The present invention relates to phacoemulsification systems and more particularly to a system for regulating pressures in the eye during phacoemulsification surgeries.
In the United States, the majority of surgically treated cataractous lenses are treated by a surgical technique called phacoemulsification. A typical surgical hand piece suitable for phacoemulsification procedures consists of an ultrasonically driven phacoemulsification hand piece, an attached hollow cutting needle surrounded by an irrigating sleeve, and an electronic control console. The hand piece assembly is attached to the control console by an electric cable and flexible tubing. Through the electric cable, the console varies the power level transmitted by the hand piece to the attached cutting needle. The flexible tubing supplies irrigation fluid to the surgical site and draws aspiration fluid from the eye through the hand piece assembly.
During a phacoemulsification procedure, the tip of the cutting needle and the end of the irrigation sleeve are inserted into the anterior segment of the eye through a small incision in the eye's outer tissue. The surgeon brings the tip of the cutting needle into contact with the lens of the eye, so that the vibrating tip fragments the lens. The resulting fragments are aspirated out of the eye through the interior bore of the cutting needle, along with irrigation fluid provided to the eye during the procedure, and into a waste reservoir.
Throughout the procedure, irrigating fluid is pumped into the eye, passing between the irrigation sleeve and the cutting needle and exiting into the eye at the tip of the irrigation sleeve and/or from one or more ports or openings formed into the irrigation sleeve near its end. This irrigating fluid is critical, as it prevents the collapse of the eye during the removal of the emulsified lens. The irrigating fluid also protects the eye tissues from the heat generated by the vibrating of the ultrasonic cutting needle. Furthermore, the irrigating fluid suspends the fragments of the emulsified lens for aspiration from the eye.
Conventional systems employ fluid-filled bottles or bags hung from an IV pole as an irrigation fluid source. Irrigation flow rates, and corresponding fluid pressure at the eye, are regulated by controlling the height of the IV pole above the surgical site. For example, raising the IV pole results in a corresponding increase in irrigation flow rate and a corresponding increase in fluid pressure at the eye. Likewise, lowering the IV pole results in a corresponding decrease in the irrigation flow rate and a corresponding lower pressure at the eye.
Aspiration flow rates of fluid from the eye are typically regulated by an aspiration pump in fluid communication with the aspirating interior bore of the cutting needle. The aspiration flow is monitored to control the pump and regulated to achieve a proper balance with the irrigation flow in an effort to maintain a relatively consistent fluid pressure at the surgical site within the eye.
While a consistent fluid pressure in the eye is desirable during the phacoemulsification procedure, common occurrences and complications create fluctuations in fluid flow and pressure at the eye. For example, varying flow rates result in varying pressure losses in the irrigation fluid path from the irrigation fluid supply to the eye, thus causing changes in pressure in the anterior chamber (also referred to as Intra-Ocular Pressure or IOP). Higher flow rates result in greater pressure losses and lower IOP. As IOP lowers, the operating space within the eye diminishes.
Blockages or occlusions of the aspirating needle also are common occurrences and procedural techniques affecting the fluid pressure at the eye during the phacoemulsification process. As the irrigation fluid and emulsified tissue are aspirated away from the interior of the eye through the hollow cutting needle, pieces of tissue that are larger than the diameter of the needle's bore may occlude the needle's tip. While the tip is occluded, vacuum pressure builds up within the tip. The drop in pressure in the anterior chamber in the eye, caused by a relatively large quantity of fluid and tissue to be aspirated out of the eye too quickly when the occlusion is removed, can potentially result in eye collapse and/or cause the lens capsule to be torn.
Various techniques have been designed to control the pressures at the eye and to reduce the surge during a phacoemulsification process. However, there remains a need for improved phacoemulsification devices that maintain a stable IOP throughout varying flow conditions. The present disclosure is directed to addressing one or more of the deficiencies in the prior art.
In one embodiment consistent with the principles of the present invention, the present invention is a phacoemulsification fluidics system for irrigating and aspirating a surgical site. The system includes a sterile solution reservoir, an irrigation path configured to extend from the sterile solution reservoir to the surgical site, and an aspiration path configured to extend from the surgical site. The system also includes a single flow control pump head associated with both the irrigation path and the aspiration path. The flow control pump head is arranged within the system to simultaneously pressurize the irrigation path in a manner that drives the irrigation fluid to the surgical site and pressurize the aspiration path in a manner that vacuums waste fluid from the surgical site.
In another embodiment consistent with the principles of the present invention, the present invention is a phacoemulsification fluidics system for irrigating and aspirating a surgical site. The system includes an irrigation path configured to extend to the surgical site, an aspiration path configured to extend from the surgical site, and a control system configured to regulate fluid flow to the surgical site. The control system includes a flow control pump head associated with both the irrigation path and the aspiration path. The flow control pump head is configured to simultaneously pump fluid through both the irrigation path and the aspiration path. The control system also includes at least one flow control shunt valve configured to control flow through at least one of the irrigation and aspiration path and at least one sensor configured to detect a parameter of fluid in at least one of the irrigation and aspiration paths. The control system also includes a controller in communication with the flow control pump head, the at least one flow control shunt valve, and the at least one sensor. The controller is structurally configured to receive data indicative of the detected parameter from the at least one sensor and structurally arranged to communicate control signals to the at least one flow control shunt valve based on the received data from the at least one sensor.
In another embodiment consistent with the principles of the present invention, the present invention is a phacoemulsification surgical console. The console includes an ultrasonic generator subsystem comprising an ultrasonic oscillation handpiece including a cutting needle. The handpiece is configured to emulsify a lens in an eye. The console also includes a fluidics subsystem. The fluidics subsystem includes a sterile solution reservoir, an irrigation path associated with the ultrasonic oscillation handpiece and configured to extend from the sterile solution reservoir to the surgical site, and an aspiration path associated with the ultrasonic oscillation handpiece and configured to extend from the surgical site. The fluidics subsystem also includes a single peristaltic pump head associated with both the irrigation path and the aspiration path. The peristaltic pump head is arranged within the system to pressurize the irrigation path in a manner that drives the irrigation fluid to the surgical site and being arranged within the system to create a vacuum in the aspiration path in a manner that vacuums waste fluid from the surgical site.
In one aspect consistent with the principles of the present invention, the present invention is a method of operating a fluidics subsystem of a phacoemulsification system. The method includes the steps of detecting a parameter of a fluid in an irrigation path of a phacoemulsification system, detecting a parameter of a fluid in an aspiration path of a phacoemulsification system, and controlling fluid flow through the irrigation and aspiration paths with a single flow control pump head associated with both the irrigation path and the aspiration paths.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The following description, as well as the practice of the invention, sets forth and suggests additional advantages and purposes of the invention.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
Reference is now made in detail to the exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.
The phacoemulsification systems and methods described herein provide and control both irrigation and aspiration during an emulsification procedure with a single flow control pump head. These systems and methods provide independent control of positive irrigation pressure and negative aspiration pressure while simplifying product manufacturing and reducing manufacturing costs, while providing simplicity and effective control without compromising surgical results.
In addition, during periods of pressure variations, including for example, during needle occlusion or leakage, the systems and methods described herein compensate for these variations. Particularly, as described below with reference to the examples herein, a controller and control shunt valves recirculate or drain excess fluid in a manner that compensates for these pressure variations in the irrigation and aspiration flow paths. Accordingly, the systems and methods disclosed herein provide a level of consistency and repeatability while maintaining control of the system to achieve satisfactory surgical results.
The irrigation path 306 extends between the sterile solution reservoir 302 and the surgical site (labeled in
The aspiration path 308 extends from the surgical site or eye to the drain reservoir 304. The aspiration path 308 carries away fluid used to flush the eye as well as any emulsified particles. Like the irrigation path, in
In some embodiments, the fluidics system 110 is arranged to provide a higher fluid volume along the irrigation path 306 than along the aspiration path 308. This may be accomplished in a variety of ways, including for example, using a larger diameter fluid line in the irrigation path than a fluid line in the aspiration path as is shown in
The single flow control pump head 310 is associated with both the irrigation and aspiration paths 306, 308. In the embodiment shown, the pump head operates in a manner that pumps fluid at an equal motor rate through both the irrigation path 306 and the aspiration path 308. In the embodiment disclosed herein, the flow control pump head 310 is a peristaltic pump head, and more particularly, a rotary peristaltic pump head having rollers that induce fluid flows in both the irrigation and aspiration paths 306, 308 to simultaneously pump fluid at the same speed through both paths. In the embodiment shown, the pump head 310 is configured to provide feedback data indicative of the speed of its operation. This feedback may be used to further control the pump to provide a desired fluid flow through the irrigation and aspiration paths 306, 308.
The irrigation and aspiration sensors 316, 318 perform the function of detecting any high pressure or vacuum conditions in the irrigation and aspiration paths 306, 308, respectively. In some embodiments, the sensors 316, 318 are pressure sensors configured to detect current pressure conditions. These sensors 316, 318 may communicate signals indicative of the sensed pressures to the controller 320. Once received, the controller 320 processes the received signals to determine whether the pressure is above or below pre-established desired thresholds, or within a pre-established desired range. Although described as pressure sensors, the irrigation and aspiration pressure sensors 316, 318 may be other types of sensors, such as flow sensors that detect actual flow past the sensors and may include additional sensors for monitoring additional parameters. In some embodiments each sensor includes its own processing function and the processed data is then communicated to the controller 320.
With reference to
Similarly, the aspiration path 308 is in communication with a vacuum pressure relief line 324. In the embodiment shown, the vacuum pressure release line 324 fluidly communicates with the aspiration path 308 to draw additional fluid between the eye and the pump head 310 to vary the fluid flow from the eye. In use, the aspiration flow control shunt valve 314 may be actuated to vary fluid flow into the aspiration path 308 from the vacuum relief line 324 when undesired vacuum pressure levels are detected at the aspiration pressure sensor 318.
The irrigation and aspiration flow control shunt valves 312, 314 are respectively associated with the pressure relief line 322 and the vacuum pressure relief line 324 and regulate the pressure in the irrigation and aspiration paths 306, 308. Accordingly, the irrigation and aspiration flow control shunt valves 312, 314 are associated with the irrigation and aspiration paths 306, 308 in a manner that controls fluid flow and modifies the fluid pressure in those paths. In some embodiments, the shunt valves 312, 314 are adjustable valves, although other valve types may be used. The first and second flow control shunt valves 312, 314 communicate with and are controlled by the controller 320 in order to provide desired fluid flow to the surgical site.
The controller 320 may include a processor and memory and may be configured or programmed to control the flow control system 300 based upon pre-established programs or sequences. In addition to controlling the flow control system 300, the controller 320 may cooperate with the footpedal subsystem 106 or other subsystem in
In use, the controller 320 is configured to receive signals from the irrigation and aspiration pressure sensors 316, 318, and process the signals to determine whether the detected parameters are outside of preset acceptable ranges or above or below preset acceptable thresholds. Based upon the received signals, the controller 320 controls the irrigation and aspiration flow control shunt valves 312, 314 to increase or decrease flow through the relief lines 322, 324 to either maintain or adjust the pressures in the irrigation and aspiration paths 306, 308 to the desired levels. In some embodiments, the controller 320 also controls the flow control pump head 310 based on preset instructions. In some embodiments, the pump head is controlled based upon the data gathered by the irrigation and aspiration pressure sensors 316, 318 and/or any of the other subsystems in
At a step 406, the controller 320 determines whether the irrigation pressure in the irrigation line 306 is at the commanded level. The irrigation pressure is detected by the irrigation pressure sensor 316. The commanded level is the level corresponding to a desired pressure set by the user. If the irrigation pressure is not at the commanded level at step 406, then the controller 320 is configured to control the fluidics subsystem 110 correct the deviation between the irrigation pressure and the commanded level. To do this, at a step 408, the controller 320 compares the detected irrigation pressure to the commanded pressure to determine whether the irrigation pressure is greater than the commanded pressure. In the embodiment described, this is accomplished by comparing signals or data obtained by and communicated from the irrigation pressure sensor 316 to the controller 320 with the user setting stored in the controller 320.
If the irrigation pressure is greater than the commanded pressure, then at step 410, the controller adjusts the irrigation flow control shunt valve 312 to increase the state or adjust toward a more open position, thereby permitting some fluid flow in the irrigation line to shunt into the pressure relief line 322. This decreases the percentage of total flow directed to the irrigation pressure sensor 316 and the surgical site and simultaneously increases the percentage of fluid flow flowing through the pressure relief line 322. Decreasing the total irrigation flow towards surgical site results in decreased fluid pressure at the surgical site.
If the irrigation pressure is less than the commanded pressure at step 408, then the controller 320 controls the irrigation flow control shunt valve 312 to decrease the state or adjust to a more closed position at step 416. This increases the percentage of total fluid flow being directed to the irrigation pressure sensor 316 and the surgical site. It simultaneously decreases the percentage of fluid flow flowing through the pressure relief line 322. Increasing the total irrigation flow towards the surgical site results in a higher fluid pressure at the surgical site. After adjusting the irrigation shunt valve at either step 410 or step 412, the method proceeds to step 414.
Returning to step 406, if the irrigation pressure is at the commanded level, then the method proceeds to step 414.
At step 414, the controller 320 determines whether the vacuum pressure in the aspiration path 308 is at the vacuum commanded level. The vacuum pressure is detected by the aspiration pressure sensor 318. The vacuum commanded level is the level corresponding to a desired input set by the user via the on-screen interface controls or the foot pedal 108, or combination of both. If the vacuum pressure is not at the commanded level at step 414, then the controller 320 is configured to control the fluidics subsystem 110 correct the deviation between the vacuum pressure and the commanded level. To do this, at a step 416, the controller 320 compares the detected vacuum pressure to the commanded vacuum pressure to determine whether the vacuum pressure is greater than the commanded vacuum pressure. In the embodiment described, this is accomplished by comparing signals or data obtained by and communicated from the aspiration pressure sensor 318 to the controller 320 with the user setting stored in the controller 320.
If the vacuum is greater than the commanded vacuum level at step 416, then the controller 320 controls the aspiration flow control shunt valve 314 to increase the state or adjust to a more open position at step 418. This decreases the percentage of total flow from the surgical site and simultaneously increases the percentage of fluid flow being drawn from the pressure relief line 324. Drawing less fluid directly from the surgical site results in an increase in the overall pressure (and a decreased vacuum) being detected by the aspiration pressure sensor 318.
If the vacuum is not greater than the commanded vacuum level at step 416, then the controller 320 controls the aspiration flow control shunt valve 314 to decrease the state or adjust the aspiration flow control shunt valve 314 to a more closed position at step 420. This increases the percentage of total fluid flow being drawn from the surgical site, and simultaneously decreases the percentage of fluid flow being drawn from the pressure relief line 324. Drawing more fluid directly from the surgical site results in a decrease in the overall pressure (and an increased vacuum) being detected by the aspiration pressure sensor 318.
Returning to step 414, if the vacuum pressure is at the commanded level, then the method returns to step 406 to monitor and control the irrigation shunt valve. Thus, the described process acts as an infinite loop by returning to step 406, such that the controller 320 continuously control the irrigation and aspiration flow control shunt valves 312, 314 based on the data from the irrigation and aspiration pressure sensors 316, 318.
One skilled in the art will recognize that additional flexibility may be achieved by controlling the pump motor speed along with controlling the shunt valves to increase or decrease flow and pressures in the irrigation and aspiration lines.
As described above, in some embodiments, the system is arranged to have more fluid than surgically necessary drawn through the irrigation path 306. It also may be arranged to draw more fluid through the irrigation path 306 than through the aspiration path 308. By drawing excess fluid through the irrigation path 306, the irrigation flow control shunt valve 312 may be continuously maintained in a partially open condition, thereby continuously being able to be controlled to increase or decrease fluid flow through the pressure relief line to vary the pressure in the irrigation path 306. Further, the system can therefore compensate for variations in the pressures caused by changes in flow rate, occlusions, or leakage of the fluid from the surgical site or else respond to changes in set pressure based on user inputs. These variations typically cause corresponding variations in the pressure levels of the irrigation and aspiration paths. Controlling the flow control shunt valves 312, 314 based on the detected pressures decreases the chance of complications resulting in the collapse of the eye.
It should be appreciated that although several different embodiments are shown, any of the features of one embodiment may be used on any of the other embodiments shown. Accordingly, any of these embodiments may include relief lines that extend to the solution reservoirs or to a fluid line or path. In some embodiments, the relief lines connect to the fluid paths near the pump head. In embodiments using a cassette, the relief lines may also be included within the cassette itself. In addition, while several embodiments are shown, still others are contemplated that include alternative arrangements of the shunt valves and connection locations of the relief lines.
From the above, it may be appreciated that the present invention provides a fluidics system having a single pump head irrigation and aspiration system for phacoemulsification surgery.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.