also preferably include some means for positively biasing the sharp end of the needle into the handle, such as a coil spring, for example, after actual retraction occurs, These biasing means preferably continue to operate to keep the sharp end of the needle retracted within the handle.

The present invention preferably includes a block extending from the needle and secured to the needle and forming part of the securing means. The block is adapted to be locked in the handle with the sharp end of the needle protruding from the handle.

This block retracts the needle into the handle when present and in response to release and retraction means. The release and retraction means are preferably operable by one hand of the user of the device. It is also particularly preferred that these means can be activated without the user having to look at the device when activated.

More specifically, it is preferred to provide a stopper element defined in the handle and on the block, respectively.
These elements engage each other to stop the block from retracting the needle.

Preferably, a trigger mechanism including a manually operable release member is provided. The trigger mechanism disengages the stop elements from each other to release the block and thereby retract the needle.

As mentioned above, the device of the present invention is for use with a cannula. The cannula fits over the needle and is thereby guided into the patient's body.

Thus, the cannula may be considered as part of the environment of the present invention. However, for some purposes, to the extent indicated in the claims, it is appropriate to consider the cannula as part of the present invention itself.

All of the above operating principles and advantages of the present invention will be more fully understood from the following detailed description considered with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, one preferred embodiment of the present invention includes a molded hollow handle 10. This embodiment also includes a nose piece firmly secured to the front end of the handle 10.
20 and a carrier block 30 slidably disposed in the handle 10.

The embodiment of FIGS. 1 and 2 also includes a latch 40 which secures the carrier block 30 near the front end of the handle proximate to the nose piece 20, and which is carried by the block 30 and extends through the nose piece 20 from the handle 10. And a needle 50 that extends.

The parts of this embodiment of the invention are specifically designed for ease of manufacture and economy. Accordingly, many details of the configuration are given in the description of this embodiment. In other words, all such details are to be included in such a manner that those skilled in the art can, at the present time, carry out the invention in the best possible manner, in particular in a very cost effective manner.

The handle 10 is preferably injection molded from a plastic such as polycarbonate, but need not be. It includes an elongated, generally cylindrical outer gripping surface 11 that is radially enlarged near the front end to form a tab stop 15.

The knob stop is at the rear of the latch housing sections 15-19 as can be better seen in FIG. The knob stopper 15 is much shorter than the outer grip surface 11 but is a true cylinder coaxial with it.

The remainder of the latch housing portions 15-19 are also circularly symmetric, except that they are bisected at their forward ends by wide transverse latch guide slots 16,18.
The transverse latch guide slots 16, 18 have a bottom surface 18 and two opposing side walls 16.

As viewed from the end of the device, each side wall 16 of the latch guide slot 16, 18 is formed along the circular chord of the knob stop 15. Thus, in effect, the latch guide slots 16, 18 divide the front of the latch housings 15-19 into two identical upright columns, as can be clearly seen in FIG. Each column is formed as a line segment on the chord.

2, a circumferential groove 19 is formed near the front ends of the latch housings 15-19. This groove 19 is spaced from the bottom surface of the latch guide slots 16,18. At the end of the rich housing there is a flange 17 with a smaller diameter than the knob stopper 15.

It is not preferable that both the groove 19 and the flange 17 have a rectangular vertical section. Rather, the grooves 19 and flanges 17 are preferably formed as arcs in longitudinal section to facilitate removal from the injection mold and to facilitate snap assembly with the nose piece 20.

A vertical center hole 12 is formed in the handle 10 so as to be exposed at the bottom surfaces of the latch guide slots 16 and 18. The hole is very generally cylindrical, but preferably has a slight taper or draft that extends toward the rear end of the handle to facilitate removal of the handle from the mold.

However, near the rear end of the hole 12, a frustoconical stopper surface 14 is formed inward to slightly sandwich the hole 12. Hole
12 extremes, short end opening at the rear end of handle 10
There are thirteen.

The end 13 of the bore is preferably slightly tapered outwardly rearward and (as shown in the drawing) is of the same length and taper as the needle guide 22. The frusto-conical stopper surface 14 has a slight taper, and the overall diametral insertion from the long part 12 of the hole to the end 13 of the hole is negligible.

Thanks to these construction details, the handle can be snapped out of an injection or other mold by a slight deformation (expansion) of the rear end. That is, no separate core pieces in the mold are required.

The nose piece 20 is a circularly symmetrical article with two main parts, a relatively elongated forward guide 22 and a radially enlarged rear canopy 21. Needle guide 22 has a central hole slightly larger than the diameter of needle 50.

At the tip of the needle guide 22, this center hole is sandwiched between thin holes 23. The diameter of this end hole 23 is chosen as a trade-off between (1) complete stabilization of the needle and (2) minimum friction in the sliding gap between the guide 22 and the needle.

The canopy 21 preferably has a true cylindrical outer surface that matches the outer surface of the knob stop 15. At the rear end of the canopy, a cavity having an internal shape is formed so as to fit tightly with the contours of the latch housings 15-19.

More specifically, the end of this cavity has a latch housing 15
There is an inward flange or lip 24 (FIG. 1) that fits and engages precisely in groove 19 of. Due to the aforementioned spacing of the groove 19 from the bottom surface 18 of the latch guide slot 16, the inward lip 24 of the nose piece 20 is similarly spaced from the bottom surface 18. The resulting gap defines a trajectory for actuation of the latch 40.

The nose piece can be made of a plastic marketed under the trade name "Delrin". The material is selected primarily because it is easy to form.

The carrier block 30 has a very narrow central hole in which the needle 50 is firmly gripped. A block 30, also made of Delrin, may be press fit, crimped and / or bonded onto the needle, or molded in place.

The outside of the carrier block 30 is circularly symmetric. It has a projecting barrel 31 which may be true cylindrical. At the rear end of the tube 31, there is a frustoconical stopper portion 32 whose front end is enlarged in the radial direction with respect to the tube 31. This stopper portion is tapered inward toward the rear end of the block 30.

The frustoconical rear surface of the stopper portion is the aforementioned inner frustoconical stopper portion of the handle 10 when the needle is completely retracted.
It is designed to sit against 13. Stopper part
At the front end of the pipe 32, an annular flat step is formed from the cylinder 31 to the outside in the radial direction for the purpose to be described later.

The front end portion 33 of the block 30 has the same diameter as the tubular portion 31. However, a circumferential latch groove is formed between the front end portion 33 and the cylinder 31. Thus, the front end portion 33 forms a flange adjacent to and immediately forward of the latch groove.

The latch 40 has a flat slide portion 41 and one end of the slide has a short push button portion 42 bent or formed at right angles to the slide 41. Keyhole-shaped cutouts 43 and 44 are defined in the slide.

The enlarged portion 43 of this cutout is closer to the push button 42. Cut out end 45 of slide 41 opposite push button 42
It is located just past the sandwiched portion 44 of 43,44. The latches can be made of suitably selected 300 series stainless steel.

Needle 50 with shaft 51, sharp tip 52 and trailing end 53 is generally known and is also made of stainless steel. It is longer than usual to allow for the extra length required to enter and penetrate the carrier block 30. The block 30 is fixed on the needle shaft 51 very near the rear end 53 of the needle.

Finally, the preferred embodiment of FIGS. 1 and 2 includes a coil spring 61 sized to surround the outer diameter of the carrier block barrel 31. This spring should be long enough to hold the mechanism fully retracted. The minimum diameter of the handle bore 12 is selected to just surround the spring 61 without significantly limiting the free expansion of the spring.

To assemble the device, the carrier block 30 is first secured to the needle 50 as described above. Next, the carrier block
Insert needle 50 through spring 61 until 30 reaches the spring.
Then, the same overall movement is continued, and the flange 33 and the cylinder 31 of the carrier block are inserted through the spring 61.

As a result of this procedure, one end of the spring is
To the step at the rear end.

Next, the needle is inserted into the keyhole-shaped cutouts 43, 44 in the slide 41 until the carrier block 30 reaches the slide 41.
This same overall movement is then continued, with the flange 33 passing through the enlarged portion 43 of the keyhole cutouts 43, 44 in the slide 41 at the front end of the carrier block.

As a result of this procedure, the slide 41 is vertically aligned with the circumferential groove (between the cylinder 31 and the flange 33) in the carrier block 30. Next, the slide 41 is moved laterally toward the push button 42 so that the narrow portion 44 of the keyhole-shaped cutouts 43, 44 is captured in the circumferential groove of the block 30.

The carrier block 30 is then inserted into the front end of the bore 12 of the handle 10 from the rear end, with the needle 50, spring 60 and latch 40 substantially threaded onto the carrier block 30 as described above.

Thus, the slide 41 is located at the latch guide slot 16, 18-2.
Mating between the two side walls 16 and abuts against the bottom surface 18 of the slot. The needle is then inserted through the hole 29 and the gap hole 23 of the nose piece 20, and the latch guide shaped front ends 16, 17, 19 are then snapped into place in the canopy 21 of the nose piece 29.

Here the handle 10 depends on the added length of the nose piece 20
Is virtually longer. When assembled in this manner, the sliding portion 41 of the latch 40 is
6, 18 located in the "track" defined between the bottom lip 19 (FIG. 1) of the nose piece 22 (FIG. 2).

Push button 42 is pulled sufficiently radially outward from latch guide housings 15-19 (or more fully, 15-21). The needle 50 is now securely anchored in place and extends forward from the effectively elongated handle.

Once the nose piece 20 is in place over the end of the handle 10, the two parts are secured together, preferably by sonic welding or the like (preferably with cement applied naturally prior to assembly, or These may be held together by a through pin or the like). This procedure is desirable to ensure the permanence of the installation-and thus the needle capture after retraction.

The present invention employs a cannula generally similar to the conventional one shown in FIG. As can be seen, it is preferred that the cannula hub be slightly shorter to minimize the overall length of the present invention, as the safety insert set of the present invention is slightly longer than some conventional insert sets.

Depending on the precise shaping of the front part of the invention, the cannula used in conjunction with the invention may thus be entirely known, or may advantageously be adapted to a shorter hub.

The cannula has been omitted from the drawings for simplicity and clarity of the drawings of the present invention. However, all of FIGS. 1 through 15 should be received by reference to FIG. 16 as incorporating a cannula located on the needle shank.

The rearmost hole 13 of the handle 10 should preferably be given the same diameter as the inside diameter of the cannula hub. And the first
Although not shown as such in the figures, it should also be given the same overall length. Thus, the conventional feature of temporary fluid connectivity via the hollow needle 50 can be maintained in the present device.

In addition, very generally known safeguards for the needles of the invention should be provided to protect against accidental destruction and contamination of the needle before use. This cover is a push button
Should be made to fit over the push button without triggering 42 and preferably between push button 42 and canopy 21 to prevent movement of slide 41 due to vibration during shipping or other handling. Must also be fitted.

However, the user may discard this safety cover. In particular, the needle is automatically wrapped without its cover,
The cover may be discarded with the present invention or separately.

The nose needle guide 22 and the back hole 13 of this preferred embodiment
Should be the same as the dimensions of the standard cannula to mate with the standard tubing. Both are about 0.6985cm in length
It should taper from 0.381 cm at the front to 0.508 cm at the rear.

Other dimensions of the preferred embodiment of FIG. 1 are generally as follows (cm).

Length from the rear end of the handle to the front of the canopy 8.89 Length from the front of the canopy to the tip of the needle 5.842 Outside diameter of the nose canopy 1.27 Outside diameter of the handle grip surface 0.889 Inside diameter of the handle hole near the trigger after 0.4201 Inner diameter of handle hole near the end 0.4318 Length of carrier block 1.5875 Outer diameter of carrier block stopper 0.4191 Outer diameter of carrier block cylinder 0.3048 Although the above embodiment is considered to be highly desirable, in principle various features Can still be omitted and the device still corresponds to the invention as broadly as possible. For example, a tension spring (rather than a compression spring as shown) may be secured to an eyelet or hook near the rear end of the needle to draw the needle into the closed handle without going through a carrier block.

Alternatively, the spring may be omitted and the needle may fall into the handle under the influence of gravity when the latch is released. Furthermore, hollowing out the needle is not strictly necessary, which is only important if one wishes to maintain the user's choice to make a temporary fluid connection through the needle.

Moreover, it is not necessary that the rear end of the needle be initially in the handle. Instead, some other element of the device may pull the rear end of the needle into the handle when unlatched.

On the other hand, it is not necessary for the rear end of the needle to come into the handle after the activation of the latch, and in principle, the "back" of the needle may protrude from the rear end of the handle. But,
In this case, appropriate measures must be taken to prevent the needle from accidentally re-projecting forward through the nose piece.

Most or all of these variations, as will be seen, are applicable to other embodiments of the invention shown in FIGS. 3 through 15 and described below. For reliable and maximally safe operation, it is preferred not to employ any of the variants mentioned in the preceding four paragraphs. Nevertheless, some or all of them can possibly be made safe and convenient by careful design, and they are therefore within the scope of some of the claims of the present invention. .

The present inventor made the actual model of the embodiment of FIGS. 1 and 2 and found that the operation was excellent. However, that embodiment may require improvement.

For example, while we believe that the variations illustrated in FIGS. 3 and 3a are preferred, the inventor has not constructed a physical model for direct comparison. In FIGS. 3 and 3a,
The push button is an annular segment plastic piece 142 formed with a non-slip peripheral surface 146, and the nose piece has cut-out portions 126, 127 to accommodate the push button 146.

This arrangement may be preferable for ease of operation. The finger of the person using the device is always a knob stopper 15
(FIGS. 1 and 2), it is unlikely that the button 146 will be actuated accidentally.

Such contingencies do not harm the patient or health care professional. The main adverse consequence is economic. That is, another insert set must be obtained. Regular users of the device will quickly know to avoid inadvertent triggering of the latch.

Another feature shown in FIG. 3 is to provide a ratchet-shaped detent 147 on the edge of the slide to interact with corresponding features (not shown) formed on the side walls 16 of the guide slots 16,18. That is. These detents 147 prevent the trigger from resetting, thereby discouraging attempts to reuse the needle.

Another desirable feature of this preferred embodiment, perhaps not explicitly shown, is as follows. Preferably, the diameter of the large end of the frustoconical stop portion 32 of the carrier block is slightly increased to provide a fluid tight seal to the inner bore 12 of the handle 10 when the trigger is not activated.

This arrangement facilitates effective fluid communication through the hollow needle by minimizing confidence in maintaining hygiene on many complex surfaces such as springs, internal cavities, etc. in front of the stopper portion 32. I do.

Various features or elements not specifically shown below appear in FIGS. 3 and 3a. Those features or elements are substantially the same as the items having the corresponding reference numbers in FIGS. 1 and 2-ie, the numbers which differ only by adding the prefix "1" in FIGS. 3 and 3a. Are identical.

FIG. 4 shows another embodiment of the present invention. The corresponding parts here have reference numbers that change with the addition of the prefix “2”.

In the embodiment of FIGS. 4-6, the latch is triggered by pressing the rear end of the handle against any surface, i.e., the table top, the user's arm, or a portion of the patient's arm. This form of the invention may be preferred in environments where a table top or other suitable positively active surface may be utilized.

However, if only softer surfaces, such as bedding or the patient's body, can be used, it may prove unsatisfactory. Another surface that may prove undesirable in this embodiment is that the outer diameter of the grip surface 211 is slightly larger.

The carrier blocks 231 to 232 in FIGS. 4 to 6 are generally the same as those in FIG. But here,
Spring 261 sits directly against the inside surface of nose piece 222.

Latch cylinder into hole 212 through the back of handle 210
Insert 241. Roughly one third or half of the latch cylinder 241 has two (or more) flexible fingers 24.
5, which terminate at their forward ends as lips or flanges 246 pointing radially outward.

The hole 212 inside the handle 210 is enlarged to make two distinct steps towards the front of the device. The first step outwardly of hole 212c (FIGS. 5 and 6) provides a shelf for catching lip or flange 246 to prevent latch cylinder 241 from dropping rearward from handle 211. .

When the finger is in place with respect to hole 212c,
The frustoconical stop portion 232 of the carrier block is pressed by a spring 261 against a pre-trigger-stop surface formed by the inside of the end of the finger 235. This is the pre-trigger state shown in FIG.

A second step outwardly of the bore 212a provides a radial relief for expansion of the fingers from the carrier block slopper section 232. Thus, when the rear end of the latch cylinder 241 is pushed forward from its FIG. 4 position, it first drives the carrier block and needle very slightly forward until the lip 246 reaches the second step. The lip 246 then springs outward relative to the hole 212a to the position shown in FIG.

The carrier block stopper portion 232 is no longer obstructed by the pre-trigger stopper surface formed by the end of the finger 245. Therefore block 23
1,232 are propelled backward by the coil spring 261 together with the needle 250.

FIG. 5 shows blocks 231 and 23 immediately after the start of this exercise.
2 and needle 250 are shown. As shown, they have just been fired rearward into the bore 232 of the latch cylinder 241.

As a result, as shown in FIG.
Stop portion 232 engages an inner stop surface 244 at the rear of latch cylinder 241. Then the needle is the handle 210
And is completely retracted in the latch cylinder 240.

The embodiment of FIGS. 7 and 8 is useful where a solid (ie, solid) needle 350 may be employed. Such a needle would be satisfactory if it was not necessary to take into account the desirability of pre-triggering a temporary fluid connection through the needle, as described above.

The use of solid needles provides some cost savings, which can be further enhanced by using a mechanism that does not have to be fluid-tight and clean inside. One such mechanism is shown in FIGS. 7 and 8.

Here the needle carrier block is a simple spool,
Short, narrow neck tube 331 separating two flanges 332
It is. In other words, the carrier block cylinder 331,332
A circumferential groove 331 is partially formed along the line.

Needle retraction sleeve 340 slides on the outside of cylinder 311. A retreat operating pin 342 extends from the retreat sleeve 341 into the groove 331 of the carrier block 330 via the slots 311s of the walls 311 and 312 of the handle 310.

Before and during insertion of the cannula in the embodiment of FIGS. 7 and 8, a hard detent (not shown) is
Hold the needle 350 and the sleeve 340 in front of the handle 310. This condition shown in FIG. 7 continues until the cannula is in place in the patient's body.

The user of the device then holds the rear end of handle 310 firmly against the solid surface and manually pulls retraction sleeve 340 back from the detent. As the user moves the retraction sleeve, the retraction pin 342 moves the carrier block 330 and the needle correspondingly rearward.

When the sleeve 340 is fully actuated to the rear of the handle 310, a positive acting ratchet detent will prevent the sleeve from advancing. These detents thus lock the needle in the retracted position.

9 and 10 show still another embodiment. The movable latch element of FIGS. 1 to 6 is mounted on the respective handle of the apparatus shown and is free of such a latch in FIGS. 7 and 8, but the movable latch of FIGS. 9 and 10. The element is mounted on the carrier block.

More specifically, a latch ear 435 (FIG. 10) extending in the radial direction is locked in the guide hole outside the carrier block, but is urged radially outward by the spring 436. These latch ears 435 engage the thicker portions 412c of the handle walls 411, 412 to prevent rearward movement of the carrier block 431 and the needle.

After use, the user squeezes the latch actuating fingers 446 on both sides of the handle exterior 411. Small bosses 447 extending inward are formed at the tips of these fingers.

When the user squeezes finger 446 inward, boss 447 urges latch ear 435 inward against the action of spring 436, disengaging the ear from thick wall portion 412c. With coil spring 46
1 propels the carrier block and the needle rearward as in the embodiment of FIGS.

After the thick wall portion 412c, the latch ears are again urged radially outward from the carrier block. Thus, when the block reaches the rear end of the handle and the needle is completely covered, the latch ear engages the rear stop 414 to stop retraction.

FIGS. 11 and 12 are included to schematically illustrate that the carrier block and spring embodiments of the present invention can generally include any mechanical arrangement of a general nature. In these figures, the releasable latch element 544 connects the carrier block 530 to the handle cylinder 51.
Temporarily stick to the front end of 1.

In the general arrangement shown, the sharp end 552 of the needle is
It protrudes from the front end 521 of the handle through 23. A spring 561 urges the carrier block 530 rearward.

It is believed that any such configuration (other than that which is not within the general relationship shown) is currently within the scope of the present invention. It does not matter whether the movable latch element is mounted on the carrier block 530, the handle 510, or both.

Generally speaking, the overall length of such a device is the sum of the two distances. The first of the two distances is twice the length of the narrow portion of the cannula-the distance essentially fixed by the required length of the cannula.

The second distance is the distance from the front of the nose piece to the back of the needle. The distance from the front of the nose piece to the back of the needle is equal to the sum of the lengths of the cannula hub, the fully compressed spring and the rear stop surface of the carrier block.

These lengths can generally be controlled to some extent by careful design. They should be minimized.

FIGS. 13, 13a and 13b show two latch elements 63
8,644 for each carrier block 630 and handle wall
FIG. Neither element 638 nor 644 moves radially or longitudinally.

However, there is an actuation mechanism that provides for relative rotation of the block 630 and the handle. When this mechanism is activated, it offsets the two elements 638,644 and the carrier block 630
Is released for retreat.

The actuation mechanism includes a pair of helical surfaces 637 cut into both sides of the rear circumference of the carrier block 630. The build-up required for these structures is provided by flat end walls 638 and cylindrical inner walls 639 as shown.

The actuation mechanism also includes a pair of actuation pins 641 that are forced against the helical surface through holes in the end wall (not shown) of the handle.
including. When the user operates the actuation pin 641, the block rotates within the handle as indicated by the arrow in FIG. 13b.

Another embodiment of the present invention is shown in FIG. 14 and FIG. Here, the movable latch element is a flexible finger 744 formed as a cutout from a portion of the handle wall 711 itself. These latch fingers 744 engage the rear side of the carrier block 730 and lock it against the action of the coil spring 761.

To release block 730 for retraction, the user pushes forward the actuation button 749 on the back of the handle. This may also or alternatively, as described in FIGS. 4-6,
This may be done by pushing the handle back against the reaction surface.

Here, the button 749 moves the operating pin 741 forward in the guide paths 712d and 712e relative to the handle. And the actuation pin forces the latch finger 744 radially outward,
Unblock block 730. As mentioned in the description of the drawings,
These drawings are only schematic.

It will be understood that the above disclosure is merely illustrative and is not intended to limit the scope of the invention, which is determined by the appended claims.

[Brief description of the drawings]

FIG. 1 is a side elevational view of a preferred embodiment of the present invention, primarily in a longitudinal section, with a needle secured to a protruding position for actuating a cannula. FIG. 2 is a FIG. 1 embodiment. FIG. 3 is an enlarged exploded perspective view cut off at one end of each part of the example, FIG. 3 is a similar view of a slightly modified form of each part in FIG. 2, and FIG. 3a is a schematic diagram when each part in FIG. 3 is assembled. FIG. 4 is a side elevational view, mainly in longitudinal section, of a second embodiment of the present invention, showing the needle in a protruding position used to start the cannula; FIG. Fig. 4 is a similar view of the embodiment of Fig. 4, wherein the needle is in the fourth position after a fraction of a second after the release mechanism has been actuated;
FIG. 6 is a view similar to that of the embodiment of FIG. 4, with the needle completely retracted, FIG. FIG. 8 is a view similar to that of the third embodiment of the present invention, showing the needle in the protruding position used to activate the cannula; FIG. 8 is a view similar to that of the embodiment of FIG. FIG. 9 is a diagram showing a completely retracted state, FIG. 9 is a schematic enlarged side elevational view of a fourth embodiment of the present invention mainly drawn in a vertical section and cut off in two regions, and FIG. FIG. 9 is a schematic enlarged cross-sectional elevational view of the same embodiment taken along line 10-10 of FIG. 9; FIG. 11 is a longitudinal section of a conceptually generalized form of a group of embodiments of the present invention; FIG. 4 is a schematic enlarged side elevation view, drawn in two planes and cut off in two areas, used to activate the cannula; It is a diagram showing the needle in the projecting position being. Many other embodiments of the present invention, some, but not all of which are illustrated and described herein, are shown in a more generalized form according to FIG. Note that it is out of group. The same caution applies equally to FIG. 12, which is a schematic perspective view of the generalized form of FIG. 11 of a group of embodiments. FIG. 13 is a very schematic enlarged perspective view of a fifth embodiment of the present invention, and FIGS. 13a and 13b are similar schematic side and end elevations of the FIG. 13 embodiment, respectively. FIG. 14 is a somewhat schematic enlarged side elevational view of a fifth embodiment of the present invention, mainly drawn in longitudinal section and cut off in two areas, showing the protruding position used to start the cannula. FIG. 15 is a schematic enlarged elevation view of the same embodiment according to the cross-section taken along line 15-15 of FIG. 14, but showing the needle in a retracted state, FIG. 16 is a schematic enlarged elevational view in longitudinal section showing the prior art in FIG. 16; [Explanation of Signs of Main Parts] 10; 210; 310; 510: Hollow handle 14; 414: Stopper surface 23; 123; 523: Hole 30; 231; 232; 332; 431; 530; 630; ... Carrier block 32; 132; 232; 332 ... Stopper part 40; 140; 240 ... Latch 50; 250; 350; 550 ... Needle 61; 261; 361; 461; 561 ... Coil spring 340 ... Needle retreat Sleeve 342 Retraction pin 435 Latch ear 744 Latch finger

Claims (4)

(57) [Claims] A needle having a hollow end having a near end and a distal end; a needle hub disposed within the handle; a needle having a sharp free end; and a fixed end connected to the needle hub; Biasing means for biasing the hub toward the proximal end of the hollow handle; being movable independently of the needle hub, and temporarily moving the needle hub against the force of the biasing means. A latch held adjacent the distal end of the hollow handle, the latch being manually driven with an amplitude less than the length of the needle and moving only a distance less than the travel of the needle. Features safety device. 2. The safety device according to claim 1, wherein said biasing means is a spring. 3. The safety device according to claim 2, wherein said spring is disposed around and coaxially with said needle hub. 4. The safety device according to claim 1, wherein said latch engages with said needle hub.