EP2665407A1

EP2665407A1 - Self-contained system suitable for being inserted into an anatomical cavity

Info

Publication number: EP2665407A1
Application number: EP12700414.1A
Authority: EP
Inventors: Charbel ACHKAR; Julien MOLINA; Yan Haentjens; Gérard SOU; Alain LE BORGNE; Fabien KOSKAS; Georges Alquie; Michel Schaller
Original assignee: Universite Pierre et Marie Curie Paris 6; Assistance Publique Hopitaux de Paris APHP; Vectrawave SA
Current assignee: Universite Pierre et Marie Curie Paris 6; Assistance Publique Hopitaux de Paris APHP; Vectrawave SA
Priority date: 2011-01-20
Filing date: 2012-01-20
Publication date: 2013-11-27
Also published as: WO2012098221A1; FR2970635B1; FR2970635A1; US20140018643A1

Abstract

The invention relates to a system (1) suitable for being inserted into an anatomical cavity (30), including: a support structure (10), an antenna (10), an assembly (22) of measuring devices, an assembly (26) for transmitting the data of the measurements carried out by the measuring devices (22), which is suitable for communicating with an external entity (E) by means of the antenna (10), and a device (24) for monitoring the assembly of measuring elements and the transmission assembly (26), said antenna consisting of the support structure (10), and the self-contained system being characterized in that the support structure (10) includes a non-conductive junction (20) supporting the assembly (22) of measuring devices, the transmission assembly (26), and/or the monitoring device (24), wherein the junction is suitable for producing an electrical discontinuity within the support structure (10) forming the antenna while mechanically supporting said support structure (10).

Description

Self-supporting system adapted to be inserted into a cavity

anatomical

The invention generally relates to the use of sensors to monitor certain physiological parameters within a body, such as blood pressure, body temperature, blood flow, etc.

More specifically, the invention relates to intravascular systems adapted to be inserted into an anatomical, natural or artificial cavity and to monitor such physiological parameters.

Such systems are already known.

For example, the document EP 1 039 831 describes an endoluminal implant capable of detecting certain parameters such as a volumetric flow, a speed, etc. The implant includes an endoprosthesis, on which sensors adapted for radiofrequency communication with an external entity are provided by means of an antenna. The antenna may consist of, or be wrapped around, the stent structure itself, and the structure may include ceramic joints to cut the curls that may be created at the same time. of the radiofrequency cou nage.

Furthermore, US Pat. No. 7,685,762 describes an endoluminal implant adapted to monitor, in particular, the blood pressure of a patient. The implant comprises anchoring means, a self-supporting structure adapted to support a capsule carrying sensors, and radiofrequency communication with an external entity.

Nevertheless, the implants of the prior art are structurally complex.

The invention therefore aims at proposing a new implant, which is of simpler structure and which makes it possible to communicate to an external entity information on physiological parameters internal to a body, which either low cost and can be inserted into the body by standard installation instruments.

For this, the invention proposes a self-supporting system adapted to be inserted into an anatomical cavity, comprising:

a support structure,

- an antenna,

- a set of measuring devices,

a set of transmission of measurement data made by the measuring devices, adapted to communicate with an external entity by means of the antenna, and

a device for controlling all the measuring and transmission elements,

said antenna being constituted by the support structure, and the self-supporting system being characterized in that the support structure comprises a non-conducting junction supporting the set of measuring devices, the transmission assembly and / or the control device and adapted for producing an electrical discontinuity in the antenna support structure while maintaining said support structure mechanically.

Some preferred but non-limiting aspects of the self-supporting system according to the invention are the following:

the non-conductive junction is a capsule, and the set of measurement devices, the transmission assembly and / or the control device are housed in said capsule,

the non-conductive junction is made in a biocompatible material,

the non-conductive junction is made of ceramic material,

the set of measurement devices comprises at least one of the sensors of the following group: a piezoresistive, piezoelectric, resistive, capacitive, inductive, optical, chemical, biological sensor,

the support structure is a stent,

the support structure is self-expanding, the transmission unit communicates by radio frequencies with the external entity, and

- The set of measuring devices, the transmission assembly and the control device are integrated in an electronic chip.

According to a second aspect, the invention proposes a device for monitoring at least one information relating to an anatomical cavity, comprising:

a self-supporting system according to the invention, and

an external entity, adapted to interrogate the self-supporting system remotely.

Some preferred but non-imitative aspects of the device according to the invention are the following:

the self-supporting system and the external entity are capable of communicating by radio frequency waves at a frequency of 13.56 MHz, and

the external entity comprises an antenna which is integrated into a belt.

Other characteristics, objects and advantages will appear on reading the detailed description which follows, and with reference to the appended drawings given by way of non-limiting examples and in which:

FIG. 1 is a view from above of an embodiment of a system according to the invention,

FIG. 2 is a side view of the embodiment of FIG.

1,

FIG. 3 is a sectional view of one embodiment of a non-conductive junction, and

FIG. 4 is a sectional view of a cavity in which the system of FIG. 1 has been deployed.

FIGS. 1 and 2 show a system 1 comprising a support structure 10, a set of measuring devices 22, a transmission assembly 26 of the measurements made by the measuring devices 22, as well as a control device 24 of the measuring and transmission assemblies 26.

The support structure 1 0 is adapted to be inserted, deployed and anchored inside the human body, especially in an anatomical cavity 30, whether natural or artificial. Typically, natural anatomical cavities may be part of the cardiovascular system (artery, vein, heart), digestive system (esophagus, stomach, intestine), ENT system (oropharynx, eye), urinary system (bladder) , genitalia (prostate), or the pulmonary system (trachea, bronchi, pleura), while artificial anatomical cavities can be elements of a prosthesis, or any system requiring remote measurements (such as extracorporeal blood circulation or in a sterile environment). It can be inserted for example by means of an appropriate instrument and is provided with anchoring means enabling it to remain in position in the cavity 30 by exerting a radial force on the walls of the cavity 30. It may be for example a stent, in particular a self-expansive Z-endoprosthesis similar to that described in document EP 0 423 91 6, which can be placed in position in the cavity 30 by means of a conventional laying instrument.

The set of measuring devices 22 comprises, in particular, sensors adapted to measure parameters of interest in the cavity 30. It may be a question of particular physical measurements (blood flow, blood pressure, temperature, etc.). or chemical (measurement of glucose level, pH, etc.). For example, the assembly 22 may comprise one or more sensors of the piezoresistive, piezoelectric, resistive, capacitive, inductive, optical, chemical, biological, etc. type. such as a pressure sensor, a temperature sensor, an ultrasonic sensor, a pH sensor, an accelerometer, an infrared detector, an electrical potential sensor, an optical sensor, an immunological sensor, a detector of oxygen, a comparative genomic hybridization chip (ARRAY chip), or a DNA chip (for Deoxyribonucleic acid).

These parameters are then transmitted to the control device 24, which is adapted to manage on the one hand the set of measuring devices 22, and on the other hand by the transmission assembly 26.

The control device 24 may be an electronic system comprising an analog-to-digital converter adapted to convert the physiological measurements at the output of the sensors (analog data) into digital data (coded according to the electrical level of the analog data). These digital data are conditioned by a digital processing unit and then transmitted by a wireless link to an external entity E, typically an external monitoring device, via the measurement transmission assembly and an antenna.

The set of transmission of measurements meanwhile comprises at least one transmitter, adapted to transmit, via the antenna, information by a wireless system to the external entity E, and a receiver, adapted to receive , via the antenna, RF radio frequency information from the external entity E.

The wireless system can operate for example by RF radio waves. This may include RFID (Radio Frequency Identification, Radio Frequency Identification), Bluetooth, Wi-Fi, Zigbee, etc.

The electronic system 24, the transmitter, the receiver 26 and, if appropriate, all or some of the sensors 22 may be integrated in one or more electronic chips. The chip may further conventionally include a microcontroller adapted to provide control of the co-ordination, data encryption / decryption, and the like. , a storage system (of EEPROM type, Electrically-Erasable Programmable Read-Only Memory or electrically erasable and programmable read only memory), to temporarily save the information transmitted by the various sensors before transmitting them to the external entity E, etc.

The external entity E comprises inter alia a reading terminal adapted to communicate with the on-board electronic system 24 of the system 1.

The transmission and reception of RF radio wave information will not be further detailed in the following and are known to those skilled in the art. It is part of the various standards that exist to date, such as the ISO / IEC 14443 standard or the ISO / IEC 15693 standard. ISO / IEC 14443 will be preferred here, since the modulation described in this standard is more adapted to the remote power supply, that it proposes a specific identifier to the field of the medical one and that it ensures the treatment of the collisions, so that it is possible to implement several chips at the same time, and therefore manage at the same time several systems 1 according to the invention at the same time in the body.

The antenna is here constituted in all or part of the support structure 10, which is then made of a conductive material such as steel. It is connected to the transmitter and the receiver 26, to allow communication between the electronic system 24 and the external entity E.

The antenna 10 can also be used for radiofrequency RF energy and supply all or part of the set of sensors and the electronic system, thus reducing the size of the system 1. For this, the system 1 comprises in addition, an energy accumulator 28, housed for example at the level of the electronic chip, in order to recover the electrical energy delivered by the RF radio waves. The energy thus recovered is then stored and distributed to the various components of the system 1, which then becomes a communication terminal without battery.

The external entity E comprises, inter alia, a communication terminal for communicating by radio waves with the electronic system 24, transmit to the energy accumulator 28 the energy required to supply the measuring assembly 22, the transmission assembly 26 and the electronic system 24. The structure support 10 further comprises a non-conductive junction 20, so that the structure 10 forms a discontinuous metal loop to prevent the formation of current loops which could reduce the efficiency of the radio frequency coupling with the external entity E.

The non-conductive junction 20 is made in a biocompatible material (which may be, for example, in accordance with standards in force, in particular the standard NF EN 10993 on the biological evaluation of medical devices), electrically insulating and having good resistance. mechanical stress. Depending on its location, the material may also be resistant to attack from its surrounding environment, for example: do not allow adhesion cel lu lar, be antithromatic botique, and / or be thermoresistant to water vapor (c ') that is to say, resistant to water vapor at 121 ° C for about twenty minutes).

For example, the junction 20 can be made of ceramics (in particular zirconia).

Furthermore, according to the embodiment illustrated in FIGS. 1 and 2, the non-conducting junction 20 has the shape of a capsule and houses all or some of the sensors 22, the transmission assembly 26, the electronic system 24 and the if necessary, the energy accumulator 28. The non-conductive junction 20 thus plays a multiple role here, and in particular:

- Mechanical support of the support structure 10, especially during the anchoring of the system 1 in the cavity 30,

- of mechanical continuity and electrical compatibility in the metal structure of the support structure 10, in order to transform it into a radiating element and to be able to use it as an antenna,

supporting and protecting the sensor assembly 22, the electronic system 24, and the transmission assembly 26, to permethe orientation of the sensor within cavity 30 as a function of the type of sensor used for the phenomenon under study. Typically, for a pressure sensor, the junction 20 is oriented so that a window 23 for measuring the pressure is directed towards the inside of the cavity 30,

- to ensure the connection between the set of sensors 22, the electronic system and the transmission assembly 26 to the antenna 10.

It allows to relel and functionalize all of the elements constituting the system 1 in a simple and economical way, in order to obtain a platform for integration of electronic microsystems with wireless communication (here by radiofrequency).

Moreover, the non-conductive junction 20 can be made by fitting the various elements that it houses, to guarantee their protection, or be hollow and include a removable cover to access its contents. .

Finally, the non-conductive junction 20 may have conical ends, as illustrated in the appended FIG. 3, made if necessary in the same material as the support structure 10, and ensuring the maintenance and the electrical connection between the elements that it houses and the structure 10.

When the support structure 10 is used as an antenna, its dimensions can influence the choice of the transmission frequency, the quality of the signal and the transmittance, as well as the amount of transferable energy.

In the first approximation, the support structure 10 can be considered as an inductive loop of a few millimeters to a few centimeters in diameter. The natural frequency of the loop, measured by opening the support structure 10 at a point to open the loop, which is the absolute maximum frequency at which the loop can be used as an inductive antenna. To use the support structure 1 0 com me antenna inductive, the transmission frequency must be a few hundred Mhz given the size of this structure.

The device can, however, operate at higher frequencies provided that the support structure 10 is broken down into several electrically discontinuous strands connected together. Alternatively, each structure 10 may have eyelets 12 adapted to cooperate with eyelets of a similar system to form a longer system.

The medium in which the RF radio waves must propagate may also have an influence on the choice of the transmission frequency. Indeed, since the system 1 must be placed deep inside the human body, the signal must cross up to ten centimeters of human tissue, the latter being mainly made up of water (70%). So that the transmission frequency is not attenuated by the medium, it is preferable to use a frequency lower than 30 MHz; which corresponds to the frequency range for which the attenuation of the signal caused by the water remains acceptable.

In view of the foregoing, suitable frequency ranges for radiofrequency communication may for example be the 134 kHz and 13.56 MHz ranges, in accordance with ISM (International Safety Management). International Safety Management Code). Given the security and confidentiality required in this type of application, it is possible for example to use the frequency of 13.56 MHz, which allows data rates (and in particular encrypted) much higher than those obtained at 134 kHz.

Note that despite the use of the support structure 10 as an antenna and the presence of the non-conductive junction 20 on the structure 10, it preserves its mechanical properties. For example, when the support structure 10 is a self-expanding stent, it retains its ability to automatically attach to the walls of the cavity, and remains retractable. It can therefore be asked and withdrawn by the same instruments that a self-expanding stent comparable but without a nonconductive junction. The system 1 can be placed temporarily in the cavity 30, or permanently. In the case of temporary use, a recovery wire is passed through the eyelets 12 of the support structure 10. The use of a suitable removal instrument then makes it possible to compress the support structure 10 in order to insert it into a corresponding diameter tube and remove the system 1 from the cavity 30. Reference can be made to the description of EP 0 423 916 for more details on the installation and removal of the system 1.

The antenna of the external entity E may be in the form of a metal loop that can be worn in particular at the size or the chest of the patient. For example, it makes it possible to remotely power the system 1 by using the support structure 10 as an inductive antenna by electromagnetic coupling at 13.56 MHz.

As a variant, the external entity E can be interfaced with a medical system (for example linked to the personal medical file).

Of course, the present invention is not limited to the embodiment described above and shown in the drawings, but the skilled person will be able to make many variations and modifications.

Claims

1. Self-supporting system (1) adapted to be inserted into an anatomical cavity (30), comprising:

a support structure (10),

an antenna (10),

a set of measuring devices (22),

a transmission assembly (26) of measurement data performed by the measuring devices (22), adapted to communicate with an external entity (E) by means of the antenna (10), and

a device (24) for controlling all the measuring and transmission elements (26),

said antenna being constituted by the support structure (10), and

the self-supporting system being characterized in that the support structure (10) comprises a non-conductive junction (20) supporting the set of measuring devices (22), the transmission assembly (26) and / or the control device (24) adapted to provide an electrical discontinuity in the antenna support structure (10) while maintaining said support structure (10) mechanically.

The self-supporting system (1) according to claim 1, wherein the non-conductive junction (20) is a capsule, and in that the set of measuring devices (22), the transmission assembly (26) and / or the control device (24) are housed in said capsule.

3. self-supporting system (1) of claims 1 and 2, wherein the non-conductive junction (20) is made of a biocompatible material.

4. self-supporting system (1) according to one of claims 1 to 3, wherein the non-conductive junction (20) is made of ceramic material.

5. self-supporting system (1) according to one of claims 1 to 4, wherein the set of measuring devices (22) comprises at least one of the following group of sensors: a piezoresistive sensor, piezoelectric, resistive, capacitive , inductive, optical, chemical, biological.

6. self-supporting system (1) according to one of claims 1 to 5, wherein the support structure (10) is an endoprosthesis.

7. self-supporting system (1) according to one of claims 1 to 6, wherein the support structure (10) is self-expanding.

8. Self-supporting system (1) according to one of claims 1 to 7, wherein the transm ission (26) communicates by radio frequency (RF) with the external entity (E).

9. self-supporting system (1) according to one of claims 1 to 8, wherein the set of measuring devices (22), the transmission assembly

(26) and the control device (24) are integrated in at least one electronic chip.

10. Device for monitoring at least one information relating to an anatomical cavity (30), characterized in that it comprises:

- a self-supporting system according to one of claims 1 to 9, and

an external entity (E) adapted to interrogate the self-supporting system (1) remotely.

1 1. Device according to claim 1 0, wherein the self-supporting system (1) and the external entity (E) are able to communicate by radiofrequency (RF) waves at a frequency of 13.56 MHz.

12. Device according to one of claims 10 and 1 1, wherein the outer entity (E) comprises an antenna which is integrated into a belt.