Patent Application
20240207092
The present disclosure relates generally to phacoemulsification systems and probes, and particularly to measurement of aspiration and irrigation parameters.
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. To correct this, a physician may recommend phacoemulsification cataract surgery. In the procedure, the surgeon makes a small incision in the sclera or cornea of the eye. Then a portion of the anterior surface of the lens capsule is removed to gain access to the cataract. The surgeon then 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. After removing the cataract with phacoemulsification, 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.
The present disclosure will be more fully understood from the following detailed description of the examples thereof, taken together with the drawings in which:
A phacoemulsification procedure for cataract removal requires strict control over intraocular pressure (IOP) to prevent damage to the eye. Real-time control over IOP can be made more robust if aspiration and irrigation parameter readings, such as of irrigation fluid pressure, aspiration vacuum level and aspiration and/or irrigation flow rates are acquired from sensors embedded at a distal end of the phacoemulsification handpiece.
Phacoemulsification handpiece typically includes dedicated rigid channels through which irrigation and aspiration is directed. One possible way to achieve robust real-time control over IOP is to embed a vacuum sensor in the aspiration channel of the handpiece and a pressure sensor in the irrigation channel of the handpiece. The sensors may be fluidly coupled to respective aspiration and irrigation channels located inside a handpiece of the phacoemulsification device (e.g., probe). In this way, the sensors measure the aspiration and/or irrigation through the handpiece no more than a few centimeters or tens of centimeters away from the eye itself.
However, as the handpiece is a reusable part, it undergoes sterilization between uses that frequently subjects the sensor to a harsh environment (such as large temperature variations and degradation of seals by steam). Moreover, a handpiece may fall or experience other mechanical damage that subjects the sensors to mechanical shock. As a result of all these stresses, the aforementioned pressure/vacuum sensors may malfunction without the user's knowledge. Operating a handpiece with a faulty pressure sensor or vacuum sensor may be hazardous to the patient.
During priming, a user covers the phacoemulsification tip with a flexible cover and then let fluid run through both the aspiration and the irrigation line to take out all the air from the system. Testing the sensors before each procedure may indicates malfunction of individual sensors. Yet, readings from a single sensor reading may be misleading (e.g., in the absence of a reference).
Examples of the present disclosure that are described hereinafter verify the integrity of the pressure/vacuum sensors during the priming phase run before each surgical procedure (e.g., phacoemulsification procedure). To this end, the disclosed technique provides sensor arrays that are embedded into a handpiece of a phacoemulsification probe. The system measures pressure with the multiple sensors and compares the readings. If readings from all sensors provide same output this is an indication that the pressure sensors are operating correctly. If not, then apparently there has been some damage and the handpiece is faulty. During the surgical procedure, the system optionally continues to measure pressure from all sensors to make sure that similar readings are received from the sensors on each of the rigid channels. The system may use the average readings.
The sensor arrays are embedded into a handpiece of a phacoemulsification probe. The disclosed solutions take advantage of the available space along the rigid flow channels to include multiple vacuum/pressure/flow sensors. In one example, a blind hole may be formed in the rigid channel and the sensor array may be mounted in the blind hole so that it may sense the pressure without obstructing the flow. Such example is shown in
In another example, each group of sensors may be mounted on a flexible Printed circuit Board (PCB) that is embedded within a rigid flow channel of the handpiece. The sensors that form a sensor array are fluidly coupled to the port made. In another example, a window may be formed in the rigid channels and the flex PCB may be mounted and sealed on the window. This example is shown in
In one example, readings are taken from all of the pressure sensors of a given sensor array and the readings are compared. It is expected that all of the readings on a same channel will provide substantially the same output. Significant differences may indicate that there is some malfunction that should be checked. A warning provided to the user to check the integrity of the device will be included.
Furthermore, in some embodiments each sensor array comprises an odd number of sensors, which can overcome malfunction of an individual sensor by enabling a majority decision. Thus, even if a single sensor provides an outlier reading, the clinical procedure can be completed without hazard.
As seen in the pictorial view of phacoemulsification system 10, and in inset 25, a phacoemulsification probe 12 (e.g., a handpiece) comprises a needle 16 and a coaxial irrigation sleeve 56 that at least partially surrounds needle 16 and creates a fluid pathway between the external wall of the needle and the internal wall of the irrigation sleeve, where needle 16 is hollow to provide an aspiration channel. Moreover, the irrigation sleeve may have one or more side ports at or near the distal end to allow irrigation fluid to flow toward the distal end of the handpiece through the fluid pathway and out of the port(s).
Needle 16 is configured for insertion into a lens capsule 18 of an eye 20 of a patient 19 by a physician 15 to remove a cataract. While the needle 16 (and irrigation sleeve 56) are shown in inset 25 as a straight object, 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, Inc., Irvine, CA, USA.
In the shown example, during the phacoemulsification procedure a pumping subsystem 24 comprised in a console 28 pumps irrigation fluid from an irrigation reservoir (not shown) to the irrigation sleeve 56 to irrigate the eye. The fluid is pumped via an irrigation tubing line 43 running from the console 28 to an irrigation channel 43a of probe 12. Eye fluid and waste matter (e.g., emulsified parts of the cataract) are aspirated via hollow needle 16 to a collection receptacle (not shown) by a pumping subsystem 26, also comprised in console 28, using an aspiration tubing line 46 running from aspiration channel 46a of probe 12 to console 28. In another example, the pumping subsystem 24 may be coupled or replaced with a gravity-fed irrigation source such as a balanced salt solution bottle/bag.
System 10 includes standalone disposable detachable add-on module 50, coupled via fluid connectors 51 and 53, to control (e.g., regulate) aspiration flow rate to reduce risks to eye 20 from irregular performance of aspiration in probe 12, such as from a vacuum surge.
An example of module 50 is an anti-vacuum surge (AVS) device, which is described in U.S. patent application Ser. No. 17/130,409, filed on Dec. 22, 2020, and titled, “A module for Aspiration and Irrigation Control,” which is assigned to the assignee of the present application.
Module 50 can discontinue aspiration in order to provide a fast response (e.g., within several milliseconds) to a detected vacuum surge. Module 50 has its own processor and can be used with existing phacoemulsification systems as a disposable element that improves control over intraocular pressure (IOP) during a surgical cataract removal procedure.
In the shown example, fast and robust IOP control (e.g., by module 50) is facilitated by module 50 receiving real-time readings from sensor arrays 23 and 27. Sensor array 23 comprises an odd number of pressure sensors (e.g., three) that are fluidly coupled to irrigation channel 43a. Sensor array 27 comprises an odd number of vacuum sensors (e.g., three or five) that are fluidly coupled to aspiration channel 46a. An example of such a sensor array is described in detail in
Phacoemulsification probe 12 includes other elements (not shown), such as one or more piezoelectric crystals coupled with a horn to drive vibration of needle 16. The piezoelectric crystal is configured to vibrate needle 16 in a resonant vibration mode. The vibration of needle 16 is used to break a cataract into small pieces during a phacoemulsification procedure. Console 28 comprises a piezoelectric drive module 30, coupled with the piezoelectric crystal, using electrical wiring running in a cable 33. Drive module 30 is controlled by a processor 38 and conveys processor-controlled driving signals via cable 33 to, for example, maintain needle 16 at selected vibration amplitude. The drive module may be realized in hardware or software, for example, in a proportional-integral-derivative (PID) control architecture.
Processor 38 may receive user-based commands via a user interface 40, which may include setting a vibration mode, duty cycle, and/or frequency of the piezoelectric crystal, and setting or adjusting an irrigation and/or aspiration rate of the pumping subsystems 24/26. In an example, user interface 40 and display 36 may be combined as a single touch screen graphical user interface. In an example, the physician uses a foot pedal (not shown) as a means of control and an encoder sensing position of the foot pedal may provide input to processor 38. Additionally or alternatively, processor 38 may receive the user-based commands from controls located in a handle 21 of probe 12.
Some or all of the functions of processor 38 may be combined in a single physical component or, alternatively, implemented using multiple physical components. These physical components may comprise hard-wired or programmable devices, or a combination of the two. In some examples, at least some of the functions of processor 38 may be carried out by suitable software stored in a memory 35 (as shown in
The apparatus shown in
In some examples, a different type of AVS module can be used that is coupled only with the aspiration part of the system (i.e., without involving irrigation).
Module 50 is an example of the aforementioned anti-vacuum surge (AVS) device, where, in the example shown in
Optionally, module 250 can be replaced with an alternate module that includes a diversion valve (i.e., a bypass valve) configured to divert irrigation flow into the aspiration channel based on processor commands according to pressure readings from sensor array 223 and/or vacuum readings from sensor array 227.
Inset 200 provides a detailed view of pressure sensor array 223. As seen, the array is made of an odd number of sensors 345. During priming, if readings from all sensors 345 provide same output this is an indication that the pressure sensors are operating correctly. If not, then apparently there has been some damage and the handpiece is faulty. The array 223 is realized on a flexible PCB substrate that is attached (e.g., glued) to rigid channel 43a.
Sensors 345 are fluidly coupled to channel 43a via one or more windows formed in the rigid channels with the flex PCB substrate of array 223 sealed against the one or more windows. A multiwire electrical cable 333 connects the sensors (e.g., via cable 33) via an interface to a processor.
The handpiece shown in
At a phacoemulsification step 304, physician 15 presses a foot pedal to a first position to activate aspiration, subsequently to a second position to activate irrigation, and finally, when the foot pedal is pressed and placed in a third position, the needle 16 is vibrated to perform the phacoemulsification.
During phacoemulsification, processor 38 receives pressure and vacuum readings from sensor arrays 223 and 227, respectively, at readings receiving step 306.
At a checking step 308, the processor checks if there is an outlier reading among the sensors. If the answer is no the process proceeds directly to IOP regulation step 312.
If the answer is yes, the processor uses a majority vote reading (i.e., discards an outlier reading), at a majority readings step 310.
At IOP regulation step 312, the processor uses accepted sensor array readings to maintain IOP within specified limits.
If required, at an alerting step 314, the processor alerts physician 15 of a possible malfunction of a sensor in the handpiece.
Inset 400 provides a detailed view of pressure sensor array 427. As seen, the array is made of an odd number of sensors 445. During priming, a processor checks the integrity of sensors 445 by comparing output readings from all of them. If they all have the same output readings, up to a tolerance, the processor determines that the pressure sensors are working well. Furthermore, during the surgical procedure, in case of a malfunctioning sensor, a majority decision can still be made based on the array readings.
The array is put inside an indentation 428 that is made into the inner wall of the rigid channel 46a, e.g., using blind drilling. Using the indentation ensures flow in the rigid channel is not disturbed by the sensors.
Further seen is a multiwire electrical cable 433 may extend through the aspiration channel or may extend outside of the channel through a dedicated port penetration through the channel.
Inset 440 provides a detailed view of pressure sensor array 447. Again, the array is made of the odd number of sensors 445, so that, during priming, the processor checks the integrity of sensors 445 by comparing output readings from all of them.
The array 447 is also put inside an indentation 448 that is made into the inner wall of the rigid channel 43a, e.g., using blind drilling. Using the indentation ensures flow in the rigid channel is not disturbed by the sensors.
As noted above, testing the sensor arrays before each procedure can indicates malfunction of individual sensors.
Next, at a priming step 503, physician 15 starts priming of system 10 to let fluid fill the aspiration and irrigation lines, at a system priming step 503. During priming the physician keeps the handpiece tip immersed in irrigation fluid accumulated inside the flexible cover.
At sensor array checking step 505, the processor checks if the output (e.g., readings) from each of the sensors 445 is substantially the same. If the answer is no, the physician replaces the handpiece and repeats the test with a new handpiece, at a new test during priming step 507. If the answer is yes, the physician can use the handpiece, at a handpiece readiness granting step 509.
A phacoemulsification system (10) includes a phacoemulsification probe (12) and a processor (38). The phacoemulsification probe has a distal end (112) configured for insertion into an eye of a patient, the probe including (i) an irrigation channel (43a) for irrigating the eye with irrigation fluid, (ii) an aspiration channel (46a) for evacuating material from the eye, and (iii) at least one sensor array (223, 227, 427, 447) fluidly coupled to at least one of the irrigation channel and the aspiration channel, the at least one sensor array comprising multiple sensors (345, 445) configured to measure a parameter indicative of fluid pressure in the irrigation channel or the aspiration channel. The processor (38) is configured to regulate at least one of irrigation flow and aspiration flow using the measured parameter.
The system (10) according to example 1, wherein the processor (38) is configured to alert a user in case of at least one of the sensors (345, 445) of the at least one of the sensor arrays (223, 227, 427, 447) malfunctioning.
The system (10) according to any of examples 1 and 2, wherein the sensor array (227, 447) is coupled with the irrigation channel (43a), and wherein the sensors (345, 445) are configured to measure a pressure of the irrigation fluid.
The system (10) according to any of examples 1 through 3, wherein the sensor array (447) is fitted into an indentation made (448) in an inner wall of the irrigation channel (43a).
The system (10) according to any of examples 1 through 4, wherein the sensor array (223, 427) is coupled with the aspiration channel (46a), and wherein the sensors (345, 445) are configured to measure a vacuum level in the aspiration channel (46a).
The system (10) according to any of examples 1 through 5, wherein the sensor array (427) is fitted into an indentation (428) made in an inner wall of the aspiration channel (46a).
The system (10) according to any of examples 1 through 6, wherein the at least one sensor array (223, 227, 427, 447) comprises an odd number of the sensors (345, 445), and wherein the processor (38) is configured to perform a majority vote among readings of the sensors (345, 445) of the array (223, 227, 427, 447).
The system (10) according to any of examples 1 through 7, wherein the at least one sensor array (223, 227, 427, 447) is comprised in a handpiece of the phacoemulsification probe (12) and is suitable for undergoing sterilization.
The system (10) according to any of examples 1 through 8, wherein the sensor array (223, 227) is disposed on a flexible PCB.
The system (10) according to any of examples 1 through 9, wherein the irrigation channel (43a) or the aspiration channel (46a) comprises a window formed therein, and wherein the flexible PCB is coupled with the window.
A phacoemulsification method includes inserting into an eye (20) of a patient a distal end (112) of a phacoemulsification probe (12), the probe including (i) an irrigation channel (43a) for irrigating the eye with irrigation fluid, (ii) an aspiration channel (46a) for evacuating material from the eye, and (iii) at least one sensor array (223, 227, 427, 447) fluidly coupled to at least one of the irrigation channel and the aspiration channel, the at least one sensor array comprising multiple sensors (345, 445) configured to measure a parameter indicative of fluid pressure in the irrigation channel or the aspiration channel. At least one of irrigation flow and aspiration flow are regulated using the measured parameter.
It will be appreciated that the examples described above are cited by way of example, and that the present disclosure is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present disclosure includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.
