GB2324243A - Air flow detection device for medical use - Google Patents

Abstract

The device, which may be used to detect air in the space between the lungs and chest wall, comprises an outer tube 10 with an air filter 12, an inner tube 11 fixed therein, a hollow needle 14 fixed or fixable to the tubes as shown and a lightweight ball 15 within the inner tube. The ball does not allow air to pass in either direction whilst in the inner tube but is pushable along the tube by slight air pressure introduced via needle 14 until it drops out into the outer tube. A removable, air-tight cap 13 covers the end of tube 10.

Description

AIR FLOW DETECTION VALVE DESCRIPTION This invention relates to an air flow detection valve.

'Tension Pneumothorax' is a life threatening condition that occurs when air is permitted to enter the space between the lungs and the chest wall.The pressure in this space can rise and so cause complete collapse of the lung. This type of injury commonly occurs in accidents with a penetrating chest injury or when a rib pierces the lung, such as in a car crash.

Standard procedures for diagnosis and treatment of 'Tension Pneumothorax' are slow and complicated, involving an X-Ray to verify the condition, and surgery in the form of a 'chest drain.'In many emergency situations the delay in waiting for an X-Ray cannot be justified. A well-informed doctor may in this instance attempt to release air trapped in the patients chest by plunging a needle into the front of the chest at the level of the second rib ( where it can do little damage ). Using an ordinary needle for this treatment can however be very risky, since if the diagnosis is incorrect, the same condition can actually be caused, by allowing air to enter the chest through the needle. In this instance the sound of air entering the chest can easily be mistaken for that of air exiting, so that the doctor may believe he has treated the condition successfully, while actually causing it, and presuming the patient has respiratory problems from a different cause, the introduction of 'Tension Pneumothorax' is quite likely to be fatal.

According to the present invention there is provided an air flow detection valve designed specifically for the diagnosis and treatment of 'Tension Pneumothorax'. This valve comprises a tube made from a clear material ( preferably plastic ) at one end of which a hollow needle is fixed, at the other end of which an air filter is fixed beneath a removable airtight cap. Within this tube is fixed a smaller tube containing a lightweight ball (preferably polystyrene ), which does not allow air to pass it whilst within the inner tube, but which can be moved easily along by a small amount of pressure until it drops out of the inner tube into the outer tube, therefore permanently witnessing the occurrence of air flow through the valve.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in perspective the valve; Figure 2 shows a section across the length of the valve.

Referring to the drawing the valve comprises an outer tube 10, fixed to one end of which is an air filter 12, fixed to the other end of which is a hollow needle 14. Fixed within the outer tubelO is an inner tube 11 , and contained within this is a lightweight ball 15,which fits the inner tube 11, so that it does not allow air to pass it in either direction whilst in the inner tube 11, but can be easily pushed along the inner tube 11 by a small amount of air pressure introduced through the through the needlel4, until it drops out of the inner tube 11, into the outer tube 10. A removable, airtight cap 13 covers the end ofthe outer tube 10.

In a suspected case of 'Tension Pneumothorax' the valve as previously described in this specification should be inserted into the patients chest at the level of the second rib. The airtight cap should then be removed allowing air trapped in the chest to pass through the valve . As this happens the lightweight ball is pushed along the inner tube until it drops out into the outer tube.This verifies permanently the flow of air through the valve. The release of the trapped air reduces the pressure on the lung and allows it to re-inflate. If the patient is not suffering from 'Tension Pneumothorax', when the needle is inserted and the cap removed, the ball simply remains at the base of the tube, (or rises very slowly with escaping blood) showing clearly the absence of trapped air. The needle and valve can then be removed having caused minimal damage.

The valve can be produced either as a single article wherein the needle is incorporated into the valve, or as two separate articles wherein the needle fits onto the valve.

This second option allows for the possibility of using a standard needle. In either case the needle must be approximately 16 gauge ( 1.7mm diameter, 50 mm length ), to allow adequate passage of air.

Claims (6)

1. An air flow detection valve comprising one tube within another tube, a lightweight ball being positioned at the base of the inner tube , fitting within it so as to prevent air from passing it in either direction but which can be easily pushed along the inner tube under slight pressure until it drops out of the end of the inner tube and into the outer tube.

2. An air flow detection valve as claimed in claim 1, wherein an air filter is fixed within the outlet end of the outer tube.

3. An air flow detector valve as claimed in claim 1 or claim 2, wherein a removable, airtight cap is fitted to the outlet end of the outer tube.

4. An air flow detection valve as claimed in claim 1 or claim 2 or claim 3, wherein a hollow needle is fixed to the inlet end of the valve.

5.An air flow detection valve as claimed in claim 1 or claim 2 or claim 3, wherein an ordinary hypodermic needle can be fitted to the inlet end of the valve.

6. An air flow detection valve substantially as described herein with reference to Figures 1 & 2 of the accompanying drawing.