GB2570117A

GB2570117A - A syringe actuation member and single-handed aspiration device

Info

Publication number: GB2570117A
Application number: GB1800403.6A
Authority: GB
Inventors: James Steptoe Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-01-10
Filing date: 2018-01-10
Publication date: 2019-07-17
Anticipated expiration: 2038-01-10
Also published as: GB201800403D0; GB2570117B

Abstract

A syringe actuation member 10 for attaching to a syringe 26. The syringe actuation member 10 comprises a first end 12 attachable to a needle end of the syringe and a second end 14 attachable to a plunger of a syringe. In use the distance between the first end 12 and second end 14 of the syringe actuation member 10 is caused to change and actuates displacement of the attached syringes plunger. The syringe actuation member 10 may comprise at least one hinge 20. The hinge may be formed by a weakened portion. The syringe actuation member may be a resilient member deformable into an arcuate shape. The first end 12 may comprise an attachment aperture 16 and the second end 14 may comprise an attachment hook 18. A syringe which comprises the syringe actuation member is also included; along with an aspiration device comprising said syringe and actuation member. The aspiration device may be an ocular anterior chamber paracentesis device, vitreoretinal aspiration device and a thyroid nodule biopsy needle along with a number of further aspiration devices. A kit of parts comprising a syringe or an aspiration device and a syringe actuation member is also included.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to syringe devices and particularly to syringe devices for medical aspiration procedures.

BACKGROUND

In general, syringes can be used to collect samples of fluid by extending a syringe plunger outwards from a syringe collection tube, thereby causing a negative pressure differential which draws fluid into the collection tube.

Within the medical field, the procedure of inserting a needle or cannula into a bodily cavity or cyst in order to aspirate fluid from within (paracentesis) is utilised for both diagnostic fluid analysis and therapeutic pressure reduction by reducing the fluid volume.

In ophthalmic interventions, such as paracentesis of the anterior chamber, or aspiration from the vitreous cavity, the procedure is performed under illuminated, magnified, direct visualisation. The aspiration of fluid from other bodily cavities in cases of joint, pericardial, or pleural effusions or from fluid-filled cysts often requires indirect visualisation utilising other imaging modalities such as ultrasonography.

An ideal paracentesis device has ten characteristics. (1) The device would be sterile to avoid the risk of infection; (2) It would enable easy penetration of the cavity wall; (3) It would enable the precise localisation of the aspirating needle or cannula within the cavity to avoid trauma to adjacent structures; (4) It would enable the position of the needle or cannula to be maintained during the procedure; (5) It would facilitate a visualised, predetermined volume of fluid to be aspirated; (6) It would permit the rate of aspiration to be controlled by the operator; (7) It would enable the desired fluid volume to be acquired in a timely manner with a short procedure time; (8) The aspirated fluid would be safety contained; (9) It would be capable of being operated with a single handed technique enabling the spare hand to manipulate a microscope or ultrasound probe to aid visualisation allowing the procedure to be undertaken by a single practitioner; (10) The device should be easily manufactured at a low cost.

The present invention provides, in its broadest sense, an actuation member and syringe device and, more particularly, a paracentesis device which fulfils the above criteria. The present invention is described in its role in performing an ocular anterior chamber paracentesis although it is not intended for the invention to be considered to be limited only to this procedure. Alternative fluid aspiration applications vary in the required depth of needle penetration in order to enter the intended fluid-filled cavity in addition to the required fluid aspiration volume, therefore, variations in the needle length and size, syringe volume and actuation member length to aspirate the desired volume are intended to be variable in order to optimise the device for each specific application.

Anterior chamber paracentesis involves the peripheral puncture of the cornea and removal of aqueous fluid from the anterior chamber of the eye. It is a widely-performed procedure and the aqueous fluid sample obtained is used for either diagnostic analysis or to facilitate a reduction in the intraocular pressure.

There is currently no standard method of performing the procedure. The traditional method involves using either a 27 or 30-gauge 0.5” needle on a 1ml syringe or tuberculin syringe/needle. This is inserted through the cornea at the limbus parallel to the iris while the patient’s head position is maintained on a slit lamp which provides an illuminated, magnified view of the eye in order to visualise the procedure. There are several limitations to this technique. Firstly, the depth of needle entry into the eye is not controlled. Secondly, it requires the coordination of two people to steadily retract the plunger without causing deviation of the needle to avoid contact with the iris, cornea or intraocular lens. Thirdly, it requires the careful withdrawal of the plunger to avoid over aspiration resulting in the collapse of the anterior chamber.

A number of alternative methods of undertaking the procedure have been published in the medical literature. May and Noll describe a technique utilising a needle and syringe without a plunger. While this has the benefit of enabling a single-handed procedure it has the disadvantage of relying on a significant pressure gradient between the atmospheric pressure and the intraocular pressure within the anterior chamber to facilitate aqueous to flow into the syringe collecting tube from the anterior chamber. Also, the syringe without the plunger does not contain the aspirate obtained. [May DR, Noll FG. An Improved Approach to Aqueous Paracentesis. Pediatr Ann 1988; 17: 821-2],

Several authors have described techniques whereby the syringe is substituted with a pipette to enable the generation of a vacuum to facilitate aqueous fluid aspiration. Wertheim et al utilised an empty saline minims® with a needle attached to achieve this aim. It relies on the ‘halfway’ compression of the minims container prior to entry into the eye to create an appropriate degree of vacuum upon release following insertion into the eye to aspirate the required volume while avoiding over aspiration. [Wertheim MS, Connell PP, Majid MA, Dick AD. The minim technique for diagnostic anterior chamber paracentesis. Eye 2009; 23: 1491-1491],

O’Rourke et al utilised a purpose made soft poly-ethylene suction-infusion bulb pipette with a 30-gauge % needle to facilitate a shorter needle entry into the anterior chamber and easier bulb compression. [O’Rourke J, Taylor DM, Wang Y. Compact bulb pipette simplifies paracentesis. Ophthalmic Surg Lasers Imaging OffJInt Soc Imaging Eye 2004; 35: 172-3],

A longer slender pipette with an equivalent 30-gauge 4mm needle was designed by Kitazawa et al. While the longer pipette size enables the device to be held more securely with one hand, controlled aspiration is still dependant on the rate of releasing the precompressed pipette. Like the other pipette devices, this does not provide any visual means of quantifying the volume aspirated during the procedure. [Kitazawa K, Sotozono C, Koizumi N, et al. Safety of anterior chamber paracentesis using a 30-gauge needle integrated with a specially designed disposable pipette. Br J Ophthalmol 2017; 101: 54850],

Patent document US2016/1287219A1 describes an alternative means of aspiration utilising a disposable negative-pressure anterior chamber paracentesis syringe. While achieving many of the ideals of a paracentesis device outlined above, the syringe described in US2016/1287219A1 has a greater number of parts, is relatively complicated and expensive and is unable to control the rate of aspiration or enable visualisation of the volume acquired.

Accordingly, there is a need in the industry for a single-handed aspiration device enabling a method which overcomes the above-mentioned disadvantages with the prior art.

It is an object of the present invention to provide a single-handed aspiration syringe device, which is simple to use, inexpensive to manufacture, reduces the risk of intraocular injury, and capable of accurately controlling the rate and volume of fluid aspiration.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a syringe actuation member for attaching to a syringe, the syringe comprising a tube having a longitudinal axis, a plunger end and a needle end, the tube plunger end being open to receive a plunger which is displaceable within the tube along the longitudinal axis thereof to increase and decrease the inner volume of the tube, the syringe actuation member comprising a first end and a second end, wherein the first end is attachable to a said needle end of a said syringe and the second end is attachable to a said plunger of the said syringe, and wherein, in use, the distance between the first end and the second end of the syringe actuation member is caused to change and thereby actuate displacement of the said plunger along the longitudinal axis of the tube of the syringe.

The distance between the first end and the second end of the syringe actuation member is advantageously caused to change by application of a force in a direction transverse relative to the direction of the longitudinal axis of said tube.

The syringe actuation member may comprise at least one hinge.

The, or each, hinge is formed from a weakened portion of the syringe actuation member.

The syringe actuation member may be a member deformable at the hinge locations forming a triangular appendage shape between the said needle end of the said syringe and the said plunger.

Alternatively, the syringe actuation member may be a resilient member deformable into an arcuate shape between the said needle end and the said syringe and the plunger.

The first end advantageously has an attachment aperture through which the needle end of the a needle adapter of said tube extends through to attach the syringe actuation member thereto and is either fixed or held in position by the needle hub.

The second end advantageously comprises a hook operable to hook around the said plunger and opposes the plunger plate thereby attaching the syringe actuation member thereto.

The syringe actuation member is advantageously detachably attachable to the said syringe.

The length of the syringe actuation member is advantageously predetermined to define a maximum volume within the said tube.

According to a second aspect of the present invention, there is provided a syringe comprising a syringe actuation member according to the first aspect of the present invention.

According to a third aspect of the present invention, there is provided an aspiration device comprising a syringe according to the second aspect of the present invention.

The aspiration device is advantageously an anterior chamber paracentesis device.

The aspiration device may alternatively be a vitreoretinal aspiration device, a Thyroid nodule biopsy device, a venepuncture device, a pericardial effusion aspiration device, an ascitic fluid aspiration device, an amniocentesis device, a pleural effusion aspiration device or a joint effusion aspiration device.

According to a fourth aspect of the present invention, there is provided a kit of parts comprising a syringe or an aspiration device and a syringe actuation member according to the first aspect of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a drawing showing a syringe actuation member according to a first aspect of the present invention;

Figure 2 is a drawing showing a syringe and an aspiration device according to second and third aspects of the present invention, in which the syringe actuation member of Figure 1 is attached to a syringe wherein the plunger is fully inserted within the syringe tube; and

Figure 3 is a drawing showing a syringe or aspiration device of Figure 2 wherein the plunger is withdrawn to provide a predetermined volume within the syringe tube.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figure 1, according to a first aspect of the present invention, a syringe actuation member 10 comprises a first end 12 and a second end 14. The first end 12 has an attachment aperture 16 and the second end 14 has an attachment hook 18.

The syringe actuation member 10 further comprises a middle hinge 20 disposed between the first end 12 and the second end 14 but offset towards the first end.

The syringe actuation member 10 further comprises a first end hinge 22 and a second end hinge 24.

The syringe actuation member 10 is formed from a single piece of material and the middle hinge 20, first end hinge 22 and second end hinge 24 are formed from a weakened region of the material. Alternatively, the syringe actuation member 10 is formed from a plurality of sub-members, each sub-member extending from the or each hinge.

In a further alternative embodiment, the syringe actuation member 10 may be formed from a single piece of resilient material, which is deformable into an arcuate shape as the first and second ends, 12 and 14, are caused to move closer to each other.

Referring also to Figures 2 and 3, in use, the syringe actuation member 10 is attached to a syringe 26. The type of syringe used is dependent on the requirements of the procedure to be undertaken. In general, the syringe 26 typically comprises a tube 28 having a longitudinal axis 30, a needle end 32 and a plunger end 34, and a plunger 36, which is displaceable within the tube 28 along the longitudinal axis 30 thereof. The needle end 32 has a hub 38 and the plunger 36 has a plunger plate 40, which is disposed on the end of the plunger 36.

The syringe actuator member 10 is attached to the syringe 26 wherein the needle end 32 extends through the attachment aperture 16 such that the first end 22 abuts the hub 38, and the attachment hook 18 hooks around the circumference of the plunger 30 and abuts the plunger plate 40.

With the syringe actuator member 10 attached to the syringe 26 it is operable as an aspiration device according to the third aspect of the present invention.

Referring to Figure 2, in use as an aspiration device, the plunger 36 is fully inserted within the syringe tube 28 such that the internal volume in the tube 28 is at least substantially zero. With the plunger 36 in this position, because the syringe actuation member 10 is longer than the distance between the hub 38 and the plunger plate 40, it extends obliquely away from the syringe 26 bending at the middle hinge 20.

The aspiration device is held horizontally by the user and supported between the thumb opposing the syringe 26 and forefingers abridging the central middle hinge 20. Application of a force on the syringe actuation member 10, in a direction transverse to the longitudinal axis 30, towards the syringe 26, transfers a force to the plunger plate 40 and cause the syringe plunger 36 to withdraw from the tube 28 causing a negative pressure differential and thereby aspirating fluid, as required, until the syringe actuation member 10 is fully extended and substantially parallel with the longitudinal axis 30, as shown in Figure 3.

In addition to using the syringe actuation device 10 with a standard syringe 26 for general introduction and aspiration of fluids, it can also be used with a syringe 26 as an anterior chamber aspiration device for undertaking anterior chamber paracentesis procedures.

Accordingly, the anterior chamber paracentesis device utilises a 4mm long 30 gauge needle with a Luer taper fitting and a 1ml Plastipak 3 piece BD syringe. The syringe actuation device attaches to the syringe in the same manner as described above and illustrated in Figures 2 and 3.

In use, the anterior chamber paracentesis device is held horizontally by the operator and supported between the thumb opposing the syringe and forefingers abridging the middle hinge. As described above, application of a force on the syringe actuation member 10, in a direction transverse to the longitudinal axis 30, towards the syringe 26 transfers a force to the plunger plate 40 to cause the syringe plunger 36 to withdraw from the tube 28 causing a negative pressure differential and thereby aspirating fluid when the needle is within a fluid filled cavity such as the anterior chamber until the syringe actuation member 10 is fully extended and substantially parallel with the longitudinal axis 30, as shown in Figure

3.

The position of the middle hinge 20 is at the gravitational centre of the device which provides balanced handling when held horizontally. The transverse force (as opposed to an axial force used with the traditional method of using a syringe) avoids disturbing the needle tip within the eye. The use of the existing syringe and gradations enables clear visualisation of the fluid volume being aspirated. At maximal depression of the syringe actuation member 10 the device is designed to limit the aspirate to 0.1ml of fluid (allowing for the dead space of the 4mm needle). The predetermined length of the syringe actuation member prevents over aspiration and avoids anterior chamber collapse.

Accordingly, the anterior chamber aspiration device, according to the present invention, enables a medical practitioner to undertake anterior chamber paracentesis procedures with a single hand and also provides the medical practitioner with improved control in mitigating lateral movement of the needle within the eye, the risk of accidental damage to the internal eye structures is also limited by utilising a 4mm needle, and enabling control of a precise predetermined volume of aspirate.

Moreover, the anterior chamber aspiration device, according to the present invention, provides a relatively simple, inexpensive and easy to use device.

The invention is not intended to be limited to the details of the embodiments described herein, which are described by of example only. It will be understood that features described in relation to any particular embodiment can be features in combination with other embodiments. It is contemplated by the inventor that various substitutions, alterations and modifications may be made to the invention without departing from the scope of the invention as defined in the claims.

Claims

1. A syringe actuation member for attaching to a syringe, the syringe comprising a tube having a longitudinal axis, a plunger end and a needle end, the tube plunger end being open to receive a plunger which is displaceable within the tube along the longitudinal axis thereof to increase and decrease the inner volume of the tube, the syringe actuation member comprising a first end and a second end, wherein the first end is attachable to a said needle end of a said syringe and the second end is attachable to a said plunger of the said syringe, and wherein, in use, the distance between the first end and the second end of the syringe actuation member is caused to change and thereby actuate displacement of the said plunger along the longitudinal axis of the tube of the syringe.

2. A syringe actuation member as claimed in claim 1, wherein the distance between the first end and the second end of the syringe actuation member is caused to change by application of a force with a single hand of a user to the syringe actuation member in a direction transverse relative to the direction of the longitudinal axis of said tube.

3. A syringe actuation member as claimed in claim 1 or 2, wherein the syringe actuation member comprises at least one hinge.

4. A syringe actuation member as claimed in claim 3, wherein the, or each, hinge is formed from a weakened portion of the syringe actuation member.

5. A syringe actuation member as claimed in claim 1 or 2, wherein the syringe actuation member is a resilient member deformable into an arcuate shape between the said needle end of the said syringe and the said plunger.

6. A syringe actuation member as claimed in any of the preceding claims, wherein the first end has an attachment aperture through which the needle end of the said tube extends to attach the syringe actuation member thereto.

7. A syringe actuation member as claimed in any of the preceding claims, wherein the second end comprises a hook operable to hook around the said plunger to thereby attach the syringe actuation member thereto.

8. A syringe actuation member as claimed in any of the preceding claims, wherein the syringe actuation member is detachably attachable to the said syringe.

9. A syringe actuation member as claimed in any of the preceding claims, wherein the length of the syringe actuation member is predetermined to define a predetermined plunger displacement and therefore maximum volume within the said tube.

10. A syringe comprising a syringe actuation member as claimed in any of the preceding claims.

11. An aspiration device comprising a syringe as claimed in claim 10.

12. An aspiration device as claimed in claim 11, wherein the aspiration device is an ocular anterior chamber paracentesis device.

13. An aspiration device as claimed in claim 11, wherein the aspiration device is a vitreoretinal aspiration device.

14. An aspiration device as claimed in claim 11, wherein the aspiration device is a thyroid nodule biopsy device.

15. An aspiration device as claimed in claim 11, wherein the aspiration device is a venepuncture device.

16. An aspiration device as claimed in claim 11, wherein the aspiration device is a pericardial effusion aspiration device.

17. An aspiration device as claimed in claim 11, wherein the aspiration device is an ascitic fluid aspiration device.

18. An aspiration device as claimed in claim 11, wherein the aspiration device is an amniocentesis device.

19. An aspiration device as claimed in claim 11, wherein the aspiration device is a pleural effusion aspiration device.

20. An aspiration device as claimed in claim 11, wherein the aspiration device is a joint effusion aspiration device.

21. A kit of parts comprising a syringe or an aspiration device and a syringe actuation member according to claims 1 to 9.