Patent Description:
Arterial lines are routinely used in critical care areas for sampling arterial blood to measure blood pressure, gases, glucose and electrolytes. Venous lines may also be used for such monitoring, and may also be used for drug delivery. Infusions, such as a saline solution may be used to keep the line open. Patients may be harmed if the wrong infusion is given to keep the line open or when poor sampling leads to delayed or inappropriate treatment,.

<CIT> dicusses an apparatus and method for automatically and periodically measuring the level of a patient's blood glucose when a patient has a catheter in a blood vessel. A wearable, disposable test unit is attached by air, fluid and electric lines to a bedside monitor. The test unit has means for measuring blood glucose. A chamber in the unit contains a pneumatic pump which draws blood into the device and then expels all but a small residual portion of blood back into the patient's blood vessel catheter. A testing area is provided adjacent the pumping chamber. A test is done either when the pumping chamber is filled with blood, or after the pumping chamber is emptied. The test cycle is repeated about every <NUM> seconds. Provision is made to automatically calibrate the device every few hours or whenever calibration is required.

<CIT> discusses apparatus, systems and methods related to monitoring intravenous fluids during administration to a subject. These apparatus, systems and methods provide near real-time monitoring of the identity of one or more components of an intravenous fluid. Preferably, the apparatus, systems and methods are directed to or effective for identifying one or more active pharmaceutical agents within an intravenous fluid during administration of the fluid to a subject.

<CIT> discusses methods and apparatuses related to measurement of analytes, including measurements of analytes in samples withdrawn from a patient, including glucose.

<CIT> discusses medical articles which exhibit a color change upon exposure to an analyte of interest and to methods of detecting analytes in bodily fluid using the same, including the detection of glucose.

<CIT> provides an implantable bioartificial active secretion system for providing a physiological regulating secretion such as insulin necessary for functionality of a physiologic activity such as glucose metabolism of a living-being host. The system includes a housing implantable within the host, in fluidic communication with tissue fluid indicative of a physiological regulating secretion need. A chamber within the housing contains a plurality of physiologically active, autonomously functioning, live secretory cells for producing the physiological regulating secretion. A continually operating two pump apparatus moves tissue fluid into contact with the secretory cells for pick up of the physiological regulating secretion for subsequent physiologically-effective dispensing into the host, while avoiding immunorejection of the host body or of the host to the secretory cells.

<CIT> discusses a syringe having a hub with an orifice, first and second barrels having an interior surface to form respective lumens, a valve, and a test indicator. The first and second barrels slideably receive respective first and second plungers for movement therein. The valve is operable to provide a fluidly communicative path between the orifice of the hub and the first and second barrel lumens. The test indicator is responsive to at least one characteristic of a bodily fluid, including glucose, the test indicator positioned to be exposed to any bodily fluid drawn into the first barrel lumen and visible from an exterior of the first barrel.

Aspects of the invention are as set out in the independent claims and optional features are set out in the dependent claims. Aspects of the invention may be provided in conjunction with each other and features of one aspect may be applied to other aspects.

Embodiments of the disclosure relate to a safety warning system that warns clinicians if a glucose containing solution is being used with an arterial or venous monitoring or flush system.

<FIG> shows an arterial pressure monitoring system <NUM> suitable for use with examples of the disclosure. Although an arterial pressure monitoring system <NUM> is shown and described, it will be appreciated that examples of the disclosure may be used with any system that is coupled to the vasculature, such as a venous monitoring system or an arterial or venous flush system.

The arterial pressure monitoring system <NUM> typically comprises an arterial line <NUM>, which has low compliance tubing for accuracy in monitoring. At one end of the line <NUM>, the system <NUM> comprises an indwelling cannula <NUM> for insertion into a patient from which arterial pressures are continuously measured. A port <NUM> allowing clinicians to draw blood samples as needed may be located upstream of the cannula <NUM>. A syringe <NUM> may also be coupled to the line <NUM> for drawing back blood or solution to clear the line <NUM> as necessary.

A three-way port <NUM>, such as a Luer® port, is coupled to the line <NUM> upstream of the port <NUM> and syringe <NUM>, and typically comprises a transducer. The three-way port <NUM> and transducer allows clinicians to regulate flow in the line <NUM> and transforms the mechanical energy of the arterial pressure through the line <NUM> into an electrical signal for display as a waveform by a haemodynamic monitor <NUM>. A bag of pressurised medical fluid <NUM>, typically at a pressure of at least <NUM> mmHg, is coupled to the three-way port <NUM>, typically via a spike, and provides a steady flush of an infusion fluid, for example of about <NUM> to <NUM>/hr through the line <NUM>. Typically a saline flush such as a solution or infusion of sodium chloride <NUM>% is used as the medical fluid for arterial lines.

Prior to use of the arterial pressure monitoring system <NUM> the line <NUM> has to be prepared. The line <NUM> is cleared of gas as this may be dangerous to patients and may affect the pressure reading recorded by the monitor <NUM>. To clear the line <NUM>, a clinician may squeeze the three-way port <NUM> to open it up and allow a higher flow rate of fluid to flow through it. For example, by squeezing the three-way port <NUM>, the flow rate may increase up to <NUM>/hr or greater. A medical fluid is used to clear the gas. Once the gas is cleared, the medical fluid is maintained at pressure and a constant flow rate, for example at about <NUM> to <NUM>/hr. This is in part to counter the natural pressure of an artery into which the cannula is inserted, in part to keep the line <NUM> open and prevent clotting, and in part to ensure effective monitoring of the patient.

As noted above, glucose containing solutions should not be used in arterial monitoring or flush systems because this can cause contamination of samples with glucose and incorrect blood glucose readings. In a clinical environment a bag of glucose solution and a bag of saline solution may look very similar. Embodiments of the disclosure may address these problems by providing a safety warning system that detects whether glucose has been used and provides an indication to the user, such as a clinician, typically a visual indication.

Embodiments of the claims may do this by providing, as shown in <FIG>, a safety warning system <NUM> comprises a receptacle <NUM> for the clinician to flush the fluid, for example the initial gas in the line <NUM> and a first quantity of the solution, into. The system <NUM> also comprises an indicator <NUM> arranged to contact the fluid that provides an indication of whether the fluid comprises glucose. The receptacle <NUM> may be expandable to receive the fluid, or as shown in <FIG>, <FIG> and <FIG>, may comprise a gas release path <NUM> to enable the fluid to displace gas to contact the indicator <NUM>.

Expandable receptacles may include receptacles <NUM> that are themselves configured to expand, such as a balloon (as described in <FIG>), or receptacles <NUM> that are configured to expand so that a fluid receiving cavity inside the receptacle increases in volume, such as a syringe and plunger (as described in <FIG>).

It will be appreciated from the discussion above that the embodiments shown in the Figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims.

In more detail, <FIG> shows a bag of medical fluid <NUM> coupled to a medical or surgical line <NUM>. In this example the medical fluid is a liquid saline solution. The line <NUM> comprises a branch downstream of the bag of medical fluid <NUM> and on one of the branches a receptacle <NUM> is coupled to the line <NUM>. The other branch provides an outlet. In other examples, however, the line <NUM> does not have a branch and the receptacle <NUM> is coupled to the outlet of the line <NUM> (for example, as shown in <FIG> and as described below). In such examples, the safety warning system <NUM> may be provided as a cap to the line <NUM>, and may need to be removed and optionally discarded before the line <NUM> is able to be used. For example, the cap may inhibit the line <NUM> from being connected to the patient until it is removed. For example, the safety warning system <NUM> is configured to be disposable. Providing the safety warning system <NUM> so that it couples to the outlet of the line <NUM> may also help to keep the line <NUM> sterile prior to use, and because it has to be removed before the line is coupled to a patient, it is more prominent to a clinician if the indicator <NUM> provides an indication of whether the fluid comprises glucose. In some examples, the safety warning system <NUM> is provided pre-coupled to the line <NUM> so that a user such as a clinician does not forget to couple it to the line <NUM> prior to use, who has to take an active step of removing the safety warning system <NUM> prior to connecting the line <NUM> to a patient.

Other components such as those described above in relation to <FIG>, such as the three-way port <NUM>, may also be coupled to the line upstream of the safety warning system <NUM> and downstream of the bag of medical fluid <NUM>.

The safety warning system <NUM> shown in <FIG> comprises a receptacle <NUM> comprising a syringe with a gas release path <NUM>, comprising a gas release valve, instead of a plunger. The receptacle <NUM> has a cavity having a volume of at least <NUM>, although it may have a volume of at least <NUM> or at least <NUM>. Inside the receptacle <NUM> is an indicator <NUM> which in this example is a chemical indicator, such as glucose oxidase and/or peroxidase. In the example shown, the indicator <NUM> is configured to change colour in contact with a glucose-containing solution. For example, the indicator <NUM> may comprise a dye, such as toluene blue, that is released upon a chemical reaction between the indicator and a glucose-containing solution. Other nanoparticle, nanorod and nano-chain based indicators may be used. Indicators based on the Fenton reaction and indicators based on a hydrogen bubble porous gold technique may also be used.

The indicator <NUM> is adapted to contact the fluid from the line <NUM>, and in the example shown in <FIG>, is arranged to contact fluid in the receptacle <NUM>. The safety warning system <NUM> comprises a one-way valve <NUM> to one side of the indicator <NUM> in the receptacle <NUM>, and a gas release valve that acts as a gas release path <NUM> to the other side of the indicator <NUM> in the receptacle <NUM> so that fluid from the line <NUM> comes into contact with the indicator <NUM>. In the example shown in <FIG>, the one-way valve <NUM> is at one end of the receptacle <NUM>, and the gas release valve is at the other end of the receptacle <NUM>, although the gas release valve may be located elsewhere on the receptacle <NUM>. In other examples, however, the safety warning system <NUM> does not comprise a one-way valve <NUM>.

The line <NUM> is adapted for connecting to a patient. The receptacle <NUM> is configured to receive fluid from the line <NUM> so that fluid received from the line <NUM> can be displaced into the cavity. The one-way valve <NUM> is configured to allow fluid to flow from the line <NUM> into the receptacle <NUM>. The gas release valve provides a gas release path <NUM> and is operable to enable fluid to displace gas to contact the indicator <NUM>. For example, the gas release valve is operable to allow medical fluid, such as liquid saline, to flow down the line <NUM> and through the one-way valve <NUM> into the receptacle <NUM>, thereby displacing gas in both the line <NUM> and inside the receptacle <NUM>.

The gas release valve in this example is configured to block in contact with liquid. The gas release valve may comprise a porous membrane, such as an air-permeable membrane, for example a microporous hydrophobic membrane (MHM). Depending on the membrane, the pore size may range from <NUM> to more than <NUM>. The membrane may be configured to react to the presence of liquid. For example, the membrane may swell in contact with liquid, or may react with the liquid, so that the membrane is no longer porous or air-permeable. For example, the membrane may comprise a chemical that reacts with the liquid. The membrane may comprise polymers such as polytetrafluorethylene (PTFE), polypropylene, polyvinylidene difluoride (PVDF) and acrylic copolymers. The gas release valve is configured to allow gas to flow therethrough, but prevents or inhibits the flow of liquid therethrough.

In this way, the receptacle retains liquid flushed through the line <NUM>. This may allow a clinician to prep and flush the line by a patient's bedside, without requiring a sink or drain. It also means that solution flushed through the line <NUM>, and the indicator <NUM>, is not lost.

In use, a clinician wishing to set up, for example an arterial monitoring system, attaches the receptacle <NUM> to an outlet of the line <NUM>, and a bag of medical fluid <NUM> to an input of the line <NUM>. An optional spike may be used to pierce the bag of medical fluid <NUM> and couple the line <NUM> to the bag of medical fluid <NUM>. The spike may be irreversible to inhibit removal of the bag of medical fluid <NUM>, for example the spike may be barbed, for example the spike may comprise a unidirectional barb. The clinician allows the medical fluid to flow through the line <NUM> so that any initial gas in the line <NUM> is displaced by the medical fluid. The clinician may apply pressure to the fluid to allow it flow through the line <NUM> and into the receptacle <NUM>, for example the bag of medical fluid <NUM> may be pressurised or may be squeezed by a device to provide pressure to the fluid.

The fluid in the line <NUM>, comprising any initial gas in the line <NUM> and the medical fluid, flows via bulk flow through the one-way valve <NUM> and into the cavity of the receptacle <NUM>. To ensure the fluid flows into the safety warning system <NUM>, the user may wish to block off the other branch in the line <NUM> (if present), for example using a tap or valve such as a three-way port such as a Luer® port. The gas release valve allows the gas to flow out of the receptacle <NUM>, but because it blocks in contact with liquid, it blocks to prevent the medical fluid (which in this example is liquid saline), and the chemical indicator <NUM>, from escaping from the receptacle <NUM>.

If the solution flowing through the line <NUM> comprises glucose, the indicator <NUM> provides a visual indication to the clinician, and in this case will change colour (for example to a dark blue colour) to indicate to the clinician that a glucose-containing solution has been used. Once the line <NUM> has been flushed, the safety warning system <NUM> may in some examples be removed before use such as in an arterial monitoring system, or in other examples may remain coupled to the line <NUM>.

In the example described above the gas release valve blocks in contact with liquid. In other examples, the safety warning system <NUM> may comprise a user-operated tap or valve to allow fluid to escape from the receptacle <NUM> and/or the line <NUM>. For example, the receptacle <NUM> may comprise a valve or tap that has a first configuration that is open and a second configuration that is closed, and that may be biased to rest in the second configuration. For example, the tap or valve may open when operated by a clinician but closes automatically again at rest.

Although the indicator <NUM> shown in <FIG> is arranged to contact fluid inside the receptacle <NUM>, in other examples the indicator <NUM> may be arranged to contact fluid in the one-way valve <NUM> or in the gas release path <NUM>. The indicator <NUM> may be arranged to be in a wall of the receptacle <NUM>, or in a wall of the one-way valve <NUM> or gas release path <NUM>. For example, the indicator <NUM> may be arranged to be on the inside wall of the one-way valve <NUM>, so that it contacts fluid that has just passed through the one-way valve <NUM>.

<FIG> shows another example safety warning system <NUM> that comprises an expandable receptacle <NUM> to receive fluid from a line <NUM>. As described above in relation to <FIG>, <FIG> shows a bag of medical fluid <NUM> coupled to a medical or surgical line <NUM>. The medical fluid <NUM> in this example is again a liquid saline solution. A receptacle <NUM> comprising a cavity is coupled to the outlet of the the line <NUM> downstream of the bag of medical fluid <NUM>. In other examples, however, the line <NUM> has a branch and the receptacle <NUM> is coupled to the line <NUM> via the branch. Other components such as those described above in relation to <FIG>, such as the three-way port <NUM>, such as a three-way Luer® valve, may also be coupled to the line upstream of the safety warning system <NUM> and downstream of the bag of medical fluid <NUM>.

The safety warning system <NUM> shown in <FIG> comprises a receptacle <NUM> broadly in the shape of a balloon. The safety warning system <NUM> comprises a one-way valve <NUM> interposed between the receptacle <NUM> and the line <NUM>. As with the example described above in relation to <FIG>, the receptacle <NUM> comprises an indicator <NUM> which in this example is a chemical indicator which changes colour in contact with a glucose-containing solution. The indicator <NUM> is adapted to contact the fluid from the line <NUM>, and in the example shown in <FIG>, is arranged to contact fluid in the receptacle <NUM>.

The line <NUM> is adapted for connecting to a patient. The receptacle <NUM> is configured to receive fluid from the line <NUM>. The one-way valve <NUM> is configured to allow fluid to flow from the line <NUM> into the receptacle <NUM>. The receptacle <NUM> is expandable and configured to expand to receive fluid from the line <NUM>. The receptacle <NUM> may have a volume of at least <NUM>, or be expandable to have a volume of at least <NUM>, or at least <NUM> or at least <NUM>. In the example shown in <FIG>, the receptacle <NUM> is configured to expand to receive a volume of fluid greater than or equal to the internal volume of the line <NUM>.

In the example shown in <FIG>, the receptacle <NUM> is closed so that it retains fluid received from the line <NUM>. This may allow a clinician to prep and flush the line by a patient's bedside, without requiring a sink or drain. It also means that solution flushed through the line <NUM>, and the indicator <NUM>, is not lost.

In use, as with the example described above in relation to <FIG>, a clinician wishing to set up, for example an arterial monitoring system, attaches the receptacle <NUM> to an outlet of the line <NUM>, and a bag of medical fluid <NUM> to an input of the line <NUM>. The clinician allows the medical fluid to flow through the line <NUM> so that any initial gas in the line <NUM> is displaced by the medical fluid. The fluid in the line <NUM>, comprising any initial gas and the medical fluid, flows via bulk flow through the one-way valve <NUM> and into the cavity in the receptacle <NUM>. Because the receptacle <NUM> is closed, it expands to receive the fluid comprising the gas and the medical fluid. Because the receptacle <NUM> is closed, it also prevents medical fluid, and in this case the chemical indicator, from escaping from the receptacle <NUM>.

<FIG> shows another example safety warning system <NUM> that, as with the example described above in relation to <FIG>, comprises an expandable receptacle <NUM> to receive fluid from a line <NUM>. As described above in relation to <FIG> and <FIG>, <FIG> shows a bag of medical fluid <NUM> coupled to a medical or surgical line <NUM>. The medical fluid in this example is again a liquid saline solution. The line <NUM> comprises a branch downstream of the bag of medical fluid <NUM> and on one of the branches a receptacle <NUM> comprising a cavity is coupled to the line <NUM>. In other examples, however, the line <NUM> does not have a branch and the receptacle <NUM> is coupled to an outlet of the line <NUM>. Other components such as those described above in relation to <FIG>, such as the three-way port <NUM>, may also be coupled to the line upstream of the safety warning system <NUM> and downstream of the bag of medical fluid <NUM>.

The safety warning system <NUM> shown in <FIG> comprises a receptacle <NUM> that is a syringe, and may be the syringe <NUM> shown in <FIG>. The safety warning system <NUM> may also comprise an optional one-way valve <NUM> (not shown) interposed between the receptacle <NUM> and the line <NUM>. As with the example described above in relation to <FIG> and <FIG>, the receptacle <NUM> comprises an indicator <NUM> which in this example is a chemical indicator which changes colour in contact with a glucose-containing solution. The indicator <NUM> is adapted to contact the fluid from the line <NUM>, and in the example shown in <FIG>, is arranged to contact fluid in the receptacle <NUM>.

As with the example described above in relation to <FIG>, the line <NUM> is adapted for connecting to a patient. The receptacle <NUM> is configured to receive fluid from the line <NUM>. The receptacle <NUM> is operable by a user, such as a clinician, to draw fluid from the line <NUM>. The receptacle <NUM> is expandable and when operated by the user expands to receive fluid from the line <NUM>. The receptacle <NUM> shown in <FIG> expands so that a fluid receiving cavity inside the receptacle <NUM> increases in volume. In the example shown, the receptacle <NUM> (in this case a syringe) expands by forcing a plunger of the syringe outwards, to increase the internal volume of the syringe. In the example shown in <FIG>, the receptacle <NUM> is also configured to expand to receive a volume of fluid greater than or equal to the internal volume of the line <NUM>.

In use, as with the example described above in relation to <FIG> and <FIG>, a clinician wishing to set up, for example an arterial monitoring system, attaches the receptacle <NUM> to an outlet of the line <NUM>, and a bag of medical fluid <NUM> to an input of the line <NUM>. The clinician allows the medical fluid to flow through the line <NUM> so that any initial gas in the line <NUM> is displaced by the medical fluid. The clinician operates the receptacle <NUM> to draw fluid from the line <NUM>, comprising any initial gas and the medical fluid, into the cavity of the receptacle <NUM> via bulk flow. As the receptacle <NUM> is operated by the clinician, its internal volume expands to receive the fluid comprising the gas and the medical fluid. Because the receptacle <NUM> is closed, it also prevents medical fluid, and in this case the chemical indicator, from escaping from the receptacle <NUM>.

As with the examples described above, if the solution flowing through the line <NUM> comprises glucose, the indicator <NUM> provides a visual indication to the clinician, and in this case will change colour (for example to a dark blue colour) to indicate to the clinician that a glucose-containing solution has been used. Once the line <NUM> has been flushed, the safety warning system <NUM> may in some examples be removed before use such as in an arterial monitoring system, or in other examples may remain coupled to the line <NUM>.

<FIG> shows another example safety warning system <NUM> that comprises a receptacle <NUM> broadly in the shape of a cylinder with a gas release path <NUM>. The safety warning system <NUM> comprises a port <NUM> at one end of the receptacle <NUM>, and is sealed at the other end. The receptacle <NUM> comprises a cavity and is coupled to a branch in a medical or surgical line <NUM> via the port <NUM>.

Inside the receptacle <NUM> is an indicator <NUM> which in this example is a chemical indicator which changes colour in contact with a glucose-containing solution. The indicator <NUM> is adapted to contact the fluid from the line <NUM>, and in the example shown in <FIG>, is arranged to contact fluid in the receptacle <NUM>.

The medical or surgical line <NUM> is coupled to a bag of medical fluid <NUM>, which in this example is again a liquid saline solution. The branch in the line <NUM> to which the safety warning system is coupled provides a gas release path <NUM> for gas to escape the receptacle <NUM>.

The line <NUM> is adapted for connecting to a patient. The receptacle <NUM> is configured to receive fluid from the line <NUM>. The port <NUM> is configured to allow fluid to flow from the line <NUM> into the receptacle <NUM>, and to allow gas to escape from the receptacle <NUM> via the gas release path <NUM>. The gas release path <NUM> enables fluid to displace gas to contact the indicator <NUM> in the receptacle <NUM>. For example, the gas release path <NUM> allows medical fluid, such as liquid saline, to flow along the line <NUM> and through the port <NUM> into the receptacle <NUM>, thereby displacing gas in both the line <NUM> and inside the receptacle <NUM>.

In use, a clinician wishing to set up, for example an arterial monitoring system, attaches the receptacle <NUM> to an outlet of the line <NUM>, and a bag of medical fluid <NUM> to an input of the line <NUM>. The clinician allows the medical fluid to flow through the line <NUM> so that any initial gas in the line <NUM> is displaced by the medical fluid. The fluid in the line <NUM>, comprising the initial gas and the liquid, flows via bulk flow through the port <NUM> and into the cavity of the receptacle <NUM>. The port <NUM> and gas release path <NUM> allows any gas in the line <NUM> and in the receptacle <NUM> to escape thereby being displaced by liquid.

<FIG> shows another example safety warning system <NUM> that comprises a receptacle <NUM> broadly in the shape of a cup with a gas release path <NUM>. The safety warning system <NUM> comprises a one-way valve <NUM> at one end of the receptacle <NUM>, and is open at the other end. The receptacle <NUM> comprises a cavity and is coupled to a branch in a medical or surgical line <NUM> via the one-way valve <NUM>.

The medical or surgical line <NUM> is coupled to a bag of medical fluid <NUM>, which in this example is again a liquid saline solution. The open end of the receptacle <NUM> provides a gas release path <NUM> for gas to escape the receptacle <NUM>.

The line <NUM> is adapted for connecting to a patient. The receptacle <NUM> is configured to receive fluid from the line <NUM>. The one-way valve <NUM> is configured to allow fluid to flow from the line <NUM> into the receptacle <NUM>. The gas release path <NUM> enables fluid to displace gas in the receptacle <NUM> to contact the indicator <NUM> in the receptacle <NUM>. For example, the gas release path <NUM> allows medical fluid, such as liquid saline, to flow along the line <NUM> and through the one-way valve <NUM> into the receptacle <NUM>, thereby displacing gas in both the line <NUM> and inside the receptacle <NUM>.

In use, a clinician wishing to set up, for example an arterial monitoring system, attaches the receptacle <NUM> to an outlet of the line <NUM>, and a bag of medical fluid <NUM> to an input of the line <NUM>. The clinician allows the medical fluid to flow through the line <NUM> so that any initial gas in the line <NUM> is displaced by the medical fluid. The fluid in the line <NUM>, comprising the initial gas and the liquid, flows via bulk flow through the one-way valve <NUM> and into the cavity of the receptacle <NUM>. The gas release path <NUM> allows gas in the line <NUM> and in the receptacle <NUM> to escape thereby being displaced by liquid which fills the receptacle <NUM>.

In the example shown in <FIG>, the receptacle <NUM> is generally held upright to prevent the loss of liquid, although in other examples the receptacle may comprises a valve to enable fluid such as gas to escape the receptacle <NUM>, such as a gas release valve. For example, the receptacle <NUM> may comprise a valve or tap, such as a Luer<ID fitting, that has a first configuration that is open and a second configuration that is closed, and that may be biased to rest in the second configuration. For example, the tap or valve may open when operated by a user but closes automatically again at rest.

As with the examples described above, if the solution flowing through the line <NUM> comprises glucose, the indicator <NUM> provides a visual indication to the clinician, and in this case will change colour (for example to a dark blue colour) to indicate to the clinician that a glucose-containing solution has been used. Once the line <NUM> has been flushed, the safety warning system <NUM> may in some examples be removed before use such as in an arterial or venous monitoring system, or in other examples may remain coupled to the line <NUM>.

The safety warning system <NUM> described above may be provided in a sealed sterile pack, for example as part of a giving set, for example for use as an arterial or venous monitoring or flush system.

Providing the safety warning system <NUM> as part of giving set may mean that a user such as a clinician is presented with a single, user-openable, sterile pack that contains many, if not all, of the components necessary for an arterial or venous monitoring or flush system to be prepared for use. The single sterile pack may hold the components in a common enclosure, which can be opened to provide access to the components by a single mechanical action, such as tearing or puncturing a wall of that enclosure. The user knows that all of the components in the pack are sterile and safe ready for use, and that they are compatible and will fit together. Providing the giving set may also mean that incorrect or incompatible components are not used incorrectly or by mistake.

The safety warning system <NUM> may be supplied already coupled to the line <NUM>, so that a clinician does not forget to attach it to the line <NUM>, for example to the outlet of the line <NUM> so that the user has to take an active step of removing the safety warning system <NUM> before the line <NUM> can be used. The giving set may be provided as a sealed sterile pack. The giving set may comprise many of the components described above in relation to <FIG>. For example, the giving set may comprise a medical or surgical line <NUM>, a spike for insertion into a bag of medical fluid <NUM> (such as the spike described above), configured to couple the bag <NUM> to the medical or surgical line <NUM>, and a safety warning system for detecting glucose in the medical fluid. The giving set may or may not comprise a medical or surgical line <NUM>, and may or may not comprise a bag of medical fluid <NUM>. The safety warning system <NUM> may be the safety warning system described above in respect of any of <FIG>, or may be a variant thereof.

For example, a giving set for use as an arterial monitoring or flush system may comprise a medical or surgical line <NUM>, a spike for insertion into a bag of medical fluid <NUM> and configured to irreversibly couple the bag <NUM> to the medical or surgical line <NUM>, a receptacle <NUM> for receiving the medical fluid from the line <NUM> and an indicator <NUM> arranged to contact the medical fluid and configured to provide an indication of whether the fluid comprises glucose. The receptacle <NUM> may allow gas to be flushed from the medical or surgical line <NUM> and retain medical fluid received from the line <NUM>.

The giving set may further comprise at least one of a three-way port <NUM> and/or a transducer for monitoring a parameter of the fluid in the medical or surgical line <NUM>, a cannula <NUM> for insertion into a patient, a port <NUM>, and a syringe <NUM>.

Components of the giving set may also be coupled together, for example mechanically coupled, so that components are not lost or misplaced. For example, the safety warning system <NUM> may be mechanically coupled to the line <NUM>, for example via a lanyard, so that even if the safety warning system <NUM> is removed from the line <NUM> it is not lost or misplaced. In this way, if the safety warning system <NUM> provides an indication that glucose is present, even if the safety warning system <NUM> is removed from an outlet of the line <NUM>, it remains coupled to the line <NUM> thereby providing an indication to the user of whether the line <NUM> contained glucose.

Another example giving set may comprise two receptacles configured to perform different clinical functions. For example, the giving set may comprise a first receptacle <NUM>, such as a syringe for receiving fluid from a medical or surgical line <NUM>, that is configured to prepare the line <NUM> for use, for example by displacing any gas in the line <NUM> with medical liquid such as liquid saline by drawing liquid saline from a bag of medical fluid <NUM> coupled to the line <NUM>. The giving set also comprises a second receptacle <NUM> such as a syringe for drawing samples of fluid such as blood from the line <NUM> for testing, although other receptacles may be used. The first receptacle <NUM> comprises a safety warning system <NUM> such as the safety warning system <NUM> described above in relation to <FIG>. The second receptacle may comprise an anticoagulant. The medical or surgical line may be the medical or surgical line <NUM> described above in relation to <FIG>. Providing, in a single sterile pack, a first receptacle <NUM>, along with the second receptacle <NUM> that is adapted for drawing samples of fluid from the line <NUM>, means that a user, such as a clinician, has to take an active step of discarding the first receptacle <NUM> when using the second receptacle <NUM>. A user is therefore reminded to use the specific first receptacle <NUM> (comprising the safety warning system <NUM>) provided in the pack with the second receptacle <NUM>, thus improving uptake in use of the safety warning system <NUM>.

An example giving set <NUM> is shown in <FIG>. The giving set <NUM> shown in <FIG> is a sealed sterile pack. The sealed sterile pack comprises a first receptacle <NUM> and a second receptacle <NUM>.

The first receptacle <NUM> shown in the example of <FIG> is a syringe, and is configured to receive fluid from a medical or surgical line. The first receptacle <NUM> comprises an indicator <NUM> arranged to contact medical fluid received, for example drawn or displaced, from a medical or surgical line, and is configured to provide an indication of whether the fluid comprises glucose. In the example shown in <FIG>, the first receptacle <NUM> comprises a safety warning system <NUM>, for example the safety warning system <NUM> described above. The first receptacle <NUM> is adapted to draw fluid from the line <NUM> such that any gas in the line <NUM> is removed from the line <NUM>. In this way the cavity of the first receptacle <NUM> may act as a deadspace. In some examples, the first receptacle <NUM> may have a larger cavity than the second receptacle <NUM> to perform this function. For example, the first receptacle <NUM> may have a cavity with a volume of at least <NUM>, at least <NUM>, at least <NUM>.

The second receptacle <NUM> shown in the example of <FIG> is also a syringe, and is adapted for sampling fluid, such as blood, from a medical or surgical line <NUM>. In the example shown in <FIG>, the second receptacle <NUM> is smaller than the first receptacle <NUM>. The second receptacle <NUM> comprises an anticoagulant <NUM> such as Heparin for this purpose. The second receptacle <NUM> may have a cavity with a volume of at least <NUM> and less than <NUM>.

In use, the first receptacle <NUM> is operated by a user, such as a clinician, to draw an initial quantity of fluid from the medical or surgical line <NUM>. This may be to prepare the line for use. If glucose is present in the fluid, the indicator <NUM> in the first receptacle <NUM> provides an indication to the user so that the user knows that the fluid contains glucose. If glucose is not present, the user may then connect the second receptacle <NUM> to the line <NUM> for sampling from the line <NUM>. Because the samples drawn from the line <NUM> may contain blood, the second receptacle <NUM> comprises an anticoagulant such as Heparin to prevent clotting in the second receptacle <NUM> so that the sample may be effectively tested.

In some examples the first receptacle <NUM> and the second receptacle <NUM> are coupled together, for example mechanically coupled, such as via a lanyard. The first receptacle <NUM> and the second receptacle <NUM> may also be coupled together by being held in a common enclosure, such as a net or perhaps the sterile pack of the giving set. Coupling the two receptacles <NUM>, <NUM> together may help prevent the first receptacle <NUM>, comprising a safety warning system <NUM>, from being accidentally displaced or discarded, and may help to ensure the specific first receptacle <NUM>, comprising the safety warning system <NUM>, is used with the second receptacle <NUM>.

The giving set <NUM> may also comprise other components such as coupling means, such as a Luer® lock connector, for coupling or connecting the receptacles <NUM>, <NUM> to a line. The giving set <NUM> may also comprise the medical or surgical line <NUM>. The first receptacle <NUM> may be pre-coupled to the line <NUM> so that a clinician does not forget to couple the first receptacle <NUM> to the line <NUM> before use.

In all of the examples described above, the indicator <NUM> may be configured to provide an indication of whether the fluid comprises glucose when the concentration of glucose in solution is greater than or equal to <NUM> mMol, greater than or equal to <NUM> mMol, greater than or equal to <NUM> mMol.

In all of the examples described above, the indicator <NUM> may cause writing or words to be displayed such as GLUCOSE or DANGER or DO NOT USE, but many other examples or pictures or symbols are possible, such as a skull and crossbones. In some examples, if glucose is not present the indicator <NUM> may provide an indication to the user, for example the indicator <NUM> may provide a reassuring word such as SAFE or SAFE TO USE or the like or pictures or symbols could be displayed.

The indicator <NUM> may also be configured to remain in the receptacle <NUM>, <NUM> so as not to contaminate the line <NUM>. For example, the indicator <NUM> may be highly viscous, for example more viscous than the medical fluid, so that it does not flow out of the receptacle <NUM>. The indicator <NUM> may also be insoluble in a medical fluid such as a liquid saline solution. The indicator <NUM> may be porous, for example the indicator <NUM> may be a gel or integrated in a mesh or web-like structure, into which the medical fluid can soak in. The indicator <NUM> may be adhered to or integrated in to a surface of the safety warning system <NUM>, such as a wall of the receptacle <NUM>, <NUM>. For example, the indicator <NUM> may be a coating on a wall or surface of the receptacle <NUM>, <NUM>, the one-way valve <NUM> or the gas release path <NUM>. In such examples, a one-way valve <NUM> may not be necessary to prevent contamination of the line <NUM> because the indicator <NUM> will not flow into the line <NUM>. The indicator <NUM> may also be configured to draw fluid from the receptacle <NUM>, <NUM> and/or line <NUM>, for example via capillary action or diffusion.

Although the indicator <NUM> described above is a chemical indicator that changes colour in contact with a glucose-containing solution, in other examples the indicator <NUM> may be an electronic indicator. For example, an electronic indicator may be battery operated.

An indicator such as an electronic indicator may be integral to the safety warning system <NUM>. The electronic indicator may also be integral to line <NUM> such that the electronic indicator is adapted to contact fluid in the line <NUM>. The electronic indicator may be configured to draw a sample of fluid from the line <NUM>, for example via capillary action. The line <NUM> may provide a gas release path to enable fluid upstream in the line <NUM> to displace gas in the line adjacent to the electronic indicator to contact the electronic indicator.

An indicator <NUM> may also be part of other components of an arterial or venous monitoring system, such as the system described above in relation to <FIG>. For example, an indicator <NUM> may be part of a sampling system of an arterial or venous monitoring or flush system.

For example, an indicator <NUM> may be included as part of sampling connector in an arterial or venous monitoring or flush system, for example a sampling connector for use as an adaptor for a three-way tap arterial blood sampling device, such as that described in<CIT>. The three-way tap arterial blood sampling device may be configured to sample fluid from a line such as line <NUM> shown in <FIG>. The sampling connector may comprise at least two apertures in fluid communication via a fluid flow conduit and a one-way valve disposed to allow fluid to flow from the first aperture, through the fluid flow conduit and out of the second aperture, but not to allow fluid to flow into the second aperture and through the fluid flow conduit to the first aperture. The first aperture may be within a male end and the second aperture may be within a female end. The male end of the sampling connector may be a Luer® lock connector with an altered taper or altered dimensions so as to fit firmly or jam when connected to a female sampling port of the sampling device, such that the sampling connector is reversibly connectable to the sampling device and is difficult to disconnect from the sampling device, wherein in use a user is impeded from removing the sampling connector. An indicator <NUM> may be included as part of the sampling connector, for example, in the fluid flow conduit, or to one side of the one-way valve, for example as part of the second aperture.

An indicator <NUM> such as an electronic indicator may also be part of the three-way port <NUM> or the monitor <NUM> shown in <FIG>. For example, the electronic indicator may comprise a sensor that is included as part of the three-way port <NUM> shown in <FIG>, or as part of the transducer.

In some examples, an electronic indicator may comprise a sensor and a control unit. The sensor may be configured to contact fluid in a medical or surgical line, such as the line <NUM> described above, and send a signal to the control unit. The sensor may be adapted specifically to monitor glucose, or it may be adapted to monitor other parameters, such as a parameter of a patient such as blood pressure. The control unit may be configured to receive signals from the sensor and process the received signals to make a determination of whether the fluid contains glucose. In response to determining that the fluid contains glucose, the control unit may further be configured to provide an alert in response to the control unit determining the presence of glucose. The alert may comprise an alarm, such as an audible alarm and/or a visual alert. Additionally or alternatively, the control unit may be configured to inhibit or stop the flow of fluid through the line <NUM> in response the control unit determining the presence of glucose, for example by controlling a tap or valve coupled to the line <NUM>. For example, the alert may comprise a signal configured to inhibit or stop the flow of fluid through the line <NUM>.

The control unit may be included as part of the monitor <NUM> described above in relation to <FIG>. For example, the control unit may also be configured to receive signals relating to a parameter of a patient, for example a blood pressure, from the sensor or from a second sensor. The sensor may be the transducer in the three-way port <NUM> described above in relation to <FIG>. The control unit may be configured to process these received signals and make a determination of the parameter of the patient in addition to making a determination of whether fluid in the line <NUM> comprises glucose.

Although visual indications have been described above, the indicator <NUM> may additionally or alternatively be configured to provide an audible indication, such as an alarm or beep. For example, the monitor <NUM> may configured to provide an audible alarm.

In some examples the safety warning system <NUM> may be configured so that the fluid contacts the indicator <NUM> by at least one of capillary action and diffusion. For example, the safety warning system <NUM> may be a collar that surrounds the line <NUM>. The collar may comprise the indicator <NUM>, for example the indicator <NUM> may be integrated into a mesh or web that surrounds the line <NUM> and is adapted to contact fluid in the line <NUM>. The indicator <NUM> may be configured to draw fluid, for example liquid, from the line <NUM> via capillary action or diffusion, and comprises a gas release path <NUM> that allows any gas in the safety warning system <NUM> and the line <NUM> to be displaced by fluid.

In some examples the safety warning system <NUM> may also be configured to provide a back pressure to the line <NUM> sufficient for arterial monitoring, once the receptacle <NUM> has received the fluid from the line <NUM>. For example, the safety warning system is configured to provide a back pressure of at least <NUM>, at least <NUM>, at least <NUM> mmHg. This may allow the safety warning system <NUM> to remain coupled to the line <NUM> in use, for example in an arterial monitoring system such as the one shown in <FIG>, although of course the safety warning system <NUM> may be adapted for use with venous systems.

In some examples the receptacle <NUM> may be arranged to draw fluid from the line into the cavity. For example, the receptacle <NUM> may comprise a negative pressure region, for example a region with a pressure less than ambient, such as less than <NUM> atmosphere. For example, the receptacle <NUM> may have a cavity with a negative pressure region. The receptacle <NUM> may be evacuated, for example the receptacle <NUM> may comprise a vacuum. Fluid may be displaced from the line <NUM> into the receptacle. In such examples, the safety warning system <NUM> may comprise a valve or tap, for example coupled to the receptacle <NUM>, to open the cavity to the line <NUM> when the safety warning system <NUM> is coupled to the line <NUM>, to draw fluid from the line <NUM>. The receptacle <NUM> may also comprise a one-way valve <NUM> as described above to inhibit loss of the fluid once it has been received.

The safety monitoring system <NUM> may also comprise instructions for use by a clinician. For example, the receptacle <NUM> may comprise instructions printed thereon for use of the safety warning system <NUM>. A giving set may additionally or alternatively comprise instructions for use by a clinician. The instructions may comprise pictorial representations of how to use the receptacle, for example.

Although the bag of medical fluid <NUM> described in the examples above is a liquid saline solution, it will be understood that in other examples the medical fluid is not limited to liquid saline solutions.

In some examples a vessel such as a bag or syringe is supplied at an outlet of the arterial sampling system to receive fluid during the initial flushing process, the vessel containing some glucose detecting mechanism.

In some examples, the safety monitoring system <NUM> is a cap or elongated cap or length of tubing or the like which allows flushing of the arterial system through the cap wherein the fluid comes into contact with the colour changing detection medium, causing colour change. The colour change may be in the whole or a portion of the device or may spell out specific words, for example GLUCOSE or DANGER or DO NOT USE, but many other examples or pictures or symbols are possible. In one example, if glucose is not present a reassuring word such as SAFE or SAFE TO USE or the like or pictures or symbols could be displayed.

Aspects of the disclosure require the use of a glucose detector in the monitoring system, pressure transducing and flush tubing which is in contact with the fluid within the system or being removed from the system.

In one example this is an electronic glucose detector with an alarm state indicating that a glucose solution has been used in error and in another example it is a colour changing indicator.

In one example a colour change may spell warning words to alert the user that glucose is present.

In one example the glucose oxidase/colour indicator commonly used on blood or urine glucose test strips is used.

In one example a sampling connector may incorporate the colour change component.

In one example a quantity of glucose colour changing indicator is located in the sampling connector so that when fluid is drawn from the sampling connector it will be coloured if glucose is present thereby indicating to the clinician that an error has occurred.

In one example a vessel such as a bag or syringe is supplied at an outlet of the arterial sampling system to receive fluid during the initial flushing process, the vessel containing some glucose detecting mechanism.

Claim 1:
A safety warning system (<NUM>) for detecting glucose in an arterial or venous monitoring or flush system, wherein the monitoring or flush system comprises a medical or surgical line (<NUM>) for connecting to a patient, the line comprising an input configured to be coupled to a bag of a medical fluid, and at least one outlet, the safety warning system (<NUM>) comprising:
a receptacle (<NUM>), configured to be coupled to one of the at least one outlets of the line, into which the medical fluid (<NUM>) from the input is configured to be displaced from the line (<NUM>); and
a colour change indicator (<NUM>) arranged to contact the medical fluid (<NUM>) from the line and configured to provide a visual indication of whether the medical fluid (<NUM>) comprises glucose.