Abstract
The invention relates to a syringe with a visual indicator and retaining elements, which is used in the application of epidural anaesthesia. The syringe has the particularity of comprising a visual indicator located at the front end of a plunger that drives the fluid contained in the barrel, which visual indicator is an element in the form of a bellows comprising two discs with a membrane between the two discs, wherein the membrane can be deformed according to the pressure in the syringe. The syringe also comprises longitudinal lateral flanges on the body of the plunger, which have a surface with a plurality of teeth, wherein the plunger is rotatable relative to its axial axis, and wherein the teeth allow the plunger to be secured.
Claims
1. A syringe with a visual indicator and retaining elements, for use in the application of epidural anesthesia, which is a syringe comprising a needle (1); a transparent barrel (2) housing the fluid to be applied in the epidural area; a front pivot (3) securing the junction between the needle and the barrel; a plunger (4) moving axially within the barrel; an outer plunger support (5) with which the anesthesiologist can move the plunger with his/her hand; and an outer reinforcement (6) of the barrel, preventing the plunger from separating from the cylinder/barrel; characterized in that the syringe also comprises the following: a visual indicator (7) located at the front end of the plunger (4), pushing the fluid contained in the barrel (2), which is a bellows-shaped element comprising two disks (70) with a membrane (71) between both disks, wherein the membrane (71) is deformable according to the pressure at which the syringe is located; at least one longitudinal side flap (41) in the plunger body (4), having a surface with a number of teeth (42), and wherein the plunger (4) is rotatable relative to its axial axis; inner hooks (81) in the barrel (2); and wherein the teeth (42) of the side fins (41) of the plunger fit into the hooks (81) retaining the position of the plunger (4), and are released by rotating the plunger (4).
2. A syringe with a visual indicator and retaining elements, according to claim 1, characterized in that the retaining ring (8) comprises hooks (80) on its outer perimeter that fit and are fixed in the outer barrel reinforcement (6).
3. A syringe with a visual indicator and retaining elements according to claim 1, characterized in that it comprises a retaining ring (8), which fits into the outer reinforcement (6) of the barrel, and which comprises the inner hooks (81) on its lower face.
4. A syringe with a visual indicator and retaining elements according to claim 1, characterized in that the hooks (81) are located on the inner face of the outer reinforcement (6) of the barrel.
5. A method of use for performing epidural anaesthesia of the syringe with visual indicator according to claim 1, characterized in that it includes the following steps: a) in an initial phase the visual indicator is expanded and at the beginning of the loading of air or liquid into the syringe, the plunger is rotated to engage the locking teeth. b) the needle is inserted into the patient and as soon as the needle is in the cartilaginous area, the cylinder is pushed, and the visual indicator is compressed and the membrane is hidden. c) When the needle reaches the epidural space the indicator expands and the membrane becomes visible.
Description
[0036] In order to complete the description and to help with a better understanding of the features of the invention, a set of figures and drawings is presented in which, by way of illustration and not limitation, the following is represented:
[0037] FIG. 1 is a representation of a cross section of the syringe of the invention when the visual indicator is expanded and visible, thus meaning that the needle is within the epidural space, or is outside the patient.
[0038] FIG. 2 is a representation of a cross section of the syringe of the invention when the visual control is compressed and hidden, thus meaning that the needle is not within the epidural space.
[0039] FIG. 3 is an expanded perspective representation of the different elements that make up the syringe, subject of the present invention.
[0040] FIG. 4 is a free perspective representation of a detail of the retaining ring.
[0041] FIG. 5 is a schematic representation of the retention between the ring and the toothed plunger.
[0042] FIG. 6 is a detailed representation of the compressed visual indicator.
[0043] FIG. 7 is a detailed representation of the expanded visual indicator.
[0044] FIG. 8 is a perspective representation, according to the figure above, where the expanded visual indicator can be seen.
[0045] FIG. 9 is a schematic representation of the syringe assembly when outside the patient.
[0046] FIG. 10 is a schematic representation of the syringe assembly when inside the patient, but the needle is not in the epidural space.
[0047] FIG. 11 is a schematic representation of the syringe assembly when it is within the patient and the needle is within the epidural space.
[0048] FIGS. 12A to 12C, which are drawings detailing a different type of visual control represented in FIGS. 5 to 7, where the detail of the compressed visual indicator and the expanded visual control is observed.
[0049] FIGS. 13A to 13C which are drawings detailing another type of visual control represented in previous figures, where the detail of the compressed visual indicator and the expanded visual indicator is observed.
[0050] FIGS. 14A to 14C, which are drawings detailing another type of visual indicator represented in previous figures, where the detail of the compressed visual indicator and the expanded visual indicator is observed.
DETAILED DESCRIPTION OF THE DRAWINGS OF THE INVENTION
[0051] As can be seen in FIGS. 1 to 3, the syringe, subject of the present invention, comprises in a preferred embodiment thereof, the usual elements of this type of medical devices, i.e., comprises a needle (1); a transparent barrel (2); a front pivot (3) that secures the junction between the needle and the barrel; a plunger (4) that moves axially within the barrel; an outer plunger support (5) with which the anesthesiologist can move the plunger with his/her hand; and an outer reinforcement (6) of the barrel that prevents the plunger from separating from the cylinder/barrel.
[0052] Additionally, in said figures, and in more detail in FIGS. 4 to 8, in order to solve the technical problem related to having a reference and visual alert of pressure change, and to be able to lock and adjust the position of the plunger, the syringe comprises the following: [0053] a visual indicator (7), which is a bellows-shaped element comprising two disks (70) facing each other and comprising a deformable membrane (71) between them, this membrane being of striking colour, and its compression and/or expansion carried out when there is a pressure change, and acting as a visual alert precisely defining the moment at which it is placed over the epidural cavity (E); [0054] and a restraining element consisting of: [0055] the plunger body (4) has at least one longitudinal side flap (41) having a toothed surface or having a number of teeth (42); and [0056] in the outer reinforcement (6) of the barrel a retaining ring (8) is fitted, which on the one hand has hooks (80) on its outer perimeter that allow it to be fitted and fixed to the outer reinforcement (6), and has inner hooks (81) on its lower face; [0057] so that the teeth (42) can be fitted to the hooks (81) of the retaining ring (8), thus leaving the plunger (4) fixed in its position, and to be released only turn with respect to its axis and release the engagement of said teeth (41) in the retaining ring.
[0058] The number of toothed side flaps (41) is variable, it being necessary that there be at least one, and where specifically in FIGS. 1 to 3 one embodiment of the invention can be seen with two flaps. Another aspect is that the faces of the discs (70) of the visual indicator (7) may be flat, as depicted in the Figures, but may have surfaces of another configuration.
[0059] Although not depicted, in a second embodiment of the invention the syringe comprises the same elements as usual of any syringe, i.e., a needle (1); a transparent barrel (2) ; a front pivot (3) that secures the junction between the needle and the barrel; a plunger (4) that moves axially within the barrel; an outer plunger support (5) with which the anesthesiologist can move the plunger with his/her hand; and an outer reinforcement (6) of the barrel that prevents the plunger from separating from the cylinder/barrel, but has the particularity that the barrel directly has the inner hooks (81), which are preferably located on the inner face of the outer reinforcement (6) of the barrel, which allow the teeth of the plunger to be fixed thereon, and therefore there is no need for a retaining ring (8).
[0060] Additionally, as can be seen in FIGS. 1 and 2, and in greater detail in FIGS. 6 to 8, the syringe may dispose of the visual control (7) in two positions, one in which the membrane (71) is compressed between the two disks (70), i.e., hidden, and means that there is pressure and that the needle has not been introduced into the epidural space; and may also have the expanded visual indicator (7), i.e., that the membrane (71) with its striking colour is visible, which means that there has been a reduction in pressure, and in particular may mean that the needle has been introduced into the epidural space.
[0061] In FIGS. 9 to 11 the use of the syringe assembly can be seen schematically, where in FIG. 9 it can be seen that the syringe is outside the patient, and the visual indicator (7) is expanded due to lack of pressure; subsequently, as seen in FIG. 10, but still the needle (1) is not in the epidural zone (E) and the visual indicator (7) is compressed and the membrane is hidden due to pressure; and finally, in FIG. 11, the needle (1) is reached into the epidural space (E), the plunger (4) is blocked and the visual indicator (7) expands and the membrane (71) becomes visible, being able at that time to release the plunger and proceeds to anesthetize. In this way it is possible to indicate that the insertion into the epidural space has been correct and that you are in the right area without puncturing, accessing or damaging the dura mater (D) or the next secondary epidural area (Z), where there could be harmful side effects.
[0062] In FIGS. 12A to 14C different possible configurations of the visual indicator (7) can be seen in two positions, one in which the membrane (71) is concealed and means that there is pressure and that the needle has not been introduced into the epidural space (FIGS. 12A, 13A and 14A); and it can also have the expanded visual indicator (7), that is, that the membrane (71) with its striking colour is visible, which means that there has been a reduction in pressure, and in particular it can mean that the needle has been introduced into the epidural space (FIGS. 12B-C, 13B-C and 14B-C).
