[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO1994008518A1 - Embout generateur de cavitation pour la desintegration de tissus - Google Patents

Embout generateur de cavitation pour la desintegration de tissus Download PDF

Info

Publication number
WO1994008518A1
WO1994008518A1 PCT/US1993/009693 US9309693W WO9408518A1 WO 1994008518 A1 WO1994008518 A1 WO 1994008518A1 US 9309693 W US9309693 W US 9309693W WO 9408518 A1 WO9408518 A1 WO 9408518A1
Authority
WO
WIPO (PCT)
Prior art keywords
tip
axis
tissue
section
peripheral edge
Prior art date
Application number
PCT/US1993/009693
Other languages
English (en)
Other versions
WO1994008518A9 (fr
Inventor
Charles D. Kelman
Martin Fox
Original Assignee
Kelman Charles D
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
Application filed by Kelman Charles D filed Critical Kelman Charles D
Publication of WO1994008518A1 publication Critical patent/WO1994008518A1/fr
Publication of WO1994008518A9 publication Critical patent/WO1994008518A9/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00—Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007—Methods or devices for eye surgery
    • A61F9/00736—Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments
    • A61F9/00745—Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments using mechanical vibrations, e.g. ultrasonic
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B17/22004—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves
    • A61B2017/22005—Effects, e.g. on tissue
    • A61B2017/22007—Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing
    • A61B2017/22008—Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing used or promoted
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/32—Surgical cutting instruments
    • A61B17/320068—Surgical cutting instruments using mechanical vibrations, e.g. ultrasonic
    • A61B2017/32007—Surgical cutting instruments using mechanical vibrations, e.g. ultrasonic with suction or vacuum means
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2217/00—General characteristics of surgical instruments
    • A61B2217/002—Auxiliary appliance
    • A61B2217/005—Auxiliary appliance with suction drainage system

Definitions

  • the present invention relates to a device for use in the medical field for assisting in the disintegration and removal of tissue, and more particularly to an improved tip element of such a device which is specifically designed for extracting the cataracted natural lens from the eye of either a human or an animal.
  • a now common medical procedure in eye surgery in ⁇ volves the complete removal of a cataracted lens from a human eye to be later replaced with an intraocular lens.
  • the known procedure includes making an incision in the cornea. To minimize patient trauma and unnecessary tissue damage, this incision is kept very small. The entire operation of disintegrating and removing the damaged natural lens tissue is performed using instruments placed within the small incision.
  • a special vibratory instrument is used to assist in the lens tissue disintegration.
  • the instrument functions effectively as a miniature jack hammer and includes detachable cutting tips which are analogous to jack hammer chisels.
  • the cutting tip is generally tubular and is oscillated by the instrument along its axis at a very high frequency.
  • the cutting tip is inserted into the incision and maneuvered by the surgeon throughout the capsular bag containing the natural lens literally being moved through the cataracted lens.
  • the movement of the vibrating cutting tip causes the lens tissue to disintegrate.
  • the resulting loose lens particles are carried from the posterior capsule by an aspiration fluid which flows into the posterior capsule by way of a first conduit and drawn under vacuum from the posterior capsule by way of the tubular cutting tip of the vibrating instrument.
  • U.S. Pat. 3,589,363 to Banko and Kelman discloses such a hand held instrument for breaking apart and removing tissue from a body site, such as cataracted lens tissue from a human eye.
  • the content of U.S. Pat. 3,589,363 is hereby incorporated by reference.
  • a first problem is that the ideal location for the above-described incision restricts the acces- sibility of the surgeon's operating instruments within the posterior cavity.
  • the typically straight cutting tips of the vibratory instrument cannot easily be maneuvered within the posterior cavity to effectively reach all parts of the lens to be removed.
  • cutting tips have now been made with a 90 arc- degree bend so that the cutting tip may be maneuvered ⁇ to reach every part of the posterior cavity while operating through the small incision.
  • This bent cutting tip feature is disclosed in my copending application serial no. 07/668,341, filed March 8, 1992, entitled: TISSUE SCRAPER DEVICE FOR MEDICAL USE, the content of which is hereby incorporated by reference.
  • a second problem encountered by surgeons during the above procedure involves the quick and clean removal of large (e.g. quarter sections) pieces of lens tissue remaining in the eye after an initial "cracking" of the lens. As the surgeon disintegrates these large pieces they may clog the tubular cutting tip, being drawn and held against the tip by the vacuum of the aspirating fluid existing therethrough.
  • the prior art has attempted to solve this problem by angling the front end of the cutting tip so that the "vacuum effect" which holds an oversized piece of lens tissue may be easily overcome by the force of the tip being drawn away from the tissue during the receding stroke of its reciprocating movement.
  • Such an angled tip is shown in the above-identified U.S. 3,589,363.
  • the intended purpose of the angled tip disclosed in U.S. 3,589,363 patent is to provide a tip having greater maneuver ⁇ ability and to create a cutting edge to more effectively break through tissue. Therefore, an ideal tip angle which maximizes effective fluid aspiration, yet still prevents tip-clogging, had not been realized.
  • a low pressure region i.e., negative pressure with respect to the surrounding fluid
  • the magnitude of negative pressure developed within the low pressure region exceeds (becomes more negative than) the negative pressure required to vaporize the particular fluid, the fluid will vaporize, creating bubbles called cavitation bubbles.
  • the rate of "collapse" of the cavitation bubbles determines the degree of assistance to disintegrating the nearby tissue. The greater the number of cavitation bubbles formed and the quicker the rate of collapse of the bubbles, the greater will be the desired damage to the nearby tissue.
  • An improved tip for use with a device for disinte ⁇ grating tissue located in a predominantly liquid environment includes an oscillation generator which provides an oscillation movement along an axis at an ultrasonic frequency.
  • the tip is connected with the oscillation generator and is moved to and for in oscillating movement along the axis.
  • the tip is positioned in proximity to the tissue such that the oscillations of the tip cause the tissue to disintegrate.
  • the tip has a specific shape and leading frontal area which pro- vides means for selectively creating and destroying cavitation bubbles within the liquid during the draw stroke of oscillation movement of the tip. The destruction of the cavitation bubbles in this manner substantially accomplishes the disintegration of the adjacent tissue.
  • the shape of the cutting tip is such that substantially more frontal area is available for producing and concentrating cavitation bubbles than with prior tips.
  • the tip includes an internal conduit extending along the length there ⁇ of. This aspiration and/or irrigation conduit is curved near the distal end of the tip and terminates at a frontal opening of the tip.
  • the tip is both curved to provide greater maneu ⁇ verability within the posterior cavity and includes a forward facing opening which is disposed at a slight angle.
  • the angled tip is such that a particular piece of tissue being disinte- grated is intermittently forced into contact with the tip and then separated immediately thereafter.
  • the curved conduit portion forms a throat behind the frontal opening.
  • the forward facing, peripheral edge surrounding the frontal opening and the forward facing outer surface of the curved tip each provide frontal surface area.
  • the throat includes a curved internal surface which provides additional frontal surface area to the tip as it is drawn away from a tissue surface. This combined frontal surface area helps create low pressure in the fluid adjacent the tissue surface. As stated above, the low pressure fluid causes cavitation bubbles to form.
  • Fig. 1 is an overall cross-sectional side view of a vibratory instrument showing a tip in accordance with the present invention attached thereto;
  • Fig. 2 is a partial cross-sectional side view of an eye showing the vibratory instrument including the cutting tip in an operational position in accordance with the invention;
  • Fig. 3 is a front view of the eye of Fig. 2;
  • Fig. 4 is a partial, sectional side view of a cutting tip assembly in accordance with a preferred embodiment of the invention.
  • Fig. 5 is a front view of the cutting tip in Fig. 4.
  • the instrument 10 includes a housing 12, an internal ultrasonic oscillation generator 14, a protective sleeve tip 16 and a tubular cutting tip 18.
  • the protective sleeve tip 16 is tubular and is attached to the housing 12.
  • the protective sleeve 16 is stationary with respect to the housing 12 and, once inserted in the eye, with respect to the patient (not shown) .
  • the cutting tip 18 is positioned within the tubular protective sleeve 16 and is attached to a forward end of the oscillation generator 14.
  • the oscillation generator 14 recip ⁇ rocates the cutting tip 18 along an axis A at a predetermined ultrasonic oscillation rate.
  • the instrument 10 also includes an irrigation fluid inlet line 20 which is in fluid communica- tion with the tubular protective sleeve 16 and an aspirating fluid outlet line 22 which communicates with an internal passage in the tubular cutting tip 18.
  • a small incision 24 is made in the cornea 26 and an opening is made in the anterior wall 28 using a scalpel or similar cutting instrument. Together, these two openings provide access to the interior of the capsular bag 30 through which the vibratory instrument 10 is inserted by a surgeon, as shown in Figs. 2 and 3.
  • the protective sleeve 16 contacts the tissue of the cornea 26 adjacent the small inci- sion 24.
  • the purpose of the protective sleeve 16 is to protect the healthy tissue (i.e., the tissue lying adjacent the inci ⁇ sion 24) from the oscillating cutting tip 18 positioned there ⁇ in.
  • the protective sleeve 16 also provides one-way isolated fluid communication directly with the posterior capsule 30 for providing irrigation fluid to the surgical site.
  • the cutting tip 18 is also positioned through inci ⁇ sion 24 but operates within the protective sleeve 16. Only a forwardmost portion 32 of the cutting tip 18 extends past the protective sleeve 16 into contact with the cataracted natural lens 34. As the oscillation generator 14 oscillates the cutting tip 18 back and forth along the axis A, the surgeon maneuvers the forwardmost portion 32 of the cutting tip 18 throughout the posterior cavity, to disintegrate and aspirate the separated particles of the cataracted lens 34.
  • the rate of oscillation of the oscillation generatox is preferably in the range between 10 khz and 25 khz.
  • the exact frequency used depends on several factors including the precise shape of the cutting tip, the type of tissue being disintegrated and the degree of disintegration desired.
  • a cutting tip 18 in accordance with the invention having a tip shaft or tube 36 positioned along an axis B, a connection end 38, a securing flange 40 and a tip end 42.
  • the tip end 42 is most important in controlling the localized densities of cavitation and bubble collapse.
  • the tip end 42 is bent with respect to the longitudinal axis B, and is positioned along a bent-portion axis C.
  • the preferred angle G between axis B and axis C is between 30 and 45 arc degrees.
  • the tip end 42 includes a tip opening 44, which is actually one end of the tube 36.
  • the tip opening 44 has a peripheral front tip surface 46.
  • the front tip surface 46 lies in a plane D which intersects the longitu ⁇ dinal axis B at a predetermined acute angle F of about 75 arc degrees (15 arc degrees from a normal line extended from axis B) . As described in greater detail below, this beveled front tip surface 46 accelerates fragment disintegration by intermit ⁇ tently "vacuum- bonding" with large tissue fragments. As the cutting tip 18 oscillates along the longitudinal axis B, the opening 44 moves along an axis E which is generally parallel to but displaced from axis B.
  • the surgeon To break up the cataracted lens, the surgeon first uses the vibrating cutting tip 18 to make a shallow and short groove near the center of the lens. The cutting tip 18 is then repositioned and another somewhat longer groove is made perpen ⁇ dicular to the first one, forming a small cross shape. During the procedure the surgeon elongates and deepens the grooves until they extend completely across the lens and almost com- pletely therethrough. The grooves are made deeper by removing small amounts of cataracted tissue along the groove-lines until eventually, the relatively brittle lens cracks. The grooves control the breakup of the lens by encouraging two intersecting cracks to separate the large lens into four relatively equal and more manageable-sized quarter sections.
  • the lens In carving out each groove, the lens has now become somewhat smaller in volume. However, the complete removal of the lens now requires that each of the four quarter sections be disintegrated.
  • the surgeon To disintegrate a quarter section in a con- trolled manner, the surgeon first positions the cutting tip 18 against a selected quarter section. The surgeon uses the cavitation effects of the oscillating tip, described in greater detail below, together with the strong suction of the aspira ⁇ tion fluid moving through the tube 36 to effectively and quickly disintegrate the quarter section.
  • the angle F formed between the plane D and the longitudinal axis B influences the amount of time the tissue will remain under the vacuum bond with the tip (for a given oscillation rate and vacuum magnitude) , therefore controlling the amount of direct tissue adherence.
  • the angle F of the peripheral front tip surface 46 allows the tip to more easily pull itself from the tissue surface by creating a "weak point" from which the "vacuum bond” may break. If, for example, the front beveled angle is 90 arc degrees or perpendicular to the longi ⁇ tudinal axis B, i.e.
  • a frontal area which includes an upper outer wall surface 48, a lower outer wall surface 52, a lower inner wall surface 50 and a upper inner wall surface 54. All wall surfaces are curved following the contours of the tubular tip 18. As the cutting tip 18 moves away from the tissue (recedes) , the upper inner wall surface 54, the outer lower wall surface 52 and the frontal surface 46 together create a local low pressure region in the area in front of the tip end 42.
  • the cavitation phenomenon encourages cavitation bubbles to form in the region of negative pressure, such as, in this case, in and adjacent to the tissue of a cataracted lens 34 of an eye.
  • the collapse of the cavitation bubbles causes the adjacent lens tissue to erode away.
  • the amount and location of tissue erosion may be controlled.
  • the peripheral front tip surface 46 is uniform in radial thickness completely around the tip opening 44.
  • the upper inner wall surface 54, the lower outer wall surface 52 and the peripheral front tip surface 46 cooperate to generate cavitation bubbles in a uniform manner.
  • the outside diameter of the tip is about 0.9mm and the wall thickness is about 0.15mm.
  • the bent portion is preferably about 3mm in length.

Landscapes

  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Surgical Instruments (AREA)

Abstract

Embout de découpage (18) amélioré utilisable conjointement avec un dispositif (10) de désintégration de tissus situés dans un milieu principalement liquide. Le dispositif (10) comporte un générateur d'oscillations (14) créant un mouvement oscillant à fréquence ultrasonore le long d'un axe (B). Un embout de découpage (18) est fixé au générateur d'oscillations et animé d'un mouvement oscillant de va-et-vient le long de l'axe (B). L'embout se place à proximité des tissus de manière que ses oscillations provoquent la désintégration au moins partielle de ceux-ci par les effets de cavitation. Ledit embout (18) présente une forme spéciale et une face avant (42) adaptée pour créer puis écraser les bulles de cavitation dans le liquide pendant le mouvement oscillant. En outre, l'embout possède un bord avant (46) en biais entourant un orifice d'aspiration, son angle oblique étant destiné à empêcher le 'collage sous vide', dû à l'aspiration, entre l'embout et les tissus désintégrés.
PCT/US1993/009693 1992-10-08 1993-10-08 Embout generateur de cavitation pour la desintegration de tissus WO1994008518A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US95865192A 1992-10-08 1992-10-08
US958,651 1992-10-08
US5521393A 1993-04-28 1993-04-28
US055,213 1993-04-28

Publications (2)

Publication Number Publication Date
WO1994008518A1 true WO1994008518A1 (fr) 1994-04-28
WO1994008518A9 WO1994008518A9 (fr) 1994-06-23

Family

ID=26733972

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1993/009693 WO1994008518A1 (fr) 1992-10-08 1993-10-08 Embout generateur de cavitation pour la desintegration de tissus

Country Status (1)

Country Link
WO (1) WO1994008518A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5910139A (en) * 1996-08-29 1999-06-08 Storz Instrument Co. Numeric keypad simulated on touchscreen
US5997528A (en) * 1996-08-29 1999-12-07 Bausch & Lomb Surgical, Inc. Surgical system providing automatic reconfiguration
US6086576A (en) * 1996-08-29 2000-07-11 Bausch & Lomb Surgical, Inc. Automatically switching the termination of a communications bus
US6117126A (en) * 1996-08-29 2000-09-12 Bausch & Lomb Surgical, Inc. Surgical module with independent microprocessor-based communication
US6126629A (en) * 1997-12-18 2000-10-03 Bausch & Lomb Surgical, Inc. Multiple port phaco needle
US6251113B1 (en) 1996-08-29 2001-06-26 Bausch & Lomb Surgical, Inc. Ophthalmic microsurgical system employing surgical module employing flash EEPROM and reprogrammable modules
US8623040B2 (en) 2009-07-01 2014-01-07 Alcon Research, Ltd. Phacoemulsification hook tip
US10258505B2 (en) 2010-09-17 2019-04-16 Alcon Research, Ltd. Balanced phacoemulsification tip

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3589363A (en) * 1967-07-25 1971-06-29 Cavitron Corp Material removal apparatus and method employing high frequency vibrations
US4169984A (en) * 1976-11-30 1979-10-02 Contract Systems Associates, Inc. Ultrasonic probe
US5222937A (en) * 1991-01-11 1993-06-29 Olympus Optical Co., Ltd. Ultrasonic treatment apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3589363A (en) * 1967-07-25 1971-06-29 Cavitron Corp Material removal apparatus and method employing high frequency vibrations
US4169984A (en) * 1976-11-30 1979-10-02 Contract Systems Associates, Inc. Ultrasonic probe
US5222937A (en) * 1991-01-11 1993-06-29 Olympus Optical Co., Ltd. Ultrasonic treatment apparatus

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5910139A (en) * 1996-08-29 1999-06-08 Storz Instrument Co. Numeric keypad simulated on touchscreen
US5997528A (en) * 1996-08-29 1999-12-07 Bausch & Lomb Surgical, Inc. Surgical system providing automatic reconfiguration
US6086576A (en) * 1996-08-29 2000-07-11 Bausch & Lomb Surgical, Inc. Automatically switching the termination of a communications bus
US6106512A (en) * 1996-08-29 2000-08-22 Bausch & Lomb Surgical, Inc. Numeric keypad simulated on touchscreen
US6117126A (en) * 1996-08-29 2000-09-12 Bausch & Lomb Surgical, Inc. Surgical module with independent microprocessor-based communication
US6251113B1 (en) 1996-08-29 2001-06-26 Bausch & Lomb Surgical, Inc. Ophthalmic microsurgical system employing surgical module employing flash EEPROM and reprogrammable modules
US6126629A (en) * 1997-12-18 2000-10-03 Bausch & Lomb Surgical, Inc. Multiple port phaco needle
US8623040B2 (en) 2009-07-01 2014-01-07 Alcon Research, Ltd. Phacoemulsification hook tip
US9233021B2 (en) 2009-07-01 2016-01-12 Alcon Research, Ltd. Phacoemulsification hook tip
US10258505B2 (en) 2010-09-17 2019-04-16 Alcon Research, Ltd. Balanced phacoemulsification tip

Similar Documents

Publication Publication Date Title
US5417654A (en) Elongated curved cavitation-generating tip for disintegrating tissue
US4816018A (en) Ultrasonic probe tip
US5213569A (en) Tip for a tissue phacoemulsification device
US6007555A (en) Ultrasonic needle for surgical emulsification
US6352519B1 (en) Removal of tissue
US3818913A (en) Surgical apparatus for removal of tissue
US6126629A (en) Multiple port phaco needle
US6217543B1 (en) Removal of tissue
EP0450578B1 (fr) Méthode et appareil pour contrÔler la fragmentation de tissu vivant par ultrasons
US6533750B2 (en) Conically shaped phaco tip
US4959049A (en) Tip for a phacoemulsification needle
US5993409A (en) Needle for surgical use
US8308735B2 (en) Phacoemulsification tip with internal oriented structures
US5562612A (en) Apparatus and method for reverse flow irrigation and aspiration of interior regions of the human eye
CA2534416C (fr) Embout et appareil de phacoemulsification et methode d'utilisation connexe
EP1700584A1 (fr) Sonde de phaco-émulsification
JP2003517331A (ja) 外面が収束しかつ内部チャネルが狭くなっている曲がり水晶体超音波吸引針
EP0642321A4 (fr) Extraction de tissus.
JPS61179150A (ja) 組織体内の細胞質除去装置
EP0482847A1 (fr) Méthode et appareil pour enlever selectivement des tissus vivants
EP1596748B1 (fr) Aiguille chirurgicale avec cible laser
WO1994008518A1 (fr) Embout generateur de cavitation pour la desintegration de tissus
WO1994008518A9 (fr) Embout generateur de cavitation pour la desintegration de tissus
WO2006101717A2 (fr) Embout de phacoemulsification
US5980529A (en) Work tip for surgical ultrasonic device

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

COP Corrected version of pamphlet

Free format text: PAGES 1/3-3/3,DRAWINGS,REPLACED BY NEW PAGES BEARING THE SAME NUMBER;DUE TO LATE TRANSMITTAL BY THERECEIVING OFFICE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA