Automated intraocular lens injector device

0001The present invention generally relates to a device that provides an intraocular lens into the eyeball, and more particularly to a method for detecting a disorder in such a device.

0002The human eye functions to provide vision by transmitting light through a transparent outer portion called the cornea and by focusing the image onto the retina with the crystalline lens. The quality of the focused image depends on many factors such as the size and shape of the eyeball and the transparency of the cornea and lens. When the transparency of the crystalline lens decreases due to age or disease, vision decreases due to the decrease in light that can be transmitted to the retina. This defect in the crystalline lens of the eye is medically known as cataract. Commonly accepted treatments for this condition are surgical removal of the lens and replacement of lens function with an artificial intraocular lens (IOL).

0003In the United States, the majority of cataract lenses are removed by a surgical technique called phacoemulsification. During this procedure, an opening is formed in the anterior capsule, and a small-diameter incision tip for ultrasonic lens emulsification suction is inserted into the diseased crystalline lens and vibrated by ultrasonic waves. The vibrating incision tip liquefies or emulsifies the crystalline lens so that it can be sucked out of the eyeball. The diseased lens, once removed, is replaced by an artificial lens.

0004The IOL is introduced into the eye through the same small incision used to remove the diseased lens. The IOL is loaded into the insertion cartridge of the IOL introducer, the tip of the insertion cartridge is inserted into the incision, and the lens is donated into the eyeball.

<p num="0005"> Many IOLs manufactured today are made from polymers with unique properties. According to these properties, the lens can be folded and unfolded into a suitable shape when donated into the eye. Several manual introducer devices are available for implanting these lenses into the eye. However, threaded-type manual introducers require the use of both hands, which is cumbersome and cumbersome. Also, in the injector type introducer, the introduced force and displacement generated are inconsistent. Therefore, there is a need for superior devices and methods for delivering IOLs into the eye.</p>

<p num="0006"> Each embodiment of the present invention includes various devices for implanting an intraocular lens (IOL) into the crystalline lens sac of the eye, as well as methods for controlling such devices. According to a preferred embodiment, the IOL introduction device comprises a tubular housing with a plunger disposed longitudinally within the tubular housing. The plunger is an electric drive system disposed in the housing and is translated forward and backward in the longitudinal direction with respect to the front end portion of the housing by the electric drive system including an electric motor. The device is configured such that when the plunger is translated toward the front of the device, its tip engages an intraocular lens insertion cartridge attached to or near the front end of the housing. To. In certain embodiments, the plunger tip, which may be a removable plastic sleeve that elastically fits against the push rod, passes through the insertion cartridge and folds the intraocular lens disposed internally. At the same time as draining, the folded lens is introduced into the crystalline lens sac of the eyeball.</p><p num="0007"> In various embodiments, the IOL-introduced device is a control circuit electrically connected to the electric motor, further comprising a control circuit configured to initiate translation of the plunger in response to user input. Consists of. The circuit is further configured to detect at least one fault condition based on the counter electromotive force generated by the electric motor and to stop the translation of the plunger assembly according to the detected fault condition. To. The detected fault condition can consist of excess resistance to forward translation of the plunger in comparison to a predetermined threshold, such as that caused by an improperly loaded or occluded insertion cartridge. Certain embodiments are inadequate for excessive resistance of the plunger to backward translation in comparison to a second predetermined threshold and / or for forward translation of the plunger in comparison to a third predetermined threshold. It can be configured to detect resistance.</p><p num="0008"> In certain embodiments, the control circuit monitors the rotational speed of the electric motor based on the counter electromotive force, and by comparing the monitored rotational speed with a predetermined threshold, at least one failure state. Configured to detect. In certain embodiments, the control circuit tracks the longitudinal position of the plunger based on the counter electromotive force generated by the electric motor, and at least one of the tracks based on the tracked longitudinal position. It is configured to detect a failure condition. In some of these embodiments, the control circuit reduces the counter electromotive force generated by the electric motor, such as by comparing the monitored rotational speed with a threshold that changes with the tracked longitudinal position. It is configured to detect at least one fault condition based on comparison with a threshold that changes with the tracked longitudinal position.</p><p num="0009"> An electric drive system including a plunger arranged in the longitudinal direction inside a tubular housing and an electric motor, which is configured to cause longitudinal parallel movement of the plunger along the main axis of the housing. In a typical method of controlling a device for implanting an intraocular lens in the crystalline lens sac of an eye, the plunger is initiated in longitudinal parallel movement in response to user input. The translation of the plunger is stopped in response to the detection of at least one failure condition based on the counter electromotive force generated by the electric motor. The detected failure states are the excess resistance to the forward translation of the plunger in comparison with the first predetermined threshold, the excess resistance to the backward translation of the plunger in comparison with the second predetermined threshold, and the first. It may include one or more of the insufficient resistances of the plunger to forward translation in comparison to a predetermined threshold of 3.</p><p num="0010"> In certain embodiments, the method may include monitoring the rotational speed of the electric motor based on the counter electromotive force, so that the fault condition compares the monitored rotational speed to a predetermined threshold. Detected by. In certain embodiments, the longitudinal position of the plunger is tracked based on the counter electromotive force, and the detection of the fault condition is based on the tracked longitudinal position. The fault state, in certain embodiments, reduces the counter electromotive force generated by the electric motor, for example, by comparing the monitored rotational speed with a threshold that changes with the tracked longitudinal position. It can be detected by comparing with the threshold value that changes with the tracked longitudinal position.</p><p num="0011"> Of course, one of ordinary skill in the art can understand that the present invention is not limited to the above features, advantages, situations or examples, and is additional if the detailed description below is read and the accompanying drawings are taken into account. Be aware of the features and benefits.</p>

0012<figref num="1">It is a perspective view of a typical IOL introduction device in which an insertion cartridge is installed.</figref><figref num="2">It is a partially broken perspective view of the activation mechanism of a typical IOL-introduced device.</figref><figref num="3">It is a figure which shows the electric drive system and the connection mechanism of a typical IOL introduction device.</figref><figref num="4">It is a figure which shows the tip part of the removable plunger which concerns on a certain embodiment of this invention.</figref><figref num="5">It is sectional drawing of the IOL introduction device which concerns on a certain embodiment of this invention.</figref><figref num="6">It is a figure which shows the activation device which was completely contracted.</figref><figref num="7">It is a figure which shows the activation device which was partially extended.</figref><figref num="8">6 is a cross-sectional view taken along line VIII of an alternative embodiment of the device of FIGS. 6 and 7.</figref><figref num="9">It is another sectional view taken along line IX of FIG. 6 and FIG.</figref><figref num="10">It is a figure which shows the wrench for the tip part of a plunger which concerns on a certain embodiment of this invention.</figref><figref num="11">It is a figure which shows the wrench for the tip of the plunger of FIG. 10 installed on the typical IOL introduction device.</figref><figref num="12">It is the schematic which shows the typical control circuit for an IOL introduction device.</figref><figref num="13">It is a processing flowchart which shows the method of controlling the IOL introduction device which concerns on a certain embodiment of this invention.</figref><figref num="14">It is a figure which shows the specific structure for detent which is used with the tip of a disposable plunger.</figref>

0013FIG. 1 shows a handheld intraocular lens (IOL) -introduced device 10 that implants an IOL into the anterior capsule of the eye. As shown, the IOL-introduced device 10 includes a cable assembly 12 that transmits power and / or control signals from a separate user console (not shown), but certain embodiments are in the main housing. The operation of the device may be controlled by including one or more batteries within 15 to power the device and / or by including one or more switches or other user input devices. The illustrated IOL introduction device 10 also comprises a cartridge mounting member 18 that holds a detachably mounted insertion cartridge 20. As described in more detail below, in certain embodiments, the insertion cartridge 20 is a disposable polymer component capable of accommodating a deployed IOL lens, with the plunger tip 25 forward from the body of the housing 15. It is a disposable polymer component that can fold and eject the lens when it is translated through the insertion cartridge 20. In certain embodiments, the cartridge mounting member 18 is a metal "conical head" that includes a unique notch that houses the IOL cartridge, from a metal "conical head" that is pressure fitted to the inner shell of the housing 15. It can be.

0014FIG. 2 is a partial fracture view of a preferred embodiment of the IOL-introduced device 10 showing the internal structure of the activation assembly 30 that translates the plunger tip 25 linearly along the main axis of the housing of the device. .. 3 and 4 provide details of the assembly of FIG. 2, and FIG. 5 shows a cross-sectional view of the IOL-introduced device 10.

0015In the illustrated embodiment, the activation assembly includes a plunger tip 25 as well as a plunger 32 configured for longitudinal translation inside the internally threaded tubular coupler 35 and an electrically driven system. It consists of 38 and. As shown in FIGS. 3 and 5, the electric drive system 38 is an electric motor 42 and a gear set 44 disposed in a welded object, held in place by a coupler sleeve 48 made of polyma. It may include an electric motor 42 and a gear set 44 configured to rotate the tubular coupler 35. The internal thread on the tubular coupler 35 meshes with the external thread-forming male coupler 46 at the rear end of the plunger 32, and upon activation of the drive system 38, the plunger 32 and in the tubular coupler 35 Forces linear translation of the plunger tip 25. The internal threads of the tubular coupler 35 and / or the threads of the male coupler 46 are intended to minimize friction (Endura 200TX, Brycoat). It is coated with a lubricant (which can be a dry film coating such as WS2, Teflon / FEP, etc.). For the tubular housing 15, the O-ring 39, which can be formed from the elastomer, provides a seal to prevent moisture and / or other contaminants from reaching the inside of the housing 15.

0016In certain embodiments, the electric drive system 38 comprises a brushless DC motor 42 that provides rotational torque to the gear set 44, which gear set rotates the tubular coupler 35 to extend or extend the plunger 32. Shrink. The gear set 44 acts to reduce the angular velocity of the motor according to a predetermined reduction ratio, for example 125: 1. This increases the torque available from the drive system 38 and reduces the linear motion of the plunger 32 to a speed suitable for the IOL introduction procedure.

0017In certain embodiments, the plunger tip 25 may be removable from the plunger 32 as shown in FIG. In these embodiments, the plunger tip 25 may consist of a disposable plastic sleeve that, in certain cases, is attached to the front end of the plunger 32 according to an "elastic fitting" mechanism. The end of the plastic sleeve that engages the IOL is more elastic than the exposed metal plunger and has a smooth surface finish, allowing the IOL to enter the eye through the insertion cartridge 20. Damage to the IOL is avoided when pushed forward. Disposable plastic sleeves can also facilitate reprocessing of the IOL-introduced device 10 during use.

00186, FIG. 7, FIG. 8 and FIG. 9 provide additional details for a representative IOL-introduced device according to certain embodiments of the present invention. 6 and 7 show longitudinal sections of the IOL-introduced device 10 with the plunger 32 in a fully contracted position and a partially extended position, respectively. At the partially extended position shown in FIG. 7, the plunger tip 25 is just beginning to pass into the insertion cartridge 20.

0019As can be seen in FIG. 6, the male coupler 46, which is hollowed out to accommodate the plunger 32 and keyed along the axis of the male coupler 46, is located in the circumferential direction at the rear end of the plunger 32. The male coupler 46 is held in a predetermined position by a holding ring 52 that fixes the male coupler 46 in a predetermined position by hooking into the groove. At the opposite end of the tubular coupler 35, the bearing assembly 54 held in place by the polymer bearing sleeve 56 holds the tubular coupler 35 in a position concentric with the housing and the tubular coupling. Promotes the smooth rotational movement of the vessel 35. The compression seal 58, which consists of an elastomer exterior and a metal channel ring, provides a seal that blocks the ingress of moisture. The plunger 32, which has a cross section with two flat surfaces, is prevented from rotating with respect to the housing by an orientation insert 60 held in place by a pin 62.

00208 (a) and 8 (b) provide cross-sectional views of two different embodiments of the IOL-introduced device, corresponding to the cross-sections shown as VIII in FIG. As seen in each of these figures, the drive shaft 82 extending from the transmission 44 engages the key forming end plate 84 of the tubular coupler 35 to apply the rotational torque of the drive system 38 to the cylinder. Transmit to the shape coupler 35. The tubular coupler 35 is surrounded by a coupler sleeve 48 and an inner shell 86 and an outer shell 88 of the housing 15. In the embodiment illustrated in FIG. 8B, the end plate 84 of the tubular coupler 35 is slotted to define a range of arcs beyond the portion of the slot occupied by the drive shaft 82. As a result, the drive shaft can freely rotate with respect to a part of the rotation when the direction is reversed. This feature can facilitate the start-up of the electric motor in certain embodiments and can also be used to calibrate the monitoring circuit for "no load" conditions in certain embodiments. As described in more detail below, this calibration can be used to establish one or more thresholds used in fault detection methods.

0021FIG. 9 provides a cross-sectional view of a certain embodiment of the IOL-introduced device 10 corresponding to the cross-section shown as IX in FIG. As described above, the plunger 32 has a non-circular cross section, and the plunger is in place by an orientation insert 60 fixed in place within the inner shell 86 and outer shell 88 of the housing by a holding pin 62. Be retained. Since the plunger 32 is prevented from rotating with respect to the housing in this way, the rotation of the tubular coupler 35 by the electric drive system 38 is along the axis of the IOL introduction device as shown in FIGS. 6 and 7. It is converted to the translational displacement of the plunger 32.

0022As shown above, in certain embodiments of the IOL-introduced device, the plunger assembly comprises two or more members including a push rod 32 and a plunger tip 25. In certain embodiments, the plunger tip 25 may consist of a removable plastic sleeve that elastically fits onto the plunger 32 and may be disposable after use. In certain embodiments, a plunger tip wrench may be used to install the plastic plunger tip 25 on the plunger 32. FIG. 10 shows a typical plunger tip wrench 90 having a plunger tip 25 held inside. FIG. 11 shows a plunger tip wrench 90 installed on the cartridge mounting member 18.

0023In the illustrated embodiment, the plunger tip wrench 90 is fixed onto the cartridge mounting member 18 in the same manner as the insertion cartridge 20. In certain embodiments, the plunger tip 25 is automatically installed on the plunger 32 in response to user activation in the installation mode. For example, after the user presses the appropriate button on the device or on the attached operator console, the plunger 32 is activated at a default speed so that the plunger is elastically fitted into the disposable sleeve. Plunger. Following this activation, the plunger 32 contracts to its original starting position at the default speed. The squeeze pulls the plunger tip 25 out of the plunger tip wrench 90, which can then be removed and replaced by the loaded IOL insertion cartridge 20. As discussed in more detail below, both operations can be automatically terminated in response to monitoring of the counter electromotive force (often referred to as "reverse EMF") generated by the rotating electric motor 42. ..

0024In certain embodiments in which the disposable plunger tip 25 is used, the plunger tip 25 and the insertion cartridge 20 are provided with a specific structure such that the plunger tip 25 is automatically removed from the plunger 32 after use. obtain. In some of these embodiments, for example, the plunger tip 25 is designed to engage the corresponding capture on the insertion cartridge 20 when the end of the plunger tip 25 has completely passed through the insertion cartridge 20. It may have one or more "teeth" or other protrusions. Once engaged, such a detent mechanism provides sufficient resistance to backward movement of the plunger tip 25 so that the disposable sleeve itself is released from the plunger. When the plunger 32 is completely contracted, the insertion cartridge 20 and the plunger tip 25 can be removed from the IOL introducer as a unit and discarded.

0025FIG. 14 shows a typical detent mechanism as discussed above. FIG. 14 (a) provides a plan view of the plunger tip 25 fully inserted into the insertion cartridge 20, while FIG. 14 (b) provides a collaborative detent on the plunger tip 25 and the insertion cartridge. A typical detent mechanism 140 having a specific detent structure is shown. In the preferred embodiment of FIG. 14B, when the plunger tip 25 is in its fully extended position, the protrusion from the plunger tip 25 engages the lower lip of the insertion cartridge 20.

0026FIG. 12 shows a typical control circuit 100 according to a certain embodiment of the present invention that controls the operation of the IOL-introduced device. The illustrated control circuit 100 is for a three-phase brushless DC motor 42 that includes a Hall effect sensor 104. Although not shown in FIG. 12, in certain embodiments the motor 42 may provide a neutral reference point; one of ordinary skill in the art will appreciate that the presence of a neutral endpoint simplifies the measurement of inverse EMF. It can, but it is not absolutely necessary. Those skilled in the art will appreciate that in any case, the circuit of FIG. 12 can be easily adapted to different types of motors, including brushed motors. In particular, those skilled in the art will appreciate that techniques for controlling brushless DC motors without the use of Hall effect sensor feedback are known.

0027The control circuit 100 includes a control processor 95 that generates a pulse width modulation (PWM) control signal for rectifying the motor 42, and an analog drive that applies the digital control signal to the stator winding inputs A, B, and C. It includes a drive circuit 98 that converts it into a signal. The control circuit 100 further includes a sampling circuit 97 that detects inverse EMF signals from the motor rotor inputs A, B and C; in certain embodiments, the sampling circuit 97 controls the voltage at the motor input. Includes an analog-to-digital converter that converts to a digital signal for use by processor 95. In certain embodiments, the sampling circuit 97 can be synchronized with the PWM control signal generated by the control processor 95, so that the inverse EMF for a given rotor input is when the drive signal for that input is floating. Only sampled. However, one of ordinary skill in the art will appreciate that in other embodiments the motor input can be sampled over the entire duty cycle and the inverse EMF signal is separated by digital processing in the control processor 95. Those skilled in the art will also understand that the sampling circuit 97 may also include a low pass filter for each of the motor input signals in certain embodiments, but such low frequencies when the motor is operating at high speed. It will be understood that the delay caused by the pass filter should be taken into account.

0028In the illustrated embodiment, the control processor 95 accesses the signals from the Hall effect sensor 104; these sensor outputs provide an indication of the rotor position of the motor as well as timing the PWM signal according to prior art. It can be used by the control processor 95 to control. Alternatively, zero crossover of the inverse EMF signal can be detected and the zero crossover time is used to synchronize the PWM signal that controls the current applied to the motor. Again, techniques for starting and controlling sensorless brushless motors using reverse EMF signals are known. Some of these techniques are, for example, in September 2003 by Janwen Xiao of Virginia Tech in Blacksburg, Virginia, "Direct Detection of Reverse EMF for Brushless DC (BLDC) Motor Drives Without Sensors. Back EMF Detection Method for Sensorless Brushless DC (BLDC) Motor It is described in a master's thesis entitled "Drives]" (available at http://scholar.lib.vt.edu/theses/available/etd-09152003-171904/unrestricted/T.pdf).

0029In certain embodiments of the invention, the reverse EMF can also be monitored and used to detect failures in the operation of the IOL-introduced device. For example, depending on the geometry of the intraocular lens and the volume of the viscoelastic body introduced into the insertion cartridge, a properly loaded cartridge will have a unique intrinsic viscous resistance to the plunger. Therefore, a known load is applied to the motor. Unloaded cartridges also have unique load characteristics that are distinguishable when compared to loaded cartridges. Due to the relationship between torque and speed in a DC motor, an increase in load is reflected in a decrease in motor speed for a given drive level. Conversely, the decrease in load is reflected in the increase in motor speed. Since the reverse EMF of a motor is directly proportional to the rotational speed of the motor, the level of the reverse EMF can be monitored to determine the speed of the motor and thus the applied load. By comparing the inverted EMF level monitored at a given moment with a given threshold, the control processor 95 can detect whether the motor is operating at the expected speed. Thus, the control processor may detect failures in operation, respond automatically (eg by shutting down), and / or provide feedback to the user.

0030For example, a cartridge that contains less viscoelastic material than is required in the loading cartridge results in an inverse EMF that is greater than expected, in which case the control processor 95 alerts the user. obtain. Conversely, when the inverse EMF value is smaller than the expected level, it suggests a clogged cartridge. Here, too, the operation of the device can be stopped and appropriate warnings can be provided to the user. Naturally, "normal" operation falls within a predetermined inverse EMF level. Therefore, two separate thresholds can be used to detect excess resistance to translation of the plunger forward and to detect inadequate resistance to translation of the plunger. (In certain embodiments, multiple separate thresholds may be applied for the opposite translation of the plunger.) The difference between these two thresholds defines the range of normal operation.

0031As discussed above, the magnitude of the inverse EMF level is directly proportional to the speed of the motor and can be used to directly monitor the speed of the motor, thus loading the load, i.e. the resistance to translation of the plunger. Can be used to indirectly monitor. Alternatively, the speed of the motor can be monitored using the reverse EMF by counting the number of zero crossings of the reverse EMF at a given time interval. This technique effectively counts the rotation of the motor; because of the fixed relationship (defined by the transmission and the threads of each of the coupling mechanisms) between the motor and the linear translation. , The number of revolutions of the motor at a predetermined time interval is directly proportional to the speed. This evaluation rate can be compared to a predetermined threshold in the same manner as discussed above to detect impaired movement.

0032In certain embodiments of the present invention, counting the zero intersections in which the reverse EMF faces in the positive and negative directions provides an additional advantage, because the longitudinal position of the plunger is always in place. This is because it can be tracked. Since the total number of net cumulative zero intersections is directly proportional to the linear translation distance of the plunger, the longitudinal position of the plunger within the device is given a calibrated reference point at any time. Can be decided. This calibrated reference point can be defined at the time of manufacture in certain embodiments or at the time of use in other embodiments. For example, the user may be instructed to fully deflate the plunger and then press the calibration button to set a "zero" position with respect to the plunger. Alternatively, any of the methods described above may be used to automatically detect a "hard stop" after the plunger contracts to represent the "zero" position of the plunger.

0033In an embodiment of the invention that monitors the longitudinal position of the plunger, the tracking position information can be used in conjunction with the inverse EMF level at a given time point to detect one or more failure states. For example, the plunger engages the insertion cartridge only over a specific range of known lateral positions. In other cases, for example, when the tip of the plunger is close to the cartridge, the plunger is expected to move with little resistance. The single or multiple thresholds used to detect a fault vary depending on the lateral position of the plunger to provide more accurate and / or more informative fault detection. For example, the threshold for detecting insufficient resistance of the plunger to motion corresponds to a predetermined range of lateral positions, which corresponds to zero resistance to a predetermined range in which free motion of the plunger is expected. Can be set to level. Over that same range, the threshold for detecting excess resistance can be set to a level corresponding to a resistance level that is somewhat lower than expected when the plunger begins to engage the insertion cartridge. .. For the lateral position where the plunger is fully engaged with the cartridge, both thresholds can be adjusted to accommodate even higher resistance levels.

0034Similarly, the threshold level may be changed depending on the direction of the plunger movement and / or between two or more modes of operation. For example, as described above, in certain embodiments, a separate operating mode may be defined for the installation of the detachable plunger tip. In this installation mode, each failure detection threshold is determined by the resistance expected when the push rod of the plunger assembly engages the plunger tip and the plunger tip being extracted from the plunger tip wrench. It can be quite different from the normal operating mode to take into account the expected rear resistance when

0035In certain embodiments of the invention, one or more of the thresholds discussed above are predetermined, for example by factory calibration, and stored in the control processor 95 or in memory accessible to the processor. To. (For those skilled in the art, this memory can consist of a program memory or a separate memory that stores factory-determined parameters, etc., as well as some conventional memory formats such as ROM, PROM, EEPROM, flash, etc. Understand that it can consist of any form of). In certain embodiments, the threshold used during operation may be adjusted for a "no-load" reverse EMF level determined at the start of the motor, or a corresponding "no-load" rotational speed. As briefly discussed earlier, this is a short time interval for each reversal of direction, during which the drive system of the IOL introducer is not engaged with the plunger. It can be facilitated by designing the drive system so that the drive system has an interval. One design method is shown in Figure 8 (b) and discussed above. In such embodiments, "no-load" levels for reverse EMF or velocity can be measured and used to establish reference levels. This reference level can be used to scale and / or convert the stored threshold level to obtain a more accurate operational threshold.

0036With the above considerations in mind, those skilled in the art would appreciate that the processing flowchart of FIG. 13 is a method of controlling an intraocular lens-introducing device according to any of the above mechanical configurations and examples of modifications thereof. It will be understood that the embodiment is shown. Those skilled in the art will also understand that this particular processing flow is not intended to be limiting and that many modifications of this method that fall within the scope of the present invention will be apparent in light of the above considerations. Let's do it. Further, for those skilled in the art, the processing flow of FIG. 13 is program memory in or associated with the control processor 95, such as read-only memory (ROM), programmable read-only memory (PROM). It can be understood that it can be performed in memory-stored software or firmware that can consist of one or more of various conventional formats such as flash memory, magnetic or optical memory devices.

0037In either case, the processing flow shown in FIG. 13 starts with the IOL-introduced device in the non-operating state. As shown in block 210, the device checks for user input indicating that the launch of the plunger assembly should be initiated. This user input is a keypad or touch screen on the operator console that is cabled to the IOL-introduced device, or a foot-operated switch that is electrically connected to the IOL-introduced device by cable or console. Alternatively, it may be derived from any of a number of conventional user input devices, such as one or more switches or buttons on the body of the IOL-introduced device itself. In either case, as shown in block 220, the control circuit initiates translation of the plunger in the indicated direction in response to user input indicating that the plunger assembly should be moved.

0038As shown in block 230, as the plunger is moved, the reverse EMF from the electric motor is monitored according to any of the techniques discussed above. In certain embodiments, the magnitude of the inverse EMF level is monitored and compared to one or more predetermined thresholds. In other embodiments, zero intersection of the inverse EMF with respect to a given time interval is detected and counted to obtain an indication of the plunger speed and is compared to one or more given thresholds. If a failure condition is detected, as shown in block 240, the movement of the plunger is immediately stopped as shown in block 260. As discussed above, the detected fault condition is either excessive resistance to forward or backward movement of the plunger when compared to a predetermined threshold level, or anterior or posterior to the plunger when compared to a predetermined threshold level. Can cope with inadequate resistance to backward movement. In any of these cases, the threshold level for fault detection can be changed according to the tracked longitudinal position of the plunger as discussed above. In addition, the operating threshold level can be adjusted according to the reference resistance or operating speed determined in the "no load" state.

0039In certain embodiments, stopping the movement of the plunger in response to a detected failure is accompanied by or follows an alarm indicating the failure to the user. In certain cases, a message indicating a particular type of failure (eg, "cartridge jam", "unloaded cartridge", etc.) may be provided to the user via a graphical user interface on the operator console. If no failure condition is detected in block 240, then the status of user input is checked, as shown in block 250. If the user input indicates that the movement of the plunger should be stopped, then the motor is deactivated and the translation of the plunger is stopped, as shown in block 260. In other cases, the user inputs that the translation of the plunger continues as shown in block 220 and that the above operation should be stopped until a failure occurs or the movement of the plunger assembly should be stopped. Iterates until it is represented.

0040In the above discussion of the processing flow of FIG. 13, it was assumed that once the plunger was started, it would continue until the user input instructed it to stop or until a failure condition was detected. Those skilled in the art will appreciate that the operation of the plunger may be restricted by a mechanical stop at either or both ends. In certain embodiments, these mechanical stops can be detected by the same fault detection mechanism as described above, i.e. by monitoring the reverse EMF level and / or motor speed. Alternatively, according to certain embodiments, tracking the longitudinal position of the plunger as described above prevents the plunger from reaching the mechanical stop and allows the plunger to reach the mechanical stop. The movement of the plunger may be automatically stopped before reaching.

0041Previous descriptions of intraocular lens-introduced devices and various embodiments of methods using such devices have been given for illustration and exemplary purposes. Of course, one of ordinary skill in the art will understand that the invention can be practiced in a manner other than those detailed herein without departing from the essential properties of the invention. Yeah. Therefore, each current embodiment is considered to be non-limiting but exemplary in all respects, and all changes that fall within the meaning and equality of the appended claims are said to be such. It is intended to be included within the meaning and equality.