GB2524859A

GB2524859A - Cannula protector (CP)

Info

Publication number: GB2524859A
Application number: GB1420740.1A
Authority: GB
Inventors: Reginald James Cheetham
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-02-25
Filing date: 2014-11-18
Publication date: 2015-10-07
Also published as: GB201403323D0; GB201420740D0

Abstract

A device and method for preventing excessive forces being applied to a cannular used during intravenous (IV) infusion comprises a clip to readily grip and release a medical tube. The clip may comprise a pressure arm which swings on a pivot until it holds the tube in position with a crimping or clamping force. The arm can then be locked into place. The clip may be located on a base or platform which may be secured to the hand or forearm of a person using straps or tapes [fig. 1].

Description

My invention may be defined as a means for improving patient's experiences in hospital when receiving an Intra Veinous (IV) infusion.

The present IV infusion treatment consists of supplying a medical infusion fluid, at a particular pressure, governed by an electronically-controlled pumping apparatus mounted with the fluid supply on an overhead support, fed into a suitable vein in a patients forearm via a cannula. For some cases such as blood transfusions the supply is not put through the electronic pressure control but relies upon the natural pressure head of the fluid supply above the patient.

In both cases a lengthy polythene tube is required to connect the overhead supply to the cannula inserted in the patients vein.

For extended periods of infusion when the patient may fall asleep involuntary movements of the patient in relation to the weighty fluid-filled IV tube may cause movement of the cannula in the vein resulting in irritation and inflammation at the vein site. It is also possible for the cannula to be pulled out resulting in bleeding and loss of treatment. In each such case a new vein site has to be chosen and a new cannula inserted. Bleeding may also require pyjama and bedding change.

The invention aims to remove the problems by providing a simple clip that can be atached to the patients hand and used to grip the polythene IV tube above the cannula to intercept the main strains that would otherwise fall on the cannula. This device I call the Cannula Protector (OP.) The Design of the OP.

The OP comprises four main parts:- 1 The Platform This consists of a rigid rectangular plate 80mm long, 50mm wide, with corner and edges rounded. At each end of the plate a pair of 16mm long slots (approximately 1mm wide) run lengthwise from each corner to provide a means of threading a pair of 20mm wide cotton tapes of approximately 50cm length. (The tapes are conveniently held in the slots with these dimensions.) See figure 1.

The platform can be positioned on either the back or palm of the hand and secured in position by tying the ends of each tape together, one round the wrist and one round the base of the fingers, leaving the thumb free. Thus, the platform forms a base for affixing the clip used for gripping the IV tube to take the strain off the cannula.

The materials used for manufacturing the components of the OP, such as the platform will determine the thickness and details of construction. Ideally all major parts would be made in moulded plastic if this would make the product economic for single patient use. However, the design is suitable for construction in metal or plastic or a combination of these materials. Initially it would be sensible to manufacture the design in metal to prove the application before committing to the manufacture of plastic moulding equipment.

2 The Channel The Channel is used to position the IV tube in alignment with the centre line of the top surface of the platform and to serve as a fixed jaw of the clip used to grip the IV tube. The channel is 25mm in length and has the cross-sectioned shape of the upper half of a compressed capital letter C. To provide adequate strength and support for fixing to the platform the channel cross-section should take the form shown in figure 2.

3 The Pressure Arm The pressure arm forms the moving jaw of the clip and is used to provide the pressure required to crimp the IV tube and hold it in position in the clip. The pressure arm swings on a pivot mounted perpendicularly to the top surface of the platform, positioned 10mm from the centre line and 14mm from End A' of the platform.

The shape of the pressure bar is chosen to ensure that when open' there is adequate clearance for inserting or removing the IV tube in or out of the channel.

The pressure arm is depicted in figure 3, showing its appropriate dimensions.

The tongue which engages with the IV tube in the channel should be 3mm in thickness. The rest of the arm may be up to 5mm thick, depending upon the requirements of the lock (see section 4).

4 The Lock When the pressure arm is closed on the IV tube and exerting the appropriate crimping force it is necessary to lock the arm in this position. The lock can be in the form of a spring-loaded bolt attached to the pressure arm. The bolt engages with a lug moulded or screwed in place on the platform. The width of the lug can determine the amount of crimping force applied and can be a means of adjustment. This is sketched in figure 4.1.

Such a bolt would automatically lock the pressure arm and needs to be unlocked by sliding the bolt knob against the spring. A much simpler form of lock is shown in figure 4.2 but it needs to be manually positioned when opening and closing the pressure arm.

This lock is in the form of a latch swivelling on a pivot screwed perpendicularly to the edge surface of the pressure arm. The angle-cross sectional latch is given a slight upturn on the top surface at the pivot end to form a stop to limit the upward swing of the latch so that it can just clear the locking lug fixed to the platform when in the locked position. An elliptical slot may be cut near the centre of the latch to allow a finger grip to made for the operator to use when positioning the lock. Because of the detailed parts, the bolt-type lock shown in figure 4.1 would best be constructed in metal.

The latch latch-type lock is shown in figure 4.2 in the form it would best take in metal construction. However, with appropriate dimensions it could also be conveniently constructed in plastic without being too bulky.

Claims

Claims A method of preventing undue forces on the cannula used to administer the Intra Veinous (IV) infusion of medical fluids into the forearm of patients.This takes the form of a clip that can be readily attached (or detatched) to the polythene tube used to supply the fluid.The clip is attached to a platform' which forms an efficient means of attachment to the patient's hand.The design can be constructed in metal or with most parts from moulded plastic as may desirable for applications for single-patient use.Amendments to the claims have been made as follows Claims 1. A cannula protector being a practical means of intercepting and removeing undue forces, normally transmitted by the feed tube, from the cannula as used in the intra veinous medical treatment of patients in hospital.
2. A cannula protector according to claim 1 in which a clip is provided to give a means of readily gripping or releasing the feed tube.
3. A cannula protector according to claim 1 in which a clip according to claim 2 may be comfortably and securely attached to the patient's hand.
4. A cannula protector according to claims 1, 2 and 3, could be adapted for use on other parts of the body where support of feed tubes may be required.