WO1997020588A9

WO1997020588A9 - Apparatus and method of reducing the pain of a subcutaneous injection

Info

Publication number: WO1997020588A9
Application number: PCT/AU1996/000792
Authority: WO
Filing date: 1996-12-09
Publication date: 1997-08-07

Abstract

A hand-held tool (1), adapted to reduce the pain caused by a subcutaneous injection from a hypodermic needle (19), said tool comprising a tip (3) extending therefrom, an operative means (6) adapted to vibrate the tip (3) whereby in use the tip (3) is placed against the tissue into which the injection is to be given, so as to induce vibrations in the tissue, both before and during the injection.

Description

APPARATUS AND METHOD OF REDUCING THE PAIN OF A SUBCUTANEOUS INJECTION

The present invention relates to an apparatus for and a method of "painless" injections, and in particular to such apparatus and methods for use in

the practice of dentistry.

In medical and dentistry work it is often necessary to administer medicinal drugs, by way of subcutaneous injections utilising hypodermic

needles A most prevalent problem that arise, with injections, is that many people suffer from a fear of needles and particularly the pain associated with

the needle penetrating the skin and the underlying tissue, and the initial introduction of the serum from the needle into the surrounding tissue.

This problem is particularly relevant to dentistry, where it is necessary to use anaesthetic injections to numb the mouth of patients such that they do not feel the pain duπng dental surgery, such as drilling , teeth removal, deep

scaling and root canal work Unfortunately the mouth is a sensitive area and some patients feel and abhor the pain caused by penetration of a hypodermic needle in preparation for dental surgery, and procrastinate about going to the

dentist as they perceive the pain of the injection as being worse than any dental problems that they may have

Several methods have attempted to overcome this problem. One

system, such as that shown in EP 239721 , and EP 302278 use specially designed gun shaped injectors which have a vibrating cannula or needle, and

supply a specific amount of, in this case insulin, to provide for quick penetration of the insulin into the surrounding tissues Another prior art DE 2408286

applies transverse vibration to the cannula

A different direction was followed in US patent no 5,437,606 where the

infected tooth itself was vibrated to cause cavitation of the dental pulp fluid to

cause a reduction or elimination of pain without the need for anaesthesia If this was not successful, the actual needle was vibrated as the needle penetrates the tissue to increase diffusion of the local anaesthesia into the

surrounding tissue, to reduce the amount of anaesthesia used

The present invention seeks to ameliorate this problem, by providing an

apparatus for and a method which reduces the pain associated with the

administration of subcutaneous injections using hypodermic needles

In one broad form the invention compπses a hand held tool, adapted to

reduce the pain caused by a subcutaneous injection from a hypodermic needle,

said tool comprising a tip extending therefrom, an operative means adapted to vibrate the tip whereby in use the tip is placed against the tissue into which the injection is to be given, so as to induce vibrations in the tissue, both before and

during the injection Preferably the tip has a substantially annular portion which is placed

against the tissue and vibrated, while the hypodermic needle is injected into the tissue surrounded by the annular portion of the tip

In another form the invention comprises a method of reducing the pain of

a subcutaneous injection, comprising the steps of applying vibrations from a vibratory tool to the area of tissue into which the injection is to given, and

administering the injection while maintaining the vibrations

Preferably the vibration is applied via a substantially annular tip portion which is placed against the tissue and vibrated, while the hypodermic needle is

injected into the tissue surrounded by or adjacent to the annular tip portion

The present invention will now be described with reference to the accompanying figures in which

Figure 1 represents schematically a cross sectional view of a hand held

vibratory tool according to one embodiment of the present invention,

Figure 2 shows several casing and tip shapes of hand held vibratory tools according to various embodiments of the present invention, Figure 3 show the shapes of several tips for embodiments of hand held

vibratory tools according to various embodiments of the present invention,

Figure 4 shows the tip of a hand held vibratory tool according to one embodiment of the present invention, in position in a patient's mouth,

Figure 5 shows a hypodermic needle being injected into a patient while a hand held vibratory tool according to one embodiment of the present

invention, is being used in a patient's mouth,

Figure 6 shows a further embodiment of the present invention in the form

of a combined hypodermic needle and vibratory tool,

Figure 7 illustrates an additional pain reduction aid in the form of a

pillow,

Figure 8 illustrates an additional pain reduction aid in the form of an

automatic hypodermic syringe,

Figure 9 illustrates an additional tip for hand held vibratory tools according to embodiment of the present invention for another dental use, Figure 10 illustrates an additional pain reduction aid in the form of a

further form of an automatic hypodermic syringe,

Figure 11 illustrates a close up view of the slow release mechanism shown in figure 10,

Figure 12 illustrates a view of another use for the vibrating tool according to an embodiment of the present invention,

Figure 13 illustrates a view of a view of another use for the vibrating tool according to an embodiment of the present invention to remove teeth, and

Figures 14 & 15 illustrate another embodiment of the present invention

One embodiment of a hand held vibratory tool (1 ) is shown in

schematically in figure 1 wherein the tool (1) compπses a housing (2), with a replaceable tip (3) The housing (2) and replaceable tip (3) being completely

autoclaveabie, preferably made from 316 (surgical grade) stainless steel, or autoclaveabie plastics The tip (3) could also be disposable and made from any

suitable material The base (4) of the housing (2) is removable, such that the

battery or batteries (5) and the motor (6) are removable, so that the housing (2)

can be autoclaved Additionally lights (7) can be fitted to provide illumination for the dental work and also to further distract the patient to assist in reducing

the pain of the needle penetration into the tissue.

As shown in figure 2, the hand held vibratory tool (1 ) can be of any desirable shape, and can have any desirable form of variable speed switch.

Preferably the switch is a simple touch switch with a positive pad, where each

touch increases the vibration and a negative pad, where each touch decreases

the vibration.

The light (7), located adjacent the tip (3), is required for illumination.

However an additional light could be located at the other end of the tool (1 ) and strobed to provide additional stimulus to distract the patient from the pain.

Preferably the tool is vibrated at between 30 - 70 Hz. Additionally the rate of vibration could be adjustable or be programmed to randomly alter to further

distract the patient.

As shown in figure 3, the tips (3) are of various shapes, depending upon

their usage. A simple tip (9), as shown in figure 5, is used in a back area near

the jaw line to assist in reducing the pain of an injection of localised anaesthetic. While the tool tip, as shown in figure 4, is used to move the lip

away to allow an injection of localised anaesthetic. Each tool tip has its specific use, while preferably each tool tip has an annular or substantially annular

extremity (10).

In using the pain reduction technique of the present invention the dentist can position the patient's head on a special pillow (11) shaped as shown in

figure 7. This pillow (11 ) incorporates a neck rest portion (12), and a small battery operated vibrator (not shown). The vibrations in the pillow help to relax the patient.

In use, topical anaesthetic can be applied to the proposed injection site. The tool tip (8) is then vibrated against the proposed injection site, to accustom the patient to the vibration. The tip (8) can be sprayed with "ultracold" or a

cotton wool cover could be sprayed with "ultracold", and then applied to the

injection site. Further the tip (8) could be connected to a "Peltier" circuit to cool the tip. The tool tip (9) is vibrated against the tissue to be injected, and as

shown in figure 5, the injection is, preferably, made into the tissue surrounded by the annular extremity (10) of the tip (9), while the vibrations take place.

However in some cases the vibrating tip can be used external of the mouth while the injection takes place internally into the gum.

Preferably, to assist in reducing the pain of the injection, it is desirable to inject the serum at a slow rate of about 1 to 2 ml. per minute. The needle can then be gently removed, while maintaining the vibrations, and the vibrating tip

(9) can be moved around the injected tissue for approximately 5 seconds, to

assist in dissipating the serum throughout the tissue.

As shown in figure 4, the tip (21 ) has an elongated annular extremity (22), which acts as a spreader to hold the lips (23) away from the area of the

mouth to be worked upon.

A further embodiment of the present invention is shown in figure 12,

wherein the vibrating tip (9) has a small suction head (24) attached thereto. To

eliminate painful palatal injections, the suction head (24) is placed on the mucosa on the palatal side the of the teeth and vibrated and the injection given

into a site on the mucosa on the other side the teeth.

In another embodiment of the present invention, as shown in figures 14

& 15, the pain reduction apparatus comprises a suction cap (41 ), connected to the an air suction source (not shown). The needle (19) of the syringe (42)is

inserted through the suction cap (41 ) to a position just above the skin or

mucosa. Preferably the cap is vibrated, at this stage. A suction is applied to the suction cap (41), so as to create a negative pressure in the cap (41 ) to draw the skin or mucosa (43) towards the needle (19) such that the needle (19)

penetrates the skin or mucosa (43) as shown in figure 15. The vibration and suction is maintained during and after the injection If required the needle can be pushed into the tissue for the injection This apparatus could also be used for palatal injections in a similar manner to that described with reference to

figure 12

Another use for the vibratory tool (1 ) is in extracting of teeth As shown

in figure 13, the tip (25) is thin and blade like and is gently inserted down the

gum line of the tooth (26) to be extracted, as the tip (25) is vibrated, and the tooth (26) levered out as a result of the vibration It has also been found that by

applying vibrations to the tooth to be extracted reduces the amount of or eliminates the need for injections of anaesthetics

The tip (9) of the vibratory tool (1) could be replaced with other standard dental tools as shown by way of example in figure 9, where the tip is used to

remove or place braces Additional uses are in the following areas,

Restorative packing of amalgam and composites to provided denser filings,

Peπodontics use as a prophylactic brush and sealer

Prosthodontics removal of metallic crowns and bridges Endodontics: compaction and condensation of gutta percha root

fillings., root canal explorer, and files for debriding root canals.

In another embodiment, as shown in figure 6, the vibrating tool (16) can

be fitted by means of clips (14) or any other suitable means to the barrel (15) of

a hypodermic syringe (13). In this embodiment the vibratory tool (16) has a side positioned vibratory link (17) to which the removable tip (9) is attached, by

any suitable means. However, preferably the shank (18) of the tip (9) is

retractable with in the vibratory link (17), which could be in the form of a slot, as the hypodermic needle (19) advances into the tissue. Preferably the annular extremity (10) of the tip (9) is initially positioned beyond the tip of the

hypodermic needle (19), whereby in use the vibratory tool is activated and the

annular extremity (10) of the tip (9) is placed against the tissue to be injected and the rate of vibration increased to the desired amount and the hypodermic needle (19) moved into the tissue surrounded by the annular extremity (10),

and the serum slowly injected into the tissue whilst maintaining the vibration.

Because not all tissue is of the same consistency, variable means, such

as the knob (20) can be used to vary the resistance of the retraction of the

shank (18). As in all of the examples of the hand held vibratory tool of the present invention, the speed of the vibrations can be adjusted by any suitable means such as a slide potentiometer, or simple positive and negative touch pads.

To assist in slowly injecting the serum into the tissue an automatic syringe, such as shown in figure 8 could be used, this syringe has a motor which at a preselected rate moves the plunger down the barrel of the

hypodermic needle.

As shown in figure 8, a housing (27) contains a replaceable or rechargeable battery (28) and a motor (29), with switch (30). Any suitable drive

and linkage system would be suitable such as a rack and pinion or a modified worm gear, to link the motor (29) and the plunger (31 ), which could have a helical (or threaded) surface (32), against which the gearing (33) engages

A further embodiment of a slow injection syringe is shown in figures 10 & 11 , wherein the syringe (34) has the plunger (35) biased by a spring (36) to force the serum from the syringe (34). a ratchet type retainer means (37) is located on the on the finger grip (38), and engages in the grooves (39) on the

shaft (40) of the plunger (35). In use the doctor releases the retainer (37) from the first groove and as the shaft (40), under the action of the spring (36), moves into the syringe (34) the retaining means (37) engages in the next groove (39) Thus with careful operation of the doctor a slow release of the serum is

obtained

In a further embodiment the vibratory hand held tool can provide a small

electrical stimulation at the tip as well as the vibration. The electrical

stimulation is at a tolerable level, to further distract the patient from the pain of the injection. The current is variable and can be regulated by any suitable

means, such as a potentiometer, to meet the needs of the patient.

The hand held vibratory tool of the present invention can be used with a disposable throw away sheath and could be of any desired shape such as having a pistol grip. The tool could be battery powered which are rechargeable

when the tool is replaced in its charger/holder, and can either be recharged by

direct contact or by an induced field.

It should be obvious to people skilled in the art that modifications and

alterations can be made to the embodiments described above without departing

from the spirit or scope of the present invention.

Claims

The claims defining the invention are

1 A hand held tool, adapted to reduce the pain caused by a

subcutaneous injection from a hypodermic needle, said tool comprising a tip extending therefrom, an operative means adapted to vibrate the tip whereby in use the tip is placed against the tissue into which the injection is to be given, so

as to induce vibrations in the tissue, both before and during the injection

2 A hand held tool according to claim 1 , wherein the tip terminates in a substantially annular extremity

3 A hand held tool according to claim 1 or 2 wherein there is a Peltier circuit connected to said tip to cool said tip

4 A hand held tool according to any one of the preceding claims

wherein a light source is provided at the end of the tool adjacent the tip

5 A hand held tool according to any one of the preceding claims wherein a suction the tip is in the form of a suction cap

6 A hand held tool according to claim 5 wherein said suction cap is connected to a source of suction so as to produce a suction on the tissue beneath the cap

7 A syringe having a barrei and a nypodermic neeαle, and naving a

hand held tool, according to any one of the preceding claims, affixed to the barrel with the tip of the hand held tool extending passed the end of the

hypodermic needle, with the tip being retractable to allow the injection to take place as the tip vibrates against the tissue, being injected

8 A method of reducing the pain of a subcutaneous injection, comprising the steps of

applying vibrations from a vibratory tool to the area of tissue into which

the injection is to given, and administering the injection while maintaining the vibrations

9 A pain reducing method according to claim 8 wherein the vibrations are continued after the injection to increase the dissipation of the serum into the tissue

10 A pain reducing method according to claim 8 or 9, wherein the tip is cooled prior to its application to the area of tissue where the injection is to be

given

11. A pain reducing method of claims 8, 9 or 10, wherein the tip is in the form of a suction cap and suction and vibration are both applied to the

injection site during injection.

12. A pain reducing method according to claim 11 wherein the needle tip is located in the cap and the suction forces the tissue below the suction cap onto the needle.

13. A method according to any one of claims 8 to 12, wherein the

serum is slowly injected into the tissue.

14. A slow injection syringe comprising: a barrel, adapted to contain the serum to be injected; a plunger located in said barrel to force the serum through said needle;

a motor ; and

a drive linkage system, connected between said motor and said plunger so as to move said plunger along said barrel at a required rate.

15. A slow injection syringe comprising a barrel, adapted to contain the serum to be injected; a plunger located in said barrel to force the serum through said needle and having a shaft which extends beyond the barrel; a biasing means located adjacent the plunger to bias the plunger to force serum out of the barrel; and releasing means to engage the shaft of the plunger , such that the shaft

can be alternately released and engaged to slowly force the serum through said needle

16 A slow injection syringe according to claim 15 wherein the

releasing mechanism comprises a detent or ratchet located on the syringe

which releasably mates in grooves on the shaft of the plunger

17 . A hand held tool substantially as herein before described with

reference to figures 1-6 and 14 &15 of the accompanying drawings.

18 A method of reducing the pain of a subcutaneous injection

substantially as herein before described with reference to the accompanying

drawings

19 An automatic syringe substantially as herein before described

with reference to figures 6 & 8 of the accompanying drawings.