Height-dependent pneumatic vitrectomy system

Abstract

A height-dependent pneumatic surgical cutting system is provided. The system includes an absolute pressure sensor for sensing ambient pressure. The system also includes a pressure-driven chamber for receiving pressurized air, a supply outlet for supplying pressurized air to a pneumatic vitrectomy handpiece, and a relief exhaust line for exhausting the pressurized air. A proportional relief valve communicates with the relief exhaust line. When the supplied air pressure sensed by the line pressure sensor exceeds a threshold opening pressure, the pressurized air is exhausted through the proportional relief valve. The threshold opening pressure and opening position are set based on feedback from the absolute pressure sensor indicative of ambient pressure, thereby making the threshold opening pressure of the proportional valve and the opening position of the proportional relief valve variable based on the sensed ambient pressure.

Description

[Technical Field]

[0001] The present disclosure relates generally to height-dependent pneumatic vitrectomy systems, and more particularly to systems and methods for driving pneumatic vitrectomy handpieces at various heights, including elevated positions. [Background technology]

[0002] This section provides background information related to the present disclosure that is not necessarily prior art.

[0003] Pneumatic vitrectomy handpieces (e.g., vitrectomy cutters) rely on injecting pressurized air pulses from a drive chamber into the handpiece, deflecting a diaphragm or piston. Deflection of the diaphragm or piston drives the inner cutting member across a port in the outer cutting member, cutting tissue drawn into the outer cutting member. The inner cutting member is traditionally driven to retract by a spring (e.g., a helical metal spring) when sufficient pressure is released from the drive chamber. Dual pneumatic drives (e.g., push-push drives) are also known that drive the inner cutting member in both directions by air pulses and coordinated exhaust of each drive chamber. Regardless of the drive mechanism, the drive pulses must be sufficient to advance and / or retract the inner cutting member in order to cut tissue, including high-speed cuts at several thousand times per minute. Summary of the Invention

[0004] This section provides an overview of the disclosure and is not a comprehensive disclosure of its entire scope or all of its functionality.

[0005] Exemplary embodiments of the present disclosure generally relate to an elevation-dependent pneumatic vitrectomy system. In one exemplary embodiment, a pneumatic surgical cutting system includes a pressure sensor for sensing ambient pressure (e.g., at the system's location). The system also includes a closed pressure chamber having an inlet for receiving pressurized air, a supply outlet for communicating the pressurized air to a pneumatic vitrectomy handpiece, and a relief outlet for venting the pressurized air from the closed pressure chamber (e.g., outside the system). A proportional valve is in communication with the relief outlet of the closed pressure chamber. When the pressure in the closed pressure chamber exceeds a threshold opening pressure of the proportional valve, the pressurized air is vented from the closed pressure chamber (e.g., outside the system) through the relief outlet. The threshold opening pressure is set based on feedback from the pressure sensor indicative of ambient pressure, thereby making the threshold opening pressure of the proportional valve variable based on the elevation of the pneumatic surgical cutting system.

[0006] In another exemplary embodiment, a pneumatic surgical cutting system includes a pressure sensor for detecting ambient pressure (e.g., at the system's location). The system also includes a drive chamber having an inlet for receiving pressurized air, a supply outlet for communicating the pressurized air to a pneumatic vitrectomy handpiece, and a relief outlet for releasing the pressurized air from the drive chamber (e.g., outside the system). A proportional valve is in communication with the relief outlet of the drive chamber, and when the pressure in the drive chamber exceeds a set pressure of the proportional valve, the pressurized air is released from the drive chamber (e.g., outside the system) through the relief outlet, and the set pressure of the proportional valve is adjusted based on feedback from the pressure sensor indicative of ambient pressure. Additionally, a pneumatic vitrectomy handpiece is in communication with the supply outlet of the drive chamber, and includes an outer cutting member and an inner cutting member positioned within the outer cutting member, the pressurized air driving the inner cutting member.

[0007] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0008] The drawings described herein are for purposes of illustrating selected embodiments only, do not depict all possible implementations, and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of an exemplary embodiment of a height-dependent pneumatic vitrectomy system. [Figure 2] FIG. 1 is a pneumatic schematic diagram of another exemplary embodiment of a height-dependent pneumatic vitrectomy system. DETAILED DESCRIPTION OF THE INVENTION

[0010] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

[0011] Exemplary embodiments of the present disclosure generally relate to systems and methods for driving a pneumatic vitrectomy handpiece at various altitudes, including elevated positions. Current pneumatic vitrectomy systems rely on a fixed control bleed to vent pressurized air from a drive chamber to reciprocate a cutting member of the handpiece. In particular, current pneumatic vitrectomy systems may include a relief valve in communication with the drive chamber that vents pressurized air from the drive chamber at a fixed threshold opening pressure (e.g., 40 psig (approximately 275.8 kPa)). When such systems are used at high altitudes (e.g., above 1000 meters), the pressure drop and reduced air density with altitude prevent the vitrectomy system from functioning effectively at high cutting speeds. To account for this difference, current pneumatic vitrectomy systems include a high-altitude derating of vitrectomy performance to account for this change in performance. The pneumatic vitrectomy system of the present disclosure uniquely modifies the drive chamber relief valve so that the threshold opening pressure of the valve is variable based on altitude. In particular, the disclosed pneumatic vitrectomy system includes a pressure sensor (e.g., an absolute pressure transducer) for sensing air pressure at the system's location, including at high altitudes. Based on a signal from the pressure sensor, the threshold opening pressure of the relief valve is modified and / or controlled to account for altitude differences. This altitude-dependent vitrectomy compressor lead allows for a higher compressor output pressure, enabling higher cutting speeds to be maintained during high-altitude vitrectomy operations. Furthermore, the disclosed pneumatic vitrectomy system can function effectively at high altitudes, eliminating the need for high-altitude derating.

[0012]

[0013] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings. The description and specific examples contained herein are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0013] 1-2 illustrate exemplary embodiments of pneumatic surgical vitrectomy systems 100, 200 incorporating one or more aspects of the present disclosure. In the illustrated embodiment, the system 100 generally includes a drive chamber 102, a relief / bleed valve 104 in communication with the drive chamber 102, and a line pressure sensor 106 for sensing air pressure within a supply line 112. The drive chamber 102 comprises a closed pressurized chamber configured to supply pressurized air pulses to a vitrectomy handpiece 108. The air pulses supplied from the drive chamber 102 actuate a cutting member of the handpiece 108 (e.g., an inner cutting member (not shown) of the handpiece 108), for example, by deflecting a diaphragm or piston within the handpiece 108. Pressurized air is released along the air supply line 112 through the relief valve 104 to return the cutting member of the handpiece 108 to its original position (e.g., by reciprocating motion).

[0014] The drive chamber 102 includes an inlet line 110 for receiving pressurized air into the drive chamber 102 through an air filter 111. The received pressurized air may be supplied from an air compressor mounted on the surgical console (shown to the left of dashed line 113) or from a wall-mounted air supply (not shown) connected to the console 113 via air line 109. The drive chamber may include one or more air compressors and, optionally, one or more pressure accumulators, as is known. The drive chamber 102 also includes a supply outlet connected to an air supply line 112 that communicates with the vitrectomy handpiece 108. To drive the cutting element of the vitrectomy handpiece 108, pressurized air flows into the drive chamber 102 through the inlet line 110, and pulses of pressurized air flow from the drive chamber 102 through the supply line 112 and into the vitrectomy handpiece 108.

[0015] The system 100 also includes a relief exhaust line 114 in communication with the supply line 112 and the relief valve 104. In particular, when the relief valve 104 is in an open position, pressurized air is exhausted from the supply line 112 through the relief exhaust line 114. The relief valve 104 is selectively opened to maintain the required pressure within the handpiece 108 during operation, including operation at high altitudes. To maintain the required pressure, when the pressure within the supply line 112 exceeds a threshold opening pressure (e.g., the set pressure of the relief valve 104), the relief valve 104 opens, allowing the cutting member of the vitrectomy handpiece 108 to retract / contract in preparation for another pressure pulse from the drive chamber 102. The relief valve 104 is a proportional valve, allowing for greater control of the exhaust flow rate at various valve opening positions compared to standard direct solenoid valves (which are either open or closed) of the prior art. Each component of the vitrectomy system 100 includes a handpiece. A control unit 115 is connected to the vitrectomy handpiece 108 for coordinating the delivery of pressurized air pulses to the handpiece 108 and the venting of air pressure in the supply line 112 to return the cutting member of the handpiece 108 to an initial open position. Specifically, the control unit 115 is in operative communication with the drive chamber 102, the proportional relief valve 104, the line pressure sensor 106, the vitreous handpiece 108, and the absolute pressure sensor 116 to control the function of the vitrectomy handpiece 108. For the sake of brevity and clarity, the aspiration functions and components of the vitrectomy system are not shown or described.

[0016] Ambient air pressure at the location of the system 100 is measured and regulated using an absolute pressure sensor 116. An absolute pressure sensor is a sealed device that functions relative to a perfect or near-perfect vacuum and can therefore generate pressure readings corrected for the effects of atmospheric pressure, which is particularly necessary at high altitudes. In particular, the absolute pressure sensor 116 (e.g., a pressure transducer) communicates with the control unit 115 and can detect changes in altitude based on a detected decrease in ambient air pressure. Feedback from the absolute pressure transducer 116 enables the control unit 115 to adjust the proportional valve 104 (control bleed) in response to ambient pressure. The control unit 115 can be said to receive a signal indicative of ambient pressure from the absolute pressure sensor and, based on the received signal, set a threshold opening pressure and open position for the proportional valve 103; for example, the higher the altitude, the smaller the opening of the proportional valve 103. When an increase in altitude is detected, the control unit 115 will compensate for the less dense air by allowing a higher pressure to build up in the actuation chamber 102. This eliminates the need to derate vitrectomy performance with altitude as in the prior art, allowing for higher cutting speeds at higher altitudes. To maintain high cutting speeds at higher altitudes, the pneumatic design allows for higher compressor output pressures. The present disclosure uses an absolute pressure sensor to sense the ambient pressure level at the system 100 and alters the control of the proportional valve to adjust the pressure level in the drive chamber to accommodate changes in altitude, thereby maintaining high cutting speeds.

[0017] In some embodiments, a spring (not shown) returns the cutting member (also not shown) of the hand piece 108 to its original position when pressurized air is released from the supply line 112 through a proportional relief valve (e.g., when the pressure in the supply line 112 exceeds a threshold pressure). In other embodiments, a second drive chamber (not shown) can supply coordinated pulses of pressurized air to the hand piece 108 to return the cutting member of the hand piece 108 to its original position when pressurized air is released from the supply line 112 (e.g., when the pressure in the supply line 112 exceeds a threshold opening pressure) (e.g., a push-push drive mechanism). In a push-push design, depending on design requirements, each drive chamber may have its own supply line to the vitreous hand piece 108 with its own line pressure sensor and proportional relief valve, or there may be separate drive chambers but only one supply line to the vitreous hand piece. An example design with two drive chambers and a single supply line is described below with reference to FIG. 2.

[0018] In the illustrated embodiment, the valve 104 is a proportional valve. The threshold opening pressure of the valve 104 is variable based on the altitude at which the system 100 is located. In particular, the threshold opening pressure of the valve 104 is set and can be adjusted or changed based on the signal obtained by the absolute pressure sensor 116. Adjustment of the pressure level and valve opening size based on the sensed absolute pressure need only be performed once at the beginning of a procedure, but periodic or continuous adjustment based on the sensed absolute pressure is also acceptable. As described above, the signal obtained by the absolute pressure sensor 116 is indicative of the ambient pressure at the location of the system 100. In this manner, the threshold opening pressure of the valve 104 can be varied based on the altitude of the system 100 (e.g., a higher threshold opening pressure can be set at a higher altitude).

[0019] Because absolute pressure sensor 116 senses, detects, measures, etc., the ambient pressure at the location of system 100, the threshold opening pressure of valve 104 is optimized for the location, i.e., altitude, at which system 100 is used. When the system is used at a high altitude location, the threshold opening pressure of valve 104 can be increased to allow for a higher compressor output pressure (e.g., to provide higher pressure air pulses to vitrectomy handpiece 108 through supply outlet 110), thereby allowing system 100 to maintain a higher cutting speed despite the increased altitude.

[0020] FIG. 2 is another example of the present disclosure and is similar to the embodiment of FIG. 1, including the use of the same reference numerals where applicable. Components of vitrectomy system 200 have been scaled down for clarity and to highlight key differences. As with FIG. 1 above, aspiration controls and components are not shown or described. Additionally, with respect to FIG. 2, control unit 115 and its connections are not shown or described. Those skilled in the art will appreciate that the control of system 200 is similar to that of system 100, except as noted below.

[0021] The primary difference between system 100 and system 200 is the use of two air compressors 202 and 204 as shown. While compressors 202 and 204 are not shown as drive chambers, they could be part of the first and second drive chambers, as in FIG. 1, and would be functionally similar. Additionally, while accumulators are not shown in FIG. 2, it is understood that the use of accumulators is permissible and that each compressor may have an accumulator attached. System 200 is particularly useful for driving push-push vitrectomy cutters, as discussed above. The use of two compressors helps ensure that a sufficiently high pressure pulse is available through source 112 to drive / push the diaphragm of the vitrectomy handpiece in a direction opposite to the diaphragm's current position. Meanwhile, drive pulses from compressors 202, 204, via a control unit in combination with line pressure sensor 106 and proportional relief valve 104, alternately ventilate both sides of the diaphragm, with pressure pulses driving and deflecting the diaphragm from the opposite side, reciprocating the cutter element of the vitreous handpiece. As shown, each compressor is in communication with an air inlet line and air filter 206, 208. As mentioned above, air inlet lines 210, 212 can receive pressurized air from an on-board air compressor or a wall air outlet in the operating room. Absolute pressure sensor 116, shown in FIG. 2, is connected to control unit 115 or a similar controller and functions similarly to that described above.

[0022] The disclosed altitude-dependent pneumatic vitrectomy system enables effective vitrectomy performance (e.g., high cutting speeds) even at high altitudes by varying the discharge flow rate of pressurized air from a supply line based on altitude (i.e., ambient pressure at the system's location). In particular, the disclosed pneumatic vitrectomy system includes a leaf valve (e.g., a proportional valve) whose threshold opening pressure and flow rate are adjusted by the vitrectomy system based on a signal from an absolute pressure sensor (e.g., an absolute pressure transducer) that indicates the ambient pressure and, therefore, the altitude of the vitrectomy system. The use of such an absolute pressure sensor allows for the utilization of a higher threshold pressure at high altitudes, effectively maintaining a high cutting speed. This eliminates the need to derate the vitrectomy performance of the pneumatic vitrectomy system based on altitude, as required in prior art vitrectomy systems.

[0023] The exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art. Specific details are described, such as examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, and that the exemplary embodiments may be embodied in many different forms, none of which should be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0024] The specific dimensions, materials, and / or shapes disclosed herein are exemplary in nature and do not limit the scope of the present disclosure. The disclosure herein of a particular value and range of values ​​for a given parameter does not exclude other values ​​and ranges of values ​​that may be useful in one or more examples disclosed herein. Furthermore, it is contemplated that any two specific values ​​for a particular parameter described herein can define the endpoints of a range of values ​​that may be suitable for that given parameter (i.e., disclosure of a first and a second value for a given parameter can be interpreted as disclosing that any value between the first and second values ​​may also be employed for the given parameter). For example, if parameter X is exemplified herein as having a value A and also as having a value Z, it is contemplated that parameter X may have a range of values ​​from about A to about Z. Similarly, the disclosure of two or more ranges of values ​​for a parameter (whether such ranges are nested, overlapping, or distinct) is contemplated to encompass all possible combinations of the ranges of values ​​that may be claimed using the endpoints of the disclosed ranges. For example, if a parameter X is exemplified herein as having a value in the range of 1 to 10, or 2 to 9, or 3 to 8, it is contemplated that the parameter X may have other ranges of values, including 1 to 9, 1 to 8, 1 to 3, 1 to 2, 2 to 10, 2 to 8, 2 to 3, 3 to 10, and 3 to 9.

[0025] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms unless the context clearly dictates otherwise. The terms "comprise," "comprising," "containing," and "having" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring performance in the particular order discussed or illustrated, unless specifically identified as such. It is also understood that additional or alternative steps may be employed.

[0026] When an element or layer is referred to as being "on," "engaged," "connected," or "coupled" to another element or layer, it may be directly on, engaged with, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," or "directly connected to," or "directly coupled" to another element or layer, there may be no intervening elements or layers present. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). As used herein, the terms "and / or" and "at least one" include any and all combinations of one or more of the associated listed items.

[0027] Terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first," "second," and other numerical terms, when used herein, do not imply an order or sequence unless clearly indicated by context. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0028] For ease of description, spatially relative terms such as "inside," "outside," "below," "below," "downward," "above," and the like may be used herein to describe the relationship of one element or feature shown in the figures to another element(s) or feature(s). Spatially relative terms may be intended to encompass various orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures were turned over, elements described as "below" or "below" other elements or features would be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein would be interpreted accordingly.

[0029] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended that the disclosure be exhaustive or limiting of the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, may be interchangeable and used in selected embodiments even if not specifically shown or described. The same may also be modified in various ways. Such variations should not be considered a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. [Explanation of symbols]

[0030] 100,200 Surgical Pneumatic Vitrectomy System 102 Drive chamber 104 Relief valve 106 Line pressure sensor 108 Handpiece 109 Air Line 110 Entrance Line 111 Air Filter 112 Air supply line 113,206,208 console 114 Relief exhaust line 115 Control Unit 116 Absolute Pressure Sensor 202,204 Air compressor

Claims

1. 1. A surgical pneumatic vitrectomy cutting system comprising: an absolute pressure sensor for sensing ambient pressure; a pressure-driven chamber having an inlet line for receiving pressurized air and a supply outlet for communicating the pressurized air to the pneumatic vitrectomy handpiece via an air supply line; a relief exhaust line in communication with the air supply line for exhausting pressurized air from the air supply line; a proportional relief valve in communication with the relief exhaust line; a line pressure sensor communicating with the air supply line and detecting the air pressure; Including, when the air pressure sensed by the line pressure sensor exceeds a threshold opening pressure set for the proportional relief valve, the pressurized air is discharged through the proportional relief valve; and the threshold opening pressure and opening position are set based on feedback from the absolute pressure sensor indicative of the ambient pressure, whereby the threshold opening pressure of the proportional valve is variable and the opening position of the proportional relief valve is also variable based on the sensed ambient pressure; Surgical pneumatic vitrectomy cutting system.

2. 2. The system of claim 1, further comprising a control unit configured to receive a signal from the absolute pressure sensor indicative of the ambient pressure and to set the threshold opening pressure and the opening position of the proportional valve based on the received signal.

3. 10. The system of claim 1, further comprising a second pressure-driven chamber for driving the pneumatic vitrectomy handpiece with a push-push drive mechanism.

4. The system of claim 1 , further comprising the pneumatic vitrectomy handpiece in communication with the air supply line comprising the pressure-driven chamber.

5. 5. The pneumatic surgical cutting system of claim 4, wherein the pneumatic vitrectomy handpiece includes a cutting member driven from a first position to a second position by pressurized air from the pressure-driven chamber, and a spring for returning the cutting member from the second position to the first position when the pressurized air is exhausted from the air supply line.

6. 1. A pneumatic surgical cutting system comprising: an absolute pressure sensor for sensing ambient pressure; a drive chamber having an inlet line for receiving pressurized air and a supply outlet connected to an air supply line for communicating the pressurized air to the pneumatic vitrectomy handpiece; a relief exhaust line in communication with the air supply line for exhausting pressurized air from the air supply line; a proportional relief valve in communication with the relief exhaust line; a line pressure sensor communicating with the air supply line and detecting the air pressure, When the air pressure detected by the line pressure sensor exceeds a threshold opening pressure set in the proportional relief valve, the pressurized air is discharged through the proportional relief valve; the threshold opening pressure and opening position are set based on feedback from the absolute pressure sensor indicative of the ambient pressure, whereby the threshold opening pressure of the proportional valve is variable and the opening position of the proportional relief valve is also variable based on the sensed ambient pressure; Line pressure sensor, and a pneumatic vitrectomy handpiece in communication with the air supply line, the handpiece including an outer cutting member and an inner cutting member positioned within the outer cutting member, the pressurized air driving the inner cutting member; 1. A surgical pneumatic cutting system comprising:

7. 7. The pneumatic surgical cutting system of claim 6, further comprising a controller configured to receive a signal from the absolute pressure sensor indicative of the ambient pressure, and to set the threshold opening pressure and the opening position of the proportional relief valve based on the received signal.

8. 7. The system of claim 6, further comprising a second drive chamber for driving the pneumatic vitrectomy handpiece with a push-push drive mechanism.

9. the pressurized air drives the inner cutting member from a first position to a second position; and the pneumatic vitrectomy handpiece including a spring for returning the inner cutting member from the second position to the first position when the pressurized air is discharged from the air supply line. The system of claim 6.

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