GB2423717A

GB2423717A - A device for indicating the penetration of a body cavity with a fluid flow indicator

Info

Publication number: GB2423717A
Application number: GB0602844A
Authority: GB
Inventors: Timothy Bateman
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 2005-02-25
Filing date: 2006-02-10
Publication date: 2006-09-06
Anticipated expiration: 2026-02-10
Also published as: GB0503900D0; GB0602844D0; GB2423717B

Abstract

A device for indicating penetration of the trachea 3 or the like has a hollow needle 2 with a cutting tip 20 and connected at one end to a handle 1. A gas flow sensor 21 in the needle 2 provides an electrical output to a processor 10 and display 12 in the handle. The display 12 indicates both level of gas flow at the tip of the needle and the direction of flow. When the display 12 indicates a gas flow with alternating direction it is immediately apparent that the needle tip 20 is in the trachea 3.

Description

I

MEDICO-SURGICAL APPARATUS

This invention relates to medico-surgical apparatus.

The invention is more particularly concerned with apparatus for indicating the penetration of a body passage, such as, for example, the trachea.

Where a percutaneous or cricothyroid tracheostomy procedure is carried out it is important to know when the needle or the like has entered the trachea. One form of apparatus used for this purpose is described in GB2393398 and employs a needle with a spring-loaded rod projecting from the patient end of the needle. Entry to the trachea is detected by observing forward movement of the rod as the tip of the needle clears overlying tissue. Other techniques involve listening for the sound of air passing through a hollow needle or feeling loss of resistance to movement of a plunger in a syringe connected to a needle when the trachea is entered. There are other surgical procedures where an instrument is inserted through tissue into a body cavity and where it would be useful to indicate penetration of the cavity.

It is an object of the present invention to provide alternative apparatus for indicating penetration of a body cavity.

According to one aspect of the present invention there is provided apparatus for indicating penetration of a body cavity including an elongate member adapted for insertion through body tissue and having a first end adapted for insertion into the body cavity the apparatus including fluid flow detection means operative to detect flow of fluid and to provide an indication thereof.

The elongate member preferably has a cutting tip adapted to penetrate the body cavity.

The fluid flow detection means may be selected from a group comprising: rotameter, pitot tube and ultrasonic flowmeter. The indication of flow is preferably provided on a handle mounted at an opposite end of the elongate member. The indication of fluid flow may be provided on a visual display, such as a numerical display. The fluid flow detection means is preferably operative to provide an indication of change of direction of flow. The apparatus is preferably arranged to provide an indication of gas flow along the trachea. The elongate member preferably has a bore extending along it through which an elongate member can be extended into the cavity.

According to another aspect of the present invention there is provided tracheostomy apparatus including a hollow needle having a cutting tip at one end, a gas flow sensor responsive to flow of gas along the trachea, an indicator mounted at the opposite end of the needle and arranged to provide an indication of gas flow along the trachea and of change in direction of the gas flow.

According to a further aspect of the present invention there is provided an assembly including tracheostomy apparatus according to the above other aspect of the invention and a guidewire insertable along the needle such that one end of the guidewire locates in the trachea and such that the apparatus can be removed from the trachea leaving the guidewire in place in the trachea.

Tracheostomy apparatus according to the present invention will now be described, by way of example, with reference to the accompanying drawing which shows the apparatus in use.

The apparatus is a unitary, self-contained, hand-held device comprising a combined handle and display I and a hollow needle 2 extending from the forward, patient end of the handle.

The needle 2 is rigid and has a pointed cutting tip 20 adapted to penetrate the trachea 3 through the overlying tissue 4. The needle 2 includes a gas flow sensor 21 of any conventional kind and could, for example, include a rotameter, pitot tube, ultrasonic flowmeter or any other device. The sensor 21 could sense gas flow through the open tip 20 of the needle or through an additional opening or openings (not shown) formed in the wall of the needle. In the case of an ultrasonic flowmeter an opening need not be necessary. The gas flow sensor need not be located within the needle 2 itself but could be within the handle 1 and be responsive to gas flow along a bore 22 extending through the needle 2 and the handle 1.

The handle 1 is generally rectangular and elongate containing a processing unit 10, battery 11 and a display panel 12. The processing unit 10 is powered by the battery 11 and receives signals via wires (not shown) from the gas flow sensor 21. The output of the processing unit 10 drives the display panel 12, which is in the form of a numeric display on which the gas flow rate is displayed in any conventional units, such as mm.sec. The display 12 also indicates the direction of flow along the trachea, that is, whether the patient is inhaling or exhaling. This may be represented by a "+" and "-" sign, or by an appropriate legend, such as "in" or "ex". Alternatively, the change in direction could be indicated in some other way, such as by a change in colour of the display. The actual quantative measure of flow is not important so the indication of flow could be provided in a non-numeric manner such as by a flashing light or by an arrow that increases in length with increased flow and changes direction when flow was reversed. It is not essential for flow to be indicated visually since it could be indicated in other ways such as, for example, by an acoustic device. The flow indicator need not be provided on the handle but could be provided on a remote unit connected with the handle by a wire, or by a wireless link.

Before use, the clinician first confirms that the patient is breathing (either by the patient himself or with the aid of a ventilator) since the functioning of the apparatus is dependent on the detection of gas flow along the trachea. If the patient is not breathing, any alternative method may be used. The apparatus is arranged to make the initial entry into the trachea 3. To do this, the clinician grips the apparatus and presses the cutting tip 20 against the skin 31 of the neck overlying the trachea 3. A preliminary scalpel cut may have been made. He then pushes the apparatus inwardly so that the tip 20 cuts through the skin 31, penetrates the underlying tissue 4, passes between the cartilages 32 overlying the trachea 3 and then enters the trachea. During insertion through the neck tissue 4, the display 12 shows a zero gas flow rate since there is no flow of gas over the tip 20 the needle 2. When the trachea 3 is penetrated, the tip 20 of the needle 2 is exposed to the bidirectional flow of gas along the trachea so the display 12 changes to show this flow, thereby giving an immediate indication to the user that the trachea has been entered. It will be appreciated that the flow rate represented on the display 12 will show a flow increasing in one direction to a maximum, then falling and passing through zero to a rising flow in the opposite direction. It will be readily apparent to the user if the flow is not of this kind. When correct entry has been confirmed, the user inserts an elongate member such as a guidewire (not shown) along the bore 22 of the apparatus sufficiently for its patient end to protrude from the tip 20 and locate in the trachea 3. The apparatus I is then removed, leaving the guidewire in place so that a dilator and tracheostomy tube can be inserted, in the usual way.

The apparatus gives the user a readily comprehensible indication of penetration of the trachea.

The invention is not confined to use in the trachea but could be used in other body cavities where fluid flows along, into or out of the cavity, such as, for example, in a blood vessel.

Claims

1. Apparatus for indicating penetration of a body cavity including an elongate member adapted for insertion through body tissue and having a first end adapted for insertion into the body cavity, wherein the apparatus includes fluid flow detection means operative to detect flow of fluid and to provide an indication thereof.

2. Apparatus according to Claim I, wherein the elongate member has a cutting tip adapted to penetrate the body cavity.

3. Apparatus according to Claim 1 or 2, wherein the fluid flow detection means is selected from a group comprising: rotameter, pitot tube and ultrasonic flowmeter.

4. Apparatus according to any one of the preceding claims, wherein the indication of flow is provided on a handle mounted at an opposite end of the elongate member.

5. Apparatus according to any one of the preceding claims, wherein the indication of flow is provided by a visual display.

6. Apparatus according to Claim 5, wherein the visual display includes a numerical display.

7. Apparatus according to any one of the preceding claims, wherein the fluid flow detection means is operative to provide an indication of change of direction of flow.

8. Apparatus according to any one of the preceding claims, wherein the apparatus is arranged to provide an indication of gas flow along the trachea.

9. Apparatus according to any one of the preceding claims, wherein the elongate member has a bore extending along it through which an elongate member can be extended into the cavity.

10. Tracheostomy apparatus including a hollow needle having a cutting tip at one end, a gas flow sensor responsive to flow of gas along the trachea, an indicator mounted at the opposite end of the needle and arranged to provide an indication of gas flow along the trachea and of change in direction of the gas flow.

11. Tracheostomy apparatus substantially as hereinbe fore described with reference to the accompanying drawings

12. An assembly including tracheostomy apparatus according to Claim 10 or 11 and a guidewire insertable along the needle such that one end of the guidewire locates in the trachea and such that the apparatus can be removed from the trachea leaving the guidewire in place in the trachea.

13. Any novel and inventive feature or combination of features as hereinbefore described.