Sensor arrangement

Abstract

The present invention relates to a sensor arrangement (2) comprising a first portion (4) comprising a first sensor (6) and a second portion (8) comprising a second sensor (10), the first sensor (6) and second sensor (10) spaced apart in an axial direction (12) and configured to measure one or more property of a fluid vessel. A flexible and / or extendable element (14) extends between the first portion (4) and the second portion (8), such that the first portion (4) and the second portion (8) are movable with respect to one another between a retracted position and an extended position. The first portion (4) and the second portion (8) spaced apart in a transverse direction (15) in the extended configuration.

Description

[0001] Sensor arrangement

[0002] The present invention relates to a flow sensor, in particular, but not limited to, a flow sensor arrangement for insertion via a catheter.

[0003] Background of the Invention

[0004] A prior art flow sensor is shown schematically in figure 1. The sensor comprises a plurality of flow sensors, such as ultrasounds sensors. Two sets of sensors A are spaced apart from one another by a distance X, which corresponds to the direction of flow of the fluid to be measured in use.

[0005] The inventor has numerous problems with the prior art arrangement. The sensitivity of the flow sensor is generally proportional to the distance X between the sensors A. It is therefore desirable to increase the distance X. However, increasing the distance between sensors increases the width of the sensor arrangement. This makes the sensor difficult to insert into a constricted space, for example, an incision or via a catheter.

[0006] The present invention aims to overcome or ameliorate one or more of the above problems.

[0007] Statement of Invention

[0008] According to a first aspect, there is provided: a sensor arrangement comprising: a first portion comprising a first sensor and a second portion comprising a second sensor, the first sensor and second sensor spaced apart in an axial direction and configured to measure one or more property of a fluid vessel; and an element extending between the first portion and the second portion, such that the first portion and the second portion are movable with respect to one another between a retracted position and an extended position, and are spaced apart in a transverse direction in the extended configuration.The element may be movable / flexible. The element may be expandable / extendable.

[0009] The vessel may comprise a physiological vessel (e.g. for bodily fluids). The sensor arrangement may comprise a medical device.

[0010] The first sensor and / or second sensor may comprise a plurality of respective sensors. The respective sensors (e.g. transducers) in the first sensor and / or second sensor may be axially aligned. The first sensor and / or second sensor may comprise between 1 and 10 sensors. The sensors may comprise ultrasound sensors (e.g. transducers).

[0011] The element may comprise a web. The web may comprise at least one pleat or fold. The web may comprise a plurality of folds. The web may comprise a concertina arrangement. The fold may comprise living hinges. The spacing between adjacent folds may be the same transverse width of the first portion and / or second portion. The web may be contained within the profile of the first portion and / or second portion in the retracted position. The web may be interposed the first portion and / or second portion in the retracted position

[0012] The element may comprise a mesh. The mesh may be collapsible and / or fordable.

[0013] The first portion and the second portion may be adjacent to one another in the retracted position. The element may be collapsed or folded in the retracted position. The first portion and the second portion may at least partially overlap one another in the retracted position. The first portion and / or second portion may be elongate (e.g. in the axial direction).The first portion and the second portion may be co-linear in the retracted position. The first portion and the second portion may be parallel in the extended position.

[0014] The element may comprise a conductor. The conductor may comprise a wire or conductive trace. The conductor may be operatively connected to the first and / or second sensor. The conductor may be embedded in or on the element or web.

[0015] The element may comprise a wire or string.

[0016] The sensors may be configured to measure a flow property of the fluid in vessel. The sensors may be paired (i.e. collectively measure said property). The sensors may be configured to measure the flow rate of the fluid in vessel; the pressure of the fluid in the vessel; and / or the diameter of the vessel. The sensors may provide a flow meter or flow sensor. The sensor arrangement may comprise a controller or processor (e.g. to process sensor data). The sensor arrangement may comprise a communication interface (e.g. wireless interface).

[0017] The first portion and second portion may comprise the same axial length. The first portion and second portion may comprise different axial lengths. The element may be provided toward an end of the first portion and / or second portion. The element may be provided at a centre of the first portion and / or second portion.

[0018] The first portion, second portion and / or element may comprise a polymer. The polymer may be flexible. The first portion and / or second portion may be less flexible than the element. The first portion and / or second portion may comprise a non-extensible material. The first portion and / or second portion may comprise a different material to the element. The first portion may comprise a different shape and / or size to the second portion. The sensor arrangement may be planar and / or non-tubular.The element may comprise one or more portions. The portions may be rigid. The rigid portions may be connected via a flexible portion. The portion(s) may be connected via a pivot or rotatable connector. The element may be pivotably connected to the second portion and / or first portion. The element may be slidably connected to the second portion and / or first portion. The element may be telescoping.

[0019] The first portion and second portion may respective elements. The first portion and second portion may be connected via an intermediate portion. The first portion and second portion may be connected to the intermediate portion via respective elements.

[0020] In the extended position, the sensors on the respective portions may be spaced in the transverse and / or axial direction (e.g. angled with respective to one another).

[0021] According to a further aspect, there is provided: a method of using the sensor arrangement of any preceding claim, comprising: inserting the sensor arrangement into the tubular device in the retracted configuration; moving the sensor arrangement out from the tubular device and around a vessel, and separating the first portion and second portion in the transverse direction.

[0022] The method may comprise inserting a tubular device an orifice (before or after insertion of the sensor arrangement). The orifice may comprise an incision. The transverse direction may be aligned with a fluid flow direction of the vessel. The vessel may comprise a blood vessel, liquid waste vessel and / or airway.

[0023] Any aspect of the invention may be combined with any other aspect of the invention where practicable.

[0024] DescriptionEmbodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings:

[0025] Figure 1 shows a schematic view of a prior art sensor arrangement;

[0026] Figure 2 shows a schematic view of a first embodiment of a sensor arrangement in a retracted position;

[0027] Figure 3 shows a schematic view of the first embodiment of a sensor arrangement in an extended position;

[0028] Figure 4 shows a schematic view of a second embodiment of a sensor arrangement in an extended position;

[0029] Figure 5 shows a schematic view of the second embodiment of a sensor arrangement in an extended position;

[0030] Figure 6 shows a schematic view of a third embodiment of a sensor arrangement;

[0031] Figure 7 shows a schematic view of a fourth embodiment of a sensor arrangement;

[0032] Figure 8 shows a schematic view of a fifth embodiment of a sensor arrangement;

[0033] Figure 9 shows a schematic view of a sixth embodiment of a sensor arrangement;

[0034] Figure 10 shows a schematic view of a seventh embodiment of a sensor arrangement.

[0035] A sensor arrangement 2 is shown in figure 2. The sensor arrangement 2 comprises a first portion 4. A first set of sensors 6 are provided on the first portion 4. A second portion 8 comprises a second set of sensors 10. The sensors 6,10 are collectively configured to measure one or more property of a fluid vessel. It can be understood that “vessel” in the present context means only suitable channel or container to provide flow of a fluid. In the present embodiment, the sensor arrangement is configured to measure one or more property of a physiological vessel (e.g. in a human or animal). The vessel maycomprise any of: a blood vessel, such as a heart, artery or vein; liquid waste vessel (e.g. ureter, urethra, bladder or kidney); airway (e.g. nasal cavity, sinus, pharynx, larynx, trachea, bronchi and bronchioles). The sensors 6,10 may be configured to determine the flow rate of the fluid in the vessel; measure the diameter of the vessel and / or the pressure of the fluid therein.

[0036] The sensors 6,10 typically comprise ultrasonic sensors, however, they may comprise any suitable sensor. The sensors 6,10 comprise ultrasound transducers. The transducers are configured to both emit and detect the ultrasounds. In other embodiments, the transmitter and received may be provided by different transducers. The sensors 6,10 may be provided as a single element, multiple elements, or an array of sensors. The sensors may include conventional ceramic transducers, micromachined ultrasound transducers (MUTs), such as capacitive micromachined ultrasound transducers (CMUTs) and piezoelectric micromachined ultrasound transducers (PMUTs); piezoelectric composite transducers; or other suitable types.

[0037] In some embodiments, additional sensors may be provided on the sensor arrangements, for example one or more of: gyroscope; accelerometer; pressure sensor; thermometer etc.

[0038] In the embodiment shown in figure 2, each set of sensors 6,10 comprises three individual sensors. However, it can be appreciated that any number of sensors may be provided, for example, between 1 and 10 sensors. The sensors 6,10 may comprise control and / or processing circuitry (e.g. to calculate the flow rate). The sensors 6,10 may comprise a communications interface (e.g. a wireless interface). The sensor arrangement 2 may comprise an antenna. The sensors 6,10 may comprise a power supply (e.g. a battery). It can be understood that the sensors 6,10 and operation thereof are generally conventional.The first portion 4 and second portion 8 comprise a base / substrate on which the sensors 6,10 are mounted. The base typically comprises a polymeric material, for example, one or more of: polyamide; polyurethane; and / or thermoplastic polyurethane (TPU). The base is flexible to allow the sensor arrangement to wrap around the vessel in use. The base is generally planar (e.g. forms a ribbon like arrangement).

[0039] The first sensor set 6 and the second sensor set 10 are spaced about an axial direction 12. This allows the sensors to be place on opposing sides of the flow path in use. The individual sensors in each set 6,10 may be spaced apart in the axial direction. However, the exact arrangement of the sensors in each set 6,10 is not pertinent, for example, the sensors may be axially and / or transversely spaced, or angled etc. The first portion 4 and second portion 8 are elongate in the axial direction.

[0040] Referring to figure 3, an element14 connects the first portion 4 and the second portion 8. The element 14 comprises a web. The web 14 extends in a transverse direction 15. The transverse direction 14 is perpendicular to the axial direction 12. The first portion 4 and the second portion 8 are transversely spaced by the web 14. The first sensor 6 and the second sensor set 10 are spaced about the transverse direction 15 accordingly. This increases the sensitivity of the sensors as the distance between the sensors increased in the direction of the fluid flow in use (i.e. the transverse direction). The first portion 4 and second portion 8 are parallel to one another.

[0041] The web 14 is flexible. This allows the first portion 4 and the second portion 8 to move between a retracted position (as shown in figure 2) and an extended position (as shown in figure 3). In the retract position, the first portion 4 and the second portion 8 are co-linear. The sensor sets 6,10 are colinear accordingly. The sensor arrangement therefore comprises a maximum width the same as the transverse width of the first portion 4 and the second portion 8. This provides a sensor of relatively small width, allowing, for example, the sensorarrangement 2 to be inserted via a catheter. In the extended position, the first portion 4 and the second portion 8 and the sensor sets 6,10 are transversely separated, thereby providing optimal sensitivity. The web 14 therefore allows easy insertion with whilst providing optimal sensor sensitivity.

[0042] In the embodiment shown in figure 3, the web 14 comprises a plurality of folds 16. This allows the web 14 to fold in on itself. The web 14 comprise a concertina / pleated structure. The fold lines 16 are spaced by the same spacing as the transverse width of the base. The web 14 therefore occupies the same profile as the base in the retracted position. The folds 16 therefore control the shape / size of the web in the retracted position. It can be appreciated that any number of fold lines may be provided as required, for example, in accordance with the length of the web 14. The fold 16 may be provided by any suitable means. The folds 16 may comprise a living hinge. The folds 16 may be formed by simple plastic deformation (e.g. a ribbon is folded to permanently deform the ribbon). In some embodiments, the panels 18 between the fold 16 may be rigid. The panels 18 may be connected via a flexible material.

[0043] The web 14 may comprise a resilient material. The web 14 therefore expands outward once released (e.g. released from the catheter). In other embodiments, the first portion 4 and second portion 8 are manually manipulated into position.

[0044] In the present embodiment, the web 14 extends generally perpendicular to the base. In other embodiments, the web 14 may be provide at any angle relative to the base / axial direction 12 (provided that at least some transverse extension is provided). The web 14 is straight. The web 14 is planar. The web 14 may comprise any suitable shape / form, for example: curved; angled; polygonal; or other complex shape.

[0045] In some embodiments, the base comprises a U-shape, for example, to allow the sensor to extend around the vessel. In the retracted position, the U-shaped base may fold over itself (e.g. to have an L-shaped profile). The U-shape mayextend out of the plane of the page, such that base wraps around the vessel in use.

[0046] In the embodiment in figures 2 and 3, the first portion 4 and the second portion 8 partially overlap in the retracted position. The overlap is provided in the region of the web 14. In the embodiment shown in figure 4, the first portion 4 and the second portion 8 completely overlap in the retracted position. The first portion 4 and the second portion 8 comprise the same axial length. The web 14 at the centre of the first portion 4 and the second portion 8. It can be appreciated that the web 14 may be provided in any suitable position.

[0047] A third embodiment of the sensor arrangement 2 is shown in figures 5 and 6. The first portion 4 is significantly longer than the second portion 8. The second portion 8 is located at an end 18 of the first portion 4. The second portion 8 is generally sized to accommodate the sensors 10 without additional space.

[0048] A fourth embodiment of the sensor arrangement 2 is shown in figure 7. The web 14 comprises a mesh, grating, expanded material, or other porous material / structure. This provides a lightweight / compact material. The mesh can be collapsed in the retracted position.

[0049] As shown in figure 8, the web 14 may comprise a conductor 20. The conductor 20 may provide power and / or communication between the second set of sensors 10 and another component in the sensor arrangement 2, for example, the first set of the sensors 6. The conductor 20 may operatively connect the sensors 6,10 to an antenna and / or a processor. The conductor 20 may extend through the web 14 (e.g. embedded thereon or therein) and the first portion 4 and / or second portion 8, as required. The conductor 20 may comprise a wire or conductive trace. The conductor 20 is flexible or otherwise configured to withstand folding, rotation, sliding, flexion or combination thereof.In the embodiment shown figure 9, the element 14 comprises plurality of pivoting portions 22. The pivoting portions are connected via pivots 24 (e.g. a rotatable connection). The pivoting of the portion 22 provides effective movement / flexion between first portion 4 and the second portion 8.

[0050] The first portion 4 and the second portion 8 are connected via an intermediate portion 26. Both the first portion 4 and the second portion 8 are connected via respective elements 14. Thus, both the first portion 4 and the second portion 8 are movable about in the transverse direction 15. It can be appreciated that such an element can be provided with the elements 14 of previous embodiments (e.g. using the web or mesh). The sensors 6,10 may be provided in the any of the folds. In alternative embodiments, only the second portion is connected via the pivotable element 14.

[0051] In an alternative embodiment, the element comprises a single pivoting portion 22. The single portion is pivotally attached to the intermediate portion 26 or first portion 4, and the second portion 8. The second portion 8 (and / or first portion 4), can then be rotated into extended position.

[0052] In the embodiment shown in figure 9, the element 14 comprises a wire 28, string or the like. The wire 28 may provide the function of the wire 20 as previously described, or may simply only perform a structural function. The wire is design to be robust enough to prevent detachment of the second portion 8. The first portion 4 and the second portion 8 are connected via an intermediate portion 26. Both the first portion 4 and the second portion 8 are connected via respective elements 14. In alternative embodiments, only the second portion is connected via the pivotable element 14.

[0053] In embodiments, the second portion 8 may be connected to the first portion 4 / intermediate portion 26 via a sliding or translatable connection. The sliding connection is orientated in the transverse direction 15. For example, a plurality of portions may be slidably attached to one another (e.g. in a telescopicarrangement). It can be appreciated that the pivot, telescoping and mesh element provide an expanding / extending type arrangement.

[0054] In some embodiments, the intermediate portion 26 may comprise a curved or U-shape.

[0055] In use, the sensor arrangement 2 may be placed around a blood vessel in a human or animal. An incision is made in the body, such that the vessel is accessible. The sensor arrangement 2 is placed into a catheter or other tubular insertion device in the retracted configuration. The catheter is placed into the incision (before or after insertion of the sensor). The sensor arrangement is pushed or otherwise expelled from the catheter and placed into arrangement around the vessel. The axial length of the sensor is wrapped circumferentially around the vessel. The first and second portion are then spaced apart in the transverse direction via manual manipulation (e.g. by a surgeon) or using the natural resiliency of the web. The transverse direction is parallel to the flow of fluid to increase the sensitivity of the measurement thereof.

Claims

Claims:

1. A sensor arrangement (2) comprising:a first portion (4) comprising a first sensor (6) and a second portion (8) comprising a second sensor (10), the first sensor (6) and second sensor (10) spaced apart in an axial direction (12) and configured to measure one or more property of a fluid vessel; anda flexible and / or extendable element (14) extending between the first portion (4) and the second portion (8), such that the first portion (4) and the second portion (8) are movable with respect to one another between a retracted position and an extended position, and are spaced apart in a transverse direction (15) in the extended configuration.

2. A sensor arrangement according to claim 1 , where the element (14) comprises a web comprising at least one pleat or fold (16).

3. A sensor arrangement according to claim 2, where the spacing between adjacent folds (16) is the same transverse width of the first portion (4) and / or second portion (8).

4. A sensor arrangement according to any preceding claim, where the element (14) comprises a mesh or wire.

5. A sensor arrangement according to any preceding claim, where the first portion (4) and the second portion (8) are adjacent one another in the retracted position, the element (14) being collapsed or folded in the retracted position.

6. A sensor arrangement according to any preceding claim, where the first portion (4) and the second portion (8) at least partially overlap one another in the retracted position.

7. A sensor arrangement according to any preceding claim, where the first portion (4) and the second portion (8) are co-linear in the retracted position and / or where the first portion (4) and the second portion (8) are parallel in the extended position.

8. A sensor arrangement according to any preceding claim, where the element (14) comprises a conductor.

9. A sensor arrangement according to any preceding claim, where the sensors (6,10) are configured to measure the flow rate of the fluid in vessel; the pressure of the fluid in the vessel; and / or the diameter of the vessel.

10. A sensor arrangement according to any preceding claim, where the first portion (4) and second portion (8) comprise the same axial length.

11. A sensor arrangement according to any preceding claim, where the element (14) is provided toward an end of the first portion (4) and / or second portion (8).

12. A sensor arrangement according to any preceding claim, where the first portion (4), second portion (8) and / or element (14) comprises a flexible polymer.

13. A sensor arrangement according to any preceding claim, where the element (14) comprises one or more portion (18,22) connected via a flexible portion (16) or pivot (24).

14. A method of using the sensor arrangement (2) of any preceding claim, comprising:inserting the sensor arrangement (2) into a tubular device in the retracted configuration;moving the sensor arrangement (2) out from the tubular device and around a vessel, and separating the first portion (4) and second portion (8) in the transverse direction.

15. A method according to claim 14, where the transverse direction (15) is aligned with a fluid flow direction of the vessel.

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