Implantable intralumenal device

Abstract

An implantable intralumenal device. The implantable intralumenal device comprising : a component configured to respond to an electrical signal; an antenna; and a fixing structure, wherein the fixing structure carries an electrical connection between the antenna and the component and the antenna is mechanically fixed to the fixing structure thereby to provide strain relief to the component from mechanical force applied to the antenna.

Description

[0001] Implantable intralumenal device

[0002] Field of Invention

[0003] The invention relates to implantable intralumenal devices . In particular it relates to providing strain relief to components of implantable intralumenal devices .

[0004] Background

[0005] Implantable intralumenal devices may generally be implanted into any part of the body and include, for example, the vasculature of the human or animal body. Where there is a need for long-term monitoring of patients the repeated use of invasive measurements increases the risk of inj ury and can ultimately lead to the physician deciding that such a procedure is too risky to undertake . Medical technology is progressing rapidly, and with it has increased the range of implantable devices available for providing a variety of internal measurements of the vital signs of a patient to a physician without the need for repeated invasive measurements .

[0006] Implantable devices are preferred for taking internal measurements , as repeatedly inserting and removing devices can be detrimental to a patient ' s health. Once implanted, the device can provide information over a long period without further risk each time they are used. Typically, intralumenal measurement devices are held (anchored) within a bodily lumen of a patient . Once held within the bodily lumen the intralumenal device takes intralumenal measurements such as intralumenal temperature, intralumenal pressure, composition of blood, and blood flow, and can do so over extended periods of time .

[0007] To make such measurements possible, intralumenal devices carry a variety of different measurement components such as electrodes and interdigitated transducers .

[0008] Communication with implants and their measurement components can be achieved through inductive coupling or through a radio frequency link from a transmitter / receiver located outside the patient ' s body.

[0009] During use, implantable intralumenal devices are subj ected to strains that can be detrimental to both the short term and long term performance of the carried measurement components .

[0010] The present application seeks to address the problem of strain on components in implantable intralumenal devices .

[0011] Summary of invention

[0012] Aspects and examples of the invention are set out in the claims and aim to address at least a part of the above described technical problem, and other problems .

[0013] An aspect of the invention is directed to an implantable intralumenal device . The implantable intralumenal device comprising : a component configured to respond to an electrical signal ; an antenna; and a fixing structure, wherein the fixing structure carries an electrical connection between the antenna and the component and the antenna is mechanically fixed to the fixing structure thereby to provide strain relief to the component from mechanical force applied to the antenna .

[0014] For example, the fixing structure may be mechanically fixed to the component, e . g . fixed directly to the component and / or to a housing of the component . This mechanical fixing is arranged so that mechanical load applied to the antenna is borne primarily by the fixing structure instead of the electrical connection between the antenna and the component . The mechanical fixing of the fixing structure to the component may be provided in addition to the electrical connection between the antenna and the component (for example, separate from the electrical connection between the antenna and the component ) . A function of the fixing structure is to isolate the component from the mechanical stresses which may occur to the antenna . The component might for example be sensor, for example a measurement sensor, for example a pressure sensor . The antenna may provide communication of the electrical signal with the component . The antenna might also provide anchoring of the sensor in the lumen .

[0015] The fixing structure thereby seeks to isolate the component from mechanical stresses which occur to the antenna, thereby to avoid mechanical stress artefacts corrupting pressure measurement . This is particularly important in the context of a sensor implanted within the cardiovascular system where the mechanical stresses (to which the antenna might be exposed) may be synchronous with the cyclical pressure changes which the component may be measuring .

[0016] The fixing structure may comprise at least one of : an interposer, and a housing, in which the component is disposed.

[0017] The antenna may be configured to anchor the implantable intralumenal device in a bodily lumen. That is to say the antenna may have the dual-function of antenna and anchor . In particular the antenna may be loop-shaped and configured in use to engage with the walls of a bodily lumen into which the device is implanted .

[0018] The antenna and fixing structure may be formed from a single piece of material . This simplifies the construction of the implantable intralumenal device and aims to improve reliability and reproducibility in the manufacturing process . For example, an integral antenna fixing structure may be formed for example from a single sheet of material . For example the antenna and fixing structure may be formed by laser-cutting the antenna and fixing structure from a sheet of material such as a sheet of nickel titanium alloy (e . g Nitinol ) sheet to form a single piece with an "fixing part" and an "antenna part" . For example the antenna and fixing structure may be formed by stamping the antenna and fixing structure from a sheet of material such as a sheet of nickel titanium alloy. The fixing structure may comprise separate parts . The antenna may also comprise separate parts . For example, the fixing structure may comprise a first and a second element . For example, the antenna may comprise a first loop and a second loop . Each of the separate parts of the fixing structure may be integrally formed with a corresponding part of the antenna . For example, a first element of the fixing structure may be integrally formed with a first loop of the antenna and a second element of the fixing structure may be integrally formed with a second loop of the antenna . The fixing structure and antenna may therefore comprise a number of integrally formed parts .

[0019] Furthermore, the component may be resiliently held, for example by a resilient member, for example a moulded resilient member ( for example silicone potting paste ) which at least partially encapsulates the component . For example, the component may be resiliently held within the housing . For example such that the connection between the fixing structure and component is resilient . For example, such that the connection between the interposer and the component is resilient . For example, such that the connection between the housing and the component is resilient .

[0020] The fixing structure may be fixed to the component for example using a biocompatible solder for example AuSn . For example the fixing structure may be rigidly fixed to the component .

[0021] The fixing structure may comprise the housing; wherein the antenna is mechanically fixed to the housing thereby to provide strain relief to the component from mechanical force applied to the antenna . The fixing structure may comprise : the interposer; wherein the antenna is mechanically fixed to the interposer thereby to provide strain relief to the component from mechanical force applied to the antenna .

[0022] The fixing structure may comprise : the housing and the interposer, wherein the antenna is mechanically fixed to the housing using the interposer . The interposer may be rigidly fixed to the housing, for example using mechanical attachment, for example locking arrangement such as a plug and socket arrangement between the interposer and housing . The mechanical attachment may for example comprise a stake attachment arrangement between the interposer and housing . The mechanical attachment may for example comprise for example a rivet and hole arrangement between the interposer and housing .

[0023] The interposer of the implantable intralumenal device may be disposed between the component and the housing . For example wherein the interposer may be provided in the housing . For example between a wall of the housing and the component .

[0024] The antenna of the implantable intralumenal device may be mechanically secured to the housing . For example using the interposer .

[0025] The antenna may comprise a first loop electrically connected to the fixing structure and / or, the antenna may comprise a second loop electrically connected to the fixing structure . For example wherein the first loop and the second loop extend from opposite ends of the fixing structure .

[0026] The interposer may comprise elements that take a number of different shapes and sizes the elements may enable the interposer to carry an electrical connection between the antenna and the component and to be fixed to the housing to provide strain relief to the component from force applied to the antenna . For example, the interposer may comprise a conductive block element . For example the interposer may comprise a tab element .

[0027] The interposer may comprise : a first element in electrical connection with the antenna, wherein the first element is mechanically secured to a wall of the housing, such as a first wall and optionally at least one other wall transverse to the first wall . For example, wherein the first element is positioned adj acent a first wall of the housing and / or wherein the first element extends into the housing through a first wall of the housing .

[0028] The interposer may comprise : a second element in electrical connection with the antenna, wherein the second element is mechanically secured to a second wall of the housing such as the second wall and optionally at least one other wall transverse to the second wall . The second element may be positioned adj acent a second wall of the housing, opposite to the first wall and / or wherein the second element extends into the housing through a second wall of the housing, opposite to the first wall . The component may be provided between the first element and the second element .

[0029] The antenna may comprise a first loop electrically connected to the fixing structure and / or, the antenna may comprise a second loop electrically connected to the fixing structure .

[0030] For example, wherein a first loop of the antenna is electrically connected to the first element and / or, a second loop of the antenna is electrically connected to the second element .

[0031] The first element of the interposer may comprise a first conductive block in electrical connection with the antenna . The conductive block may be positioned adj acent a first wall of the housing. The first conductive block may be mechanically secured to a wall of the housing, such as the first wall and optionally at least one other wall transverse to the first wall .

[0032] The second element of the interposer may also comprise a second conductive block in electrical connection with the antenna . The component may be provided between the first conductive block and the second conductive block . The second conductive block may be positioned adj acent a second wall of the housing, opposite to the first wall .

[0033] The first element of the interposer may comprise a first plate ( for example a tab) in electrical connection with the antenna . The first plate may extend into the housing through a first wall of the housing for example through a slot in the housing . The first plate may be mechanically secured to a wall of the housing, such as the first wall and optionally at least one other wall transverse to the first wall .

[0034] The second element of the interposer may comprise a second flat plate in electrical connection with the antenna . The component may be provided between the first plate and the second plate . The second flat plate may extend into the housing through a second wall of the housing opposite the first wall for example through a slot in the second wall .

[0035] In one configuration, the antenna may comprise a first loop electrically connected to the interposer and / or a second loop electrically connected to the interposer . For example, the antenna may comprise a first loop electrically connected to the first conductive block and / or the antenna may comprise a second loop electrically connected to the second conductive block .

[0036] In another configuration the antenna may comprise a first loop electrically connected to a first plate of the interposer and / or the antenna may comprise a second loop electrically connected to a second plate of the interposer .

[0037] The first and / or second loops described above may be integral with the first and / or second elements for example integral with first / second plates and / or first / second conductive blocks .

[0038] The antenna may extend from opposite ends of the housing in particular the first loop and the second loop of the antenna may extend from opposite ends of the housing . The component may be configured to respond to an electrical signal having a first known frequency band and is configured to respond to an electrical signal having a second known frequency band and wherein the antenna may be configured to operate in the first known frequency band and wherein the antenna is configured to operate in the second known frequency band. For example, the component may respond to a second frequency band. The component may for example comprise a pressure sensor that is responsive in a first frequency band and a reference sensor that is responsive in a second frequency band.

[0039] The first known frequency band and / or the second known frequency band may be between 850MHz and 950MHz, for example between 910MHz and 930MHz , for example between 915MHz and 920MHz .

[0040] The component may comprise a piezoelectric substrate and the housing may comprise a ceramic for example Zirconium dioxide .

[0041] Brief Description of Drawings

[0042] Some practical implementations will now be described, by way of example only, with reference to the accompanying drawings in which :

[0043] Figure la shows a schematic diagram of an implantable intralumenal device 100 ;

[0044] Figure lb shows a schematic diagram of an implantable intralumenal device 100b; Figure 2 shows a schematic diagram of an implantable intralumenal device 200 ; and

[0045] Figure 3 shows a schematic diagram of an implantable intralumenal device 300 ;

[0046] Figure 4 shows a picture of an implantable intralumenal pressure sensor 400 ;

[0047] Figure 5a shows a cross-sectional schematic diagram of an implantable intralumenal device 600 ; and

[0048] Figure 5b shows a plan schematic diagram of an integral antenna and interposer used in the implantable intralumenal device 600. In the drawings like reference numerals are used to indicate identical elements .

[0049] Specific Description

[0050] Provided below are a number of examples of implantable intralumenal devices . The term intralumenal means within a lumen for example within a bodily lumen . This term, intralumenal, may include lumens of intravascular vessels and lumens of the gastrointestinal system. The intravascular vessels may include arteries , arterioles, capillaries , venules and veins .

[0051] The example implantable intralumenal devices are of particular use when positioned in the intravascular vessels of the heart such as the Aorta; Pulmonary Artery; Pulmonary Vein; superior Vena Cava and the Inferior Vena Cava . Figure 1 - Fixing Structure - Housing and interposer

[0052] Figure 1 shows an implantable intralumenal device 100 that comprises a component 120, a fixing structure comprising an interposer 130 and a housing 110 , and an antenna 140.

[0053] The fixing structure may alternatively comprise the interposer 130 or the housing 110.

[0054] The structure of the implantable intralumenal device 100 will now be described.

[0055] The component 120 is housed within the housing 110. For example, the component 120 is partially encased by the housing 110. The component 120 might for example be a component for making an intralumenal measurement .

[0056] The interposer 130 is fixed to the housing 110 and the interposer 130 is electrically connected to the component 120. The interposer 130 may electrically connect to the component using vias in a casing of the component 120 and may connect directly to the component 120. The interposer 130 is also electrically connected to the antenna 140.

[0057] The antenna 140 electrically connects to the interposer 130. The antenna may at least partially extend from the housing 110 and may be positioned outside of the housing 110.

[0058] The interposer 130 and the antenna 140 may be integral being formed from a single piece of material so as to be a unitary piece . The antenna 140 may directly connect to the interposer 130 or alternatively or in addition connect to the housing 110. For example using a mechanical connection such as a rivet and hole arrangement to secure the antenna 140 to the housing 110.

[0059] The function of the implantable intralumenal device 100 shown in Figure 1 will now be described.

[0060] The implantable intralumenal device 100 seeks to minimise strain on component 120. A source of strain on the component 120 may originate from forces applied to the antenna 140.

[0061] The interposer 130 provides strain relief to the component 120 from force applied to the antenna 140. In particular, the fixation of the interposer 130 to the housing 110 provides a strain relief . In addition, the interposer 130 provides an electrical connection between the antenna 140 and the component 120.

[0062] The component 120 is configured to respond to an electrical signal . Thereby allowing the component 120 to be interrogated by another device 500 for example one that, in use, is external to the body of a patient .

[0063] The component 120 may be configured to perform a measurement within a bodily lumen in response to the electrical signal . For example, the component may comprise a pressure sensor that responds to an electrical signal with a pressure measurement . The antenna 140 is configured to provide communication of the electrical signal with the component .

[0064] The antenna 140, which is electrically connected to the component 120 via the interposer 130 , may receive and transmit electrical signals from the component 120 and communicate these to another device 500. The antenna 140 may also receive signals from another device 500 and communicate these to the component in the form of an electrical signal, for example an RF transmitter seeking to interrogate the component 120.

[0065] In some examples, the antenna 140 and interposer 130 may together form an antenna .

[0066] In addition to functioning as an antenna, the antenna 140 may also be configured to anchor the implantable intralumenal device in the bodily lumen .

[0067] When acting as an anchor or otherwise, forces may be applied to the antenna 140 for example by the walls of the bodily lumen or blood flowing through the lumen . The transmission of these forces from the antenna 140 to the component 120 are reduced by the fixing of the interposer 130 to the housing 110.

[0068] Several improvements may be made to the strain relief provided by the interposer 130 by altering the relative mechanical stiffness of parts of the implantable device 100 for example the housing 110, component 120 , interposer 130 and / or antenna 140. The relative mechanical stiffness (and therefore the strain relief ) can be tuned through the choice of material of each of the housing 110, component 120 , interposer 130 and / or antenna 140 and / or by the fixings between some or all of the housing 110, the component 120, the interposer 130 and / or the antenna 140.

[0069] For example, further improvements to the strain relief provided by the interposer 130 may be achieved by rigidly fixing ( rather than fixing) the interposer 130 to the housing 110.

[0070] For example, the interposer 130 can be fixed or rigidly fixed to the housing 110 using a mechanical connection. For example a plug and socket arrangement . For example, a click-in self-locking arrangement between the housing 110 and interposer 130. For example a rivet and hole arrangement between the interposer 130 and the housing 110.

[0071] Alternatively, or in addition, an adhesive might be used to fix or rigidly fix the interposer 130 to the housing 110.

[0072] The component 120 may be resiliently held in the housing 110 to further improve the strain relief provided by the component 120. The component 120 may be resiliently held in the housing 110 , for example by a resilient member, for example a moulded resilient member, for example silicone potting paste, which may at least partially encapsulate the component 120. The component 120 may be spaced from the housing. For example, the component 120 may be spaced from the housing by the resilient member . For example, the component 120 may be suspended by the interposer 130 and spaced from the housing 110.

[0073] Furthermore, whilst the connection from the interposer 130 to the component 120 is mainly electrical in nature the interposer 130 may be fixed to the component 120. For example, rigidly fixed. This may be achieved using a biocompatible solder such as biocompatible AuSn eutectic solder .

[0074] The interposer 130 may also be at least partially resiliently held in the housing 110 for example by a resilient member, for example a moulded resilient member, for example silicone potting paste, which at least partially encapsulates the interposer 130. The same or different resilient members may be used to resiliently hold the interposer 130 and / or the component 120.

[0075] Any combination of resiliently held component 120 and / or interposer 130 , rigidly fixed interposer 130 , and an interposer 130 rigidly fixed to the component 120 may further improve the strain relief provided by the interposer 130.

[0076] The implantable intralumenal device 100 of Figure 1 will now be described in use .

[0077] In use the implantable intralumenal device 100 is positioned in a bodily lumen of a patient . The implantable intralumenal device 100 may be held in place by antenna 140 or in the alternative by other anchoring means . Once the implantable intralumenal device 100 is in position in the bodily lumen the component 120 is interrogated by a device 500 external to the body using an interrogation signal via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 and the interposer 130. The antenna 140 thereby communicates an electrical signal to the component based on the interrogation signal . The component 120 may respond to the interrogation signal and may for example produce a return signal in response to the received interrogation signal . In the case where a return signal is produced, the return signal is received by the antenna 140 via the interposer 130 and the antenna 140 transmits the response signal to the external device 500.

[0078] In use, the antenna 140 may be exposed to the hostile environment of the bodily lumen . The antenna 140 may therefore be subj ected to a number of different forces such as the flow of blood past the device 100 and force from contact with the walls of the blood vessel .

[0079] The interposer 130 in the device 100 mediates the connection between the antenna 140 and the component 120 - the interposer 130 is fixed to the housing 110 and provides strain relief to the component 120 from forces applied to the antenna 140 , thereby providing an improvement over a direct unmediated connection between antenna 140 and component 120.

[0080] Figure lb - Fixing Structure - Housing Figure lb shows a further example implantable intralumenal device 100b . The implantable intralumenal device 100b is identical to the intralumenal device 100 in both structure and function except as described below.

[0081] Figure 1 shows an implantable intralumenal device 100 that comprises a component 120 , a fixing structure comprising a housing 110 , and an antenna 140. The interposer 130 is absent from the device 100b .

[0082] The structure of the implantable intralumenal device 100 will now be described.

[0083] The component 120 is housed within the housing 110. For example, the component 120 is partially encased by the housing 110. The component 120 might for example be a component for making an intralumenal measurement may comprise a pressure sensor encased in a component casing .

[0084] The antenna 140 is fixed to the housing 110 and the housing 130 carries an electrically connection from the antenna to the component 120.

[0085] The antenna 140 electrically connects to the housing 110 for example to electrical vias within walls of the housing . The antenna 140 may at least partially extend from the housing 110 and may be positioned outside of the housing 110.

[0086] The housing 110 and the antenna 140 may be integral . The housing 110 and the antenna may be formed from a single piece of material so as to be a unitary piece .

[0087] The antenna 140 is mechanically connected to the housing . For example using a rivet and hole arrangement between the housing 110 and the antenna 140. For example the may comprise an antenna tab that has a hole which will align with a hole in the housing . The antenna tab may be inserted through a slot in the housing and a rivet used to mechanically fix the antenna tab to the housing. An adhesive coating on the antenna tab may strengthen this form of providing strain relief . The component may then be soldered to the end of the tab which has traversed the slot as far as the cavity in the housing accommodating the component .

[0088] The function of the implantable intralumenal device 100b shown in Figure 1 will now be described.

[0089] The implantable intralumenal device 100 seeks to minimise strain on component 120. A source of strain on the component 120 may originate from forces applied to the antenna 140.

[0090] The fixing structure, in this example the housing 110 provides strain relief to the component 120 from force applied to the antenna 140. In particular, the fixation of the antenna 140 to the housing 110 provides a strain relief . In addition, the housing 110 facilitates an electrical connection between the antenna 140 and the component 120.

[0091] The component 120 is configured to respond to an electrical signal . Thereby allowing the component 120 to be interrogated by another device 500 for example one that in use, is external to the body of a patient .

[0092] The component 120 may be configured to perform a measurement within a bodily lumen in response to an electrical signal . For example, the component may comprise a pressure sensor that responds to an electrical signal with a pressure measurement .

[0093] The antenna 140 is configured to provide communication of the electrical signal with the component 120.

[0094] The antenna 140, which is electrically connected to the component 120 via the housing 110, may receive and transmit electrical signals from the component 120. The antenna 140 may also receive signals from another device 500 for example an RF transmitter seeking to interrogate the component 120.

[0095] In addition to functioning as an antenna, the antenna 140 may also be configured to anchor the implantable intralumenal device in the bodily lumen .

[0096] When acting as an anchor or otherwise, forces may be applied to the antenna 140 for example by the walls of the bodily lumen or fluid flowing through the lumen . The transmission of these forces from the antenna 140 to the component 120 are reduced by the fixing of the antenna 140 to the fixing structure which in this case is housing 110.

[0097] Several improvements may be made to the strain relief provided by the housing 110 by altering the relative mechanical stiffness of parts of the implantable device 100 for example the housing 110 , component 120 , and / or antenna 140.

[0098] The relative mechanical stiffness (and therefore the strain relief ) can be tuned through the choice of material of each of the housing 110, component 120 , and / or antenna 140 and / or by the fixings between some or all of the housing 110, component 120, and / or antenna 140.

[0099] For example, further improvements to the strain relief provided by the housing 110 may be achieved by rigidly fixing ( rather than fixing) the antenna 140 to the housing 110.

[0100] For example, the antenna 140 can be fixed or rigidly fixed to the housing 110 using a mechanical connection such as a rivet .

[0101] Alternatively, or in addition, an adhesive might be used to fix or rigidly fix the antenna 140 to the housing 110.

[0102] The component 120 may be resiliently held in the housing 110 to further improve the strain relief provided by the component 120. The component 120 may be resiliently held in the housing 110 , for example by a resilient member, for example a moulded resilient member, for example silicone potting paste, which may at least partially encapsulate the component 120. The component 120 may be spaced from the housing for example by the resilient member or for example suspended by the interposer . Any combination of resiliently held component 120 and / or rigidly fixed antenna 140 may further improve the strain relief provided by the housing 110.

[0103] The implantable intralumenal device 100b of Figure lb will now be described in use .

[0104] In use the implantable intralumenal device 100 is positioned in a bodily lumen of a patient . The implantable intralumenal device 100 may be held in place by antenna 140 or in the alternative by other anchoring means .

[0105] Once the implantable intralumenal device 100 is in position in the bodily lumen the component 120 is interrogated by a device 500 external to the body using an interrogation signal via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 and the housing 110. The component 120 responds to the interrogation signal and may for example produce a return signal in response to the received interrogation signal . In the case where a return signal is produced, the return signal is received by the antenna 140 via the housing 110 and the antenna 140 transmits the response signal to the external device 500.

[0106] In use, the antenna 140 may be exposed to the hostile environment of the bodily lumen . The antenna 140 may therefore be subj ected to a number of different forces such as the flow of fluid past the device 100 and force from contact with the walls of the blood vessel . The housing 110 in the device 100b mediates the connection between the antenna 140 and the component 120 - the housing 110 provides strain relief to the component 120 from forces applied to the antenna 140, thereby providing an improvement over a direct unmediated connection between antenna 140 and component 120.

[0107] Figure 2 - Conductive block interposer

[0108] Figure 2 shows a further example implantable intralumenal device 200. The implantable intralumenal device 200 is identical to the intralumenal device 100 in both structure and function except as described below. The implantable intralumenal device 200 is a more specific example of the implantable intralumenal device 100. In particular it shows a specific implementation of the interposer 130.

[0109] The implantable intralumenal device 200 comprises a housing 110 , a component 120 , an interposer 130 and an antenna 140.

[0110] As with the intralumenal device 100 described above the component 120 is housed in the housing 110.

[0111] In the device 200 of Figure 2 the component 120 is resiliently held in the housing 110 by a moulded resilient member 150. The moulded resilient member 150 partially encapsulates the component 120. The component 120 is spaced from the housing 110 by the moulded resilient member 150. The moulded resilient member 150 may be for example silicone potting paste . The resilient member seeks to improve the connection between the housing 110 and component 120 by making the connection resilient .

[0112] The interposer 130 is positioned between the component 120 and the housing 110. The interposer 130 is electrically connected to the component 120.

[0113] In the example device 200 shown in Figure 2 the interposer 130 is housed in the housing 110 and comprises a first conductive block 134 .

[0114] A first connector 132 electrically connects to the component 120 and extends from the component 120 to the first conductive block 134 , electrically connecting to the first conductive block and thereby electrically connecting the first conductive block 134 and component 120. The first connector 132 is optional and the first conductive block 134 may form a direct electrical connection with the component 120. The interposer 130 may electrically connect to the component 120 using vias in a casing of the component 120. In the example shown in Figure 2 the first conductive block 134 or first connector 132 may electrically connect to the component 120 using vias in a casing of the component 120.

[0115] The first conductive block 234 is positioned adj acent to a wall of the housing 110 , in this example it is positioned adj acent to end wall 112 of the housing 110.

[0116] The first conductive block 134 is mechanically rigidly fixed to the end wall 112 of the housing 110. In this example a plug and socket arrangement with a click-in self-locking arrangement between the housing 110 and interposer 130 is used. Alternatively, a rivet arrangement may be used to secure the interposer 130 and in particular the first conductive block 134 to the housing 110. The first conductive block 134 may be further fixed for example mechanically rigidly fixed to side walls 114 , 116 of the housing 110 adj acent to end wall 112 . The interposer 130 is thereby disposed between the component 120 and the housing 110.

[0117] As well as having an electrical connection to the component 120 , via the first connector 132 or a direct connection, the first conductive block 134 also electrically connects to the antenna 140 , in other words the interposer 130 electrically connects the component 120 and the antenna 140.

[0118] The interposer 130 may include further conductive blocks and there may be further connectors in similar arrangements to mediate further electrical connections between the component 120 and the antenna 140. An example of this is described in more detail below in reference to Figure 3.

[0119] In the example shown in Figure 2 the electrical connection to the antenna 140 is provided through the housing 110.

[0120] The antenna 140 is electrically connected to the first conductive block 134 through the housing 110. This electrical connection may be achieved by passing at least part of the antenna 140 through an opening or openings in the housing or the housing 110. In an alternative or in addition the housing 110 may comprise a via or a number of vias or slots to enable an electrical connection between the interposer 130 and the antenna 140. For example where the antenna 140 terminates on the outside of the housing 110.

[0121] The antenna 140 may be mechanically secured to the housing 110. In particular, the antenna 140 may terminate on the outside of housing 110.

[0122] The first conductive block 134 and the antenna 140 may be integrally formed from a single piece of material so as to be a unitary piece . For example the interposer 130 and antenna 140 may be cut from a single sheet of material . For example first conductive block 134 and antenna 140 may be cut from a single sheet of material .

[0123] The antenna 140 may also be configured to function as an anchor for the implantable intralumenal device 200 in a bodily lumen . The function of the implantable intralumenal device 200 shown in Figure 2 will now be described.

[0124] The implantable intralumenal device 200 seeks to minimise strain on component 120 originating from force applied to antenna 140. The fixation of the interposer 130 to the housing 110 provides strain relief to the component 120 from force applied to the antenna 140.

[0125] In this example, the first conductive block 134 of the interposer 130 is rigidly mechanically attached to the end wall 112 of the housing 110. The rigid attachment of the conductive block 134 to the housing further minimises strain that may be transmitted from the antenna 140 to the component 120 through the housing 110. Advantageously in device 200 the component 120 is resiliently held by resilient member 150 which also provides strain relief in that the connection between the housing 110 and the component 120 is resilient .

[0126] Furthermore, the combination of rigidly fixed interposer 120 and resiliently held component 120 provides a relative mechanical stiffness between the parts of device 200 that further reduces the transmission of force from the antenna 140 to the component 120 thereby providing strain relief to the component 120.

[0127] The interposer 130 also provides an electrical connection between the antenna 140 and the component 120.

[0128] The component 120 is configured to respond to an electrical signal . Thereby allowing the component to be interrogated by another device 500 for example one that, in use, is external to the bodily lumen . The component 120 may for example be a measurement component configured to perform a measurement within a bodily lumen that may be interrogated by an external device 500 to take a measurement . For example, the component 120 may be sensor . For example a pressure sensor .

[0129] The antenna 140 is configured to provide communication of an electrical signal with the component 120. The antenna 140, which is electrically connected to the component 120 via the interposer 130, may receive and transmit electrical signals from the component 120. The antenna 140 may also receive signals from another device 400 and communicate these to the component 120 for example an RF transmitter seeking to interrogate the component 120.

[0130] In use the implantable intralumenal device 200 is positioned in a bodily lumen of a patient . The implantable intralumenal device 200 may be held in place by antenna 140 or in the alternative by other anchoring means . The device 200 may also not be held in place .

[0131] Once the implantable intralumenal device 200 is in position in the bodily lumen the component 120 is interrogated by a device 500 external to body using an interrogation signal via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 and the interposer 130 and communicated to the component 120 as an electrical signal . The component 120 responds to the interrogation signal and produces a return signal in response to the received interrogation signal . The return signal is received by the antenna 140 via the interposer 130 and the antenna 140 then transmits the response signal to the external device 500. The return signal may contain information regarding a particular measurement parameter . For example, the return signal may contain information regarding a blood pressure measurement . In use, the antenna 140 may be exposed to the hostile environment of the bodily lumen . The antenna 140 may therefore be subj ected to a number of different forces such as the flow of blood past the device 200 and force from contact with the walls of the blood vessel .

[0132] The interposer 130 , and in particular the first conductive block 134 , in the device 200 mediates the connection between the antenna 140 and the component 120 - the first conductive block 134 of the interposer 130 is fixed to the housing 110 and provides strain relief to the component 120 from forces applied to the antenna 240, thereby providing an improvement over a direct unmediated connection between antenna 140 and component 120.

[0133] Figure 3 - Dual loop antenna and conductive block interposer Figure 3 shows an implantable intralumenal device 300. The implantable intralumenal device 300 is identical to the intralumenal device 100 and 200 in both structure and function other than as detailed below. The implantable intralumenal device 300 is a more specific example of the implantable intralumenal device 100.

[0134] The structure of the implantable intralumenal device 300 will now be described.

[0135] The implantable intralumenal device 300 comprises a housing 110 , a component 120, an interposer 130 and an antenna 340. As with the intralumenal device 100 and 200 described above the component 120 is housed in the housing 110. In the device 300 of Figure 3 the component 120 is resiliently held in the housing 110 by a moulded resilient member 150. The moulded resilient member 150 partially encapsulates the component 120.

[0136] The component 120 is spaced from the housing 110 by the moulded resilient member 150. The moulded resilient member 150 may be for example silicone potting paste .

[0137] The interposer 130 is positioned between the component 120 and the housing 110. The interposer 130 is electrically connected to the component 120.

[0138] In the example device 300 shown in Figure 3 the interposer 130 is located in the housing 110 and comprises a first conductive block 134 and a second conductive block 138 .

[0139] A first connector 132 electrically connects to and extends from the component 120 to the first conductive block 134 . The first connector 132 electrically connects to the first conductive block 134 , thereby electrically connecting the first conductive block 134 and the component 120.

[0140] The second connector 136 electrically connects to and extends from the component 120 to the second conductive block 138 . The second connector 136 electrically connects to the second conductive block 138 , thereby electrically connecting the second conductive block 138 and the component 120. The first and second connectors 132 , 136 are optional and the first and second conductive blocks 134 , 138 may form a direct electrical connection with the component 120. The interposer 130 may electrically connect to the component 120 using vias in a casing of the component 120. In the example shown in Figure 3 the first and second conductive blocks 134 , 138 or first and second connectors 132 , 136 may electrically connect to the component 120 using vias in a casing of the component 120.

[0141] The first conductive block 134 is positioned adj acent to a wall of the housing 110 , in this example it is positioned adj acent to the end wall 112 of the housing 110.

[0142] The first conductive block 134 is mechanically rigidly fixed to the end wall 312 of the housing 310 using a mechanical connection in this case a plug and socket arrangement such as a click-in self-locking arrangement between the housing 110 and first conductive block 134 . Alternatively stakes / rivets may be used to secure the first conductive block 134 to the housing 110. The first conductive block 134 may be further fixed for example mechanically rigidly fixed to side walls 114 , 116 of the housing 110 that are adj acent to end wall 112 .

[0143] The second conductive block 138 is positioned adj acent to a wall of the housing 110 , in this example it is positioned adj acent to the end wall 118 of the housing 110.

[0144] The second conductive block 138 is mechanically rigidly fixed to the end wall 118 of the housing 310 using a mechanical connection in this example a plug and socket arrangement, such as a click-in self-locking arrangement between the housing 110 and second conductive block 138 . Alternatively stakes / rivets that are configured to secure the second conductive block 138 to the housing 110 may be used. The second conductive block 138 may also be further fixed for example mechanically rigidly fixed to side walls 114 , 116 of the housing 110 that are adj acent to end wall 118.

[0145] The interposer 130 comprising the first conductive block 134 and the second conductive block 138 is thereby disposed in the housing 110 between the component 120 and the walls of the housing 110. The component 120 is positioned between the first conductive block 134 and the second conductive block 138.

[0146] As well as having an electrical connection to the component 120 , via the first connector 132 , the first conductive block 134 also electrically connects to the antenna 140.

[0147] Similarly, the second conductive block 138 , in addition to electrically connecting to the component 120 via the second connector 136, the second conductive block 138 also electrically connects to the antenna 140.

[0148] The interposer 130 and in particular the first and second conductive blocks 134 , 138 electrically connects the component 120 and the antenna 140. In the example shown in Figure 3 the electrical connection to the antenna 140 from the interposer 130 is provided through the housing 110.

[0149] In the example device 300 of Figure 3 the antenna 140 is provided exterior to the housing 110 and comprises a first loop 142 and a second loop 144 . The first loop 142 extends from wall 112 of the housing 110 and the second loop 144 extends from opposing wall 118 of the housing 110.

[0150] The first loop 142 and second loop 144 extend from opposite ends of the housing 110.

[0151] The first loop 142 electrically connects to the first conductive block 134 through the housing 110. In more detail a first end 142a and second end 142b of the first loop 142 electrically connect to the first conductive block 134 through the housing 110.

[0152] The second loop 144 electrically connects to the second conductive block 138 through the housing 110.

[0153] In more detail a first end 144a and second end 144b of the second loop 144 electrically connect to the second conductive block 138 through wall 118 of the housing 110.

[0154] This electrical connection may be achieved by passing the antenna 140 for example the first and second ends 142a, 142b of the antenna 140 through an opening or openings in the housing and attaching the first and second ends 142a, 142b to second block 138 for example soldering the first and second ends 142a, 142b to the second conductive block 138 .

[0155] The first conductive block 134 and the first loop 142 may instead be integrally formed from a single piece of material so as to be a unitary piece . Similarly, the second conductive block 138 and the second loop 144 may be integrally formed from a single piece of material so as to be a unitary piece . In such a way the interposer 130 may be made to be integral with the antenna 140. The housing may comprise a via or a number of vias to which the first and second ends 142a, 142b, 144a and 144b attach thereby terminating the antenna 140 on the outside of the housing 110 and enabling an electrical connection between the interposer 130 in particular the first and second conductive blocks 134 , 138 and the antenna 140.

[0156] The antenna 140 may be mechanically secured to the housing 110. For example, the first ends 142a, 144a and the second ends 142b, 142b of the first and second loops 142 , 144 may be secured to the walls 112 , 118 of the housing 110.

[0157] The antenna 140 of Figure 3, specifically the first loop 142 and the second loop 144 , are configured to also function as an anchor for the implantable intralumenal device 300 when the device 300 is deployed in a bodily lumen .

[0158] The function of the implantable intralumenal device 300 shown in Figure 3 will now be described. As with the implantable devices 100 , 100b and 200 described above . The implantable intralumenal device 300 seeks to minimise strain on component 120 through the use of a fixing structure . A source of strain on the component 120 may originate from forces applied to the antenna 140.

[0159] The component 120 is configured to respond to an electrical signal . Thereby allowing the component 120 to be interrogated by another device 500 for example one that, in use, is external to the bodily lumen .

[0160] The component 120 may for example be a measurement component configured to perform a measurement within a bodily lumen . The component 120 may be interrogated by an external device 500 to take a measurement . For example, the measurement component may be a pressure sensor which could be interrogated to take an intravascular blood pressure measurement .

[0161] The fixation of the interposer 130 in particular the fixation of the first and second conductive blocks 134 , 138 to the housing 110 provides strain relief to the component 120 from force applied to the antenna 140.

[0162] In this example, the first conductive block 134 of the interposer 130 is rigidly attached to the end wall 112 of the housing 110. The second conductive block 138 of the interposer 130 is rigidly attached to the end wall 118 of the housing 110. The rigid attachment of the conductive blocks 134 , 138 to the housing 110 further minimises transmission of strain from the antenna 140 to the component through the housing 110.

[0163] Advantageously in device 300 the component 120 is resiliently held by resilient member 150 which also provides strain relief . Furthermore, the combination of rigidly fixed conductive blocks 134 , 138 and resiliently held component 120 provides a relative mechanical stiffness between the parts of device 300 that further reduces the transmission of strain from the antenna 140 to the component 120.

[0164] The interposer 130 also provides an electrical connection between the antenna 140 and the component 120.

[0165] The antenna 140 may be configured to operate in the first known frequency band for example a frequency band between 850MHz and 950MHz ; 910MHz and 930MHz or 915MHz and 920MHz .

[0166] The antenna 140, which is electrically connected to the component 120 via the interposer 130, may receive electrical signals from the component 120 and may transmit electrical signals received from the component 120. The component 120 may receive electrical signals from the antenna 140. For example the antenna 140 may receive signals from another device 500 for example an RF transmitter seeking to interrogate the component 120.

[0167] The implantable intralumenal device 300 of Figure 3 will now be described in use . In use the implantable intralumenal device 300 is positioned in a bodily lumen of a patient . The implantable intralumenal device 300 is held in place by antenna 140 , the first loop 142 and the second loop 144 anchor the implantable intralumenal device within the bodily lumen by engaging with the walls of the bodily lumen . Once in position in the bodily lumen the component 120 is interrogated by a device 500 external to body using an interrogation signal via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 and the interposer 130.

[0168] The component 120 responds to the interrogation signal produces a return signal in response to a received interrogation signal .

[0169] The return signal is received by the antenna 140 via the interposer 130 and the antenna 140 transmits the response signal to the external device 500.

[0170] In use, the antenna 140 is exposed to the hostile environment of the bodily lumen. The antenna 140 is subj ected to forces for example from the flow of blood past the implantable intralumenal device 300 and from the walls of the blood vessel . This is particularly relevant for device 300 where the first and second loops 142 , 144 of the antenna 140 anchor the device 300 in the bodily lumen .

[0171] Direct connection of the antenna 140 to the component 120 would result in the forces applied to the antenna 140 , for example by the walls of the lumen, being transmitted to the component 120. In contrast, the interposer 130 and in particular the first and second conductive blocks 134 , 138 in the implantable intralumenal device 300 mediate the connection between the first and second loops 142 , 144 of the antenna 140 and the component 120.

[0172] In use, the interposer 130 provides strain relief to the component 120 from forces applied to the antenna 140.

[0173] Figure 4 - Implantable intralumenal pressure sensor

[0174] Figure 4 shows an implantable intralumenal device 400 for making intralumenal blood pressure measurements . The implantable pressure sensor 400 is identical to the intralumenal devices 100, 100b, 200 , 300 in both structure and function other than as described below. The device 400 is a more specific example of the implantable intralumenal devices 100 , 200, 300 and is an example of a specific implementation of these devices to measure intralumenal blood pressure .

[0175] There are a number of challenges when designing implantable intralumenal devices . Amongst these challenges is the miniaturisation of devices so that they can be deployed via a catheter into blood vessels . Devices with diameters that can be accommodated in catheters which are needed to access smaller blood vessels can be very difficult to achieve, for example devices that can be used in 7 French Gauge (outer diameter 2 . 333mm) catheters . A particular difficulty in miniaturised devices is how to ensure that various parts can operate in close proximity . Typically, implantable intralumenal devices have a separate antenna and anchor . Arranging the antenna and anchor such that one does not interfere with the function of the other is challenging, particularly in devices that operate in the RF frequency band.

[0176] To address this problem the function of anchoring is provided by antenna 140 in the device 400 of Figure 4 . This "dual function" antenna 140 eliminates the need for a separate anchor and antenna and enables further miniaturisation of the device which otherwise would not be possible . For example, devices for use with catheter sizes 7 French Gauge (outer diameter 2 .333mm) and a catheter size 8 French Gauge (outer diameter 2. 667mm) are envisaged. However, a problem arises in that the "dual function" antenna when acting as an anchor is exposed to forces from the bodily lumen which can negatively effect operation of components ( sensors ) within the intralumenal device that are connected to and communicate with external devices via the antenna .

[0177] In the example shown in Figure 4 , the antenna 140 has a first and second loop 142 , 144 that are external to and extend from opposite ends 112 , 118 of a ceramic ( zirconium dioxide ) housing 110. The loops 142 , 144 provide a dipole radio frequency antenna and are constructed from a memory metal - tubular nitinol (a nickel titanium alloy) . The loops 142 , 144 are configured in use to engage with the walls of a bodily lumen into which the device 400 is implanted. The natural undistorted shape of the loops 142 , 144 has the loops 134 , 138 extending out from the respective ends of the housing but also out of the plane of housing 110 i . e extending both above and below the housing . This natural undistorted shape of the loops 142 , 144 maintains the function of the antenna and is effective at engaging the wall of a bodily lumen providing a secure anchoring of the device within the bodily lumen . This particular antenna and anchor design can allow the antenna and anchor to remain consistent between devices configured for placement in differently sized lumens . In such cases only the housing 110 and / or component 120 might need to be varied to accommodate the device into a differently sized lumens . The antenna 140 is electrically connected to a pressure sensor 120 which is housed in the housing 110. To make a pressure measurement, the pressure sensor 120 is interrogated via the antenna 140 by a radio frequency transceiver 500 external to the body of the patient using a radio frequency interrogation signal in a frequency band. For example, in a first frequency band. For example in a first frequency band between 850MHz and 950MHz . The interrogation signal is received by the pressure sensor 120 via the antenna 140.

[0178] The pressure sensor 120 responds to the interrogation signal and produces a return signal in response to the received interrogation signal based on the intralumenal blood pressure in the bodily lumen .

[0179] The return signal is received by the antenna 140 from the pressure sensor 120 and the antenna 140 transmits the response signal to the external radio frequency transceiver 500. The characteristics of the return signal ( for example the frequency) are then used to determine the intralumenal blood pressure .

[0180] However, the dual function of antenna and anchor subj ects the antenna 140 to forces that it might not otherwise experience ( for example forces from the walls of the bodily lumen) . These forces can result in strain in parts connected to the antenna 140 such as the pressure sensor 120.

[0181] In this example, the pressure sensor 120 of device 400 comprises an interdigitated transducer 122 deposited on a deformable piezoelectric substrate 124 . The pressure sensor 120 is configured and arranged in the housing to make intralumenal blood pressure measurements when deployed in a bodily lumen based on deformation of the piezoelectric substrate .

[0182] The pressure sensor 120 is sensitive to strain and additional strain, not arising from deformation of the piezoelectric substrate by blood pressure, might result in erroneous and / or inaccurate blood pressure measurements . There is therefore a need to reduce (or eliminate ) the transmission of strain from the antenna 140 to the connected pressure sensor 120.

[0183] The implantable intralumenal device 400 seeks to address this issue by utilising a fixing structure comprising; an interposer 130 and housing 110 to provide strain relief to the pressure sensor 120 from force applied to the antenna 140. The interposer in this example comprises first and second conductive blocks 132 , 134 are positioned within the housing 110. Other interposer structures may also be used. For example, the interposer shown in Figure 5B wherein the interposer comprises an interposer tab and is integral with antenna 140 may be implemented in the device 400 in place of the conductive block arrangement .

[0184] The first conductive block 134 is rigidly mechanically fixed to the inside of end wall 112 of the housing 110 and the second conductive block 138 is rigidly mechanically fixed to the inside of the opposite end wall 118 of the housing 110. For example the conductive blocks 134 , 138 may be rigidly mechanically fixed to the housing 110 using a click-in self-locking arrangement between the housing 110 and interposer 130.

[0185] First and second ends 142a, 142b of the first loop 142 are passed through the housing and are soldered to first conductive block 134 thereby electrically connecting the first loop to the first conductive block . The first conductive block is also electrically connected to the pressure sensor 120.

[0186] In a similar construction, first and second ends 144a, 144b of the second loop 144 are passed through the housing 110 and are soldered to the second conductive block 134 thereby electrically connecting the second loop 144 to the second conductive block 138. The second conductive block 138 is also electrically connected to the pressure sensor 120.

[0187] The first and second conductive blocks 134 , 138 mediate the connection between the first and second loops 142 , 144 of the antenna 140 and the pressure sensor 120. The rigid mechanical fixing of the conductive blocks to the ceramic housing 110 provides strain relief to the pressure sensor 120 from the intralumenal forces applied to the first and second loops 142 , 144 and seeks to improve the accuracy and reliability of the intralumenal pressure measurements provided by the device by reducing strain on the pressure sensor .

[0188] In addition, the pressure sensor 120 is resiliently held in the housing 110 by a moulded resilient member 150 in this device 400 silicone potting paste which partially encapsulates the pressure sensor 120 has been used.

[0189] The moulded resilient member 150 spaces the pressure sensor 120 from the housing 110 and provides a beneficial relative mechanical stiffness that reduces transmission of strain from the housing 110 and / or antenna to the pressure sensor 120.

[0190] This is particularly beneficial in combination with the strain relief provided by the fixing structure comprising the interposer ( i . e the first and second conductive blocks 132 , 134 ) .

[0191] The device 400 of Figure 4 will now be described in use .

[0192] The device 400 is deployed from a catheter into a target site in a bodily lumen of a patient . The device 400 is navigated to a target site compressed into a delivery catheter for example in the manner of a self-expanding stent .

[0193] Once at the target site an outer sheath of the catheter is retracted to uncover the device 400 while the device 400 remains in a fixed position (prevented from retracting by the outer sheath) .

[0194] The nitinol loops 142 , 144 at each end of the device 400 spring out and engage the walls of the blood vessel at the target site . The device 400 therefore immediately anchors via the nitinol loops 142 , 144 to the lumen walls on deployment from the catheter . The loops 142 , 144 are curved so that, when they engage with the inner wall of the blood vessel , they extend at least partially out of the plane of the device .

[0195] At deployment a distal most of the loops 142 , 144 is released first from the catheter . The distal most loop is released by withdrawing the outer sheath. As the outer sheath is withdraw the distal most loop expands away from the catheter and parts of the distal most loop contact the vessel wall . The contact points are approximately on a diameter of the vessel cross-section . The loops 134 , 138 are configured to expand to diameter slightly greater than that of the blood vessel in which they are deployed. On deployment the loops 142 , 144 therefore exert a small outward pressure on the vessel wall at the location (the target site) where it is deployed from the vessel .

[0196] For example, the unconstrained loops 142 , 144 may be configured to expand to approximately 12mm wide and so in an 8-10mm vessel the loop will exert a small outward pressure on the vessel wall . The size and shape of the loops 142 , 144 may be configured for deployment into a particular blood vessel and / or for deployment from a particular catheter .

[0197] As the outer sheath is withdrawn further the body (housing) 110 of the sensor 400 will be released, gently anchored by the distal loop . As the sheath is further withdrawn the other loop (the proximal most loop) is released from the catheter like the distal loop . The loops come to rest in a roughly oval shape with a slight curve in their plane . The housing 110 and the pressure sensor 120 are thereby positioned approximately in the middle of the bodily lumen by the deployed loops 142 , 144 .

[0198] Once in position in the bodily lumen the pressure sensor 120 may interrogated by a device 500 external to body using an interrogation signal in the first frequency band via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 ( loops 142 , 144 ) and the interposer 130.

[0199] The pressure sensor 120 , in this example an interdigitated transducer on a piezoelectric substrate, responds to the interrogation signal in the first frequency band and may for example produce a return signal in response to the received interrogation signal . The return signal is indicative of the sensed pressure at the target site .

[0200] The return signal is received by the antenna 140 via the interposer 130 and the antenna 140 transmits the response signal to the external device 500. In this manner, a pressure measurement may be made using device 400. In use, the antenna 140 is exposed to the hostile environment of the bodily lumen. The antenna 140 (loops 142 , 144 ) is subj ected to forces for example from the flow of blood past the implantable intralumenal device 300 and from the walls of the blood vessel . This is particularly relevant for device 400 where the first and second loops 142 , 144 of the antenna 140 anchor the device 400 in the bodily lumen .

[0201] Direct connection of the antenna 140 to the component 120 would result in the forces applied to the antenna 140 , for example by the walls of the lumen, being transmitted to the component 120. In contrast, the fixing structure comprising the interposer 130 and in particular the first and second conductive blocks 134 , 138 in the implantable intralumenal device 400 mediate the connection between the first and second loops 142 , 144 of the antenna 140 and the component 120.

[0202] In use, the interposer 130 provides strain relief to the component 120 from forces applied to the antenna 140. This reduces or eliminates the detrimental effect of the forces applied to the antenna 140 on the pressure sensor 120 , thereby improving the accuracy and reliability of pressure measurements made using device 400.

[0203] Figure 5 - Integral interposer and antenna

[0204] Figure 5 shows a cross-section of an implantable intralumenal device 600 for making intralumenal blood pressure measurements . The implantable intralumenal device 600 is identical to the intralumenal device 100 in both structure and function other than as described below.

[0205] The device 600 is a more specific example of the implantable intralumenal device 100 and provides an example of a specific implementation of the interposer 130 and antenna 140. This specific implementation of the interposer 130 is shown in Figure 5b .

[0206] The structure of the implantable intralumenal device 600 will now be described.

[0207] The device 600 comprises a housing 110 ; a component 120 ; and a fixing structure comprising interposer 130 ; and an antenna 140. The component 120 is housed within the housing 110. For example, the component is partially encased by the housing 110. The component 120 might for example be a component for making an intravascular measurement .

[0208] In this example, the interposer 130 and the antenna 140 are integral being formed from a single piece of material so as to be a unitary piece . In particular, an antenna part 140a is integral with an interposer tab 130a . The interposer tab 130a having a hole 137 for receiving a rivet 139 therethrough.

[0209] For example, the antenna and interposer part may be formed together by cutting from a single sheet of material . For example, by laser cutting. For example, by stamping . For example the antenna part may be formed by laser cutting it from a thin Nitinol sheet with an integral interposer tab . Alternatively, the interposer tab 130a could be separate to the antenna 140a and the two components could be connected for example by soldering.

[0210] The housing 110, specifically a wall 112 , 114 , 116, 118 of the housing 110 has a slot 111 configured to receive the interposer tab and a hole 113 configured to receive a rivet 138 . As shown in Figure 5a, there are two slots 111 in the walls 112 , 114 of the housing 110. Each slot receives an interposer tab 130a . The interposer tabs are fixed to the walls 112 , 114 of the housing 110 by rivets 139 passed through the aligned holes 113 and 131 of the housing 110 and the interposer tabs 130a . The example shown in Figure 5a demonstrates j ust one example of fixing an integral antenna 140 and interposer 130 to the housing 110.

[0211] Other methods of fixation which fix an integral interposer 130 to the housing 110 thereby to provide strain relief to the component 120 from force applied to an integral antenna 140 are also envisaged. The integral interposer tab 130a may take a number of different shapes and sizes for example it may be a conductive block such as the conductive blocks 134 , 138 described above or a flat plate as shown in in Figure 5b . The interposer tab 130a may be fixed to the housing 110 using a mechanical method such as using rivet 139 and hole 137 (as shown in Figure 5a) or a plug and socket arrangement with the housing 110.

[0212] In more detail , the housing 110 has a slot 111 perpendicular to the plane of the interposer tab 130a; the interposer tab 130 has a hole 113 which aligns with a hole 131 in the housing such that when the tab 130 is inserted through slot 111 in the housing; a rivet 139 can be used to mechanically fix the interposer tab . An adhesive coating on the interposer tab 130 may strengthen this form of providing strain relief .

[0213] The interposer tabs 130a extend into the housing 110 and electrically connect to the component 120 housed therein . For example, the component 120 may be soldered to an end of the interposer tab 130 which has traversed the slot 111 as far as the cavity in the housing 110 accommodating the component 120. The interposer tab may electrically connect to the component using vias in a casing of the component .

[0214] The interposer tabs 130a electrically connect to the antenna parts 140a .

[0215] The antenna parts 140a electrically connect to the interposer tabs 130a . The antenna parts 140a may at least partially extend from the housing 110 and may be positioned outside of the housing 110 as shown in Figure 5a . In the example, shown in Figure 5a the antenna parts 140a extend from opposite ends of the housing 110. The antenna parts 140a are shown as loops in Figure 5a however other types of antennae are envisaged for example helical antenna could be used.

[0216] The antenna parts 140a may be configured to anchor the implantable intralumenal device in the bodily lumen . A pair of antenna parts 140a each integral with an interposer tab 130a are shown in Figure 5a . However, the antenna 140 and interposer 130 of an implantable intralumenal device 600 may comprise only a single antenna part 140a and interposer tab 130a or it may comprise two or more antenna parts 140a and interposer tabs 130a .

[0217] The function of the implantable intralumenal device 600 shown in Figure 5a will now be described. The implantable intralumenal device 600 seeks to minimise strain on component 120. A source of strain on the component 120 may originate from forces applied to the antenna 140.

[0218] The interposer 130 provides strain relief to the component 120 from force applied to the antenna 140. In particular, the fixation of the interposer tab 130a to the housing 110 provides a strain relief . In addition, the interposer tab 130a provides an electrical connection between the antenna 140 and the component 120.

[0219] The component 120 is configured to respond to an electrical signal . Thereby allowing the component 120 to be interrogated by another device 500 for example one that, in use, is external to the bodily lumen .

[0220] The component 120 may be configured to perform a measurement within a bodily lumen in response to an electrical signal . For example, the measurement component may be a pressure sensor that responds to an electrical signal with a pressure measurement . The antenna 140 is configured to provide communication of the electrical signal with the component 120. .

[0221] The antenna 140, which is electrically connected to the component 120 via the interposer tab 130a, may receive and transmit electrical signals from the component 120. The antenna 140 may also receive signals from another device 500 for example an RF transmitter seeking to interrogate the component 120.

[0222] In addition to functioning as an antenna, the antenna 140 , in particular loops 140a, 140b may also be configured to anchor the implantable intralumenal device in the bodily lumen.

[0223] The fixation of the interposer 130 in particular the fixation of the interposer tabs 130a to the housing 110 provides strain relief to the component 120 from force applied to the antenna 140.

[0224] In this example, the interposer tabs 130a of the interposer 130 are rigidly attached to the end walls 112 , 118 of the housing 110 using a rivet 139.

[0225] The rigid attachment of the interposer tabs 130a to the housing 110 further minimises transmission of strain from the antenna 140a to the component 120.

[0226] The antenna 140a and interposer 130a being integral simplifies the construction of the device 600 and aims to improve reliability and reproducibility in the manufacturing process . The interposer 130 also secures the antenna 140 to the housing 110. The implantable intralumenal device 600 of Figure 5a will now be described in use .

[0227] In use the implantable intralumenal device 600 is positioned in a bodily lumen of a patient . The implantable intralumenal device 600 is held in place by antenna 140, the loops 140a anchor the implantable intralumenal device within the bodily lumen by engaging with the walls of the bodily lumen.

[0228] Once in position in the bodily lumen the component 120 is interrogated by a device 500 external to body using an interrogation signal in the first frequency band via the antenna 140. The interrogation signal is received by the component 120 via the antenna 140 and the interposer 130.

[0229] The component 120 responds to the interrogation signal in the first frequency band and may for example produce a return signal in response to a received interrogation signal .

[0230] In the case where a return signal is produced, the return signal is received by the antenna 140 via the interposer 130 and the antenna 140 transmits the response signal to the external device 500.

[0231] In use, the antenna 140 is exposed to the hostile environment of the bodily lumen. The antenna 140 is subj ected to forces for example from the flow of blood past the implantable intralumenal device 600 and from the walls of the blood vessel . This is particularly relevant for device 600 where the loops 140a of the antenna 140 anchor the device in the bodily lumen . The fixing structure comprising interposer 130 and in particular the interposer tabs 130a mediate the connection between the loops 140a of the antenna 140 and the component 120.

[0232] In use, the interposer 130 provides strain relief to the component 120 from forces applied to the antenna 140.

[0233] General features and alternatives

[0234] In the above examples 100, 100b 200 , 300, 600 the component 120 may comprise a sensor for example a pressure sensor, for example a pressure sensor on a piezoelectric substrate . In such devices the strain relief provided by the interposer 130 is particularly beneficial because pressure sensors on piezoelectric substrates are particularly sensitive to strain .

[0235] Where the antenna is also configured to anchor the device within the lumen the anchor may be subj ected to further forces from the walls of the bodily lumen and the reduction in the transmission of strain by the interposer is particularly beneficial .

[0236] In the above example 300 , 600 the antenna is a loop antenna having two loops , however other differently shaped antenna may also be used in this device and in devices 100 , 100b, 200 , 600 for example a single loop antenna, a helical antenna etc . .

[0237] The devices 100, 100b, 200 , 300 , 400 , and 600 may be configured for deployment into a particular blood vessel or lumen of a human, for example a human adult, for example a human adult male or a human adult female . The blood vessels into which devices 100 , 100b , 200 , 300 , 400 , and 600 may be deployed may include the pulmonary artery and / or the aorta . In particular the pulmonary artery and / or the aorta of a human for example a human adult male or a human adult female . The devices 100 , 100b, 200 , 300 , 400 , and 600 may also be configured to be deployed into a subclavian artery for example to monitor systemic hypertension . Another example of a blood vessel into which the devices 100 , 100b , 200 , 300 , 400 , and 600 may al so be configured to be deployed i s a renal artery for example so that the device can be used to monitor renal conditions . The si ze and shape of the devices 100 , 100b , 200 , 300 , 400 , and 600 may be configured for deployment of the device from a particular catheter for example for deployment from catheters of si ze 2 French Gauge ( outer diameter 0 . 667mm) to 34 French Gauge ( outer diameter 11 . 333mm) . In particular , catheter of si zes 7 French Gauge ( outer diameter 2 . 33mm) or 8 French Gauge ( outer diameter 2 . 667mm) .

[0238] In particular , the si ze and shape of the antenna and / or component 120 and / or housing 110 may be configured for deployment into a particular blood vessel of lumen of a human for example a human adult for example a human adult male or human adult female . For example , these parts may be configured for deployment from a particular catheter , for example a catheter of si ze 7 French Gauge ( outer diameter 2 . 33mm) or 8 French Gauge ( outer diameter 2 . 667mm) .

[0239] In particular the loops 140a , 142 , 144 may be configured for deployment into a particular blood ves sel of a human for example a human adult for example a human adult male or human adult female . The blood vessel may include the pulmonary artery or the aorta in particular the pulmonary artery or the aorta of a human for example a human adult male or a human adult female . The size and shape of the antenna and in particular the loops 140a, 142 , 144 may be configured for deployment from a particular catheter for example a catheter of size 7 French Gauge (outer diameter 2 .33mm) or 8 French Gauge (outer diameter 2 . 667mm) .

[0240] Alternatively the dimensions of the housing 110 and / or component 120 may be configured to enable delivery by different catheter sizes whilst keeping the dimensions of the antenna part constant . The antenna 140 and component 120 may be responsive to a first frequency band. The first frequency band may be for example a frequency band between 850MHz and 950MHz ; 910MHz and 930MHz or 915MHz and 920MHz . The antenna 140 may be further configured to operate in frequency bands other than the first frequency band. For example, the antenna 140 may be configured to operate in a second frequency band. The second frequency band may be for example a frequency band between 850MHz and 950MHz ; 910MHz and 930MHz or 915MHz and 920MHz .

[0241] Similarly, the component 120 may respond to frequency bands other than the first frequency band. For example, the component 120 may also respond to a second frequency band. The component 120 may for example carry a pressure sensor that is responsive in a first frequency band and a reference sensor that is responsive in a second frequency band. In the above examples the housing 110 may be constructed from a mechanically stiff biocompatible material such as a ceramic for example Zirconium dioxide (also known as Zirconia) . It can be further advantageous for the housing to be opaque to X-ray radiation so that it can be easily located in-situ by X-ray imaging techniques .

[0242] The use of a ceramic housing is advantageous because as well as being mechanically stiff material the material can be easily machined so that it can provide a mechanical attachment point for the interposer 130 and / or the antenna 140.

[0243] Also, in the above examples the antenna 140 may be constructed from a suitable biocompatible metal or metal alloy. It is advantageous particularly where the antenna is configured to anchor the device for the metal to be deformable to and capable of a maintaining a shape for example the antenna can be constructed from Nickel titanium (also known as nitinol ) .

[0244] The interposer 130 may be made from an electrically conductive material such as a metal . In examples where the interposer is directly attached to the antenna 140 it is advantageous to select a metal that is solderable using AuSn solder or to coat a metal to facilitate a soldered connection . The interposer may be made from a nickel titanium alloy (Nitinol ) for example the interposer may be integral with the antenna and formed from the same material as the antenna . The above examples are to be understood as illustrative examples . Further examples are envisaged. It is to be understood that any feature described in relation to any one example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the examples , or any combination of any other of the examples .

[0245] Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims .

Claims

1. Claims1. An implantable intralumenal device comprising :3.a component configured to respond to an electrical signal ; an antenna;4.and a fixing structure,5.wherein the fixing structure carries an electrical connection between the antenna and the component and the antenna is mechanically fixed to the fixing structure thereby to provide strain relief to the component from mechanical force applied to the antenna .6.2 . The implantable intralumenal device of claim 1 , wherein the fixing structure comprises at least one of : an interposer, and a housing, in which the component is disposed.

3. The implantable intralumenal device of any preceding claim, wherein the antenna is configured to anchor the implantable intralumenal device in a bodily lumen .8.4 . The implantable intralumenal device of any preceding claim, wherein the fixing structure and the antenna are integral being formed from a single piece of material . 5 . The implantable intralumenal device of any preceding claim, wherein the component is resiliently held, for example by a resilient member, for example a moulded resilient member which at least partially encapsulates the component .

6. The implantable intralumenal device of claim 2 to 5 , wherein the fixing structure comprises the housing; wherein the antenna is mechanically fixed to the housing thereby to provide strain relief to the component from mechanical force applied to the antenna .10.7 . The implantable intralumenal device of any of claims 2 to 6, wherein the fixing structure comprises : the interposer; wherein the antenna is mechanically fixed to the interposer thereby to provide strain relief to the component from mechanical force applied to the antenna .11.8 . The implantable intralumenal device of claims 2 to 7 , wherein the fixing structure comprises : the housing and the interposer, wherein the antenna is mechanically fixed to the housing using the interposer .

9. The implantable intralumenal device of claim 8 wherein, the interposer is rigidly fixed to the housing .

10. The implantable intralumenal device of claim 8 or claim 9 , wherein the interposer is disposed between the component and the housing .

11. The implantable intralumenal device of claims 8 to 10 , wherein the interposer comprises : a first element in electrical connection with the antenna, wherein the first element is mechanically secured to a wall of the housing .14.12 . The implantable intralumenal device of claim 11 , wherein the first element is positioned adj acent a first wall of the housing and / or wherein the first element extends into the housing through a first wall of the housing .

13. The implantable intralumenal device of any of claims 11 or 12 , wherein the interposer comprises :16.a second element in electrical connection with the antenna, wherein the second element is mechanically secured to a second wall of the housing such as the second wall and optionally at least one other wall transverse to the second wall .17.14 . The implantable intralumenal device of claim 13 , wherein the second element is positioned adj acent a second wall of the housing, opposite to the first wall and / or wherein the second element extends into the housing through a second wall of the housing, opposite to the first wall .18.15 . The implantable intralumenal device of any of claims 13 or 14 , wherein the component is provided between the first element and the second element .

16. The implantable intralumenal device of claims 11 to 15 , wherein the first element is a flat plate and / or the second element is a flat plate or wherein the first element is a first conductive block and / or the second element is a second conductive block .20.17 . The implantable intralumenal device of any preceding claim, wherein the antenna comprises a first loop electrically connected to the fixing structure and / or, wherein the antenna comprises a second loop electrically connected to the fixing structure .21.18 . The implantable intralumenal device of claim 17 , wherein the first loop and the second loop extend from opposite ends of the fixing structure .

19. The implantable intralumenal device of any preceding claim wherein the component is configured to respond to an electrical signal having a first known frequency band and is configured toresponse to an electrical signal having a second known frequency band and wherein the antenna is configured to operate in the first known frequency band and wherein the antenna is configured to operate in the second known frequency band.

20. The implantable intralumenal device of any preceding claim, wherein the component comprises a piezoelectric substrate .

21. The implantable intralumenal device of any preceding claim, wherein the housing comprises a ceramic .25.22 . The implantable intralumenal device of any preceding claim, wherein the fixing structure is rigidly fixed to the component for example using a biocompatible solder .

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