GB2544310A

GB2544310A - A medical tool for guiding a needle

Info

Publication number: GB2544310A
Application number: GB1519975.5A
Authority: GB
Inventors: Alaib Khalid
Original assignee: Graduates Medical Co Ltd
Current assignee: Graduates Medical Co Ltd
Priority date: 2015-11-12
Filing date: 2015-11-12
Publication date: 2017-05-17
Also published as: GB201519975D0

Abstract

There is provided a medical tool 100 for guiding a needle. The medical tool comprises a head portion 120 having a cradle 130a,130b,132a,132b for cradling the needle to point the needle in a first direction FD2, the cradle comprising at least two needle supporting points that are spaced apart from one another along the first direction. The portion has first and second plates 122,124 fixed in planes that make an angle of between 45 and 90 degrees with one another. The first direction FD2 is parallel to both of the planes, and the cradle and the first and second plates are substantially opaque to X-rays (e.g made from aluminium).

Description

A MEDICAL TOOL FOR GUIDING A NEEDLE

DESCRIPTION

The present invention relates to a medical tool for guiding a needle, for example for delivering pain relieving injections.

BACKGROUND OF THE INVENTION

In some situations, needle injections into the human body need to be very precise, so that the injected fluid is delivered to the correct site. One such situation is the delivery of pain relieving fluid into the spine, where the location of the injected fluid has to be correct. If such fluid is injected into slightly the wrong location, then the result can be paralysis, or even death, of the patient.

To help ensure that the fluid is delivery to the correct site, it is known to take X-ray pictures of the patient as the needle inserted into the patient’s back, so that the tip of the needle can be viewed on each X-ray picture, and the fluid delivered once the tip of the needle has reached the correct location.

One of the difficulties with this approach is that multiple X-ray pictures have to be taken as the needle is progressively inserted, exposing the patient to higher levels of radiation. The point where the needle is inserted into the skin of the patient may not result in the needle reaching the correct location, and so the needle may need to be withdrawn and re-inserted, leading to more X-rays and radiation exposure. Additionally, the patient may become uncomfortable and shift their position slightly whilst the needle is being inserted, increasing the difficulty of reaching the correct site for fluid delivery.

Each X-ray picture provides a two-dimensional view of a three dimensional space, and so the needle tip can appear to be at the correct location in the two-dimensional picture, even when it is actually in the wrong location in the three-dimensional space. It is therefore necessary to align the direction in which the X-ray picture is taken, with the direction in which the needle is inserted, to help prevent errors of this type. It can be awkward to correctly align the X-ray camera with the needle. Typically, the needle appears as a black dot in the X-ray picture when the camera is correctly aligned with the needle, rather than appearing as a straight line when the camera is misaligned.

It is therefore an aim of the invention to address one or more of the above problems.

SUMMARY OF THE INVENTION

According to various embodiments of the invention, there is provided a medical tool for guiding a needle, according to any one of the appended claims. The medical tool comprises a head portion having a cradle for cradling the needle to point the needle in a first direction, the cradle comprising at least two needle supporting points that are spaced apart from one another along the first direction. The portion has first and second plates fixed in planes that make an angle of between 45 and 90 degrees with one another. The first direction is parallel to both of the planes, and the cradle and the first and second plates are substantially opaque to X-rays.

Since the first and second plates are set at different angles to one another and are both parallel to the first direction in which the needle will be inserted, an X-ray picture of the medical tool in position upon the human body can be taken, prior to inserting the needle into the skin. Since the cradle and the first and second plates are substantially opaque to X-rays, the alignment of the camera with the first direction can be checked by looking at how the first and second plates appear within the X-ray picture. If the camera is in alignment, then only the edge thicknesses of the first and second plates will be seen in the image, whereas if the camera is not in alignment, then the sides of one or both of the plates will be visible in the image, and will help indicate how the camera needs to be adjusted to bring it into alignment. The angle of between 45 and 90 degrees between the first and second plates means that the plates allow alignment in both left/right and forward/backward orientations to be performed. Once the camera is in alignment with the first direction, an X-ray picture can be used to check that the site where the fluid needs to be injected is also directly in line with the first direction, so that it will be reached by the needle when the needle is inserted in the first direction. The tool may be used to perform regional and advanced chronic pain blocks, and for minor orthopaedic procedures under X-ray.

The cradle helps to guide the needle in the first direction as it is inserted into the skin, due to the at least two needle supporting points that are spaced apart from one another along the first direction. Since the needle does not need to be inserted until after the medical tool has been placed in the correct location and orientation to guide the needle, the tip of the needle should reach the correct site at the first attempt, and not need to be withdrawn and re-inserted. This significantly reduces the overall number of X-rays required, and provides a better overall experience to the patient.

The head portion may be arranged so that the cradle appears as a cross shape when it is viewed along the first direction, the cradle arranged to cradle the needle substantially at the centre of the cross. Then, the cross shape will appear as a target in the X-ray pictures, the centre of the target indicating whereabouts the medical tool will guide the needle. The cross shape may for example be formed by the first and second plates crossing one another, or additional members forming the cross shape may be present in the head portion.

Advantageously, the head portion may comprise a third plate fixed in a plane parallel to the plane of the first plate, the second plate being connected to the first plate and the third plate. Then, additional members forming the shape of a cross can span between the plates. The plates can be used to help align the X-ray camera with the medical tool, and the crossed additional members can be used to align the medical tool with the site where the injection fluid is to be delivered, by viewing the X-ray picture(s). The crossed additional members define the needle supporting points at the crossing points of the additional members, so the crossed additional members appear as a target within the X-ray pictures.

The cradle may cradle the needle at an exterior of the medical tool, such that the cradle can be withdrawn from the needle in a direction perpendicular to the first direction. Then, the medical tool can be moved away from the needle once the needle has been inserted, for example in preparation for injecting the fluid, or to take a final X-ray to double-check the needle’s position before actually injecting the fluid.

Preferably, the medical tool comprises a handle portion connected to the head portion. The handle portion may be repeatedly removable and attachable to the head portion, so that the handle portion and the head portion can be treated separately. For example, the head portion may be sent for sterilisation after it has been used, whereas there may not be any need for the handle portion to be sterilised. Additionally, the head portion may be disposed after use and replaced with a new head portion in preparation for the next use. A magnet may be embedded in the head portion or the handle portion to allow easy attach ment/rem ova I of the head portion from the handle portion.

DETAILED DESCRIPTION

Embodiments of the invention will now be described by way of non-limiting example only and with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic perspective diagram of a known X-ray apparatus suitable for use with medical tools according to embodiments of the invention;

Fig. 2 shows a schematic perspective diagram of a medical tool according to a first embodiment of the invention;

Fig. 3 shows a schematic perspective diagram of a medical tool according to a second embodiment of the invention;

Fig. 4 shows another schematic perspective diagram of the medical tool of

Fig. 3;

Fig. 5 shows a schematic representation of an X-ray picture of the medical tool of Fig. 3, when the tool is out of alignment with an X-ray camera and a target part of a human spine;

Fig. 6 shows a schematic representation of an X-ray picture of the medical tool of Fig. 3, when the tool is in alignment with an X-ray camera and the target part of the human spine;

Fig. 7 shows a schematic diagram of a needle for injecting a pain relieving fluid;

Fig. 8 shows a schematic representation of an X-ray picture of the medical tool of Fig. 3 and the needle of Fig. 7, when inserting the needle into the target part of the human spine; and

Fig. 9 shows a schematic representation of an X-ray picture of the needle of Fig. 7 when it has been inserted into the target part of the human spine.

The figures are not to scale, and same or similar reference signs denote same or similar figures.

The schematic diagram of Fig. 1 shows a known X-ray apparatus 1, for taking X-rays of a patient. The apparatus 1 comprises a base 2, and a table 4 that is supported horizontally by the base. The table 4 is intended for a patient to lie upon it whilst X-ray images are taken. The apparatus 1 also comprises an adjustable pillar 6, which supports an X-ray camera 8. The X-ray camera 8 faces in the direction DC, for taking X-ray images of in the direction DC of a patient lying on the table 4. The adjustable pillar 6 can be used to change the position and the orientation of the X-ray camera 8, so that the direction DC in which the images are taken can be varied. A first embodiment of the invention will now be described with reference to Fig. 1, which shows a medical tool 10 comprising a handle portion 12 and a head portion 20. The head portion 12 is formed of aluminium, so that it is substantially opaque to X-rays, although other types of materials opaque to X-rays could be used in alternate embodiments. The handle portion 12 is also formed of aluminium, although other types of materials could alternatively be used.

The head portion 20 is formed by first and second steel plates 22 and 24, which are set at an angle ANG1 of 90 degrees to one another. The plates 22 and 24 cross one another to meet along an interface INT1, such that they define an X shape when the head portion 20 is viewed from the direction of the handle portion 12. The plate 22 has two portions 22a and 22b, either side of the interface INT 1, and the plate 24 has two portions 24a and 24b, either side of the interface INT 1.

The two portions of each plate may be formed integrally with one another, for example a slot may be cut half way along the interface INT1 of one plate, so that it can be slotted into an equivalent slot of the other plate. Or, the two portions of one of both plates may be formed separately and joined together, either joined directly together, or joined via the other plate.

The handle portion 12 comprises a steel shaft 14. An end portion 15 of the steel shaft is welded to the interface INT1 of the head portion 20, between the plate portions 22a and 24b, thereby fixing the handle and head portions together. Alternatively, the end portion 15 could be fitted into a socket mounted between the plate portions 22a and 24b.

The interface INT1 between the two plates 22 and 24 runs in a first direction FD1, and the corner extending along the interface INT1 and between the plate portions 24a and 24b creates a cradle for guiding a needle along the direction FD1. Any point along the interface INT1 where the plate portions 24a and 22b meet one another may be considered as a needle supporting point, for guiding the needle along the direction FD1. The interface INT1 and the first direction FD1 are parallel to both of the first and second plates 22 and 24. Although the first and second plates cross at an angle of 90 degrees in this embodiment, alternate embodiments where the first and second plates cross at an angle of as low as 45 degrees are also contemplated.

In use, the medical tool 10 can be held over a patient, and used to guide a needle into the patient, by sliding the needle along the interface INT1 between the two plates, so that it moves in the direction FD1. Prior to inserting the needle, a X-ray may be taken of the medical tool 10 above the patient’s body, to ensure that the direction FD1 points to the part of the body that the needle tip needs to be guided to, and to ensure that the direction FD1 is aligned with the direction DC of the X-ray camera. If the direction FD1 is properly aligned with the direction DC, then the X-ray image will show the edges 22c and 24c of the plates 22 and 24, but the major faces of the plates will not be visible, since the major faces of the plates are parallel to the direction FD1. The angle ANG1 is between the first and second plates is between 45 and 90 degrees, so that the appearance of the plates in the X-ray image can be used to properly align the first direction FD with the X-ray camera axis DC. This will be described in more detail with reference to the second embodiment.

The second embodiment of the invention will now be described. Referring to Fig. 3, a medical tool 100 according to the second embodiment comprises a handle portion 112 connected to a head portion 120. Both the head and handle portions are formed of steel, although alternate X-ray blocking materials could be used in other embodiments.

The head portion 120 has a proximal end 140 where the handle portion 112 is connected, and a distal end 142 opposite from the proximal end 140. The head portion 120 comprises a second plate 124 that forms the proximal end of the head portion. The second plate 124 is connected to a first plate 122 along a first edge, and connected to a third plate 126 along a second edge that is opposite to the first edge. The first and third plates 122 and 126 are parallel to one another, and are both orthogonal to the second plate 124. In this embodiment, the first, second, and third plates are all the same size as one another.

The head portion 120 further comprises first and second pairs of members that are connected between the first, second, and third plates. The first pair of members comprises a first member 130a and a second member 130b, at an upper side of the head portion 120, and the second pair of members comprises a first member 132a and a second member 132b, at a lower side of the head portion 120.

The first and second members 130a and 130b cross one another to define a first needle supporting point, at an upper side of the head portion 120. The first and second members 132a and 132b also cross one another to define a second needle supporting point, at a lower side of the head portion 120. Accordingly, the first and second pairs of members together define a cradle for supporting a needle along the first direction FD2.

The first member 130a is connected from an upper corner at the first edge of the second plate 124, to an upper corner at a distal edge 126a of the third plate 126. The first member 132a is connected from a lower corner at the first edge of the second plate 124, to a lower corner at the distal edge 126a of the third plate 126. The second member 130b is connected from an upper corner at the second edge of the second plate 124, to an upper corner at a distal edge 122a of the first plate 122. The second member 132b is connected from a lower corner at the second edge of the second plate 124, to a lower corner at the distal edge 122a of the first plate 122.

In an alternate embodiment, the first members 130a and 132a may be formed as a single plate member instead of two separate members, and the second members 130b and 132b may be formed as a single plate member instead of two separate members, to create a cradle similar to the cradle of Fig. 2. Optionally, apertures may be made through these plate members to reduce weight and/or improve visibility.

Another perspective view of the medical tool 100 is shown in Fig. 4, where the connection between the handle portion 112 and the head portion 120 can be better seen. The handle portion 112 has a magnet 113 embedded in an end of a shaft 114 of the handle portion. The magnet 113 magnetically attracts the head portion so the second plate 124 of the head portion can be held at the end of the shaft 114. Therefore, the handle portion 112 and the head portion 120 can be easily separated/attached whenever desired.

The use of the medical tool 100 will now be described with reference to Figs. 5 to 9, which show schematic representations of X-ray images taken of a patient’s spine using the X-ray apparatus of Fig. 1, which assist in the insertion of a needle into the patient’s spine so that a pain-relieving fluid can be delivered.

Firstly, the medical tool 100 needs to be held in correct alignment with the axis DC of the X-ray camera and the part of the spine where the needle tip is to be inserted. To achieve this alignment, the medical tool 100 is held over the person’s spine 200, and the X-ray camera 8 (see Fig. 1) is adjusted to roughly point in alignment with the head portion 120 of the medical tool. Then, an X-ray image is taken. Fig. 5 shows a schematic representation of this X-ray image, and it can be seen that the first direction FD2 of the medical tool 100 is out of alignment from the camera direction DC, because the plates 122 and 124 appear thicker than the plate 126, and both the first and second pairs of members can be seen.

The thickness of the plate 124 and the positions of the pairs of members in the X-ray image of Fig. 5, indicate that the handle of the tool needs to be moved towards the person’s spine 200 to bring the first direction FD2 of the tool into better alignment with the X-ray camera 8. The greater thickness of the plate 122 than the thickness of the plate 126 indicates that the X-ray camera 8 needs to be moved slightly to the left, to centre the camera axis DC mid-way between the plates 122 and 126.

Once these adjustments have been made and the medical tool is believed to be in the correct position, another X-ray image can be taken to verify the position of the medical tool, and a schematic representation of this image is shown in Fig. 6. It can be seen in Fig. 6 that the first direction FD2 of the medical tool 100 and the axis DC of the X-ray camera 8 are correctly aligned with one another, because the first pair of members directly overlie the second pair of members, such that only the first pair of members 130a and 130b appear in the image, and the thicknesses of the plates 122, 124, and 126 all appear the same as one another. It can also been seen in Fig. 6 that the tool is correctly aligned with a part 210 of the person’s spine that is to be injected with pain relieving fluid, because the part 210 is pointed to by the first direction FD2, along which the medical tool 100 will guide a needle. The first pair of members 130a and 130b make a cross over the part of the spine where the fluid will be injected, forming a target that is easily visible in the X-ray image. A schematic diagram of a needle 400 for delivering the pain relieving fluid is shown in Fig. 7. The needle comprises a shaft 405 for insertion into the patient, and a head 410 to which a tube (not shown in Figs.) carrying the pain relieving fluid can be attached. Now that the medical tool 100 is in the correct position, as verified in Fig. 6, the needle 400 can be inserted into the patient whilst being guided by the two needle supporting points defined by the first and second pairs of members.

An X-ray image of the needle being inserted into the patient can be taken if desired, and a schematic representation of this image is shown in Fig. 8. Since the needle is being guided by the medical tool 100 along the first direction FD2, which is in line with the X-ray camera axis DC, the head 410 of the needle hides the shaft 405 of the needle from the X-ray image, as the shaft 405 is directly beneath the head 410.

Once the needle 400 has been inserted, the medical tool 100 can be withdrawn from the needle 400, and a final X-ray picture can be taken to verify the needle has been inserted into the correct part of the patient. A schematic representation of this image is shown in Fig. 9, where the head 410 of the needle can be seen overlaying the part 210 of the spine where the pain relieving fluid is to be injected. A tube for delivering the pain relieving fluid can then be attached to the head 410 of the needle, and the pain relieving fluid can be injected into the patient via the needle 400.

Clearly, the same procedure could be carried out using the medical tool 10 of the first embodiment, using the thicknesses of the first and second plates 22 and 24 to judge the correct alignment of the medical tool 100 with the X-ray camera axis DC.

Many other variations of the described embodiments falling within the scope of the invention will also be apparent to those skilled in the art.

Claims

1. A medical tool for guiding a needle, the medical tool comprising a head portion having a cradle for cradling the needle to point the needle in a first direction, the cradle comprising at least two needle supporting points that are spaced apart from one another along the first direction, the head portion having first and second plates fixed in planes that make an angle of between 45 and 90 degrees with one another, the first direction being parallel to both of the planes, the cradle and the first and second plates being substantially opaque to X-rays.

2. The medical tool of claim 1, wherein the cradle when viewed along the first direction appears as a cross shape, the cradle arranged to cradle the needle substantially at the centre of the cross.

3. The medical tool of claim 2, wherein the first and second plates form the cross shape.

4. The medical tool of claim 3, wherein the first and second plates define the at least two needle supporting points of the cradle along an interface between the first and second plates.

5. The medical tool of claim 1 or 2, wherein the cradle comprises at least two members defining the at least two needle supporting points, the at least two members being connected to the first and second plates.

6. The medical tool of claim 5 when appended to claim 2, wherein the at least two members define the cross shape and define the at least two needle supporting points at meeting points of the at least two members.

7. The medical tool of claim 5 or 6, wherein the head portion comprises a third plate fixed in a plane parallel to the plane of the first plate, the second plate being connected to the first plate and the third plate.

8. The medical tool of claim 5, 6, or 7, wherein the at least two members are two further plates fixed in planes that make an angle of between 45 and 90 degrees with one another, the first direction being parallel to both of the planes of the two further plates, the two further plates defining the at least two needle supporting points of the cradle along an interface between the two further plates.

9. The medical tool of claim 5, 6, or 7, wherein the at least two members comprise first and second pairs of members, the first and second pairs of members being spaced apart from one another along the first direction, the member of each pair crossing one another to define one of the needle supporting points.

10. The medical tool of claim 9 when appended to claim 7, wherein each pair of members comprises a first member connecting from a proximal end of the head portion at the connection between the first and second plates, to a distal end of the head portion at an edge of the third plate, and a second member connecting from the proximal end of the head portion at the connection between the second and third plates, to a distal end of the head portion at an edge of the first plate.

11. The medical tool of any preceding claim, wherein the cradle cradles the needle at an exterior of the medical tool, such that the cradle can be withdrawn from the needle in a direction perpendicular to the first direction.

12. The medical tool of any preceding claim, further comprising a handle portion connected to the head portion.

13. The medical tool of claim 12, wherein the handle portion is repeatedly removable and attachable to the head portion.

14. The medical tool of claim 13, wherein the handle portion is repeatedly removable and attachable to the head portion by a magnet embedded in the head portion or the handle portion.

15. A medical tool substantially as described herein with reference to the accompanying drawings.