WO2019086822A1

WO2019086822A1 - Medical devices

Info

Publication number: WO2019086822A1
Application number: PCT/GB2018/000135
Authority: WO
Inventors: Eric Pagan; Mark DARST RICE; Jonathan McNeill FLINT; Jesus Arturo CABRERA
Original assignee: Smiths Medical International Limited
Priority date: 2017-10-31
Filing date: 2018-10-18
Publication date: 2019-05-09
Also published as: GB201717924D0

Abstract

A tracheostomy tube (1) or other medical device has an RFID tag (30) mounted on its flange (11) that monitors and records temperature change when the tube is used and decontaminated in an autoclave so as to produce a log of temperature cycles to which the tube is subjected. A separate RFID reader (40) is used to interrogate the RFID tag (30) on the tube to indicate to the clinician whether the tube has been correctly decontaminated.

Description

MEDICAL DEVICES

This invention relates to medical devices of the kind including a treatment indicator.

Cost pressures on hospitals and other medical establishments have led to an increase in the re-use of medical devices after decontamination. Many medical devices are, however, intended only for single use so as to ensure sterility, prevent cross-contamination and ensure that the device functions as intended. Re-use of these single-use devices can adversely affect the performance of the device and the properties of the materials from which it is made. This can cause the device to fail and may result in injury to the patient. Ineffective decontamination after use may also lead to infection. Medical devices intended to be re-used must be properly cleaned and sterilised after each use. It can be difficult to check that such devices have been correctly treated after use.

Various proposals have been made for arrangements to indicate sterilisation. For example, GB647379 describes an indicator with an opaque substance that can be fused by the heat of sterilisation. US 1788104 describes a label with an opaque covering that is absorbed by the label at sterilising temperatures. US5518927 describes an indicator with a colour-change material that is changed gradually over repeated decontamination cycles. JP2015198910 describes an indicator that is changed by successive sterilisation cycles. GB1701116.4 describes an indicator to show treatment by an aqueous treatment technique. Conventional sterilisation indicators may not be able to record whether a sterilisation \ technique has been effective, that is, at the required temperature, pressure and time.

Although the manufacturer's packaging of medical devices are clearly marked to indicate whether or not the device is intended only for single use, it may not be apparent after the device has been removed from the packaging whether or not it has been previously used.

It is an object of the present invention to provide an alternative medical device.

According to one aspect of the present invention there is provided a medical device of the above-specified kind, characterised in that the treatment indicator includes an electrical temperature sensor, a circuit for recording the response of the electrical temperature sensor to elevated temperature and the time for which the device is subject to elevated temperature, that the treatment indicator is arranged to provide a response to an interrogating signal from a separate reader, the response being indicative of the elevated temperature and the time for which the device has been subject to the elevated temperature.

The treatment indicator preferably includes an RFID tag. The treatment indicator may be arranged to record multiple cycles of elevated temperature. The medical device may be a tracheal tube.

According to another aspect of the present invention there is provided a reader for use with a medical device according to the above one aspect of the present invention.

According to a further aspect of the present invention there is provided an arrangement including a medical device according to the above one aspect of the present invention and a reader for reading the treatment indicator on the medical device.

The reader may include a display on which a temperature/time chart is displayed. According to a fourth aspect of the present invention there is provided reader for use in an arrangement according to the above further aspect of the present invention.

According to a fifth aspect of the present invention there is provided a method of using a medical device of the kind including a treatment indicator including an electrical temperature sensor and a circuit for recording the response of the temperature sensor to elevated temperature and the time for which the device is subject to elevated temperature, the method including the steps of using the medical device on a patient, removing the medical device from the patient, subsequently subjecting the device to a decontamination process including a time at an elevated temperature such that the time at the elevated temperature is recorded by the treatment indicator, subsequently reading the treatment indicator with a separate reader to determine whether or not the device has been correctly decontaminated, and reusing the device on a patient only if the reader indicates that the device has been correctly decontaminated.

The medical device is preferably a tracheostomy tube.

According to a sixth aspect of the present invention there is provided a medical device for use in a method according to the above fifth aspect of the present invention]

According to a seventh aspect of the present invention there is provided an arrangement of a medical device and a reader for use in a method according to the above fifth aspect of the present invention.

A tracheostomy tube, according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the tracheostomy tube; and

Figure 2 is a simplified chart indicating typical treatment cycles.

With reference first to Figure 1 there is shown a medical device in the form of a tracheostomy tube 1 having a curved shaft 10, a mounting flange 11 and a coupling 12. The shaft 10 has a circular section and is curved along its length from its forward, patient end 13 to its rear, machine end 14. The shaft 10 could have an inflatable sealing cuff towards its patient end but, in the present example, is shown as being uncuffed. The shaft 10 is typically made of a flexible plastics material, such as silicone, PVC or polyurethane.

The coupling 12 is mounted at the rear, machine end 14 of the shaft 10. The coupling 12 has an outer slightly tapered coupling surface 16 adapted to receive in mating engagement a cooperating female coupling (not shown) at one end of tubing extending to a ventilator. The interior surface 17 of the coupling 12 is adapted to receive the hub at the machine end of a removable inner cannula (not shown).

The flange 11 is mounted on the tube 1 between the forward end of the coupling 12 and the machine end 14 of the shaft 10. The flange 11 is generally rectangular with curved opposite longer sides and projects radially outwards from the tube. Towards opposite ends, the flange 11 has two D-shape mounting apertures 21 and 22 adapted to receive opposite ends of a neck strap (not shown) by which the tube 1 is stabilised on the patient. The flange 11 is mounted with the coupling 12 by two narrow webs 23 and 24, which allow the flange to flex relative to the coupling so that it can conform to the patient's anatomy in the region of the tracheostomy. As so far described the tracheostomy tube 1 is entirely conventional.

The tube 1 differs from previous tubes by the provision of a treatment indicator 30 arranged to provide a warning when the tube has been treated by a decontamination process involving an elevated temperature, such as autoclaving. The indicator 30 could be mounted on the rear face 25 of the flange 11, that is, the side facing away from the skin surface. On one side of the rear face 25 the flange 11 has a shallow recess 26 in which the indicator 30 is mounted. The indicator can be mounted anywhere on the tube 1 but is preferably on a component that cannot easily be removed and replaced. In silicone tubes the indicator could be integrally mounted. It is also possible that in-mould printed labels could be deployed in other materials, such as polyurethane, PVC and thermoplastic elastomers TPE.

The treatment indicator 30 is provided by an RFID tag including a temperature sensor 31 and a circuit with a timer 32 and a recorder or store 33. The indicator 30 may also include a pressure sensor (not shown). The indicator 30 may be powered by the output of the temperature sensor 31 or by a power source such as a battery or capacitor charged by an output from a separate, remote RFID reader 40.

The treatment indicator 30 is arranged to record the temperature changes to which the tube is exposed. For example, Figure 2 is a chart indicating four different temperature cycles, indicated "A" to "D".

The baseline of the chart at around 20°C shows when the tube 1 is being stored and not used during a surgical procedure. Cycle "A" shows a rise to 37°C indicating that the tube has been inserted in the body. After a time at body temperature the temperature drops briefly back to the baseline and then rises to around 130°C indicative that the tube is subject to autoclave treatment. The time ΪΑ for which the tube 1 is subject to this temperature is sufficient for effective sterilisation. Cycle "B", however, indicates a second surgical procedure followed by a heat treatment but in this case the temperature is below that for effective sterilisation. Cycle "C" shows a further surgical procedure and subsequent temperature treatment that does reach a sufficiently high temperature but this is only maintained for a short time tc insufficient to ensure effective sterilisation. Cycle "D" shows a fourth surgical procedure in the body but this is not followed by any treatment at elevated temperature.

In use, when the clinician is presented with a tube 1 that is not in the manufacturer's original packaging, he or she scans the tube with the RFID reader 40 to determine whether or not the tube has been passed through a cleaning cycle following any previous use. The reader 40 may include a graphics screen 41 on which a temperature/time chart is displayed in the manner illustrated in Figure 2. Alternatively, the temperature and time information could be presented numerically in table form. Or, the reader 40 could just give a "SAFE" output (if the tube has not been previously exposed to body temperature, or if any body temperature excursion is followed by a treatment temperature that is high enough and for sufficient time) or an "UNSAFE" output (if the tube has been raised to body temperature and has not subsequently been effectively heat treated).

Where the treatment indicator includes a pressure sensor this would be used to confirm that the pressure during the heat treatment had risen sufficiently for effective autoclaving.

The arrangement of the present invention enables medical devices to be re-used safely. Many medical facilities cannot afford to use medical devices that have to be disposed of after a single use so are forced to reuse the devices after suitable cleaning. The

arrangement of the present invention enables a reliable record to be maintained of the entire lifetime cleaning of each device. It also enables a device that has not been correctly sterilised to be identified easily. One advantage of the present invention is that it enables any warning to be provided on a reader separate from the device itself and not visible to the patient so that there is no risk of unduly alarming the patient.

It will be appreciated that the invention is not confined to use with tracheostomy tubes but could be used with other medical devices that might be reused, such a laryngeal masks, rubber endobronchial tubes, urology catheters and others.

Claims

1. A medical device (1) including a treatment indicator (30), characterised in that the treatment indicator (30) includes an electrical temperature sensor (31), a circuit (32, 33) for recording the response of the electrical temperature sensor (31) to elevated temperature and the time for which the device (1) is subject to elevated temperature, that the treatment indicator (30) is arranged to provide a response to an interrogating signal from a separate reader (40), the response being indicative of the elevatedj temperature and the time for which the device (1) has been subject to the elevated temperature.

2. A medical device (1) according to Claim 1 , characterised in that the treatment

indicator includes an RFID tag (30).

3. A medical device (1) according to Claim 1 or 2, characterised in that the treatment indicator (30) is arranged to record multiple cycles of elevated temperature.

4. A medical device according to any one of the preceding claims, characterised in that the medical device is a tracheal tube (1).

5. A reader (40) for use with a medical device (1) according to any one of the preceding claims.

6. An arrangement including a medical device accordmg to any one of Claims 1 to 4 and a reader (40) for reading the treatment indicator (30) on the medical device (1).

7. An arrangement according to Claim 6, characterised in that the reader (40) includes a display (41) on which a temperature/time chart is displayed.

8. A reader (40) for use in an arrangement according to Claim 6 or 7.

9. A method of using a medical device (1) of the kind including a treatment indicator (30) including an electrical temperature sensor (31) and a circuit (32, 33) for recording the response of the temperature sensor (31) to elevated temperature and the time for which the device (1) is subject to elevated temperature, the method including the steps of using the medical device (1) on a patient, removing the medical device (1) from the patient, subsequently subjecting the device (1) to a decontamination process including a time at an elevated temperature such that the time at the elevated temperature is recorded by the treatment indicator (30), subsequently reading the treatment indicator (30) with a separate reader (40) to determine whether or not the device (1) has been correctly decontaminated, and reusing the device (1) on a patient only if the reader (40) indicates that the device (1) has been correctly

decontaminated.

10. A method according to Claim 9 wherein the medical device is a tracheostomy tube (1)·

11. A medical device (1) for use in a method according to Claim 9 or 10.

12. An arrangement of a medical device (1) and reader (40) for use in a method

according to Claim 9 or 10.