[go: up one dir, main page]

WO2025152925A1 - Capteur de force, cathéter de détection de force, dispositif d'ablation et appareil médical - Google Patents

Capteur de force, cathéter de détection de force, dispositif d'ablation et appareil médical

Info

Publication number
WO2025152925A1
WO2025152925A1 PCT/CN2025/072276 CN2025072276W WO2025152925A1 WO 2025152925 A1 WO2025152925 A1 WO 2025152925A1 CN 2025072276 W CN2025072276 W CN 2025072276W WO 2025152925 A1 WO2025152925 A1 WO 2025152925A1
Authority
WO
WIPO (PCT)
Prior art keywords
section
annular portion
force sensor
force
sensor according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2025/072276
Other languages
English (en)
Chinese (zh)
Inventor
闫宜斌
张立喆
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Bywave Sensing Technology Co Ltd
Original Assignee
Beijing Bywave Sensing Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN202420098134.0U external-priority patent/CN222528812U/zh
Priority claimed from CN202410058363.4A external-priority patent/CN120313768A/zh
Application filed by Beijing Bywave Sensing Technology Co Ltd filed Critical Beijing Bywave Sensing Technology Co Ltd
Publication of WO2025152925A1 publication Critical patent/WO2025152925A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/04—Measuring force or stress, in general by measuring elastic deformation of gauges, e.g. of springs

Definitions

  • the present disclosure relates to the field of medical devices, and in particular to a force sensor.
  • the force sensor is particularly suitable for a catheter-based diagnosis and treatment system.
  • the present disclosure also relates to a force sensing catheter with the force sensor, and an ablation device.
  • Atrial fibrillation is one of the most common arrhythmias in clinical practice, with a prevalence of 0.4% to 1% in the general population, and its incidence rate increases significantly with age. The disease can lead to high disability and mortality rates.
  • Catheter ablation can cure atrial fibrillation (AF) and improve patients' symptoms, and the effectiveness of ablation is closely related to the degree of contact between the ablation catheter and the atrial tissue. Permanent transmural damage to all atrial fibrillation ablation points is the key to ensuring a high success rate of the operation and reducing recurrence, and it is also the difficulty of ablation.
  • the research and development of the new pressure contact monitoring catheter focuses on improving tissue adhesion, improving the safety of catheter operation, and being able to better control the size of the damage at the ablation point, thereby increasing the effectiveness of ablation.
  • the present disclosure provides a force sensor, the force sensor comprising a sensor body, the sensor body comprising a first section, a second section, and an intermediate section located between the first section and the second section and connecting the first section and the second section. At least a portion of the outer surface of the intermediate section is inwardly recessed relative to the outer surface of the first section and the outer surface of the second section to form a gap between the first section and the second section.
  • the sensor body further comprises an annular portion, the annular portion defining at least a portion of the axial boundary of the gap, wherein the thickness of the annular portion is less than the width of its annular surface.
  • the annular portion includes a first annular portion and a second annular portion, wherein the first annular portion defines a portion of the axial boundary of the gap and connects the first end of the middle section with the first section, and the second annular portion defines a portion of the axial boundary of the gap and connects the second end of the middle section with the second section.
  • the annular portion extends in a transverse direction perpendicular to the axial direction or at an angle between 0 and 15° relative to the transverse direction.
  • the first section, the second section and the middle section each have a side wall surrounding the hollow portion, wherein the side wall of the middle section is parallel to the side wall of the first section and the side wall of the second section.
  • the first segment, the second segment and the middle segment all have a circular cross-section, wherein the outer diameter of the middle segment is smaller than the inner diameter of the first segment and smaller than the inner diameter of the second segment; and the first segment and the second segment have the same inner diameter and outer diameter.
  • one of the first segment and the second segment is directly connected to the middle segment, and the other of the first segment and the second segment is connected to the middle segment via the annular portion.
  • the optical sensor device comprises: a plurality of reflective members passing through the first section in an axial direction; and a plurality of optical fibers passing through the second section in an axial direction and the number of the optical fibers being the same as the number of the reflective members, wherein one end of each reflective member extends into the gap and is opposite to an end of each optical fiber extending into the gap.
  • the width-to-thickness ratio of the annular portion is between 2-3.
  • the sensor body is an integrated structure.
  • the present disclosure also provides a force sensing catheter, comprising a flexible elongated body having a distal end; and a force sensor according to any one of the above items, the force sensor being arranged at the distal end within the flexible elongated body.
  • the present disclosure also provides an ablation device, which includes the force sensor according to any embodiment or the ablation device according to any embodiment.
  • FIG. 1A, 1B, 1C, 1D, and 1E show various views of a force sensor according to a first embodiment of the present disclosure
  • FIGS. 1A, 1B, 1C, 1D, and 1E show various views of a force sensor according to a first embodiment of the present disclosure, in which an optical sensor device is omitted compared to FIGS. 1A, 1B, 1C, 1D, and 1E;
  • 3A, 3B, and 3C show various views of a force sensor according to a second embodiment of the present disclosure
  • FIG. 4A, 4B, and 4C show various views of a force sensor according to a third embodiment of the present disclosure
  • FIG6 illustrates a dimensioned cross-sectional view of a force sensor according to a first embodiment of the present disclosure
  • FIG. 7A, 7B, 7C, and 7D show various views of a force sensor according to a fifth embodiment of the present disclosure
  • 8A, 8B, 8C, 8D, and 8E show various views of a force sensor according to a sixth embodiment of the present disclosure
  • 9A , 9B, and 9C are views showing a force sensor according to a seventh embodiment of the present disclosure.
  • Reference numerals list 100 Sensor body 10 Section 1 20Second Section 30 Middle section 31 First end of the middle section 32 The second end of the middle section 41 first annular portion 42 second annular portion 40 Clearance 33 first recess 34 Second recessed portion 35 Central Area 351 First end of the central section 352 Second end of the central section 36 Accommodation 200 Optical sensor devices 51Reflection component 52 Fiber 43 holes
  • the outer surface of the middle section 30 is inwardly concave relative to the outer surface of the first section 10 and the outer surface of the second section 20 to form a gap 40 between the first section 10 and the second section 20.
  • the deformation between the first section 10 and the second section 20 will mainly occur in the first annular portion 41 and the second annular portion 42. Since the first annular portion 41 and the second annular portion 42 are not located on the cylindrical outer surface of the sensor body 100, but are located in a very hidden position that is difficult to touch during operation, the deformed part is prevented from being directly subjected to force, thereby improving the measurement accuracy of the force applied to the sensor.
  • the annular portion is a symmetrical annular structure with the central axis of the sensor body 100 as the central axis, the cross-sectional inertia moment of the sensor body 100 in all directions can be completely equal, thereby minimizing the sensitivity difference of sensors in all directions and improving the overall accuracy of the sensor.
  • the thickness of the annular portion is also smaller than the thickness of any one of the first section 10 and the second section 20. More preferably, the thickness of the annular portion is smaller than the thickness of any one of the first section 10, the second section 20 and the middle section 30.
  • the thin-walled degree of the annular portion can also be specifically expressed by the width-to-thickness ratio of the annular portion.
  • the width of the annular portion that is, the width of the annular surface of the annular portion, is equal to the distance between the outer peripheral edge and the inner peripheral edge of the annular portion, and is also equal to the distance between the two components connected thereto.
  • the width of the first annular portion 41 is the distance between the first section 10 and the middle section 30, and the width of the second annular portion 42 is the distance between the second section 20 and the middle section 30.
  • the width of the annular portion is also equal to the length of the annular portion extending in the radial direction.
  • the width of the annular portion is marked with w in FIG. 6 .
  • the thickness of the annular portion is the wall thickness of the annular portion.
  • its wall thickness can be measured in the axial direction.
  • its thickness can be its average thickness, or the thickness at its middle position.
  • the width of the annular portion is marked with d in Figure 6.
  • the force sensor disclosed in the present invention has a very small size.
  • the outer diameter of the sensor body 100 is generally in the range of 1.5 mm to 3 mm, the length of the sensor body 100 is in the range of 1 mm to 8 mm, and the thickness of the annular portion is in the range of 0.05 mm to 0.1 mm, for example, 0.06 mm.
  • the width-to-thickness ratio is too high, the manufacturing process will be too difficult and the structural strength of the sensor body 100 will be reduced.
  • the width-to-thickness ratio w/d of the annular portion between 2 and 3, sufficient deformation can be provided to improve the accuracy of the sensor, and the structural strength of the sensor is also ensured, reducing the manufacturing difficulty.
  • first annular portion 41 and the second annular portion 42 both extend in a transverse direction perpendicular to the axial direction of the sensor body 100.
  • first annular portion 41 and/or the second annular portion 42 may be at an angle of between 0 and 30°, particularly between 0 and 15°, and more preferably between 0 and 10° relative to the transverse direction.
  • the sensor body 100 preferably satisfies one or more of the following features:
  • the sensor body 100 is an integrated structure.
  • the first section 10 , the second section 20 and the middle section 30 all have circular cross sections, wherein the outer diameter of the middle section 30 is smaller than the inner diameter of the first section 10 and smaller than the inner diameter of the second section 20 .
  • the side walls of the middle section 30 are parallel to the side walls of the first section 10 and the side walls of the second section 20 .
  • the first section 10 and the second section 20 have the same inner diameter and outer diameter.
  • the senor body 100 can be manufactured in a simple manner using a standard cylindrical blank.
  • the manufacturing method may include: (1) providing a cylindrical blank with a certain wall thickness; (2) widening the inner diameter at the first end of the cylindrical blank to form the inner surface of the first section 10; (3) widening the inner diameter at the second end of the cylindrical blank to form the inner surface of the second section 20; (4) machining a groove from the outer wall of the cylindrical blank to form the gap 40.
  • the aforementioned steps (2), (3), and (4) do not have to be performed in the order described, but can be performed in any order.
  • the manufacturing methods include but are not limited to laser processing, oil-cut wire processing, electric discharge machining, etc.
  • the optical sensor device 200 of the force sensor is held by the sensor body 100 and is configured to sense the deformation of the sensor body 100 caused by the force and transmit a signal representing the deformation.
  • the optical sensor device 200 is a combination of a reflective member 51 and an optical fiber 52.
  • the optical sensor device 200 is a Bragg grating of the optical fiber 52.
  • the accommodating portion 36 may be a through hole, such as a circular, elliptical, polygonal, square, rectangular, or irregularly shaped through hole.
  • the accommodating portion 36 may be a groove open to the outer surface of the sensor body 100, and the cross-sectional shape of the groove may be composed of a circular arc, a curve, a straight line, and a combination of curves.
  • the first section 10 and the second section 20 each have three accommodating portions 36, and for any section, the three accommodating portions 36 are evenly arranged at positions close to the circumference.
  • the optical sensor device 200 may be a combination of a reflective member 51 and an optical fiber 52, wherein a plurality of reflective members 51 pass through the first section 10 in the axial direction, and a plurality of optical fibers 52 pass through the second section 20 in the axial direction and the number of the reflective members 51 is the same as the number of the reflective members 51, so that the reflective members 51 and the optical fibers 52 are in a one-to-one correspondence.
  • the embodiment shown in FIGS. 1A-1E is such a case.
  • One end of each reflective member 51 extends into the gap 40 and is opposite to the end of each optical fiber 52 extending into the gap 40. There is a gap between the end of the reflective member 51 and the end of the optical fiber 52.
  • the optical fiber 52 is configured to emit light to the reflective member 51 and collect light reflected from the reflective member 51. Light is emitted through the end face of the optical fiber 52 and reaches the corresponding end face of the reflective member 51 through the gap. Similarly, the reflected light from the reflective member 51 reaches the optical fiber 52 through the gap.
  • deformation occurs at the annular portion between the first section 10 and the second section 20, causing a change in the distance between the end face of the optical fiber 52 and the end face of the reflective component 51. The change in distance can be used to obtain the magnitude and direction of the force applied to the sensor, as described below.
  • the force sensor disclosed in the present invention may adopt the following three demodulation schemes.
  • the first method is to use the principle of white light interference demodulation, which involves the case where the optical sensor device 200 is a reflective component 51 and an optical fiber 52.
  • the annular portion between the second section 20 and the first section 10 is deformed, thereby causing the distance between the reflective component 51 and the optical fiber 52 to change.
  • the change in the distance between the reflective component 51 and the optical fiber 52 at three or more positions in the gap 40 is calculated by the principle of white light interference demodulation, and the magnitude and direction of the force at the far end can be calculated.
  • the second method is to use the principle of light intensity demodulation, which involves the case where the optical sensor device 200 is a reflective component 51 and an optical fiber 52.
  • the annular portion of the second section 20 and the first section 10 deforms, causing the distance between the reflective component 51 and the optical fiber 52 to change.
  • the change in distance causes the intensity of light reflected from the end face of the reflective component 51 received by the optical fiber 52 to change.
  • the magnitude and direction of the force at the far end can be calculated by the change in light intensity at three or more positions distributed in the gap 40.
  • the third method is to use the fiber 52 Bragg grating principle.
  • This scheme involves the case where the optical sensor device 200 is a fiber 52 Bragg grating.
  • the two ends of the fiber 52 Bragg grating are fixed in the accommodating parts 36 of the second section 20 and the first section 10 respectively.
  • the annular part between the second section 20 and the first section 10 is deformed, thereby causing the fiber 52 Bragg grating to be subjected to tension or pressure.
  • the fiber 52 Bragg grating is subjected to tension or pressure, its central wavelength will change accordingly.
  • the magnitude and direction of the force at the far end can be calculated.
  • the force sensors according to other embodiments of the present disclosure are described below with reference to FIGS. 3A to 5C .
  • the first section 10 , the second section 20 , and the middle section 30 are arranged similarly to the first embodiment, and each of them has two annular portions.
  • the difference between these embodiments and the first embodiment mainly lies in the specific shape of the annular portion.
  • FIG. 3A, 3B, and 3C show various views of a force sensor according to a second embodiment of the present disclosure.
  • the annular portion has an uneven wall thickness.
  • the first annular portion 41 and the second annular portion 42 have a right-angled trapezoidal shape.
  • the wall thickness of the first annular portion 41 and the second annular portion 42 is thinner as it approaches the central axis of the force sensor, and thicker as it is farther away from the central axis of the force sensor.
  • the first annular portion 41 and the second annular portion 42 have a parallelogram shape.
  • the first annular portion 41 and the second annular portion 42 form an acute angle relative to the lateral direction of the sensor body 100.
  • the acute angle is preferably less than 30°, and more preferably, less than 15°.
  • 5A, 5B, and 5C show various views of a force sensor according to a fourth embodiment of the present disclosure.
  • the first annular portion 41 and the second annular portion 42 have irregular shapes, and the first annular portion 41 and the second annular portion 42 are not flat thin walls, but have annular surfaces composed of curved surfaces.
  • the size of the gap 40 increases in a direction away from the central axis, and the two axial sides of the gap 40 are defined by curves. This solution can also ensure that the deformation of the first section 10 relative to the second section 20 mainly occurs in the annular portion, while allowing the processing accuracy requirements of the sensor body 100 to be reduced.
  • FIG. 7A-7D show a force sensor according to a fifth embodiment of the present disclosure.
  • This embodiment has only one annular portion, namely, the first annular portion 41.
  • the second section 20 is directly connected to the middle section 30, and the first section 10 is connected to the middle section 30 through the annular portion.
  • the first section 10 can be directly connected to the middle section 30, and the second section 20 can be connected to the middle section 30 through the annular portion.
  • the second section can be set to have an outer diameter smaller than the outer diameter of the first section, or even equal to the outer diameter of the middle section 30.
  • FIGS. 8A-8E show a force sensor according to a sixth embodiment of the present disclosure. Different from the previous embodiments, this embodiment has two gaps 40.
  • the annular portion of this embodiment includes a first annular portion 41 and a second annular portion 42 .
  • the first annular portion 41 connects the first end 351 of the central section 35 and the first recessed portion 33
  • the second annular portion 42 connects the second end 352 of the central section 35 and the second recessed portion 34 .
  • the force sensor of any embodiment of the present disclosure may be disposed in a force sensing catheter having a flexible, elongated body with a distal end, wherein the force sensor is disposed at the distal end within the flexible, elongated body.
  • the force sensor compresses or bends in response to a contact force applied to the distal end of the flexible, elongated body, such as a contact force generated when the distal end contacts the wall of a blood vessel or an organ.
  • the force sensing catheter may have a width and a length suitable for insertion into a blood vessel or an organ of the human body.
  • the force sensing catheter may include a proximal portion, a middle portion, and a distal portion, wherein the distal portion may include an end effector that accommodates the force sensor.
  • the specific structure of the force sensing catheter used in the force sensor of the present disclosure is not limited.
  • the force sensing catheter can be a hollow structure (ie, having an inner cavity) or a non-hollow structure (ie, having no inner cavity).
  • the ablation device may have a catheter for delivering energy (such as radiofrequency energy, cryoenergy, etc.) to a specific part of the heart.
  • energy such as radiofrequency energy, cryoenergy, etc.
  • a force sensor may be installed, for example, at the tip of the catheter to monitor the contact force between the catheter and the heart tissue in real time. This monitoring helps ensure that the catheter is in full contact with the target tissue and improves the ablation effect.
  • the present disclosure also relates to a medical device, which may include a force sensor according to any embodiment of the present disclosure, or include a force sensing catheter according to any embodiment of the present disclosure.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)

Abstract

L'invention concerne un capteur de force, comprenant un corps (100) de capteur, le corps (100) de capteur comprenant une première section (10), une seconde section (20), et une section intermédiaire (30) située entre la première section (10) et la seconde section (20) et reliant la première section (10) et la seconde section (20). Au moins une partie de la surface extérieure de la section centrale (30) est évidée vers l'intérieur par rapport à la surface extérieure de la première section (10) et à la surface extérieure de la seconde section (20), de manière à former un espace (40) entre la première section (10) et la seconde section (20). Le corps (100) de capteur comprend en outre une partie annulaire, la partie annulaire définissant au moins une partie d'une limite axiale de l'espace (40), et l'épaisseur de la partie annulaire étant inférieure à la largeur d'une surface annulaire de celle-ci. L'invention concerne également un cathéter de détection de force, un dispositif d'ablation et un appareil médical.
PCT/CN2025/072276 2024-01-15 2025-01-14 Capteur de force, cathéter de détection de force, dispositif d'ablation et appareil médical Pending WO2025152925A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN202420098134.0U CN222528812U (zh) 2024-01-15 2024-01-15 力传感器和力感测导管
CN202410058363.4A CN120313768A (zh) 2024-01-15 2024-01-15 力传感器和力感测导管
CN202420098134.0 2024-01-15
CN202410058363.4 2024-01-15

Publications (1)

Publication Number Publication Date
WO2025152925A1 true WO2025152925A1 (fr) 2025-07-24

Family

ID=96470730

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2025/072276 Pending WO2025152925A1 (fr) 2024-01-15 2025-01-14 Capteur de force, cathéter de détection de force, dispositif d'ablation et appareil médical

Country Status (1)

Country Link
WO (1) WO2025152925A1 (fr)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080294144A1 (en) * 2007-05-24 2008-11-27 Giovanni Leo Touch Sensing Catheter
CN201983895U (zh) * 2010-10-24 2011-09-21 陈孝忠 新型内压传感器
CN102341053A (zh) * 2009-01-09 2012-02-01 恩杜森斯公司 光学纤维力感测导管
CN103607961A (zh) * 2011-04-14 2014-02-26 因都森有限责任公司 用于导管的紧凑型力传感器
CN106768500A (zh) * 2017-01-23 2017-05-31 湖南埃普特医疗器械有限公司 一种医用导管压力测量装置
US20190307505A1 (en) * 2018-04-05 2019-10-10 St. Jude Medical International Holding S.À R.L. Force sensing catheter system
CN114152370A (zh) * 2021-11-09 2022-03-08 天津大学 一种用于微创手术穿刺力测量的高精度光纤光栅力传感器
CN116952416A (zh) * 2023-08-28 2023-10-27 北京佰为深科技发展有限公司 力传感器和力感测导管
CN116973009A (zh) * 2023-09-04 2023-10-31 北京佰为深科技发展有限公司 力传感器和力感测导管

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080294144A1 (en) * 2007-05-24 2008-11-27 Giovanni Leo Touch Sensing Catheter
CN102341053A (zh) * 2009-01-09 2012-02-01 恩杜森斯公司 光学纤维力感测导管
CN201983895U (zh) * 2010-10-24 2011-09-21 陈孝忠 新型内压传感器
CN103607961A (zh) * 2011-04-14 2014-02-26 因都森有限责任公司 用于导管的紧凑型力传感器
CN106768500A (zh) * 2017-01-23 2017-05-31 湖南埃普特医疗器械有限公司 一种医用导管压力测量装置
US20190307505A1 (en) * 2018-04-05 2019-10-10 St. Jude Medical International Holding S.À R.L. Force sensing catheter system
CN114152370A (zh) * 2021-11-09 2022-03-08 天津大学 一种用于微创手术穿刺力测量的高精度光纤光栅力传感器
CN116952416A (zh) * 2023-08-28 2023-10-27 北京佰为深科技发展有限公司 力传感器和力感测导管
CN116973009A (zh) * 2023-09-04 2023-10-31 北京佰为深科技发展有限公司 力传感器和力感测导管

Similar Documents

Publication Publication Date Title
US11439354B2 (en) System and method for three-dimensionally mapping heart by using sensing information of catheter
US9149198B2 (en) Multi-array monophasic potential medical device
US11511077B2 (en) Catheter for sensing shape and contact force by using FBG optical fiber and catheter system therefor
EP2026708B1 (fr) Cathéter avec bout à orifices multiples pour évaluation optique de lésions
CN110944591B (zh) 光学力感测导管系统
US8048063B2 (en) Catheter having tri-axial force sensor
US20040073110A1 (en) Transseptal access tissue thickness sensing dilator devices and methods for fabricating and using same
US8515521B2 (en) Coupler assembly for catheters
CN110087572A (zh) 带有纵向安装的花键的面向远端的电极阵列
US10219702B2 (en) Single fiber force-sensing of both axial and bending catheter tip forces
US20200238047A1 (en) Catheter for sensing pressure applied to front end thereof by using optical fiber and catheter system therefor
CN110650676B (zh) 用于接触力感测的导管与弹簧元件
WO2025152925A1 (fr) Capteur de force, cathéter de détection de force, dispositif d'ablation et appareil médical
US20190307505A1 (en) Force sensing catheter system
WO2019154409A1 (fr) Capteur de pression et cathéter électrophysiologique
CN220602769U (zh) 力传感器和力感测导管
CN117838282A (zh) 一种集合三维标测和脉冲场消融的导管
CN116973009A (zh) 力传感器和力感测导管
US20230000545A1 (en) Ablation catheter tip with flexible electronic circuitry
CN222528812U (zh) 力传感器和力感测导管
WO2020208587A1 (fr) Pointe de cathéter d'ablation avec circuit électronique flexible
CN221865942U (zh) 一种软体驱动器及采用软体驱动器的消融导管远端
WO2021105903A1 (fr) Pointe de cathéter d'ablation à circuit électronique flexible
US11666280B2 (en) Catheter having a fiber optic force sensor with a mirror having a patterned reflectance
CN120313768A (zh) 力传感器和力感测导管

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 25741486

Country of ref document: EP

Kind code of ref document: A1