Technical Field

The present invention refers to a cannula for injections, particularly indicated for performing subcutaneous infiltrations.

Background Art

The use of subcutaneous infiltrations is known for treating various pathologies and to reduce inflammation or other painful syndromes.

However, the sector in which subcutaneous infiltrations constitute a fundamental and irreplaceable method of treatment is cosmetic medicine.

Indeed, the treatment of wrinkles and/or the nourishment of tissues

(for example, increasing the volume of the lips) involves the inoculation of suitable substances (such as for example hyaluronic acid, collagen, polylactic acid, agarose, hydroxylapatite, silicone or other filler products) which, by filling the tissues underlying the wrinkle (or the internal tissues of the lips, in the example cited above) from within the dermis, ensure that the desired result is achieved by mechanical effect (by filling an internal cavity, a reduction in the wrinkle, or an increase in volume of the lips, will be noted externally).

The internal cavities are not natural cavities but are channels made with the cannula for inoculating the substance.

More generally, with particular reference to the use of hyaluronic acid, this has applications for the following treatments:

- Lips: fullness and plumpness;

- Volume and contour area of the lips;

- Folds (e.g. nasolabial folds);

- Remodelling of the face contours (e.g. cheeks and chin);

- Wrinkles;

- Post-acneic scar tissue sequelae;

- Post-traumatic scar tissue sequelae;

- Blemishes in soft tissues; - Rhinoplasty sequelae.

The indicated substances are thus injected in extremely small doses into the affected regions by means of a syringe fitted with an extremely narrow needle.

For the indicated treatments, in the past syringes were adopted that had traditional needles, of the type normally adopted for venipuncture: these needles have a cutting end that is adapted to cut through the tissues so as to permit the body of the needle to pass through such tissues. Often the point of the needle is constituted by multiple cutting edges achieved by mutually incident planes in order to ensure that the incision of the skin is not performed by piercing (as happens when a conical point is used) but by incision (a real small cut of the dermis).

Nowadays these needles are practically no longer used for treatments involving subcutaneous infiltrations of substances because, once the dermis has been crossed, the needle could cut blood vessels or other tissues: in addition, if the substance is inoculated in a blood vessel, there could be problems arising from the incompatibility of the substance with the cardio/circulatory system.

In any case, the incision of a blood vessel determines an oedema due to the exit of blood: a consequence of this is that it is impossible for medical personnel to immediately verify the correct localisation of the inoculated substance because the oedema deforms the part and distorts assessments.

For this reason special cannulas are used for infiltration that do not have sharp ends. The use of these cannulas will always be subordinate to an incision of the dermis performed with a needle of the traditional type (needle with cutting ends).

Working with this type of cannula, which has the orifice for emitting the substance along the lateral surface of such cannula, in proximity to the end, is particularly complex for medical personnel, who can only assume the actual direction along which the substance will be emitted. For extremely localised treatments, this can determine a scant quality of the result.

Secondly, it should be noted that these inoculations are performed by medical personnel who are working in reverse: in practice, the cannula is inserted for all of the necessary length and the emission of substances is performed during the extraction phase (possibly including appropriate pauses during such phase to favour the correct distribution of the substance). In this phase it is essential to avoid the release of substance in the thickness of the dermis (or in very close proximity to it) because this would determine the thickening of the dermis or at any rate would modify its characteristics so as to damage its aspect (at least locally). This assessment of the position of the cannula at which it is necessary to cease the release of substances rests solely with the medical personnel and their experience: this is therefore particularly risky because not all cannulas are the same or have the same shape and hence the margin of risk for the patient is in any case non- negligible.

Disclosure of the Invention

The aim of the present invention is to solve the above mentioned drawbacks, by devising a cannula for injections with which it is possible to precisely know the direction of emission of the substance during its injection.

Within this aim, an object of the invention is to provide a cannula for injections in which it is possible to exactly identify the distance between the incision to allow the passage of the cannula through the dermis and the hole through which the substance is emitted/released.

A further object of the present invention is. to provide a cannula for injections with which it is possible to precisely calibrate and establish the distance between two consecutive releases of substances under the dermis in a manner that is simple and instinctive for the operating medical personnel.

A further object of the present invention is to devise a cannula for injections that has a low cost, is easily and practically implemented and safely applied.

This aim and these objects, as well as others which will become better apparent hereinafter, are achieved by a cannula for injections adapted to be associated with an inoculation device such as a syringe or the like, characterised in that it comprises a tubular body of narrow gauge which is provided with a longitudinal internal cavity for connecting an opening that is substantially axial and which is located at a bushing for coupling to the respective inoculation device, to an exit hole that is located in proximity to the end head of the cannula on a side wall of said tubular body, said bushing comprising at least one suitable reference sign that is aligned in the direction of said exit hole.

Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the cannula for injections according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a first embodiment of a cannula for injections according to the invention;

Figure 2 is a perspective view of a second embodiment of a cannula for injections according to the invention;

Figure 3 is a perspective schematic view of a cannula for injections according to the invention during its use.

Ways of carrying out the Invention

With reference to the figures, the reference numeral 1 generally designates a cannula for injections.

The cannula 1 is of the type that is adapted to be associated with an inoculation device such as a syringe or the like. Being known the adoption of pistol-shaped dispensers and other similar apparatuses, the cannula 1 according to the invention can effectively be coupled with any type of inoculation device.

Specifically it should be noted that the cannula 1 comprises a tubular body 2 of narrow gauge which is provided with a longitudinal internal cavity 3.

The external diameter of the tubular body 2 is normally less than 2 mm and is preferably comprised between 0.9 and 1.5 mm (diameters that substantially correspond respectively to the values of 20 and 30 gauge, gauge being a unit of measurement that is particularly used in the medical sector for identifying the thicknesses of needles and cannulas).

The internal cavity 3 is adapted to connect a substantially axial opening 4, which is located at a bushing 5 for coupling to the respective inoculation device, to an exit hole 6 that is located in proximity to the end head 7 of the cannula 1 on a lateral wall of the tubular body 2.

The bushing 5 comprises at least one suitable reference sign 8 that is aligned in the direction of the exit hole 6.

In this way the operator will effectively be able to recognise the ^■ direction of emission of the flow of substances from the exit hole 6 and therefore such operator will be able to localise the treatment on the patient with the maximum precision.

According to a particular embodiment of undoubted practical and applicative interest, the cannula 1 comprises, along the outside surface of the tubular body 2, at least one line 9 for indicating a preset distance from the exit hole 6.

In practice, by observing the line 9 it will always be possible to know that the cannula 1 is inserted under the dermis only for a certain length: this will ensure that the operator will avoid inoculating the substance when only a short portion of the cannula 1 is inserted under the dermis.

In order to optimise the criteria for using the cannula 1 according to the invention it should be noted that it is advantageous to devise cannulas 1 in which the lines 9 are a plurality, mutually equidistant, so as to define a graduated scale, for measurements and indications of length.

Such graduated scale is relative to the distance of each individual line 9 from the exit hole 6.

Specifically, in order to devise a cannula 1 that is perfectly adapted for cosmetic treatments involving subcutaneous infiltration of substances (such as hyaluronic acid, collagen, poly lactic acid, agarose, hydroxylapatite, silicone or other filler products) the end head 7 of the cannula 1 is preferably rounded (or at any rate blunted) and does not comprise sharp ends, points and/or corners adapted to make incisions in human or animal tissues. In this way the risk is completely prevented of incision of the blood vessels which, during cosmetic treatments, could cause the exit of blood with consequent formations of oedema which would make complicated to assess the effective success of the treatment.

According to a particular embodiment of undoubted practical and applicative interest, the reference sign 8 has a width that is equal to the width of the exit hole 6, so as to unambiguously identify the direction of flow of the dispensed substance: indeed, the dispensed flow will have a width (upon exiting from the hole 6) that is equal to the diameter of such hole, and knowing this width is a guarantee to the medical personnel operating that they are acting with the maximum possible precision. Alternatively it is advisable that, in the case where the mark or line 8 is thin, such mark or line be aligned with the axis of symmetry of the hole 6, thus identifying the direction of the flow of the substance emitted (but without any information on its width).

A further possible alternative embodiment is that of having a reference sign 8 constituted by at least one pair of lines placed at a mutual distance that is equal to the width of the exit hole 6: in this way, too, it is possible to univocally identify the direction of the flow of the dispensed substance.

According to the particular type of treatment to be performed, the cannula 1 can have a tubular body 2 that is rigid or flexible: the use of a body 2 that is partially rigid in some of its portions and flexible in others is not excluded.

The correct use of the cannula 1 involves the execution of a series of consecutive phases.

In a first phase (a) it is necessary to make an opening in the dermis of the patient with a suitable incision device: a traditional syringe needle (for example of the type used for venipuncture) or a special blade (for example a scalpel) could be normally used. The possibility that the cannula 1 can comprise a head 7 with a sharp profile is not excluded a priori, even though this embodiment, as described previously, is not suitable for subcutaneous infiltrations.

A subsequent phase (b) involves inserting the cannula 1 into such opening in the dermis beginning from the end head 7 up to, possibly, the entire insertion of the tubular body 2.

The third phase (c) requires a rotation of the inoculation device associated with the cannula 1 until the reference mark on the bushing 5 is aligned with the surface element (a portion of the lips, a wrinkle, a scar etc.) of the area of the patient that is desired to be treated.

Only at this point is it possible to perform the last phase (d) of dispensing at least one substance present in the inoculation device at the point/area identified.

It must, however, be specifically pointed out that treatments are generally not localised and limited to a single point (for example the treatment of a wrinkle must be performed for the entire extent of such wrinkle) and therefore it may be necessary, during the phases (c) and (d), to perform suitable intermediate phases.,

Indeed, at the end of a first dispensing, it is advisable to partially extract, by executing an intermediate phase (e), the cannula 1 up to an indicator line 9 located on the outside surface of the tubular body 2: the utility of the lines 9 lies precisely in the ability to measure, simply by means of a rapid observation of them, the depth of penetration of the cannula 1 by identifying the point at which the substances are about to be dispensed with the maximum precision.

A further intermediate phase (f) (which actually constitutes a terminal phase for the specific treatment being executed), provides for stopping any dispensing of substances when the indicator line 9 that is nearest to the exit hole 6 exits the opening in the dermis thus becoming visible to the operating medical personnel. This means that the hole 6 is close to the thickness of the dermis and any dispensing could cause problems and counter-indications precisely because of the fact that the substance could end up in the layer of dermis, contrary to what is prescribed by the cosmetic treatment being executed.

Advantageously, the cannula 1 for injections according to the invention makes it possible to precisely know the direction of emission of the substance during its injection, and it simplifies the work of the medical personnel who can localise the flow of substance during dispensation in a precise and targeted manner.

Usefully, the cannula 1 for injections according to the invention makes it possible to exactly identify the distance between the incision through the dermis to allow the passage of the cannula 1 and the hole 6 through which the substance is emitted/released: the operating medical personnel knows the precise position in which they are inoculating the substance simply by observing the cannula 1 partially inserted into the dermis of the patient.

Advantageously, the cannula 1 for injections according to the invention makes it possible to precisely calibrate and establish the distance between two consecutive releases of substances under the dermis in a manner that is simple and instinctive for the operating medical personnel who can then base their actions straightforwardly on the observation of the lines 9.

The invention thus conceived is susceptible of numerous modifications and variation, all of which are within the scope of the appended claims; in addition, all the details may be replaced by other technically equivalent elements.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

In addition, it should be noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

In practice the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.