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

Definitions

• the present disclosure relates generally to phacoemulsification systems , and particularly to control of a phacoemulsification probe tip traj ectory .
• a cataract is a clouding and hardening of the eye' s natural lens , a structure which is positioned behind the cornea, iris and pupil .
• the lens is mostly made up of water and protein and as people age these proteins change and may begin to clump together obscuring portions of the lens .
• a physician may recommend phacoemulsification cataract surgery .
• the surgeon makes a small incision in the sclera or cornea of the eye .
• a portion of the anterior surface of the lens capsule is removed to gain access to the cataract .
• the surgeon uses a phacoemulsification probe , which has an ultrasonic handpiece with a needle .
• the tip of the needle vibrates at ultrasonic frequency to sculpt and emulsify the cataract while a pump aspirates particles and fluid from the eye through the tip .
• Aspirated fluids are replaced with irrigation of a balanced salt solution to maintain the anterior chamber of the eye .
• the softer outer lens cortex is removed with suction .
• An intraocular lens ( IOL ) is then introduced into the empty lens capsule restoring the patient ' s vision .
• Fig . 2 is a flow chart that schematically illustrates a method for controlling a phacoemulsification needle , to prevent emulsified particles from sticking , in accordance with an example of the present disclosure .
• a phacoemulsification system is used to remove a natural eye lens with a cataract by breaking it into smaller pieces and emulsifying the pieces using a handpiece comprising a hollow needle . The eye lens fragments are then aspirated from the eye through the needle .
• emulsified particles may stick to the external wall of the phacoemulsification needle , creating what is termed a "lollipop" effect . Removal of the needle from the eye while particles are stuck to the needle wall may cause trauma to the eye .
• Examples of the present disclosure that are described herein provide a method for correcting the possible presence of stuck particles .
• the vacuum level in the line rises ( i . e . , the pressure decreases ) .
• the vacuum level remains high as the needle penetrates into the lens and divides the lens into sections.
• the vacuum level drops when emulsified material from the sections begins to be aspirated into the aspiration line, and this is a time when emulsified particles may stick to the needle wall.
• a processor looks for the drop in vacuum level described above, and if the drop is detected, the processor toggles the ultrasonic vibration trajectory of the needle within the eye to a different trajectory for a preset period of time, after which the trajectory is switched back to its initial trajectory.
• the initial trajectory may be longitudinal (with respect to the longitudinal axis of the needle)
• the latter trajectory may be elliptical (e.g. , a combination of longitudinal and transverse (or side to side) movement with respect to the longitudinal axis of the needle) . Toggling in this manner may remove particles stuck to the needle.
• the processor may toggle between a number of different trajectories of vibrating the phacoemulsification needle, e.g., longitudinal, planar (e.g., transverse) , torsional, elliptical, as well as in combinations and sub-combinations of such trajectories.
• trajectories of vibrating the phacoemulsification needle e.g., longitudinal, planar (e.g., transverse) , torsional, elliptical, as well as in combinations and sub-combinations of such trajectories.
• Fig. 1 is a pictorial view of a phacoemulsification system 10 constructed to operate in accordance with an example of the present disclosure.
• Fig. 1 includes an inset 25, and, as shown in the figure and the inset system 10, includes a phacoemulsification probe/handpiece 12 comprising a needle 16.
• Needle 16 is configured to be inserted into a lens capsule 18 of an eye 20 of a patient 19.
• Needle 16 is mounted on a horn 14 of probe 12, and is shown in inset 25 as a straight needle.
• any suitable needle may be used with phacoemulsification probe 12 , for example , a curved or bent tip needle commercially available from Johnson & Johnson Surgical Vision, Irvine , CA, USA.
• a physician 15 holds handpiece 12 by a handle 121 so as to perform a phacoemulsification procedure on the eye 20 of patient 19 .
• the physician may activate the handpiece using a foot pedal (not illustrated in Fig . 1 ) .
• Handpiece 12 comprises a piezoelectric actuator 22 , which is configured to vibrate horn 14 and needle 16 in one or more resonant vibration modes of the combined horn and needle element .
• the vibration of needle 16 is used to break a cataract into small pieces .
• an irrigation sub-system 24 which may be located in a console 28 , pumps irrigation fluid from an irrigation reservoir to an irrigation sleeve 17 surrounding at least a portion of needle 16 , so as to irrigate the eye 20 .
• the combined structure of needle 16 and irrigation sleeve 17 is called hereinafter a "phacoemulsification tip . "
• the fluid is pumped via a tubing line ( irrigation line ) 43 running from the console 28 to the probe 12 .
• Irrigation sub-system 24 is described in more detail below .
• An aspiration sub-system 26 also typically located in console 28 , aspirates eye fluid and waste matter (e . g . , emulsified parts of the cataract ) from the patient' s eye 20 via needle 16 to a collection receptacle (not shown) .
• Aspiration sub-system 26 comprises a pump which produces a vacuum that is connected from the sub-system to probe 12 by an aspiration tubing line 46 .
• a gauge or sensor 47 in line 46 measures the aspiration vacuum and/or pressure .
• Gauge 47 may be in any convenient location in line 46 , including , but not limited to , a location m or m proximity to handpiece 12 or a location in or in proximity to the console 28 .
• Irrigation sub-system 24 and aspiration sub-system 26 are both controlled by a processor 38 .
• the processor controls the flow volume rate at which the irrigation subsystem pumps fluid .
• the processor also controls the vacuum, pressure , and/or aspiration rate of the aspiration subsystem, using a pressure reading from gauge 47 .
• processor 38 may be combined in a single physical component or, alternatively, implemented using multiple physical components .
• the physical components may comprise hard-wired or programmable devices , or a combination of the two .
• at least some of the functions of processor 38 may be carried out by suitable software stored in a memory 41 .
• the software may be downloaded to a device in electronic form, over a network, for example .
• the software may be stored in tangible , non-transitory computer-readable storage media, such as optical , magnetic, or electronic memory .
• Processor 38 may receive user-based commands via a user interface 40 , which may include setting and/or adj usting a vibration mode , power level , duty cycle , and/or a frequency of piezoelectric actuator 22 , setting and/or adj usting a stroke amplitude of needle 16 , and setting and/or adj usting an irrigation rate , an aspiration rate , and/or an aspiration vacuum of irrigation sub-system 24 and aspiration sub-system 26 . Additionally, or alternatively, processor 38 may receive user-based commands from controls located in handpiece 12 , to , for example , select a traj ectory 44 , or another traj ectory, for needle 16 . The implementation of a trajectory such as trajectory 44 is further described below.
• Processor 38 may present results of the phacoemulsification procedure on a display 36.
• user interface 40 and display 36 may be one and the same, such as a touch screen graphical user interface.
• Fig. 1 may include further elements, which are omitted for clarity of presentation.
• physician 15 typically performs the procedure using a stereo-microscope or magnifying glasses, neither of which are shown.
• Physician 15 may use other surgical tools, in addition to probe 12, which are also not shown to maintain clarity and simplicity.
• Console 28 further comprises a multi-channel piezoelectric drive system 100 comprising drive modules 30 , 30 2 , ... 30 N , each coupled, using wiring in a cable 33, to a stack of piezoelectric crystals of piezoelectric actuator 22.
• Drive modules 302, 30 2 , ... 30 N generically termed drive modules 30, are controlled by processor 38 and convey phase-controlled driving signals via cable 33 to piezoelectric actuator 22.
• piezoelectric actuator 22 vibrates needle 16, which performs a vibrational/ultrasound trajectory 44, the trajectory typically comprising one, or a combination, of longitudinal, transverse, and/or torsional ultrasonic vibrations synchronized one with the other.
• emulsified matter from the eye 20 of patient 19 is aspirated by aspiration sub- system 26.
• aspiration sub- system 26 there are some instances during the procedure when the emulsified matter may stick to the external wall of the needle, causing what is termed a "lollipop" effect. It may be difficult or even impossible for the physician to know that material is stuck to the needle, so that attempts to remove the needle from the eye with the stuck material may cause trauma. Even if the physician is aware of material being stuck to the needle, the only way to remove the material may be to insert another tool, e.g. , a chopper or vacuum probe, to collect the material .
• another tool e.g. , a chopper or vacuum probe
• Fig. 2 is a flow chart that schematically illustrates a method for controlling a phacoemulsification needle (such as needle 16) , to prevent emulsified particles from sticking, in accordance with an example of the present disclosure. Implementing the steps of the flow chart prevents the lollipop effect from occurring.
• a phacoemulsification needle such as needle 16
• the vacuum level in the aspiration line typically increases due to partial or complete occlusion of the distal end of the needle.
• the vacuum level may increase to a relatively high level, i.e., the pressure falls to a relatively low level.
• Typical pressure values for this stage range from approximately -300 mmHg to approximately -650 mmHg. The levels stay generally constant until the needle begins to break the lens into sections .
• the needle breaks up the sections it begins to form emulsified particles, which are aspirated into aspiration line 46.
• the aspiration of the emulsified particles at this time reduces the vacuum level in the line, for example, by at least 50 mmHg (i.e. , the pressure increases by at least 50 mmHg) .
• steps of the flow chart check for this reduction in vacuum level, which typically occurs over a relatively short period of time of approximately 3 msec. If this kind of reduction is observed, the flow chart describes actions which may reduce the likelihood of emulsified particles from sticking to the wall of the needle.
• physician 15 inserts needle 16 in the lens capsule 18 of patient 19 and provides instructions to processor 38 so that the processor configures drive modules 30 to generate trajectory 44 as a first trajectory, herein assumed to comprise a substantially longitudinal trajectory.
• a first trajectory herein assumed to comprise a substantially longitudinal trajectory.
• Such a longitudinal trajectory may be efficient for initially breaking up the eye lens into small sections .
• a decision step 184 while monitoring the pressure in the aspiration line, the processor checks if a vacuum reduction, corresponding to the preset vacuum change level of step 180, has occurred within the preset time period. If decision step 184 returns negative ("No") , i.e. , no vacuum reduction is detected within the preset time period, control returns to step 184, so that the processor continues to monitor the aspiration line pressure iteratively. If decision step 184 returns positive ("Yes") , i.e., the processor detects that a vacuum reduction is occurring, control transfers to a switching step 188.
• the processor reconfigures drive modules 30 to generate trajectory 44 as a second trajectory, different from the first trajectory, e.g. , a substantially elliptical trajectory (combination of longitudinal and transverse) .
• the elliptical trajectory may shake off material stuck to needle 16.
• Processor 38 maintains the switch to the second trajectory for a predefined period of time, herein assumed to be a period between approximately 10 ]is and approximately 10 msec.
• FIG. 2 The example flow chart shown in Fig. 2 is chosen purely for the sake of conceptual clarity. For example, additional steps, such as audiovisual alert may be included.
• a method comprises inserting a needle (16) of a phacoemulsification handpiece (12) into an eye (20) of a patient (19) , and vibrating the needle in a first trajectory. Matter from the eye (20) is aspirated via an aspiration line (46) while the needle is vibrated in the first trajectory. An indication is received, of a vacuum level in the aspiration line (46) . Determined is, that the vacuum level has changed by at least a preset vacuum level change, and in response vibrating the needle is switched to a second trajectory, different from the first traj ectory .
• Exmaple 2 The method according to example 1, wherein the first trajectory comprises a longitudinal vibration, and the second trajectory comprises an elliptical vibration.
• switching to vibrate the needle (16) in the second trajectory comprises vibrating the needle in the second trajectory for a predefined period of time.
• determining that the vacuum level has changed comprises determining that the vacuum level has changed by at least the preset vacuum level change during a time period less than or equal to a preset time period.
• a system (10) includes a needle (16) of a phacoemulsification handpiece (12) , an aspiration line (46) , and a processor (38) .
• the needle is configured for insertion into an eye (20) of a patient (19) , and being vibrated m a first traj ectory .
• the aspiration line is configured for aspiration of matter from the eye via the needle while the needle is vibrated in the first traj ectory .
• the processor ( 38 ) is configured to ( i ) receive an indication of a vacuum level in the aspiration line , and ( ii ) determine that the vacuum level has changed by at least a preset vacuum level change , and in response switching to vibrate the needle in a second traj ectory, different from the first traj ectory .
• the methods and systems described herein can also be used in other surgical applications that may require a multi-channel piezoelectric resonant system to drive a moving member, such as ultrasonic blades , and other types of actuators .

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)

Applications Claiming Priority (3)

Publications (1)

Family

ID=82748745

Family Applications (1)

Country Status (2)

Families Citing this family (1)

Family Cites Families (4)

• 2022
  • 2022-07-13 EP EP22748442.5A patent/EP4380519A1/de active Pending
  • 2022-07-13 WO PCT/IB2022/056467 patent/WO2023017333A1/en unknown

Also Published As

Similar Documents

Legal Events