Sealing element with shape memory alloy

Abstract

A sealing device (1) for a medical device, the sealing device (1) comprising: an annular outer support member (2) having an inner surface (2a), a deformable annular sealing member (3) comprising an outer surface (3a), the annular outer support member (2) being arranged above the deformable annular sealing member (3), the deformable annular sealing member (3) is arranged such that an inner surface (2a) of the annular outer support member (2) faces an outer surface (3a) of the deformable annular sealing member (3), and a body (4) formed of a shape memory alloy surrounded by the deformable annular sealing member (3) wherein the body (4) extends in an axial direction (x) and is configured to assume an expanded state at a first temperature, and assumes a contracted state at a second, higher temperature wherein the body (4) contracts in the axial direction (x) in the contracted state, resulting in expansion of the deformable annular sealing member (3) in the radial direction (R).

Description

Technical Field

[0001] The present invention relates to a sealing device preferably for a medical device, a medical device, and a method of sealing a medical device using the sealing device according to the present invention. Background Art

[0002] In medical devices, it is generally desirable to be able to detachably connect the components of the medical device to each other such that a sealed connection is formed between the two components.

[0003] For example, it is desirable to provide such a detachable sealed connection between a balloon and a catheter to provide a balloon catheter with a replaceable balloon, thus providing the possibility of combining different balloons and catheters.

[0004] So far, there has been no known solution for detachably sealing a balloon onto a catheter. Generally, for example, threaded connections are used for detachable connections between components of medical devices.

[0005] Generally, the detachability of the known solutions is not based on the difference between physiological and non - physiological conditions, so it cannot be safely excluded that the connection may become detached again under physiological conditions, for example by the action of mechanical forces suitable for this purpose, and thus pose a risk to the patient.

[0006] Based on the above, the problem to be solved by the present invention is to provide an improved sealing device, a medical device, and a method for sealing a medical device using the sealing device according to the present invention, in order to allow a releasable gas - tight and liquid - tight sealed connection between two components. Preferably, the sealing device should be able to seal under physiological conditions (such as body temperature) and can be released under non - physiological conditions (such as at a temperature below body temperature), ideally without tools. In addition, it is particularly desirable to provide a sealing device with a soft surface such that no damage is caused to sensitive mating components. Summary of the Invention

[0007] This problem is solved by a sealing device having the features of claim 1, a medical device having the features of claim 11, and a method having the features of claim 15.

[0008] According to claim 1, a sealing device is disclosed, comprising:

[0009] -(annular) outer support member, which includes an inner surface,

[0010] -a deformable (annular) sealing member, the deformable (annular) sealing member including an outer surface, the outer support member being configured to be arranged on the (annular) sealing member such that the inner surface of the (annular) outer support member faces the outer surface of the (annular) sealing member, and

[0011] - A body formed of a shape memory alloy, wherein the body is embedded in a (ring-shaped) sealing member, wherein the body extends in an axial direction and is configured to assume an expanded state at a first temperature and a contracted state at a higher second temperature, wherein the body contracts in the axial direction in the contracted state, thereby causing the deformable (ring-shaped) sealing member to expand in a radial direction, in particular such that when a (ring-shaped) outer support member is disposed above the (ring-shaped) sealing member, the outer surface of the sealing member moves towards the inner surface of the (ring-shaped) outer support member, thereby allowing a circumferential portion of the component to be clamped in a sealed manner between the inner surface and the outer surface.

[0012] The higher second temperature enables the body to contract, and thus clamping and / or sealing is possible, which is not possible at the first lower temperature.

[0013] The present invention can enable a balloon to be replaced on a catheter in a clinical environment. So far, the balloon and the catheter have been manufactured as a single unit, which means that a large amount of material must be reserved in the clinic. With the present invention, for example, a universal catheter can be provided, on which balloons of different lengths and diameters can be installed using the sealing device according to the present invention, for example, by clamping each end section of the balloon in a sealed manner between the outer surface of the (ring-shaped) sealing member and the inner surface of the (ring-shaped) outer support member. The latter can already be provided on the corresponding end sections of the balloon, that is, can be an integral part of the balloon. This allows people to reuse the catheter multiple times by cleaning and disinfecting the catheter after surgery. This also allows the use of more expensive materials in the manufacture of the catheter. At the same time, the amount of waste is reduced.

[0014] Of course, the present invention can also be applied to other fields other than balloons / catheters, where it is important to achieve a non-removable seal under physiological conditions, but which can be easily released (preferably without tools) under non-physiological conditions (for example, for clamping components).

[0015] According to an embodiment of the present invention, the body is a (ring-shaped) structure surrounding an internal space in a circumferential direction orthogonal to the axial direction, and has an inner side facing the internal space and an outer side facing away from the inner side.

[0016] According to another embodiment of the present invention, the deformable (ring-shaped) sealing member includes an inner portion disposed on the inner side of the body and an outer portion disposed on the outer side of the body, in particular so as to cover the body from all sides.

[0017] Furthermore, according to another embodiment of the present invention, the deformable (ring-shaped) sealing member can surround a through-opening of the sealing device. The through-opening is configured to receive a component, in particular a component of a medical device, wherein in particular, the component is a shaft of a catheter.

[0018] The deformable (annular) sealing member, particularly its inner part, may include an inner surface.

[0019] In another embodiment of the present invention, the sealing device may include an (annular) inner support member, wherein the inner surface of the deformable (annular) sealing member is bonded to the (annular) inner support member. The (annular) inner support member may define the through-opening and is configured to be bonded to the component received in the through-opening.

[0020] In another embodiment, the (annular) inner support member may not have a through-opening. Instead, the (annular) inner support member may have a recess for receiving a component, particularly a component of a medical device, wherein in particular, the component is the shaft of a catheter. Such an inner support member can be used at the end of the sealing device, preferably at the distal end of the catheter.

[0021] The first temperature may be less than 30 °C and the second temperature may be greater than or equal to 35 °C.

[0022] A shape memory alloy material is a metal alloy capable of changing its shape according to temperature and returning to its original shape. This shape change is due to a change in crystal phase. The shape memory alloy material may be selected from nickel-titanium alloys, copper-aluminum-nickel alloys, copper-zinc-aluminum alloys, iron-manganese-silicon alloys. A preferred shape memory alloy material may be based on a nominal composition of 50:50 atomic percentage of nickel and titanium.

[0023] The deformable (annular) sealing member may be formed of an elastic material, preferably an elastomer, more preferably a thermoplastic elastomer.

[0024] According to another aspect of the present invention, a medical device is disclosed, which includes at least one sealing device according to the present invention, wherein the medical device includes a first component having a circumferential end portion configured to be arranged between the outer surface of the deformable (annular) sealing member and the inner surface of the (annular) outer support member.

[0025] The medical device may include a second component configured to be arranged in the through-opening surrounded by the deformable (annular) sealing member.

[0026] The medical device may be a balloon catheter, wherein the first component is the balloon of the balloon catheter and the second component is preferably the catheter shaft of the balloon catheter, wherein in particular, the catheter shaft includes a lumen configured to communicate with the internal space enclosed by the balloon, for example, so as to be able to inflate the balloon via the lumen.

[0027] In particular, the circumferential end portion of the balloon defines an opening through which the catheter shaft is inserted into the balloon to arrange the balloon on the catheter shaft.

[0028] According to another aspect of the invention, another sealing device can also be used to seal the opposite circumferential end portion of the balloon, which defines another opening of the balloon for inserting a catheter shaft so as to mount the balloon on the catheter shaft. Here, further, the other circumferential end portion of the balloon is configured to be disposed between the outer surface of the deformable (annular) sealing member and the inner surface of the (annular) outer support member of the other sealing device.

[0029] The catheter shaft is configured to be disposed in a through-opening surrounded by the deformable (annular) sealing member of the other sealing device. The catheter shaft may include an outer shaft member and an inner shaft member, and the inner shaft member is slidably disposed in the inner cavity of the outer shaft member such that the catheter shaft can be extended by partially pulling out the inner shaft member from the outer shaft member.

[0030] Here, a distal sealing device according to the invention is disposed on the distal end portion of the inner shaft member, wherein the (annular) inner support member of the sealing device accommodates the distal end portion of the inner shaft member in its through-opening and is coupled to the inner shaft member.

[0031] However, the sealing device according to the invention can be used not only for medical devices. The sealing device can be used in any other device that requires sealing, preferably a device that requires a tubular or rod-shaped object (such as a shaft). The seal can be used as a heat shrink fit collar, heat shrink fit ring or heat shrink fit clamp. The sealing device can be used as a hose clamp or fastener.

[0032] In addition, the proximal sealing device according to the invention has a through-opening defined by the inner surface of the deformable (annular) sealing member (i.e., not including the (annular) inner support member). Thus, when the body enters its contracted state by raising the temperature, the deformable (annular) sealing member of the proximal sealing device can also reversibly clamp the inner shaft member. In particular, in order to reduce the risk that the inner shaft member is squeezed by the proximal sealing device in the contracted state of the body of the proximal sealing device, the inner shaft member may include a support structure, in particular a support ring. Such a support structure / ring can be formed by an X-ray marker of a balloon catheter disposed on the inner shaft member.

[0033] According to yet another aspect of the invention, a method for sealing a medical device using at least one sealing device according to the invention is disclosed, the method comprising the following steps:

[0034] - Providing a medical device including a first component

[0035] - Disposing a circumferential portion of the first component between the inner surface of the (annular) outer support member and the outer surface of the deformable (annular) sealing member, and

[0036] - Heat the body such that the body assumes its contracted state, thereby causing the deformable (annular) sealing member to expand in the radial direction such that the outer surface of the deformable (annular) sealing member moves towards the inner surface of the (annular) outer support member and sealingly clamps the circumferential portion of the first component between the inner and outer surfaces.

[0037] The method according to the invention can be further characterized in corresponding embodiments by the embodiments and features described above with respect to the sealing device and the medical device according to the invention. In particular, the first component is the balloon of a balloon catheter, wherein the circumferential portion of the balloon is preferably the circumferential end portion of the balloon, which defines an opening for inserting the catheter shaft of the balloon catheter (see also above). BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Hereinafter, embodiments of the invention and other features and advantages of the invention will be described with reference to the drawings, in which:

[0039] Figure 1 A schematic cross-sectional view showing an embodiment of the sealing device according to the invention is shown,

[0040] Figure 2 showing the conversion of the body of the sealing member from its expanded state to its contracted state and vice versa,

[0041] Figure 3 showing a medical device, here in the form of a balloon catheter, which uses the sealing device according to the invention to mount the balloon to the catheter in a sealed manner, and

[0042] Figure 4 showing a medical device including an extendable catheter shaft for accommodating balloons of different lengths using the sealing device according to the invention. DETAILED DESCRIPTION

[0043] Figure 1 In combination Figure 2 An embodiment of a sealing device 1 according to the invention is shown. The sealing device 1 is particularly suitable for medical devices, such as balloon catheter 100, but can also be applied to other fields that also require a detachable sealing device.

[0044] As Figure 1 and Figure 2As shown, the sealing device 1 includes an annular outer support member 2 and an annular deformable sealing member 3. The annular outer support member 2 includes an inner surface 2a, and the annular deformable sealing member 3 includes an outer surface 3a. The annular outer support member 2 is configured to be disposed on the annular deformable sealing member 3 such that the inner surface 2a of the annular outer support member 2 faces the outer surface 3a of the annular deformable sealing member 3. In addition, the sealing device 1 includes a body 4 formed of a shape memory alloy, wherein the body 4 is encapsulated by the annular deformable sealing member 3, and wherein the body 4 extends in the axial direction x and is configured to assume an expanded state at a first temperature and a contracted state at a higher second temperature. The body 4 contracts in the axial direction x relative to the expanded state, thereby causing the annular deformable sealing member 3 to expand in the radial direction R.

[0045] The expanded state is shown on Figure 2 the left hand side, while the contracted state of the body 4 is shown on Figure 2 the right hand side. As can be inferred from Figure 2 this, due to the body contracting in the axial direction x, the deformable body 4 contracts in this direction and thereby expands radially in the radial direction R. In particular, the corresponding radial direction R extends orthogonally to the axial direction x. Thus, the circumference of the annular deformable sealing member 3 increases in the contracted state. This allows a circumferential portion 102 of a component (e.g., a component of a medical device such as a balloon 101) to be sealingly clamped between the inner surface 3a and the outer surface 2a.

[0046] As Figure 2 shown, the clamping can be activated by heating H, i.e., increasing the temperature of the body 4, which causes the shape memory alloy to transition to its contracted state (see the right hand side). On the other hand, in the case where the body 4 is cooled C again, the body 4 returns to its expanded state (see the left hand side), thereby causing the sealing device 1 to disengage. If desired, an additional external force can be applied to disengage the sealing device.

[0047] The body 4 may have a recess 4a. The recess 4a may be cut out in the body 4. Optionally, the force transmission from the body 4 made of shape memory alloy to the deformable sealing member 3 may be enhanced by integrating at least one force transmission body 7 between the annular deformable sealing member 3 and the body 4. The force transmission body 7 between the annular deformable sealing member 3 and the body 4 may be positioned at the distal and proximal (cut) edges of the recess 4a of the body 4. The force transmission body 7 may be a separate piece of material or may be formed by folding a tongue that is formed when the recess is cut out but not cut at the distal and proximal edges. In the latter case, the force transmission body 7 projects radially outwards or inwards from the body 4. When separate pieces of material are inserted, they may project both radially outwards and inwards. The force transmission body 7 has an increased area for force transmission compared to the distal and proximal (cut) edges of the recess 4a of the body 4. On the one hand, the at least one body causes an increase in the force directed in the axial direction x, and on the other hand, when the body 4 contracts, it can prevent the body 4 made of shape memory alloy (e.g., NiTi) from contracting or pressing into the deformable sealing member 3.

[0048] Preferably, the body 4 is an annular structure formed of shape memory alloy and surrounds an internal space in the circumferential direction U orthogonal to the axial direction x. The body / annular structure 4 includes an inner side 4a facing the internal space and an outer side 4b facing away from the inner side 4a. In particular, the annular deformable sealing member 3 circumferentially surrounds the body 4 and thus includes an inner part 30 arranged on the inner side 4a of the body 4 and an outer part 31 arranged on the outer side 4b of the body 4. In addition, the face side of the annular structure 31 may also be covered by the annular deformable sealing member 3.

[0049] In addition, the sealing device 1 includes a through-opening 6 for receiving a second component 103 of the device to be sealed, such as a catheter shaft 103 (see Figure 3 and Figure 4 ). In particular, the annular deformable sealing member 3 of the sealing device includes a circumferential inner surface 3b. Preferably, the annular inner support member 5 of the sealing device is connected to the inner surface 3b of the annular deformable sealing member 3 and defines the through-hole 6. Preferably, the annular inner support member 5 is configured to be arranged on the second component 103 and, for example, bonded to the second component 103 by an adhesive.

[0050] Figure 3 The application of the sealing device 1 in the frame of a medical device 100 is shown, here for example in the form of a balloon catheter 100. The balloon catheter includes a first component 101 in the form of a balloon 101, which has two opposite circumferential end portions 102, each circumferential end portion defining an opening for receiving a catheter shaft 103 that forms the second component of the balloon catheter 100.

[0051] Here, the sealing device 1 is mounted on the catheter shaft 103 such that the catheter shaft 103 is received in the slot opening 6 of the sealing device 1 as described above. In particular, the annular inner support member 5 is disposed on and coupled to the catheter shaft 103. Then, the end portion 102 of the balloon 101 is disposed on the outer surface 3a of the annular deformable sealing member 3 of the sealing device 1, as referenced above Figure 1 above. Finally, the annular outer support member 2 is placed over the end portion 102 (see Figure 1 ), where the annular outer support member 2 may already be provided on the portion 102 of the balloon 101 (e.g., as an integral element thereof). Now heat the H sealing devices 1 as described above to cause them to expand radially and thus activate the sealing members 1. Cool the sealing members 1 again to cause the annular deformable sealing member 3 to contract and allow the balloon to be released from the annular sealing member 3.

[0052] In addition, as Figure 4 shown, in a preferred embodiment of the medical device 100, the catheter shaft 103 may include an outer shaft member 103b and an inner shaft member 103a, the inner shaft member 103a being slidably disposed within the lumen of the outer shaft member 103b such that the catheter shaft 103 can be extended by partially pulling the inner shaft member 103a out of the outer shaft member 103b. This allows one to easily fit balloons of different lengths onto the catheter shaft since the distance between the two sealing members 1 mounted on the catheter shaft is now variable.

[0053] In particular, as specifically incorporated herein Figure 1 above, the distal sealing device 1 may be disposed on the distal end portion of the inner shaft member 3a, where the annular inner support member 5 of the sealing device 1 receives the distal end portion of the inner shaft member 3a in its through opening 6 (see Figure 1 ), and is coupled to the inner shaft member 3a. In addition, a proximal sealing device 1' according to the present invention (e.g., as incorporated above Figure 1 above) is mounted on the catheter shaft at the end of the outer shaft member 103b and has a through opening 6 defined by the inner surface 3b of the annular deformable sealing member 3 (i.e., excluding the annular inner support member 5). Thus, when the body 4 is caused to enter its contracted state by raising the temperature, the annular deformable sealing member 3 of the proximal sealing device 1' can also reversibly clamp the inner shaft member 3a. In particular, to reduce the risk of the inner shaft member 103a being squeezed by the proximal sealing device 1' in the contracted state of the body 4 of the proximal sealing device 1', the inner shaft member 103a may include a support structure 104, particularly a support ring 104. Such a support structure / ring 104 can be formed by an X-ray marker of the balloon catheter 100 disposed on the inner shaft member 103a.

[0054] The present invention provides an advantageous reversible sealing device which, in particular under the action of heat, increases its circumference and, under the action of cold, again reduces its circumference. The sealing device is particularly suitable for producing a firm liquid-tight and gas-tight seal between one space and another under physiological conditions (for example at body temperature), but preferably in such a way that the sealing device can be released under non-physiological conditions (for example at a temperature below 30 degrees). In addition, the sealing device can be used as a clamping element. In particular, the sealing device according to the invention provides easy handling under clinical conditions, it is fail-safe, easy to sterilize and very easy to use.

Claims

1. A sealing device (1), particularly for a medical device (100), the sealing device (1) comprising: - an external support member (2), the external support member comprising an inner surface (2a), - a deformable sealing member (3), the deformable sealing member comprising an outer surface (3a), the external support member (2) being configured to be arranged above the deformable sealing member (3) such that the inner surface (2a) of the external support member (2) faces the outer surface (3a) of the deformable sealing member (3), and - a body (4) formed of a shape memory alloy, wherein the body (4) is surrounded by the deformable sealing member (3), wherein the body (4) extends in an axial direction (x) and is configured to assume an expanded state at a first temperature and a contracted state at a higher second temperature, wherein the body (4) contracts in the axial direction (x) in the contracted state, thereby causing the deformable sealing member (3) to expand in a radial direction (R).

2. The sealing device according to claim 1, wherein The outer surface (3a) of the deformable sealing member (3) is configured to move towards the inner surface (2a) of the external support member (2) when the external support member (2) is arranged on the deformable sealing member (3) and the body (4) assumes its contracted state, thereby allowing a circumferential portion (102) of a component (101) to be sealingly clamped between the inner and outer surfaces (2a, 3a).

3. The sealing device according to claim 1 or 2, wherein, The body (4) is a structure surrounding an internal space in a circumferential direction (U) orthogonal to the axial direction (x), and has an inner side (4a) facing the internal space and an outer side (4b) facing away from the inner side (4a).

4. The sealing device according to any one of the preceding claims, wherein, The deformable sealing member (3) comprises an internal portion (30) arranged on the inner side (4a) of the body (4) and an external portion (31) arranged on the outer side (4b) of the body (4).

5. The sealing device according to any one of the preceding claims, wherein, The deformable sealing member (3) surrounds a through-opening (6) of the sealing device (1), the through-opening (6) being configured to receive a component, particularly a component (103) of a medical device (100), wherein in particular the component is a shaft of a catheter.

6. The sealing device according to claim 5, wherein, The sealing device (1) comprises an internal support member (5), wherein the inner surface (3b) of the deformable sealing member (3) is bonded to the internal support member (5), and wherein the internal support member (5) defines the through-opening (6) and is configured to be bonded to the component received in the through-opening (6).

7. The sealing device according to any one of the preceding claims, wherein, The first temperature is less than 30 °C, and the second temperature is greater than or equal to 35 °C.

8. The sealing device according to any one of the preceding claims, wherein, The body (4) is formed of a material selected from nickel-titanium alloys, copper-aluminum-nickel alloys, copper-zinc-aluminum alloys, and iron-manganese-silicon alloys.

9. The sealing device according to any one of the preceding claims, wherein, The deformable sealing member (3) is formed of an elastic material, preferably an elastomer, more preferably a thermoplastic elastomer.

10. The sealing device according to any one of the preceding claims, wherein, The external support member (2) is an annular external support member, and wherein, the deformable sealing member (3) is an annular deformable sealing member and / or the body (4) is an annular body and / or the internal support member (5) is an annular internal support member.

11. A medical device (100) comprising at least one sealing device (1) according to any one of the preceding claims, wherein, The medical device (100) includes a first component (101) having a circumferential end portion (102) configured to be disposed between an outer surface (3a) of the deformable sealing member (3) and an inner surface (2a) of the external support member (2).

12. The medical device according to claim 11, wherein, The first component is a balloon.

13. The medical device (100) according to claim 11 or 12, wherein, The medical device (100) includes a second component (103) configured to be received in the through-opening (6) surrounded by the deformable sealing member (3).

14. The medical device according to claim 13, wherein, The second component is a catheter shaft.

15. A method for sealing a medical device (100) using the sealing device (1) according to any one of claims 1 to 10, the method comprising the following steps: - providing a medical device (100) including a first component (101), - disposing a portion (102) of the first component (101) between an inner surface (2a) of the external support member (2) and an outer surface (3a) of the deformable sealing member (3), and - heating the body (4) such that the body (4) assumes its contracted state, thereby causing the deformable sealing member (3) to expand in the radial direction (R), such that the outer surface (3a) of the deformable sealing member (3) moves towards the inner surface (2a) of the external support member (2), and sealingly clamping the circumferential portion (102) of the first component (101) between the inner surface (2a) and the outer surface (3a).

Images