DESC:FIELD OF INVENTION
The present invention relates to catheter assembly. More particularly, the present invention discloses a modified catheter assembly for Blood control septum configured for restricting undesired blood flow.

PRIOR ART
Most prior art uses a single-time blood control system to restrict blood flow when the IV catheter is inserted into a patient's vein. This blood restriction only works in interim - before the first Luer connection is made - or about 10 seconds. This limits the catheter's ability to restrict blood flow in case of an accidental Luer detachment or Luer replacement.

Some prior artworks do attempt to change this by using an elastic membrane, which restricts blood flow, but failure of this mechanism as a suitable alternative to traditional IV Catheters is highly probable as a robust mechanism like a rubber spring, which also enables MRI compatibility has not been used in the design.

In the prior art a Spanish Patent publication ES2834969T3 discloses multipurpose blood monitoring safety catheter assembly including a valve actuator that moves in a catheter assembly between a first position where a valve is closed and a second position where the valve is closed. valve is open, the valve actuator comprising: a shaft portion at a distal end of the valve actuator which is configured to pierce the valve; an engagement portion at a proximal end of the valve actuator that is configured to engage with a Luer device; a diameter reduction region connecting the shaft portion and the coupling portion; and a plurality of windows extending radially through the valve actuator to discharge fluid, the plurality of windows are disposed in the diameter reduction region, where each of the plurality of windows does not extend a full length of the diameter reduction region; and each of the plurality of windows is elongated in a circumferential direction.

SUMMARY OF INVENTION
The present invention disclose a modified catheter configured for the use of a re-closing Rubber Spring (102 in fig. 1) which ensures restriction of undesired blood flow from the catheter, in the case of accidental disconnection or while Luer replacement. The invention therefore adapts the use of a novel Rubber spring instead of a traditional metallic coiled spring enables the device to be MRI compatible.

Therefore, such as herein described there is provided a modified catheter assembly comprising of a catheter; a needle having a sharp distal tip disposed within the catheter; a catheter hub connected to the catheter having the needle passing therethrough, the catheter hub including: an inner diameter; a valve that selectively permits or blocks a flow of fluid through the catheter: a valve actuator that moves between a first position, and a second position; and a rubber spring that returns the valve actuator from the second position to the first position.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Fig 1 illustrates a modified catheter assembly including a rubber spring in accordance with the present invention;
Fig 2 illustrates a modified catheter assembly including a loaded rubber spring in accordance with the present invention;
Fig 3 illustrates a modified catheter assembly under the condition of unloaded rubber spring (after loading condition) restricting undesired blood flow in accordance with the present invention;
Fig 4(a) and (b) illustrates the rubber spring structure and dimension in a plan A-A view in accordance with the present invention;

DETAILED DESCRIPTION
There are a few critical parts used in this mechanism as can be seen in the accompanying figures –
Fig.1: Catheter Body (101),
Rubber Spring (102),
Blood control septum (103),
Actuator (104),
Needle (105),
Fig. 2: Catheter Body (201),
Loaded Rubber Spring (202),
Blood control septum (203),
Actuator (204),
Luer (205) and
Fig. 3 Catheter Body (301),
Rubber Spring (302),
Blood control septum (303),
Actuator (304)

After successful catheter insertion, the needle (fig. 1) is pulled out (fig. 3) which causes the Blood control septum to close and restrict blood flow from the patient's vein within the Catheter Body, not allowing blood to flow out while a Luer connection is made. Hence a nurse does not need to hold the patient’s vein in order to prevent spillage from catheter. When the Luer is pushed inside the Catheter body to make said connection (fig.2) it pushes against the Actuator which moves and opens the Blood control septum to allow the flow of IV liquid into the patient's vein. This forward movement of the Actuator also causes the Rubber Spring to contract, essentially loading the rubber Spring.

In the case of Luer replacement/accidental disconnection (fig. 3), the loaded Rubber Spring (202) unloads and expands, causing the Actuator to be pushed out of the Blood control septum, hence restricting undesired blood flow. The use of the rubber spring to control the movement of the Actuator allows undesired blood flow restriction to function repetitively, whenever it is needed, unlike prior artworks where blood spillage is prevented only once or in previous works where blood spills after a random time interval due to lack of a robust re-closing system.

There is one previous art which has addressed this issue of multiple use blood spillage by suggesting the use of a coiled metallic spring, but this invention is not practical to be used in a hospital setting as it is not compatible with MRI due to the embedded metallic element.

In the embodiment according to FIG. 1 and 2, the mechanical impulse is transferred from the actuator to the fluid control valve, thereby permitting the flow of fluid through the catheter. The actuator has a driving body, which can be accelerated and decelerated or braked, separately from the penetration needle. The actuator is then accelerated in a guide over a distance by a preloaded helical compression rubber spring, as soon as disconnection of the catheter from the Luer, thereby restricting flow of fluid through catheter. A non-limiting example of a suitable preloaded or pre-compressed spring element is a silicone rubber spring as shown in Fig 4, for the return of actuator to its original position.

For the embodiment according to FIG. 3, a mechanical impulse is transferred from the actuator to the penetration needle. The Luer is coupled to the bottom side of the actuator, which is formed as a cylinder so as to be leak-proof.

FIG. 3 illustrates an embodiment of the invention wherein the rubber spring and the actuator have to be penetrated at very low speeds. The rubber springs herein disclosed have a strong regressive character, such that a maximum force is created at the end of the spring movement in the direction of the loading, to provide the maximum pressure as required in use.

In yet another exemplary embodiment the dimensions of the rubber spring include the top outer diameter 3mm – 5mm, bottom inner diameter is 2mm – 3mm and the total width is 4 – 6mm. The internal structure include conical ribs configured for grip and regression.

Medical grade Silicone is an inert material, whereas steel is corrosive. The configuration of the IV catheter is such that during IV administration/ blood sampling, the spring, meant for re-closing of the blood control septum/valve will come in direct contact with the contents (blood, IV fluids, etc.), sometimes these devices can stay in use for up to 72 Hours or more (in some places up to one week)

1. Materials of composition
Liquid Silicon Rubber (LSR)
2. Physical Property - Hardness of material used (in Shores)
65 Shore (Tolerance +/- 3)
3. Physical Property Spring (tensile) Force Observed in Rubber Spring
5.5 Newtons (+/-0.5) 4.
4. Method of Manufacture –
Rubber Injection Moulding

The application of a Silicone spring replacing a metallic coiled spring thus eliminates the possibility of metal toxicity in patients which is possible when using a metallic spring due to Nickel leaching from the Medical grade steel component which will be in constant contact with patient’s blood 1

Due to the inertness of silicone material the application of a Silicone spring replacing a metallic coiled spring also eliminates the chances of metal allergies in patients which is possible when using a metallic spring due to Nickel leaching from the Medical grade steel component 2

A metallic spring is therefore not practical to be used in this way, also because metallic materials, both in implants and surface applications corrode over time and cause Inflammatory and unwanted immune response in patients.

Use of Silicone increases compatibility with all kinds of drugs due to its inert nature. For example - Drugs like Doxurobicin are commonly used by Intravenous infusion in cancer patients, whose cytotoxic properties increase significantly when it comes in contact with metal ions. 4 These used with a metallic spring inside the catheter can result in sepsis or other toxic reactions in the patient

References -
1. Santonen, Tiina, Helene Stockmann-Juvala and Anders Zitting. “Review on toxicity of stainless steel.” (2010).
2. Teo WZW, Schalock PC. Metal Hypersensitivity Reactions to Orthopedic Implants. Dermatol Ther (Heidelb). 2017 Mar;7(1):53-64. doi: 10.1007/s13555-016-0162-1. Epub 2016 Dec 19. PMID: 27995484; PMCID: PMC5336431.
3. Merritt, Katharine. "Role of medical materials, both in implant and surface applications, in immune response and in resistance to infection." Biomaterials 5.1 (1984): 47-53.
4. Jablonska-Trypuc A, Swiderski G, Kretowski R, Lewandowski W. Newly Synthesized Doxorubicin Complexes with Selected Metals-Synthesis, Structure and Anti-Breast Cancer Activity. Molecules. 2017 Jul 4;22(7):1106. doi: 10.3390/molecules22071106. PMID: 28677642; PMCID: PMC6152354.

1. Functional Testing and experimental data –

Testing Reports & Empirical Data

These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.

,CLAIMS:
1. A modified catheter assembly comprising:
a catheter;
a needle having a sharp distal tip disposed within the catheter;
a catheter hub connected to the catheter having the needle passing therethrough, the catheter hub including:
an inner diameter;
a valve that selectively permits or blocks a flow of fluid through the catheter: a valve actuator that moves between a first position, and a second position; and a rubber spring that returns the valve actuator from the second position to the first position.

2. The modified catheter assembly as claimed in claim 1, wherein the said spring is pre-loaded non-toxic silicon rubber spring.

3. The modified catheter assembly as claimed in claim 1, wherein the said loaded Rubber Spring (202) unloads and expands, causing the Actuator to be pushed out of the Blood control septum, thereby restricting undesired blood flow.

4. The modified catheter assembly as claimed in claim 1, wherein the dimensions of the said rubber spring include the top outer diameter 3mm – 5mm, bottom inner diameter is 2mm – 3mm and the total width/ length is 4 – 6mm.

5. The modified catheter assembly as claimed in claim 1, wherein the internal structure of said rubber spring include conical ribs configured for grip and regression.

6. The modified catheter assembly as claimed in claim 1, wherein the Luer is pushed inside the Catheter body to make said connection where it pushes against the Actuator which moves and opens the Blood control septum to allow the flow of IV liquid into the patient's vein.

7. The modified catheter assembly as claimed in claim 6, wherein said forward movement of the Actuator also causes the Rubber Spring to contract, essentially loading the rubber Spring.