WO2006129084A1

WO2006129084A1 - Clip for ultrasound probe

Info

Publication number: WO2006129084A1
Application number: PCT/GB2006/001978
Authority: WO
Inventors: Malcolm John Watson; George A. Corner
Original assignee: Greater Glasgow Health Board (North Glasgow University Hospital Division)
Priority date: 2005-05-31
Filing date: 2006-05-31
Publication date: 2006-12-07
Also published as: GB0511009D0

Abstract

A clip (10) for use with an ultrasound probe (30) of the type having a channel (33) for receiving and guiding a needle is described. The clip has a body- formed from an elastically deformable material and a posterior and anterior face. A portion of the clip nearest to the posterior face is bulbous. The clip is configured such that it can be inserted into the channel of a probe in a direction transverse to the channel itself, and is held within the channel under tension.

Description

Clip for ultrasound probe

The present invention relates to the field of ultrasonography, and in particular to a clip for use with an ultrasound probe.

Ultrasonongraphy is widely used in medicine in a variety of diagnostic and therapeutic procedures, primarily in the fields of gynaecology and obstetrics, gastroenterology, cardiology, urology and endocrinology. Among other applications, medical ultrasonography is used in the detection of malignant and benign tumours, to monitor blood flow within various vital organs, in the early stages of pregnancy to confirm intrauterine and exclude ectopic pregnancy and in later pregnancy to assess foetal growth and to exclude abnormalities. Ultrasonography is also useful for delineating the interfaces between tissues, for example in the identification of a suitable lumbar interspace for administration of anaesthetic. A variety of ultrasound techniques have been developed for such applications. Developments in the field of ultrasonography have seen ultrasound transducer probes provided with a gap in the transducer array at the probe application surface leaving a space into which a needle or associated object can be inserted, such as described in the Applicant' s co-pending Application. This gap can be used to visualise the insertion of said object into the patient, and as a means to guide the object to a target area. A drawback of this technique is the rigorous sterilization procedures required as a result of the direct contact of the needle with the body of the ultrasound probe and application of the probe to the area of incision.

In the practice of medical ultrasonographic techniques it is necessary that rigid sterilization procedures are in place to prevent cross-contamination of any equipment utilized during procedures. However, it is accepted that repeated sterilization of ultrasound probes by conventional techniques such as gas sterilization, deteriorates the adhesive used for the joints of the probe body, causing a subsequent reduction in the lifetime of the probe. Moreover, the weakening of the joints of the probe body could have implications if the probe were to become inoperable either immediately before or during a serious medical procedure.

Replaceable, or easily sterilizable auxiliary fixtures which fit into such a gap in a transducer array and thus prevent the needle from coming into direct contact with the ultrasound probe are known. However, contamination of the ultrasound probe is still a possibility due to splashing of fluids during the procedure, direct contact of the probe body with the patient's skin and handling of the probe by the probe operators. Traditional cleaning methods such as using alcohol to wipe the surface of the probe may not be sufficient to remove all contaminants. In order to overcome these limitations, a cover, such as a bag or sheath can be placed around the ultrasound probe in order to completely eliminate any contact between the body of the probe and the patient being treated. Sterile sheaths for use with ultrasound probes are known, such as those supplied by Civco Medical Instruments (IA, USA) , and are typically formed from latex or a synthetic polymer, having a thickness of several tens of microns or less.

An inherent difficulty with the use of such a sterile sheath is that the sheath will not automatically conform to the shape of the channel. This means that the sheath will stretch across the channel. This revises the possibility of rupture or puncture of the sheath during insertion of the needle, thus compromising the sterility of the whole procedure. Moreover, a cover or sheath specifically provided with an area shaped to conform to the gap in the transducer array, would still leave the edges of the sheath vulnerable to puncture by a misguided needle during insertion.

A band unit which holds a cover, such as a bag or sterile sheath, covering an ultrasound probe in position, has been disclosed [US 4,491,137]. This band unit can be either integral with or auxiliary to a guide means. The. band unit comprises a back plate with free ends extending from the upper and lower ends of the plate. The lower free end is provided with saw-toothed edges while the upper free end comprises a slit. In use, the bag is placed around the ultrasound probe. The band unit is then placed in the gap in the transducer array and the free ends are wound around to the back side of the probe, where the saw-toothed portion of the lower free end is engaged in the slit of the upper free end, thus holding the bag in position. While this band unit has obvious utility for a conventional ultrasound probe it would have several shortcomings when applied for use with a lateral orientated transducer, i.e. one which comprises a substantially rectangular ultrasound probe wherein the height is relatively much less than the length or width. Such an orientation comprises transducer elements arranged in at least one row on a portion of the bottom surface of the ultrasound probe. Lateral oriented transducers are described in the Applicant's co-pending Application and US 4,387,721. To be of utility for a transducer with such an orientation, the free ends of the band unit would have to be of sufficient length to traverse the entire length of the ultrasound probe. This would be inconvenient for operational reasons as the presence of the band across the probe unit would interfere with the smooth grip of the unit by the operator. Furthermore, difficulties would arise with the engagement of the free ends of the band unit at the rear surface of the ultrasound probe at which position the connection cable (for the electrical connection of the transducer elements to a transmitting-receiving device) typically protrudes in a unit with such a lateral configuration.

The present invention identifies the drawbacks of the conventional techniques and procedures, and proposes a clip which overcomes the limitations previously addressed. The aims and objects of the invention will become apparent from reading the following description.

According to a first aspect of the invention, there is provided an ultrasound probe clip for use with an ultrasound probe of the type comprising a housing having a channel adapted to receive a needle and being covered by a sheath, the clip being configured to protect the sheath within the channel from needle damage, where said ultrasound probe clip is elastically deformable such that it can be deformed to facilitate insertion into the channel and will then reform such that it is held in the channel under tension.

Advantageously as the clip is configured to be held in the channel under tension it does not require any additional attachment or locking mechanisms to hold it in place.

In addition, and advantageously the clip is configured such that it can be inserted into the channel at an angle transverse to the channel, therefore the sheath will not be displaced from, and will be held within the channel of the ultrasound probe.

Preferably the clip comprises an anterior face which, in use, is located in the channel of the ultrasound probe nearest to a surface of a target object, and a posterior face opposite the anterior face. Preferably the clip also has an outer face which in use faces the channel of the ultrasound probe, and an inner face which forms an opening through which a needle can be guided, which is located perpendicular to the anterior and posterior faces.

Preferably at least a portion of the clip is bulbous. Preferably at least a portion of the clip nearest to the posterior face is bulbous.

The clip is preferably made from an elastically deformable material.

Preferably, the target object is a human body.

Preferably the clip is adapted to receive a needle.

Typically the clip is of a size which is equal to or slightly greater than the size of the channel in the ultrasound probe housing.

Preferably the clip has an arcuate cross section.

Preferably the posterior face is generally curvilinear in shape.

Preferably the clip is of a one-piece moulded construction.

Preferably the cross section of the clip is widest at the posterior face and tapered towards the anterior face.

Preferably the clip is flanged at the posterior face. Preferably the clip is also flanged at the inner face.

Optionally the clip is made from polyurethane. More preferably, the clip is formed of a non-allergenic material.

Preferably the clip is disposable.

Optionally the clip can be provided in a sterilizable multi-use or reusable format.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which:

Figure 1 shows a perspective front view of the clip according to an embodiment of the invention;

Figure 2 shows a perspective side view of the clip of Figure 1;

Figure 3 shows a top plan view of the clip of Figure 1;

Figure 4 shows a perspective disassembled view of the clip of Figure 1 and a suitable ultrasound probe which is covered by a sterile sheath;

Figure 5 shows a perspective assembled view of the clip of Figure 1 and a suitable ultrasound probe which is covered by a sterile sheath; and

Figure 6 is an illustration of an ultrasound probe known in the prior art with which the ultrasound probe clip can be used. Referring firstly to Figures 1, 2 and 3, the drawings show a clip generally depicted at 10. The clip 10 is for use with an ultrasound probe of the type comprising a housing having a channel used as a guide for the subsequent insertion of a needle. The channel is adapted to receive and guide a needle. In use the probe is covered by a sheath which provides a sterile barrier between the probe and the target object on which the probe is used. An example of such a probe, known in the prior art is shown as Figure 6. The ultrasound probe 30 can be seen to comprise a standard ultrasound transducer 31 as commonly employed by those skilled in the art of ultrasonography, and an ultrasound waveguide 32. The ultrasound waveguide 32 can be further seen to comprise a channel 33 extending from reflecting section of the posterior face 34 through to the anterior face 35 of the probe. Rear wall of the channel 33 (i.e. that located opposite to the open side of the channel 33) is perpendicular to the planar anterior face 35. The channel 33 provides the user with an improved guide for the insertion of a needle. In use, the probe 30 is covered by a sterile sheath (not shown) .

The clip 10 is substantially complementary in shape to the channel 33 and of a size which is equal to or slightly greater than the channel 33. The clip 10 is manufactured from an elastically deformable material and can therefore be deformed by the exertion of pressure or "squeezing" such that it can be inserted into the channel 33. Once in position the elastically formable material re-expands slightly to fit snugly within the channel 33 and the clip 10 will therefore be held in position under channel 33 without the requirement of additional attachment or locking means.

Referring to Figures 1 to 3 it can be seen that the clip 10 is tapered and has an arcuate, curved cross section. The clip 10 has a posterior face 20, anterior face 21 and inner 22 and outer 23 face. In use, when located in the channel 33 of the ultrasound probe the anterior face 21 is located nearest to the target object on which the ultrasound probe is being used, whilst the posterior face 20 is located opposite the anterior face 21. The outer face 23 sits adjacent to and facing the ultrasound probe channel 33 when in use, whilst inner face 22 forms the opening 38 through which a needle can be guided. The posterior 20 and inner faces 21 are flanged, having lips 25. Side walls 24 of the inner 22 and outer 23 face are tapered such that the clip 10 and consequently the opening 38 of the clip 10 are narrower nearer anterior face 21 than posterior face 20.

At least part of the clip 10, in the depicted and preferred embodiment being the part nearest to the posterior face 20 is bulbous or swollen 40, in other words wider than the remaining portion of the clip 10, which facilitates the holding of the clip 10 within the ultrasound probe channel 33 under tension. The bulbous part 40 together with lips 25 effectively act to lock the clip 10 into the channel 33 and hold the sheath in place within the channel but away from the needle tip in use. The clip 10 is a one piece moulded construction which when in position delimits a gap or opening 38 through which a needle can be inserted. The opening 38 when viewed from the posterior face is generally U-shaped. The opening 38 when viewed from the anterior face is also U-shaped but is much narrower than when viewed from the posterior face. The clip 10 is widened at the top end 20 along the direction of the transducer arrays and tapered towards the anterior face 21. The clip 10 is tapered towards a waist 11 at which there is an inward projection, or ledge 12 against which the needle can be rested to stabilise the needle during the injection procedure. From the waist 11, the clip 10 is gently tapered towards the anterior face 21. As the anterior face 21 can come into contact with the skin of the patient during the procedure, the anterior face 21 terminates in a flat blunt edge to minimise damage to the patient's skin.

During use, a cover, such as a sterile sheath is used to cover the ultrasound probe to maintain sterility between the patient and the probe. The sheath, by its nature will encase the probe, however it will not automatically conform to the shape of the channel 33 in the probe, which is engineered to act as a needle guide. This means that the sheath will stretch across the gap used for guidance and is at risk of puncturing in use, thus compromising the sterility of the operation.

The clip 10 herein described fits into the channel 33 in the transducer array of the probe once the transducer has been covered by the disposable sterile sheath. This sheath extends from the front of the probe, where it is held in place by the clip 10, along the body of the probe and back along the probe cable towards the system body where it is attached to the cable with an elastic band (such as supplied with Civco latex-free transducer covers) .

As the walls of the clip 10 are capable of being elastically deformed the clip 10 can be compressed before and during insertion into the gap or channel 33 in the ultrasound probe following which the clip 10 will then elastically re-expand [until the further expansion of the side walls of the clip 10 is prohibited by the surface of the ultrasound probe aligning the gap or channel 33] to conform completely to the gap or channel 33 in the transducer array. This allows the clip 10 to be held in place under tension. This side loading mechanism of the clip pushes the sheath against the wall of the channel during insertion to reduce the risk of sheath penetration. The clip 10 acts to hold the sheath in position in the channel 33. The clip 10 is therefore suitable for use with a lateral orientated transducer, i.e. one which comprises a substantially rectangular ultrasound probe wherein the height is relatively much less than the length or width.

Advantageously as the clip 10 can be elastically deformed it can be inserted into the channel in a direction transverse to the direction of the channel itself. Furthermore, the shape of the clip, comprising bulbous end 40, acts to retain and lock the clip into position within the channel. It will be appreciated that as a result the sheath will be pushed against the channel 33 wall and held within said channel 33. In contrast clips known in the prior art are rigid and typically must be inserted into the channel 33 in a direction parallel to the channel itself. In this case the sheath is often pushed downward (in other words out of the channel towards the target object) where it may "bunch" and be punctured in use. The clip 10 of the present invention is advantageous as the sheath will not be pushed out of the channel 33 when the clip 10 is inserted.

Referring to Figures 4 and 5, the drawings show a suitable ultrasound probe generally depicted at 13, with a channel 14 in the outer probe surface corresponding to a channel in the transducer array. The sterile sheath 15 surrounds the ultrasound probe 13. In practice, the clip 10 is inserted into the gap 14 in the transducer array. The clip 10 is gently compressed and inserted into the gap at an angle transverse to the transducer array which ensures that the sterile sheath 15 is forced against the wall of the channel 14 and held securely against the probe body. As a result, a space 16 sufficient for a needle or other associated device such as a cannula or catheter is created within the channel 14 by the clip, which allows the needle or associated device to be inserted without the risk of penetration or piercing of the sterile sheath 15. Furthermore, the flanges or lips 25, provided at the posterior face 20 and inner surface of the clip, provide an additional barrier between the sterile sheath 15 and the edges of the space 16 to ensure that the sheath is not punctured by a misguided needle. The flanges or lips 25 are provided with smoothed edges to prevent snagging of the sterile sheath 15 on the clip 10. The clip 10 is formed in a manner which allows it to be retained in the gap under tension, meaning that the sterile sheath 15 is held firmly back in the slot of the gap 14 and that the clip will not slide out, or move during the procedure. The clip 10 is preferably supplied in a single-use sterile format however it is understood that the securing 10 means may also be formed of a material which withstands autoclave sterilisation allowing it to be a multi-use piece of equipment.

Once inserted, the clip 10 can be used as a guide means to direct the needle towards a target area, for example, for the purposes of injection. It will be appreciated that the needle can be moved within the opening 38 at posterior face 20 and rested against the inner face 2 of the opening to adjust the orientation of the needle. In addition, the inclusion of the ledge or inward projection 12 further assists fine adjustment of the orientation of the needle which can be rested against it. The ledge 12 also acts to stabilise the needle in the selected position.

In use, the needle is inserted centrally at the widened posterior face 20 of the clip 10 where the rigid plastic surface protects against snagging or tearing of the sterile sheath 15 by the needle. The narrowed waist 11 of the clip 10 then further guides the needle towards the appropriate target area. Advantageously the widened posterior face 20 allows the angle of insertion of the needle to be chosen freely. The inward projection 12 provides an additional means of guidance for the needle, providing a ledge against which the needle can be stabilised during injection.

To further clarify, during the procedure, the ultrasound probe itself will not directly contact the patient's body. The sterile sheath 15 is preferably manufactured from medical grade polymer, the use of which is standard in medical sheaths and will preferably be disposable.

It is preferable that the clip be formed from a non- allergenic material. The clip 10 is preferably made from polyurethane, the use of which is standard in many implantable and non-implantable medical devices.

It will be evident that various modifications and improvements could be made to the above-described apparatus and methods within the scope of the invention. For example, the above description is written in the context of administering anaesthetic to patients. However, the methods and apparatus apply equally to the alignment of catheters and insertion of cannulas as well as those direct injection methods described.

In addition, alternative shapes of clip could be used to conform to alternative ultrasound probe configurations within the scope of the invention. For example, to conform to ultrasound probes with curvilinear, rather than rectangular arrays of ultrasound transducers, or to ultrasound probes with different ultrasound probe body shapes.

The present invention in one of its aspects provides an improved means for securing a cover around an ultrasound probe, suitable for securing said cover around the probe and protecting said cover from snagging or puncture. Used in conjunction with appropriate apparatus, such as an ultrasound probe with a channel in the transducer array, the clip provides a simple method for ensuring that adequate sterility has been achieved for the use of ultrasound transducer probes which eliminates the necessity of repeated and possibly damaging sterilization of the transducer probe itself. In effect, the clip prevents the needle from breaching the sheath by acting as a barrier between the needle and the sheath by pushing the sheath into the gap away from the needle. The clip therefore protects the sterile sheath from puncture by the regional anaesthetic needle in the transducer gap and avoids transducer contamination.

Further modifications may be made without^' departing from the scope of the invention herein intended.

Claims

1. An ultrasound probe clip for use with an ultrasound probe of the type comprising a housing having a channel adapted to receive a needle and being covered by a sheath, the clip being configured to protect the sheath within the channel from needle damage, where said ultrasound probe clip is elastically deformable such that it can be deformed to facilitate insertion into the channel and will then reform such that it is held in the channel under tension.

2. An ultrasound probe clip as claimed in Claim 1 where at least a portion of the clip is bulbous.

3. An ultrasound probe clip as claimed in the preceding Claims comprising a body having an anterior face which in use is located nearest to a target object on which the ultrasound probe is being used, and a posterior face opposite said anterior face, where at least a portion of the clip nearest to the posterior face is bulbous.

4. An ultrasound probe clip as claimed in the preceding Claims having an arcuate, curved cross section.

5. A clip as claimed in Claims 3-4 where the posterior face is generally curvilinear in shape.

6. An ultrasound probe clip as claimed in the preceding Claims comprising an outer face and an inner face, where the inner face forms an opening through which a needle can be guided.

7. An ultrasound probe clip as claimed in Claim 6 where the posterior and inner faces are flanged.

8. An ultrasound probe clip as claimed in Claims 6 to 7, where the inner face has an inward projection or ledge against which a needle can be rested to stabilise said needle.

9. An ultrasound probe clip as claimed in Claims 3-8 where the body is tapered from the posterior face to the anterior face.

10. An ultrasound probe clip as claimed in Claim 9, where the width of the body at the posterior face is wider than the width of the body at the anterior face.

11. A clip as claimed in the preceding Claims being of a one-piece moulded construction.

12. A clip as claimed in the preceding Claims made from polyurethane .

13. A clip as claimed in the preceding Claims being of a size which is equal to or slightly greater than the size of the channel in the ultrasound probe housing.

14. A clip as claimed in the preceding Claims made of an elastically deformable material.