VACUUM OSCILLATION PREVENTION IN A VENTURI SURGICAL SYSTEM
20210213183 ยท 2021-07-15
Inventors
Cpc classification
A61F9/00736
HUMAN NECESSITIES
G05B11/42
PHYSICS
International classification
Abstract
Control methods for generating a venturi vacuum in a substantially oscillation-free manner for a surgical system. The control methods generally include utilizing real-time readings from a venturi vacuum generator inlet pressure transducer and a vacuum pressure transducer on the vacuum side of the venturi vacuum generator. These values may be employed in real-time to ascertain the emergence of an oscillation region on the vacuum side which may then be addressed by way of a bleed control proportional valve. When employed in combination with a throttle control proportional valve at the inlet side of the venturi vacuum generator, pressures may be manipulated in light of one another and/or individually as directed through a central controller. Thus, the presentation of oscillations on the vacuum side may be avoided to provide for a more stable vacuum supported surgical procedure.
Claims
1. A method of generating a venturi vacuum, the method comprising: directing a regulated pressure supply from a pneumatic pressure source to a venturi vacuum generator to provide a vacuum to a vacuum line; monitoring inlet pressure to the vacuum generator with a venturi inlet pressure transducer; monitoring vacuum pressure of the vacuum line connected to the vacuum generator with a vacuum pressure transducer; obtaining monitored inlet and vacuum pressure values at a system controller; and adjusting at least one of a throttle level of the pressure supply to the vacuum generator and a vacuum pressure bleed level from the vacuum line with the controller based on the monitored values to substantially preventing vacuum oscillation in the vacuum line.
2. The method of claim 1 wherein the adjusting further comprises: employing a throttle control proportional valve to maintain the throttle level at a maximum throttle to prevent vacuum oscillation; and employing a bleed control proportional valve to control the bleed to achieve an operator determined vacuum level.
3. The method of claim 1 wherein the adjusting further comprises: maintaining a set vacuum bleed level for the preventing of the oscillation; and employing a throttle control proportional valve to achieve an operator determined vacuum level.
4. The method of claim 1 wherein the adjusting further comprises: detecting a predetermined vacuum level below a vacuum level oscillation region; moving a throttle control proportional valve to a maximum corresponding to a maximum vacuum for the venturi vacuum generator; opening a bleed control proportional valve to a predetermined maximum level based on the detecting; employing a PID (proportional-integral-derivative) control algorithm at the controller in coordination with the monitored values to adjust a throttle control proportional valve to maintain a maximum venturi inlet pressure; and adjusting a bleed control proportion valve to achieve an operator determined vacuum pressure level.
5. The method of claim 1 wherein the adjusting further comprises: detecting a predetermined vacuum level below a vacuum level oscillation region; employing a PID control algorithm at the controller and accounting for the monitored values in real-time to adjust a throttle control proportional valve and a bleed control proportional valve to attain an operator determined vacuum level within a predetermined transitional vacuum range upon the detecting of the predetermined vacuum level; detecting a vacuum level exceeding a predetermined transitional vacuum range but below the vacuum level oscillation region; employing the PID control algorithm to adjust the throttle control proportional valve to a maximum corresponding to a maximum vacuum for the venturi vacuum generator; and adjusting a bleed control proportion valve to achieve an operator determined vacuum pressure level.
6. The method of claim 1 wherein the adjusting further comprises: detecting vacuum level oscillation from the vacuum pressure transducer; opening a throttle control proportional valve to a maximum corresponding to a maximum vacuum for the venturi vacuum generator; opening a bleed control proportional valve to a predetermined maximum level; employing a PID control algorithm at the controller and accounting for the monitored values in real-time to ensure maintenance of the throttle control proportional valve at the maximum and to adjust the bleed control proportional valve to provide an operator determined vacuum level.
7. A venturi vacuum system comprising: a venturi vacuum generator; a pressure source to direct a pressure at the vacuum generator; a venturi inlet pressure transducer to monitor the pressure at the vacuum generator; a vacuum line to attain a vacuum pressure from the vacuum generator; a vacuum pressure transducer to monitor the vacuum pressure; and a system controller for directing a throttle device to adjust a throttle of the pressure directed at the vacuum generator and for directing a bleed device to drain vacuum from the vacuum line based on real-time monitoring of the pressure directed at the vacuum generator and the vacuum pressure in the vacuum line connected to the vacuum generator.
8. The venturi vacuum system of claim 7 wherein the directing of the throttle and bleed devices is for substantially avoiding oscillation of the vacuum pressure in the vacuum line.
9. The venturi vacuum system of claim 8 wherein the throttle device is a throttle control proportional valve and the bleed control device is a bleed control proportional valve.
10. The venturi vacuum system of claim 8 wherein the system controller comprises a processor for running a PID algorithm for the avoiding of the oscillation.
11. The venturi vacuum system of claim 7 wherein the vacuum line terminates at a surgical tool.
12. The venturi vacuum system of claim 11 wherein the surgical tool is a vitrectomy probe.
13. A method of dampening oscillation from a venturi vacuum system, the method comprising: driving a fluid flow through a venturi vacuum generator at a pressure level below a corresponding oscillation region of vacuum pressure from the generator in a vacuum line running therefrom; increasing the flow to a pressure at the vacuum generator for reaching the oscillation region in the vacuum line; and applying a bleeding of pressure to the vacuum line during the increasing for the dampening of the oscillation.
14. The method of claim 13 further comprising: employing an inlet pressure transducer at the vacuum generator to determine the flow of pressure thereat in advance of the increasing; and employing a vacuum pressure transducer at the vacuum line to determine the vacuum pressure thereat in advance of the bleeding.
15. The method of claim 14 further comprising running a PID-based algorithm program at a processor of a controller in communication with the transducers to direct the increasing of the flow pressure at the generator and the bleeding to the vacuum line.
16. The method of claim 14 wherein the increasing of the flow pressure at the generator and the bleeding to the vacuum line are responsive to predetermined pressure values from the transducers.
17. The method of claim 14 wherein the increasing of the flow pressure at the generator and the bleeding to the vacuum line are responsive to a detection of oscillation by the vacuum pressure transducer.
18. The method of claim 13 wherein the increasing of the flow pressure at the generator comprises increasing the pressure to a maximum throttle corresponding to a maximum vacuum pressure at the vacuum line from the generator for a sustained period.
19. The method of claim 18 wherein the bleeding of the pressure to the vacuum line is introduced by opening a bleed control proportional valve to a maximum level for a temporary period.
20. The method of claim 13 further comprising performing a surgical procedure with a tool incorporating a terminal end of the vacuum line.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0019] In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the embodiments described may be practiced without these particular details. Further, numerous variations or modifications may be employed which remain contemplated by the embodiments as specifically described.
[0020] Embodiments are described with reference to certain types of vitrectomy probe surgical procedures. In particular, a vitrectomy procedure is illustrated, in which vitreous humor is removed to address retinal detachment. However, tools and control methods detailed herein may be employed in a variety of other manners. That is, the application of a venturi vacuum system of uniquely tailored, anti-oscillation features may be utilized to address vitreous hemorrhage, macular pucker, macular holes, vitreous floaters, diabetic retinopathy or a variety of other eye or even non-eye related conditions. Regardless, so long as the venturi vacuum system incorporates oscillation reduction or elimination features as detailed herein, appreciable benefit may be realized.
[0021] Referring now to
[0022] Referring now to
[0023] Continuing with reference to
[0024] In the surgical environment, this source 120 may be drawn from a common line that runs throughout a facility, from a mobile base unit, high pressure cylinder, compressor or other appropriate source. While this degree of pressure to support the airflow 125 is available, a throttle device 155 is provided which is utilized to actually govern the air pressure and flow that reaches the vacuum generator 150. This device 155 may specifically be a throttle control proportional valve as illustrated. So, for example, while 40 SLPM is available, a maximum throttle of about 30 SLPM may be established for the illustrated vacuum generator 150 based on its own design tolerances and maximum efficiency. This, in turn may translate to 60 PSI being available as noted but with the throttle maximum being configured to maximize pressure at about 50 PSI to the venturi vacuum generator 150. Reference to PSI values here are valuable given that real-time pressure readings are available from transducers 175, 180 for the oscillation elimination control methods detailed below.
[0025] Continuing with the example of a 50 PSI maximum supplied to vacuum generator 150, it is understood that in the range just below the maximum throttle, (e.g., 45just under 50 PSI), the generator 150 may be prone to display undesirable oscillations. If not addressed, this could affect performance of a tool at the end of a suction or vacuum line 110 that is facilitated by the system 100. Thus, the vacuum line 110, which is in fluid communication with the venturi generator 150 for sake of generating the noted suction, is also in fluid communication with a bleed control device 101. This device 101 may be a bleed control proportional valve, which, when operated in concert with other features of the system 100 as described below, may be utilized to dampen or substantially eliminate the noted oscillations.
[0026] The system 100 of
[0027] In the embodiment shown, the controller 105 sits apart from the throttle device 155 and venturi inlet pressure transducer 175 but may communicate as noted via wireless means. Alternatively, system components including these features and others for which controller communications are desirable may be wired together as part of a single mobile or stationary unit.
[0028] Continuing with reference to
[0029] Perhaps more notably, however, the system embodiment depicted in
[0030] Continuing with the 670 mmHg maximum venturi generator 150 example, recall that a more than sufficient pressure supply 120 is available which facilitates an airflow 125 that is modified by the throttle device 155 as it passes to and through the venturi generator 150. So, for example, at the outset of operations, the throttle device 155, may be directed by the controller 105 to steadily increase pressure reaching the generator 150 beginning with 0 PSI and reaching about 45 PSI. This can be confirmed by the inlet pressure transducer 175 throughout this initial ramping up of the pressure. Once more, the true effect of this ramping up on the suction side may also be monitored directly by the vacuum pressure transducer 180. For example, these detections may confirm whether the ramping up resulted in an expected corresponding ramping up of vacuum from 0 to 550 mmHg. Further, to the extent that the ramping up was more (or less) than expected on the vacuum side, the throttle level may be correspondingly lowered (or raised) as directed by the controller 105.
[0031] Continuing further with the example above, suction through the vacuum line 110 may be applied across the entire range of 0-550 mmHg in support of a procedure as illustrated in
[0032] Recall that the oscillations are a natural effect of pressure directed at the generator 150 (e.g. 45-50 PSI in the present example). In the present example, this is translated on the vacuum side to oscillations at 550-670 mmHg. Thus, the bleed device 101, a proportional valve, may be opened during exposure to these pressure ranges while the throttle is increased to a higher level. In this manner, a vacuum of 550-670 mmHg in the vacuum line 110 can be achieved and corresponding oscillations in this operating region would not present. This is detailed further below.
[0033] Referring specifically now to
[0034] Continuing with reference to
[0035] Referring now to
[0036] In
[0037] Referring again to
[0038] At a predetermined vacuum level (e.g. at 540 mmHg) below the region of oscillation (e.g. 550-670 mmHg) the throttle may be immediately taken to its maximum as illustrated in
[0039] With added reference to
[0040] Referring specifically to
[0041] Given the millisecond response time capabilities of such a system 100 in its PID control algorithm to obtain the desired vacuum level in vacuum line 110, it is unlikely that this manner of detecting initial oscillation and or sudden jumps of throttle level and bleed level would result in any measurable oscillation as felt by the surgeon during a procedure as illustrated in
[0042] Of course, it may also be advantageous to avoid sudden jumps in throttle level and bleed level. Thus, in one embodiment, a more transitional approach to increasing the throttle and introducing the bleed may occur. In this embodiment, the throttle increase is more steady with the bleed introduced well before reaching the lower end of the oscillation region. It may be advantageous to begin the bleed and throttle coordination efforts much earlier than just below the oscillation region. Specifically, with reference to
[0043] Although not clearly shown, it is apparent that the vacuum level increases more steadily in
[0044] Notice that after the transitional period, the maintenance of the throttle at maximum and the draw down of the bleed proceeds as before. However, as a practical matter, the vacuum range is more steady. For example, note the absence of the initial vacuum jump for the top chart of
[0045] Indeed, referring specifically now to
[0046] Referring now to
[0047] Embodiments described hereinabove include a venturi facilitated vacuum system with the unique ability to substantially prevent oscillations from reaching a surgical suction tool supported by the system. Avoiding the effect of oscillations on a surgical tool as detailed herein not only provides the surgeon with a more stable manner of performing surgery but also affords continuous vacuum assistance without the need to halt a procedure. That is, the need to pause a procedure or operate only outside of certain regions of vacuum assistance may be avoided. Rather, the surgeon is now afforded continuously usable suction power throughout the procedure in the full vacuum range of 0 to maximum.
[0048] The preceding description has been presented with reference to presently preferred embodiments. However, other embodiments and/or features of the embodiments disclosed but not detailed hereinabove may be employed. Furthermore, persons skilled in the art and technology to which these embodiments pertain will appreciate that still other alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle and scope of these embodiments. Additionally, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.