Patent Description:
Microsurgical procedures frequently require precision cutting and/or removing various body tissues. For example, certain ophthalmic surgical procedures require cutting and removing portions of the vitreous humor, a transparent jelly-like material that fills the posterior segment of the eye. The vitreous humor, or vitreous, is composed of numerous microscopic fibrils that are often attached to the retina. Therefore, cutting and removing the vitreous must be done with great care to avoid traction on the retina, the separation of the retina from the choroid, a retinal tear, or, in the worst case, cutting and removal of the retina itself. In particular, delicate operations such as mobile tissue management (e.g. cutting and removal of vitreous near a detached portion of the retina or a retinal tear), vitreous base dissection, and cutting and removal of membranes are particularly difficult.

During vitreoretinal surgery as e.g. disclosed in Document <CIT>, a viscous fluid, such as a liquid tamponade (e.g., silicone oil or perfluoron) may be used to seal retinal tears and allow for scar formation. The user/surgeon may control the injection of the liquid tamponade via a foot pedal and may provide the pressure required to push the relatively viscous liquid tamponade (e.g., about <NUM>,<NUM> cP silicone oil) through a trocar cannula into the vitreous chamber. If the user/surgeon becomes distracted during the filling process, the liquid tamponade may overfill the vitreous chamber and generate unacceptable high intraocular pressure (IOP) in the vitreous chamber. Similarly, in a liquid tamponade extraction procedure, the high viscosity of the liquid tamponades may render it difficult to extract. This may undesirably lead to sustained or prolonged high intraocular pressure in the eye. Thus, there is a need for improved ophthalmic surgical devices, systems, and methods.

In some exemplary aspects, the present disclosure is directed to an ophthalmic surgical system that includes viscous fluid control system for automating the injection and extraction of liquid tamponades in a patient's eye during an ophthalmic surgical procedure. The system may include a syringe pump connected to an actuation line. The syringe pump may provide pressures for viscous fluid injection into or extraction from a vitreous chamber of an eye of a patient through the actuation line. The system also may include a controller that receives sensor data relating to an IOP of the eye and controls the syringe pump to regulate the viscous fluid injection or extraction based on a comparison of the IOP to a pressure threshold value.

In some implementations, the controller may also determine whether the IOP is above an upper threshold and control the syringe pump to reduce or stop an injection pressure in response to the IOP being above the upper threshold. The controller further may determine whether the IOP is below a lower threshold and control the syringe pump to reduce or stop an extraction pressure in response to the IOP being below a lower threshold.

Some implementations include a foot pedal system that receives user input for controlling the injection/extraction of the viscous fluid in the eye. The controller may control the syringe pump based on the user input received at the foot pedal system when the IOP is below an upper threshold and above a lower threshold. When the IOP is above the upper threshold or below the lower threshold, the controller may override the user input received from the foot pedal system.

In additional exemplary aspects, the present disclosure is directed to an ophthalmic surgical system that may include an actuation line, an infusion line, a powered syringe, and a console for regulating injection or extraction of viscous fluid in a patient's eye during an ophthalmic surgical procedure. The infusion line may have a proximal end, a distal end, and an infusion passage extending therethrough, and the distal end of the infusion line may be configured to enter into a vitreous chamber of the patient's eye. The actuation line may have a proximal end and a distal end. The powered syringe may be coupled to the distal end of the actuation line. The console may be coupled to the proximal end of the infusion line and the proximal end of the actuation line, and may include a syringe pump, an infusion chamber, an infusion pump, and a controller. The syringe pump may be configured to provide pressures for viscous fluid injection or extraction in the vitreous chamber. The infusion chamber may be in fluid communication with the infusion passage, and the infusion pump may be configured to provide low viscosity fluid infusion from the infusion chamber to the vitreous chamber through the infusion passage. The controller may be configured to receive sensor data relating to an IOP of the patient's eye, and regulate the viscous fluid injection/extraction based on a comparison of the IOP to a pressure threshold value.

In some implementations, the system may further include one or more sensors disposed adjacent to and/or in the patient's eye. The one or more sensors may be configured to detect, at a location adjacent to and/or in the patient's eye, the IOP and generate and provide the sensor data to the controller. For example, the one or more sensors may be disposed adjacent to and/or at the distal end of the infusion line.

In another exemplary aspect, the present disclosure is directed to a method of treating an ophthalmic condition. The method may include receiving sensor data from a sensor adjacent to or in an eye of a patient and monitoring an intraocular pressure (IOP) of the eye based on the sensor data. The method may further include determining whether the IOP is above an upper threshold or below a lower threshold. The method may also include, in response to determining that the IOP is above the upper threshold, stopping or reducing a viscous fluid injection, and in response to determining that the IOP is below the lower threshold, stopping or reducing a viscous fluid extraction.

It is to be understood that both the foregoing general description and the following drawings and detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following.

The accompanying drawings illustrate embodiments of the devices, systems, and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure.

These figures will be better understood by reference to the following Detailed Description.

For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, systems, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.

The present disclosure relates generally to devices, systems, and methods for automating the injection and removal of liquid tamponades in a patient's eye based on an intraocular pressure (IOP) as detected at a location adjacent to or in a patient's eye during ophthalmic surgical procedures. Pressure changes and excessively low or high pressures can complicate the performance of such procedures, putting the patient at risk. In some aspects described herein, an infusion line may include sensors, such as a pressure sensor and/or a flow rate sensor disposed adjacent to or at a distal end, that enter into a vitreous chamber of the patient's eye. The devices, systems, and methods disclosed herein may enable a surgeon to better monitor important pressures and to react quickly to pressure spikes or drops that arise during an ophthalmic surgical procedure. Further, the system may automatically adjust the injection/extraction of the liquid tamponade in response to the detected IOP. By improving the surgeon's abilities or by enabling the system to respond to pressure conditions during an ophthalmic surgical procedure, outcomes for patients may be improved.

<FIG> illustrates an ophthalmic surgical system <NUM> according to an exemplary embodiment. The surgical system <NUM> may include a console <NUM> that has a mobile base housing <NUM>, an associated display screen <NUM> that may show data relating to system operations and performance during an ophthalmic surgical procedure, and a foot pedal <NUM> in communication with the console <NUM>. The surgical system <NUM> also may include a hand piece <NUM> that may be utilized during an ophthalmic surgical procedure. Depending on the implementation, the hand piece <NUM> may be, for example, a vitrectomy cutter hand piece, an ultrasonic hand piece, an aspiration hand piece, a powered/active syringe or other hand piece. The surgical system <NUM> may also include an actuation line <NUM> having a proximal end coupled to the console <NUM> and a distal end coupled to the hand piece <NUM>, and an infusion line <NUM> having a proximal end coupled to the console <NUM> and a distal end <NUM> having an infusion tip <NUM> configured to enter into a vitreous chamber of a patient's eye. The surgical system <NUM> may also include at least one IOP sensor <NUM>, which may include, for example without limitation, a pressure sensor and/or a flow rate sensor. The IOP sensor <NUM> may be disposed adjacent to the distal end <NUM> of the infusion line <NUM> as shown in <FIG>. Alternatively, or in addition, the IOP sensor <NUM> may be disposed at the distal end <NUM> of the infusion line <NUM> and/or at a distal end of the hand piece <NUM> and configured to enter into the vitreous chamber of the patient's eye, as shown in <FIG>.

The console <NUM> of the surgical system <NUM> includes features that allow for control of the hand piece <NUM>. For example, the actuation line <NUM> may include pneumatic and/or electrical supply lines to couple the hand piece <NUM> to the console <NUM>. The actuation line <NUM> may facilitate control and monitoring of the hand piece <NUM> by transmitting data between the hand piece <NUM> and the console <NUM>.

The console <NUM> of the surgical system <NUM> further includes features that allow communication of sensor data between the IOP sensor <NUM> and the console <NUM>. For example, the infusion line <NUM> may include electrical supply lines to couple the IOP sensor <NUM> to the console <NUM>. The infusion line <NUM> may facilitate taking measurements at the IOP sensor <NUM> by transmitting data between the IOP sensor <NUM> and the console <NUM>.

The console <NUM> further includes a computer system (<FIG>) that may include one or more processors in communication with a memory having computer instructions to control the hand piece <NUM>, display information on the screen <NUM>, and receive and process input commands and data. The surgical system <NUM> may include a network interface for communication with a network. These features facilitate control and monitoring of the hand piece <NUM> during operation. Additionally, these features may facilitate the monitoring, data processing, and control for the IOP sensor <NUM>. Some embodiments of the surgical system <NUM> further include a pressure sensor <NUM> disposed on or about the mobile base housing <NUM> to sense an ambient pressure. This ambient pressure may be atmospheric pressure.

Some aspects of the surgical system <NUM>, such as the hand piece <NUM>, the infusion line <NUM>, and the IOP sensor <NUM>, are described in further detail in <CIT>, entitled "Pressure-Sensing Vitrectomy Surgical Systems and Methods".

<FIG> is a block diagram of the surgical system <NUM> of <FIG> showing various subsystems. The console <NUM> includes a computer system <NUM>, which includes a controller <NUM> and a memory <NUM>. The console <NUM> further includes a sensor interface <NUM>, a syringe pump <NUM>, a hand piece subsystem <NUM>, an infusion chamber <NUM>, an infusion drive mechanism such as an infusion pump <NUM>, and a foot pedal subsystem <NUM>. The infusion pump <NUM> may be a part of the infusion chamber <NUM> or may be provide as a separate component coupled to the infusion chamber <NUM>.

The controller <NUM> may be one or more processors such as microprocessors, logic devices, microcontrollers, application specific integrated circuits (ASICs), programmable logic devices (PLDs), or other suitable processing systems and be configured to run operating systems and applications. The controller <NUM> is configured to execute computer instructions stored on the memory <NUM> and access data stored in memory <NUM>. Further, the controller <NUM> is configured to display information on panel display screen <NUM>.

The controller <NUM> is configured to receive, through the sensor interface <NUM>, sensor data relating to an IOP of a patient's eye from the IOP sensor <NUM>, an infusion sensor <NUM>, and/or an aspiration sensor <NUM>. The IOP sensor <NUM> may be disposed adjacent to the patient's eye during the ophthalmic surgical procedure. The IOP sensor <NUM> may be configured to determine, at a location adjacent to the patient's eye, the sensor data, and provide the sensor data to the controller <NUM>. For example, in some implementations, the IOP sensor <NUM> may be disposed adjacent to the distal end <NUM> of the infusion line <NUM> such that the IOP sensor <NUM> is just outside the eye and just upstream of the infusion line <NUM> during the ophthalmic surgical procedure. The IOP sensor <NUM> may include a pressure sensor <NUM> (e.g., fiber optic pressure sensors, electrical pressure sensors such as piezoelectric pressure sensors, microelectromechanical system (MEMS) pressure sensors, or other pressure sensors) that measures a pressure (e.g., a pressure drop just outside the eye, which may not be able to be accurately measured by a pressure sensor located inside the console <NUM>) and/or a flow rate sensor <NUM> that measures a flow rate of fluid through a tubing such as the infusion line <NUM>. The controller <NUM> may calculate an IOP value, such as a predicted IOP value, based on the sensor data, which may include one or both of the pressure data and the flow rate data.

Alternatively, or in addition, the IOP sensor <NUM> may be disposed inside the patient's eye during the ophthalmic surgical procedure. The IOP sensor <NUM> may be configured to determine, at a location in the vitreous chamber, the sensor data and provide the sensor data to the controller <NUM>. For example, the IOP sensor <NUM> may be disposed at the distal end <NUM> of the infusion line <NUM> such that the IOP sensor <NUM> is in the vitreous chamber of the patient's eye during the ophthalmic surgical procedure. The IOP sensor <NUM> may include the pressure sensor <NUM> that measures pressure data. The controller <NUM> may calculate an IOP value, which may be an actual IOP value when the IOP sensor <NUM> is located in the patient's eye, based on the sensor data, which includes the pressure data.

Implementations including the infusion sensor <NUM> or the aspiration sensor <NUM> monitor or detect the flow rate of fluid entering the patient's eye or leaving the patient's eye. For example, the infusion sensor <NUM> may be associated with the infusion line <NUM> in a manner permitting it to monitor or detect pressure in the infusion line, flow through the infusion line, or some other parameter indicative of pressure or flow. In some implementations, the infusion sensor <NUM> monitors a pump speed of the infusion pump <NUM>. In some such implementations, the infusion sensor is simply feedback from a processor or motor on the infusion pump <NUM> indicative of the pump speed. In some implementations, the infusion sensor <NUM> may include a pressure sensor or flow rate sensor as described above with reference to the IOP sensor.

The actuation line <NUM> may be used to inject viscous fluid (e.g., liquid tamponades) into or remove viscous fluid from the vitreous chamber. The syringe pump <NUM> may supply pressures into the actuation line <NUM>. The actuation line <NUM> has the proximal end coupled to the console <NUM>, the distal end coupled to the hand piece <NUM>. In some implementations, the hand piece <NUM> may include a powered syringe configured to inject or extract viscous fluid into or from the eye. The syringe pump <NUM> may provide a positive pressure or a negative pressure that injects or extracts the viscous fluid in the powered syringe into or away from the eye. The syringe pump <NUM> is connected with the actuation line <NUM> and the hand piece <NUM>. The syringe pump <NUM> may provide positive or negative pressure for viscous fluid injection and/or extraction from the vitreous chamber by the hand piece <NUM>.

The hand piece <NUM> may be in communication with the hand piece subsystem <NUM> via a pneumatic or electrical line provided in the actuation line <NUM>. The controller <NUM>, which is in communication with the hand piece subsystem <NUM>, may control one or more aspects of the hand piece <NUM>, such as an on or off state or a cutting rate of the hand piece <NUM>.

The infusion line <NUM> is used to deliver low viscosity fluid (e.g., a liquid such as balanced salt solution (BSS®), a gas such as air, or other fluid) such as replacement fluid or irrigation fluid from the infusion chamber <NUM> into the vitreous chamber. The infusion chamber <NUM> is in fluid communication with the infusion line <NUM>. The infusion line <NUM> may have the proximal end coupled to the console <NUM>, the distal end (e.g., an engagement member) <NUM> configured to enter into the vitreous chamber of the patient's eye, and an infusion passage extending therethrough. The infusion chamber <NUM> may be in fluid communication with the infusion passage through the infusion line <NUM>, and the infusion passage is in fluid communication with the vitreous chamber of the patient's eye.

The infusion chamber <NUM> may store low viscosity fluid and is configured to provide fluid infusion into the vitreous chamber through the infusion passage of the infusion line <NUM>. Some implementations employ the infusion pump <NUM> to infuse fluid to or otherwise irrigate the surgical site. The infusion pump <NUM> may be any of a variety types of pumps, including a peristaltic pump, a syringe pump, a pressurized fluid pump, or some other infusion pump. Control of the pump may permit the computer system <NUM> to increase, decrease, or hold steady flow through the pump based on received information from the infusion sensor <NUM>, the foot pedal subsystem, or other information. In some implementations, the computer system <NUM> may include a pre-stored threshold that serves as an upper limit for fluid flow rate or pressure introduced to the surgical site through the infusion line. In such implementations, if the requested fluid amount exceeds the threshold, the infusion pump <NUM> may be disabled or its speed may be capped to avoid damage to the sensitive tissues in the patient's eye.

The foot pedal <NUM> receives actuation from a foot of a user and transmits actuation data to the foot pedal subsystem <NUM>. The foot pedal subsystem <NUM> includes an interface between the foot pedal <NUM> and the controller <NUM>, and may receive actuation data from the foot pedal <NUM>, process the actuation data, and transmit the actuation data to the controller <NUM>. The controller <NUM> receives the actuation data from the foot pedal subsystem <NUM> and, in response, may regulate the syringe pump <NUM>, fluid infusion through the infusion line <NUM>, and/or one or more aspects of the hand piece <NUM> based on the actuation data, as further described herein. The foot pedal <NUM> may be a wired foot pedal as shown in <FIG> or a wireless foot pedal (not shown).

The controller <NUM> monitors for changes in the IOP based on the sensor data, and regulates the viscous fluid delivery and/or removal from the vitreous chamber of the patient's eye by the hand piece <NUM> based on the changes in the IOP. In some implementations, the controller <NUM> may control the syringe pump <NUM> to regulate the viscous fluid delivery/removal from the vitreous chamber. For example, the controller <NUM> may control the syringe pump <NUM> by reducing a pressure generated by the syringe pump <NUM> in response to the IOP (e.g., an IOP value such as a predicted IOP value or an actual IOP value) exceeding a threshold IOP level (e.g., a threshold value). In another example, the controller <NUM> may turn on a negative pressure generated by the syringe pump <NUM> in response to the IOP rising above a threshold and/or an actuation of the foot pedal <NUM>. Accordingly, the controller <NUM> may perform automatic braking of the viscous fluid delivery/removal by the hand piece <NUM>. In a further example, the controller <NUM> may control the syringe pump <NUM> based on a difference between the IOP and a target IOP level (e.g., a target value or range) to reduce the difference between the IOP and the target IOP level.

<FIG> illustrates a cross-sectional view of an eye <NUM> undergoing a procedure involving a hand piece <NUM> (e.g., the hand piece <NUM> in <FIG> and <FIG>) and an infusion line or infusion cannula <NUM> (e.g., the infusion line <NUM> in <FIG> and <FIG>). Both the hand piece <NUM> and the infusion line <NUM> may be coupled to a console (e.g., the console <NUM> in <FIG> and <FIG>). In <FIG>, the hand piece <NUM> and the infusion line <NUM> are respectively inserted through the sclera <NUM> and into the vitreous chamber <NUM> of the eye <NUM>. The infusion line <NUM> is used to deliver low viscosity fluid such as replacement fluid or irrigation fluid into the vitreous chamber <NUM> during an ophthalmic surgical procedure (e.g., vitrectomy, fluid/air exchange, air/gas exchange, silicone oil injection, and/or other ophthalmic surgical procedures). Fluid infusion may be regulated by increasing or decreasing a pressure level of the irrigation fluid by a surgical system (e.g., the surgical system <NUM> of <FIG> and <FIG>). The hand piece <NUM> may be a powered/active syringe (e.g., pneumatic, hydraulic, electric, etc.).

The infusion line <NUM> includes a flexible elongate member <NUM>. Some implementations include a rigid engagement member <NUM> (e.g., the distal end in <FIG>) affixed at the distal end. The rigid engagement member <NUM> may be more rigid than the flexible elongate member <NUM>. The flexible elongate member <NUM> and the rigid engagement member <NUM> have a central lumen (e.g., an infusion passage) running therethrough. The infusion line <NUM> may provide low viscosity fluid to the vitreous chamber <NUM> from a fluid source (e.g., the infusion chamber <NUM> in <FIG> and <FIG>), carried through the central lumen, in order to maintain an appropriate IOP as portions of the vitreous humor and/or fluid in the vitreous chamber <NUM> are removed.

In some implementations, the infusion line <NUM> may include one or more pressure sensors, for example, a pressure sensor <NUM>, a pressure sensor <NUM>, or both. In some implementations, one or more of the pressure sensors <NUM> and <NUM> may correspond with the IOP sensor <NUM>, and in some implementations, one or more of the pressure sensors <NUM> and <NUM> may correspond with the infusion sensor <NUM>. The pressure sensor <NUM> may be disposed on the infusion line <NUM> and adjacent to the distal end of the infusion line <NUM> such that it remains outside, but in close proximity to, the eye <NUM> during the ophthalmic surgical procedure. In some implementations, the pressure sensor <NUM> may sense a pressure just outside the eye <NUM>, which may be used to determine the IOP (e.g., an actual IOP value or a predicted IOP value that is closer to an actual IOP value than possible using sensors located in the console) during the surgical procedure. In some implementations, the pressure sensor <NUM> is disposed on the rigid engagement member <NUM> (e.g., at a distal portion of the rigid engagement member <NUM>) such that it enters into the vitreous chamber <NUM> during the ophthalmic surgical procedure. The pressure sensor <NUM> may sense an internal eye pressure in the vitreous chamber <NUM>, which may be used to determine the IOP (e.g., an actual IOP value) during the surgical procedure.

Depending on the implementation, the hand piece <NUM> may include one or more pressure sensors, such as a pressure sensor <NUM>, a pressure sensor <NUM>, and/or a pressure sensor <NUM>. Each of the pressure sensors <NUM>, <NUM>, and <NUM> may measure a pressure at a different location. In some implementations, one or more of the pressure sensors <NUM>, <NUM>, and <NUM> may correspond with the IOP sensor <NUM>, and in some implementations, one or more of the pressure sensors <NUM> and <NUM> may correspond with the aspiration sensor <NUM>. Depending on the implementation, the pressure sensor <NUM> may be disposed on a housing of the hand piece <NUM> and may measure an ambient pressure such as atmospheric pressure. In some examples, the ambient pressure sensor <NUM> is provided as pressure sensor <NUM> on an exterior surface of the console <NUM>, as shown in <FIG>. The pressure sensors <NUM> and <NUM> may be disposed at a tip (e.g., a cutter) of the hand piece <NUM>. The pressure sensor <NUM> may be disposed on the hand piece <NUM> and may measure an internal eye pressure in the vitreous chamber <NUM> outside the cutter, which may be used to determine the IOP (e.g., an actual IOP value) during the ophthalmic surgical procedure. The pressure sensor <NUM> may be disposed within the tip so as to measure an internal pressure that is internal to the hand piece, which may be used to characterize the pressure supplied through actuation line <NUM> (e.g., the actuation line <NUM> in <FIG> and <FIG>) to the hand piece <NUM>.

In addition to their respectively sensed pressures, pressure sensors <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> may be used in conjunction to provide a differential pressure, such as a pressure representative of the IOP of the eye <NUM>. Generally, the IOP is a gauge pressure reading determined by the difference between the absolute pressure in the eye (as measured by a pressure sensor in the eye such as the pressure sensor <NUM> and/or <NUM>) and atmospheric pressure (as measured by the pressure sensor <NUM> and/or pressure sensor <NUM> in <FIG>). Therefore, in some exemplary embodiments, pressure readings of pressure sensor <NUM> and/or <NUM> are taken simultaneously or nearly simultaneously with pressure readings of atmospheric pressure sensor <NUM> and/or <NUM> so that the actual IOP can be calculated as a function of the measured pressures.

The pressure sensors <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may each be a fiber optic pressure sensor, an electrical pressure sensor such as a piezoelectric pressure sensor, a MEMS pressure sensor, or another pressure sensor. The pressure sensors <NUM>, <NUM>, and <NUM> may be miniaturized pressure sensors capable of entering a small orifice through which the cutter of the hand piece <NUM> or the engagement member <NUM> enters the eye <NUM>. As the pressure sensors <NUM> and <NUM> are disposed outside the eye and do not enter the eye through the small orifice, the pressure sensors <NUM> and <NUM> do not have size constraints and, thus, are not limited to such miniaturized pressure sensors. Accordingly, the pressure sensors <NUM> and <NUM> may be any appropriate type of pressure sensor.

The pressures that may be sensed by the hand piece <NUM> and/or the infusion line <NUM> facilitate improved control by the surgical system by providing additional information that can be processed by the surgical system and used for automated flow and pressure control. For example, by measuring and determining the IOP of the eye <NUM>, the surgical system may be able to avoid the collapse or pressure spike of the eye <NUM> due to excessive delivery or excessive removal of viscous fluid by the hand piece <NUM> during an ophthalmic surgical procedure by automatically adjusting the supplied injection/extraction pressure.

As illustrated in <FIG>, some embodiments may include redundant pressure sensors. For example, the pressure sensor <NUM> of the infusion line of <NUM> may be considered redundant due to the presence of the pressure sensor <NUM> of the hand piece <NUM>. In some embodiments, only one pressure sensor to measure an internal eye pressure may be provided by the combined use of the hand piece <NUM> and the infusion line <NUM>, such that either the hand piece <NUM> or the infusion line <NUM> includes a pressure sensor within the vitreous chamber <NUM>. Similarly, in some embodiments only one ambient pressure sensor is present. In other embodiments, data for a single pressure is obtained using multiple pressure sensors. The data from each pressure sensor may be provided directly or a mathematical combination of the pressure sensors may be used to provide a single value. Using the pressure measurements obtained from the pressure sensors depicted in <FIG>, the surgical system may automatically control viscous fluid injection/extraction and, further, may allow a surgeon to exercise improved control of hand piece <NUM> and the infusion line <NUM> during a surgical procedure.

<FIG> is a flowchart showing a process <NUM> performed by the surgical system <NUM> of <FIG> and <FIG> for automating viscous fluid delivery/removal in a patient's eye during an ophthalmic surgical procedure.

At block <NUM>, a controller such as the controller <NUM> of the surgical system <NUM> receives sensor data from one or more sensors such as the IOP sensor <NUM> disposed adjacent to or in the patient's eye.

At block <NUM>, the controller <NUM> monitors for changes in IOP. The controller <NUM> may determine an IOP (e.g., an IOP value such as a predicted IOP value or an actual IOP value) based on the sensor data and detect changes in the IOP.

At block <NUM>, the controller <NUM> regulates viscous fluid delivery/removal responsive to the changes in the IOP. The controller <NUM> may control the syringe pump <NUM> to regulate the viscous fluid delivery/removal in response to the changes in the IOP. The syringe pump <NUM> may provide injection/extraction pressure to the hand piece <NUM> which performs viscous fluid injection or extraction from a vitreous chamber of the patient's eye.

For example, the controller <NUM> may provide threshold control of the syringe pump <NUM> such that in response to the IOP falling below a threshold such as a threshold IOP level (e.g., a threshold value), the controller <NUM> automatically reduces a negative pressure generated by the syringe pump <NUM> and/or automatically increases a positive pressure generated by the syringe pump <NUM>. Further, the controller <NUM> may, in response to the IOP rising above the threshold, automatically increase the negative pressure generated by the syringe pump <NUM> and/or reduce the positive pressure generated by the syringe pump <NUM>.

In another example, the controller <NUM> may provide on/off control of the syringe pump <NUM> such that in response to the IOP falling below or rising above a threshold, the controller <NUM> automatically turns on/off the syringe pump <NUM>. In a further example, the controller <NUM> may provide control-loop feedback control such as proportional-integral-derivative (PID) control of the syringe pump <NUM>. The controller <NUM> may determine a difference between the IOP and a target IOP level (e.g., a target value or range) and, in response, automatically adjust the syringe pump <NUM> to reduce the difference between the IOP and the target IOP level. Advantageously, the surgical system <NUM> safeguards against low or high IOP and prevents collapsing or overfill of the eye.

In some implementations, the regulation of the viscous fluid injection/aspiration, by control of the syringe pump <NUM> or otherwise, may be coordinated with regulation of the low viscosity fluid infusion/aspiration. The controller <NUM> may prioritize regulating viscous fluid injection/extraction, prioritize regulating low viscosity fluid infusion/aspiration, or simultaneously regulate viscous and low viscosity fluid infusion/aspiration.

At block <NUM>, the controller <NUM> may detect an actuation of the foot pedal <NUM>. For example, the controller <NUM> may detect the actuation of the foot pedal <NUM> through a foot pedal subsystem such as the foot pedal subsystem <NUM>. The controller <NUM> may receive actuation data from the foot pedal <NUM> through the foot pedal subsystem <NUM>. The actuation data may indicate, for example, whether the foot pedal <NUM> is actuated, how far the foot pedal <NUM> is depressed, and/or how fast the foot pedal <NUM> is depressed.

At block <NUM>, the controller <NUM> may control the viscous fluid injection or extraction based on the actuation of the foot pedal <NUM>. For example, based on the actuation of the foot pedal <NUM> by the user, the controller <NUM> may control the syringe pump <NUM> to maintain, increase, or decrease the viscous fluid injection or extraction pressure.

<FIG> shows exemplary implementation of a viscous fluid injection/delivery control responsive to changes in IOP. <FIG> shows exemplary implementation of a viscous fluid extraction/removal control responsive to changes in IOP. Accordingly, <FIG> and <FIG> each show different implementations that may make up a part of blocks <NUM>-<NUM> in <FIG>.

As shown in <FIG>, during a viscous fluid injection/delivery process, the controller <NUM> may regulate the injection/delivery of viscous fluid in response to changes in IOP. During a vitreoretinal surgical procedure, after the vitreous is cut and removed (e.g., aspirated), the eye may be filled with a salt solution (e.g., BSS) and repair procedures may be performed (e.g., repair retinal). After the repair procedure is completed, the salt solution in the eye may be replaced with air. A viscous fluid, such as a liquid tamponade (e.g., silicone oil or perfluoron solution), may then be injected into the eye by a hand piece <NUM> to replace the air. The liquid tamponade may fill the eye to seal retinal tears and allow for scar formation. During the viscous fluid injection process, the air or air pressure may be delivered via infusion line <NUM> or <NUM>. In some embodiments, the air pressure from infusion line <NUM> or <NUM> may be maintained at a constant level as the viscous fluid is introduced to replace the air and to fill the eye.

At block <NUM>, the controller <NUM> may receive a control signal to inject/deliver the viscous fluid into the eye. The control signal may be input by the user/surgeon at the foot pedal <NUM>. For example, the user/surgeon may press on the foot pedal <NUM> to generate an injection signal to the controller <NUM> instructing the controller <NUM> to inject or pump viscous fluid into the eye via the hand piece <NUM> or <NUM>.

At block <NUM>, the controller <NUM> may detect the IOP in the eye. As noted above, the IOP may be detected or estimated based on sensor signals received from one or more sensors. In some examples, the IOP or changes in IOP may be measured or calculated based on signal data output from the sensors.

At block <NUM>, the controller <NUM> may determine whether the IOP is above an acceptable upper threshold. The acceptable upper threshold may be set automatically by the controller to a default value based on the safety recommendations for IOP. In some embodiments, the user/surgeon may input an upper limit for the IOP to avoid over-pressurizing the eye. The controller <NUM> the compare the detected or calculated IOP against the upper threshold value to determine whether the IOP has exceeded the upper threshold value. If so, the controller <NUM> may automatically reduce or stop the viscous fluid injection flow at block <NUM>. For example, the controller <NUM> may stop or lower the injection pressure of the viscous fluid at the hand piece <NUM>, such as by stopping the syringe pump <NUM>. In another example, the controller <NUM> may open a pressure release valve (not shown) to relieve injection pressure. As such, even if the user/surgeon continues to press on the foot pedal <NUM> requesting more viscous fluid injection, the controller <NUM> may stop or reduce the viscous fluid flow/pressure to avoid over filling or over-pressurizing the eye. Accordingly, the controller <NUM> may override the user input to increase injection pressure when the IOP has already exceeded the safety limit.

If the controller <NUM> determines that the IOP does not exceed the upper threshold value, the controller <NUM> may increase or maintain the viscous fluid injection based on the viscous fluid injection signal input from the user/surgeon (e.g., via the foot pedal <NUM>) at block <NUM>. For example, the controller <NUM> detects an actuation of a foot pedal such as the foot pedal <NUM> by a user. The controller <NUM> may detect the actuation of the foot pedal <NUM> through a foot pedal subsystem such as the foot pedal subsystem <NUM>. The controller <NUM> may receive actuation data from the foot pedal <NUM> through the foot pedal subsystem <NUM>. The actuation data may indicate, for example, whether the foot pedal <NUM> is actuated, how far the foot pedal <NUM> is depressed, and/or how fast the foot pedal <NUM> is depressed.

If the controller <NUM> determines that the IOP does not exceed the upper threshold value, the controller <NUM> regulates the viscous fluid injection/delivery responsive to actuation of the foot pedal <NUM>. The controller <NUM> may further control the syringe pump to regulate the viscous fluid injection into the vitreous chamber of the patient's eye. For example, if the controller <NUM> provides on/off control, the controller <NUM> may, in response to the actuation of the foot pedal <NUM>, turn on the syringe pump <NUM>. In another example, if the controller <NUM> provides control-loop feedback control, the controller <NUM> may, in response to the actuation of the foot pedal <NUM>, adjust the syringe pump <NUM> such as by adjusting the positive pressure generated by the syringe pump. Thus, the controller <NUM> may control the syringe pump to maintain or increase the positive pressure to maintain or increase the viscous fluid injection into the eye. Accordingly, the controller <NUM> may continuously monitor the IOP and may automatically control the viscous fluid injection based on IOP to avoid overfilling or over-pressurizing the eye during a viscous fluid injection/delivery process.

Referring now to <FIG>, during a viscous fluid extraction/removal process, the controller <NUM> may regulate the extraction/removal of viscous fluid in response to changes in IOP. After the retinal tears are sealed and scar has formed, the patient may returned for a follow up procedure to remove the viscous fluid (liquid tamponade) from the eye. Typically, in the follow up procedure, the viscous fluid (liquid tamponade) may be removed and replaced with a low viscosity fluid, such as a salt solution. The viscous fluid may be extracted by the hand piece <NUM> while the salt solution is infused into the eye by the infusion line <NUM>.

At block <NUM>, the controller <NUM> may receive a control signal to remove the viscous fluid from the eye. The control signal may be input by the user/surgeon at the foot pedal <NUM>. For example, the user/surgeon may press on the foot pedal <NUM> to generate an extraction signal to the controller <NUM> instructing the controller <NUM> to remove or suction the viscous fluid from the eye via the hand piece <NUM> or <NUM>.

At block <NUM>, the controller <NUM> may determine whether the IOP is below an acceptable lower threshold. The acceptable lower threshold may be set automatically by the controller <NUM> as a default value based on the general safety recommendations for IOP. In some embodiments, the user/surgeon may input a lower limit for the IOP to avoid under-pressurizing or collapsing the eye. The controller <NUM> may compare the detected or calculated IOP against the lower threshold value to determine whether the IOP has dropped below the lower threshold value. If so, the controller <NUM> may automatically reduce or stop the viscous fluid removal/extraction flow at block <NUM>. For example, the controller <NUM> may stop or lower the negative pressure generated by the syringe pump <NUM> to reduce the extraction flow of the viscous fluid at the hand piece <NUM>. As such, even if the user/surgeon continues to press on the foot pedal <NUM> requesting more viscous fluid removal, the controller <NUM> may stop or reduce the viscous fluid extraction pressure to avoid collapsing or under-pressurizing the eye. Accordingly, the controller <NUM> may override the user input to increase vacuum pressure when the IOP has already dropped under than the safety limit.

If the controller <NUM> determines that the IOP does not drop below the lower threshold value, the controller <NUM> may increase or maintain the viscous fluid extraction/removal based on the viscous fluid extraction signal input from the user/surgeon (e.g., via the foot pedal <NUM>) at block <NUM>. For example, the controller <NUM> detects an actuation of a foot pedal such as the foot pedal <NUM> by a user. The controller <NUM> may detect the actuation of the foot pedal <NUM> through a foot pedal subsystem such as the foot pedal subsystem <NUM>. The controller <NUM> may receive actuation data from the foot pedal <NUM> through the foot pedal subsystem <NUM>. The actuation data may indicate, for example, whether the foot pedal <NUM> is actuated, how far the foot pedal <NUM> is depressed, and/or how fast the foot pedal <NUM> is depressed.

If the controller <NUM> determines that the IOP does not drop below the lower threshold value, the controller <NUM> regulates the viscous fluid extraction/removal responsive to actuation of the foot pedal <NUM>. The controller <NUM> may further control the syringe pump <NUM> to regulate the viscous fluid extraction/removal from the vitreous chamber of the patient's eye. For example, if the controller <NUM> provides on/off control, the controller <NUM> may, in response to the actuation of the foot pedal <NUM>, turn on the syringe pump <NUM>. In another example, if the controller <NUM> provides control-loop feedback control, the controller <NUM> may, in response to the actuation of the foot pedal <NUM>, adjust the syringe pump <NUM> such as by adjusting the negative pressure generated by the syringe pump <NUM>. Thus, the controller <NUM> may control the syringe pump <NUM> to maintain or increase the negative pressure to maintain or increase the viscous fluid extraction/removal from the eye. Accordingly, the controller <NUM> may continuously monitor the IOP and may automatically control the viscous fluid extraction based on IOP to avoid collapsing or under-pressurizing the eye during a viscous fluid extraction/removal process.

In a further example, the controller <NUM> simultaneously regulates the removal of the viscous fluid and the infusion of the salt solution. In response to the IOP being below a threshold IOP level, the controller <NUM> simultaneously regulates infusion and extraction by adjusting both the infusion (e.g., by controlling pressure at the infusion line <NUM>) and the extraction (e.g., by controlling the negative pressure at the actuation line <NUM>) in a coordinated fashion. Alternatively, the regulation of viscous fluid extraction and the regulation of low viscosity fluid infusion are separately controlled, each having its own parameters, thresholds, and/or control operations or mechanisms.

<FIG> is a flowchart showing a process <NUM> for operating the surgical system <NUM> of <FIG> during an ophthalmic surgical procedure.

At block <NUM>, a user, such as a surgeon performing the ophthalmic surgical procedure, may insert a distal end of an infusion line such as the distal end (e.g., the engagement member) <NUM> of the infusion line <NUM> into a vitreous chamber of the patient's eye.

At block <NUM>, the user may position a sensor such as the IOP sensor <NUM> adjacent to (e.g., in close proximity to) or inside a patient's eye. In embodiments in which the IOP sensor <NUM> is disposed adjacent to and/or at the distal end <NUM> of the infusion line <NUM> (e.g., sensor <NUM> and/or <NUM> in <FIG>), block <NUM> is accomplished by performing block <NUM>. In embodiments in which the IOP sensor <NUM> is disposed on the tip of the hand piece <NUM> (e.g., sensor <NUM> in <FIG>), block <NUM> is accomplished by performing block <NUM>. In other embodiments, the IOP sensor <NUM> is coupled to a separate line from the actuation line <NUM> and the infusion line <NUM>, and the user places the IOP sensor <NUM> adjacent to and/or in the patient's eye separately from the actuation line <NUM> and the infusion line <NUM>.

At block <NUM>, the user inserts a tip of a hand piece such as the hand piece <NUM> into the vitreous chamber of the patient's eye. The hand piece <NUM> is coupled to a distal end of the actuation line <NUM>.

At block <NUM>, the user may inject or extract viscous fluid from the vitreous chamber of the patient's eye using the hand piece <NUM>, which is powered by the syringe pump <NUM> in the console <NUM>.

At block <NUM>, the user allows automatic throttling of the viscous fluid based on sensor data measured by the IOP sensor <NUM>. The surgical system <NUM> (e.g., by the controller <NUM>) automatically regulates the viscous fluid injection/extraction based on the sensor data measured by the IOP sensor <NUM>, as further described above in connection with controller <NUM> of <FIG> and block <NUM> of <FIG>. For example, the surgical system <NUM> may automatically turn off or reduce a negative pressure generated by the syringe pump <NUM> in response to the IOP being lower than (or equal to or lower than) a threshold IOP level (e.g., a threshold value). In another example, the surgical system <NUM> may automatically turn off or reduce a positive pressure generated by the syringe pump <NUM> in response to the IOP being larger than (or equal to or larger than) a threshold IOP level (e.g., a threshold value).

At block <NUM>, the user actuates a foot pedal such as the foot pedal <NUM> to control the viscous fluid injection/extraction. For example, the user may actuate the foot pedal <NUM> to resume viscous fluid extraction from the vitreous chamber of the patient's eye or increase the negative pressure generated by the syringe pump <NUM>. In another example, the user may actuate the foot pedal <NUM> to resume viscous fluid injection into the vitreous chamber of the patient's eye or increase the positive pressure generated by the syringe pump <NUM>.

In some embodiments, other types of powered syringes besides pneumatic powered syringes may be used. For example, hydraulic powered or electric powered syringes may be used for viscous fluid injection/extraction. The controller <NUM> may similarly control the injection/extraction of viscous fluid by these other types of powered/active syringes. Besides liquid tamponades, the system may also automatically regulate the injection/extraction of other types of viscous fluids for eye surgical procedures, such as stem cells, adhesives, and the like.

Claim 1:
An ophthalmic surgical system (<NUM>), comprising:
a syringe pump (<NUM>) connected with an actuation line (<NUM>), the syringe pump (<NUM>) being configured to provide an injection pressure for viscous fluid injection in a vitreous chamber (<NUM>) of an eye (<NUM>) of a patient or an extraction pressure for viscous fluid extraction from the vitreous chamber (<NUM>) of the eye (<NUM>) of the patient;
a controller (<NUM>) configured to:
set a pressure threshold value;
receive sensor data relating to an intraocular pressure of the eye (<NUM>); and
control the syringe pump (<NUM>) to regulate the viscous fluid injection or extraction based on a comparison (<NUM>, <NUM>) of the intraocular pressure to the pressure threshold value; and
a foot pedal system (<NUM>) configured to receive user input for controlling the viscous fluid injection or extraction in or from the vitreous chamber of the eye (<NUM>); wherein
the syringe pump is configured to alternatively provide the injection pressure or the extraction pressure for the viscous fluid injection or extraction in or from the vitreous chamber (<NUM>) of the eye (<NUM>) of the patient;
the controller (<NUM>) is further configured to
determine (<NUM>) whether the intraocular pressure is above an upper pressure threshold value and
control the syringe pump (<NUM>) to reduce or stop (<NUM>) the injection pressure in response to the intraocular pressure being above the upper pressure threshold value;
determine (<NUM>) whether the intraocular pressure is below a lower pressure threshold value and
control the syringe pump (<NUM>) to reduce or stop (<NUM>) the extraction pressure in response to the intraocular pressure being below the lower pressure threshold value;
to control the syringe pump (<NUM>) based on the user input received at the foot pedal system (<NUM>) when the intraocular pressure is below the upper pressure threshold value and above the lower pressure threshold value; and
to override the user input received from the foot pedal system (<NUM>) when the intraocular pressure is above the upper pressure threshold value or below the lower pressure threshold value.