Fluid reservoir for an aspiration line of a medical system

Abstract

Fluid reservoir (113; 213; 313) for an aspiration line (107) of a medical system, wherein the aspiration line (107) serves to aspirate a fluid from a surgical site on a living being by means of a fluid pump of the medical system in a suction direction, comprising: - a shell (214; 314) enclosing a chamber (219; 319) designed to hold a fluid; - a separating element (215; 315) that divides the chamber (219; 319) into a first sub-chamber (219a; 319a) and a second sub-chamber (219b; 319b); - a first fluid connection (220; 320) designed to fluidically connect the first subchamber (219a; 319a) to an outer surface of the shell (214; 314), and designed to be connected to a first part (107a) of the aspiration line (107) to be connected to the fluid pump; - a second fluid port (222; 322) designed to fluidically connect the second subchamber (219b; 319b) to the outer surface of the shell (214; 314), and designed to be connected to a second part (107b) of the aspiration line (107) to be directed towards the surgical site; and - a backflow preventer that the separating element (215; 315) has to fluidically connect the first subchamber (219a; 319a) with the second subchamber (219b; 319b), wherein the backflow preventer is designed to prevent a flow of fluid from the first subchamber (219a; 319a) into the second subchamber (219b, 319b) in the opposite direction to the suction direction, and wherein the separating element is a flexible separating element (215; 315), and the flexible separating element (215; 315) is designed in such a way as to achieve a pumping effect of the fluid reservoir (113; 213; 313) in the second subchamber (219b; 319b) when the flexible separating element (215; 315) is deformed by a certain positive pressure difference between the first subchamber (219a; 319a) and the second subchamber (219b; 319b), which enables the conveyance of a certain fluid delivery volume, characterized by the fact that the specific fluid flow volume is chosen depending on the type of operation performed on a living being.

Description

[0001] The present invention relates to medical systems and in particular to a fluid reservoir for an aspiration line of a medical system.

[0002] Several surgical techniques exist for treating conditions such as clouding of the eye's lens, medically known as cataracts. The most widely used technique is phacoemulsification, in which a thin hollow needle attached to a handpiece is inserted into the lens (Greek: phakos), which lies within its capsular bag. The needle is then vibrated by a motor in the handpiece, causing it to vibrate ultrasonically. An irrigation fluid is typically delivered to the surgical site via an irrigation line, and the vibrating needle emulsifies the lens in its immediate vicinity. The resulting lens particles, and possibly other particles and fluids, along with the irrigation fluid itself, can then be aspirated through an aspiration line using an aspiration pump.Once the lens has been completely emulsified and removed, a new artificial lens can be inserted into the now empty capsular bag, so that a patient treated in this way can regain good vision.

[0003] When the eye lens is fragmented using a hollow needle vibrating at ultrasonic frequency, it is unavoidable that a relatively large lens particle may become lodged in front of the needle's tip during a surgical procedure, potentially blocking the suction opening. This condition is called an occlusion. In such a case, the aspiration fluid pump connected to the aspiration line, such as a peristaltic or diaphragm pump, generates a significantly higher suction pressure in the line compared to an unoccluded state. This pressure can help to clear the occlusion. Additionally, the movement of the hollow needle can deliver sufficient energy to the lens particle obstructing the needle, causing it to fragment.

[0004] A sudden removal of the occlusion at a high suction pressure applied to the suction opening of the hollow needle can lead not only to the aspiration fluid containing the lens particles being drawn into the aspiration line, but also to the accidental suctioning of the capsular bag or parts of the iris of a treated eye.

[0005] Reversing the direction of flow of the aspiration fluid pump, which leads to a backflow (reflux) of the aspiration fluid, can be used in the form of a reflux function to both eliminate an occlusion caused by a large lens particle and to push a suctioned capsular bag or suctioned parts of an iris away from the hollow needle, so that a normal suction of the aspiration fluid through the hollow needle can take place again.

[0006] In other surgical procedures on the eye of a living being, such as a human or an animal, it is sometimes also necessary to break up and suction out tissue. Such surgical procedures include, for example, vitrectomy, in which parts of the vitreous humor (Latin: corpus vitreum) are removed, or the entire vitreous humor of the eye is removed, for example, to treat the retina. During a vitrectomy, the jelly-like vitreous humor is broken up using a cutter or vitrectomy inserted into the vitreous cavity, and the resulting vitreous fragments are suctioned out through an opening in the vitrectomy.To ensure tonification or stability of the eye, a fluid, such as first a balanced saline solution (BSS) and then a gas or oil, is infused through an infusion cannula inserted into the eye to replace the aspirated vitreous components. Occlusion of the vitrectomy's suction opening can also occur during vitrectomy; this can be resolved by intentionally reversing the flow direction through the suction opening.

[0007] Ophthalmic surgical systems, such as those used for phacoemulsification, typically comprise a console with a cassette holder, a cassette designed to be inserted into the cassette holder, an irrigation line, an aspiration line, and a handpiece fluidically connected to the irrigation and aspiration lines. The handpiece may, for example, have a hollow needle for treating the eye. The cassette usually includes at least one irrigation fluid pump, to which the irrigation line is connected or can be connected, and which delivers irrigation or treatment fluid to the eye via the irrigation line, handpiece, and hollow needle.The cassette typically also includes at least one aspiration fluid pump, to which the aspiration line is connected or can be connected, and which serves to aspirate fluid from the eye being treated via the hollow needle, handpiece, and aspiration line. The cassette is usually designed to form an interface between the handpiece and the console, and in particular to prevent the irrigation fluid from coming into contact with the driving elements of the irrigation fluid pump and / or console, in order to ensure sterility during surgery.

[0008] Fig. Figure 14 shows a console 400 of an ophthalmic surgical system with a cassette holder 401. Such a console is shown, for example, in DE 10 2021 111 178 A1.

[0009] To facilitate successive surgical procedures on the eyes of different patients and to guarantee appropriate hygiene, a separate, sterile, single-use cassette is typically inserted into the console for each patient, and the irrigation and aspiration lines, usually supplied as a tubing set, are replaced. This generates large amounts of waste and is more time-consuming for consecutive surgical procedures.

[0010] Some ophthalmic surgical systems allow a single cassette to be used for multiple patients throughout the day. Such a cassette is called a day cassette. When patients change, only the irrigation and aspiration lines are replaced. Because contaminated aspiration fluid remains in the cassette, and particularly in the aspiration pump, after each patient's surgical procedure, a newly connected aspiration line filled with fresh treatment fluid serves as a contamination barrier for the next patient.However, to provide reflux functionality even with a day cassette without contaminating the next patient with aspiration fluid from a previous patient, such ophthalmic surgical systems utilize a patient-proximal section of the aspiration line as a reflux volume available for reflux procedures. This volume is normally sufficient to perform several reflux procedures. Assuming that contaminated fluid is backflushed for each reflux procedure, the available uncontaminated fluid is gradually depleted until the reflux volume is exhausted. To ensure that no further reflux procedures are performed after the reflux volume is depleted, the console must monitor the volume of fluid delivered during the reflux procedures.

[0011] WO 95 / 03 085 A1 concerns a multi-function check valve, and DE 699 31 462 T2 refers to a valve for the left ventricle of a heart.

[0012] One object of the present invention is to provide a device for an ophthalmic surgical system and an ophthalmic surgical system that allows for the simple multiple use of a cassette for different patients.

[0013] This problem is solved by a fluid reservoir according to claim 1, an aspiration line according to claim 7 and an ophthalmic surgical system according to claim 9.

[0014] The invention provides a fluid reservoir for an aspiration line of a medical system, wherein the aspiration line serves to aspirate a fluid from a surgical site on a living being by means of a fluid pump of the medical system in a suction direction, comprising a shell enclosing a chamber designed to receive a fluid, a separating element that divides the chamber into a first sub-chamber and a second sub-chamber, a first fluid connection designed to fluidically connect the first sub-chamber to an outer surface of the shell and designed to be connected to a first part of the aspiration line to be connected to the fluid pump, and a second fluid connection designed to fluidically connect the second sub-chamber to the outer surface of the shell and designed to be connected to a second part of the aspiration line directed towards the surgical site.and a backflow preventer, which the separating element has, to fluidically connect the first subchamber to the second subchamber, wherein the backflow preventer is designed to prevent fluid flow from the first subchamber to the second subchamber in the opposite direction to the suction direction, and wherein the separating element is a flexible separating element. The flexible separating element is designed such that, upon deformation of the flexible separating element caused by a certain positive pressure difference between the first subchamber and the second subchamber, a pumping effect of the fluid reservoir in the second subchamber is achieved, enabling the delivery of a certain fluid flow volume. The certain fluid flow volume is selected depending on the type of operation performed on a living organism.

[0015] The invention further provides an aspiration line for a medical system, wherein the aspiration line serves to aspirate a fluid from an operating site on a living being by means of a fluid pump of the medical system in a suction direction, with a first part which is designed to be fluidically connected to the fluid pump, and a second part which is to be directed towards the operating site, wherein the aspiration line has a fluid reservoir according to the invention which is fluidically connected between the first part and the second part of the aspiration line.

[0016] The invention further provides an ophthalmic surgical system for treating an eye of a living being, comprising a console having a cassette receiving area, a cassette designed for insertion into the cassette receiving area, an irrigation line, an aspiration line according to the invention, and a handpiece for treating the eye, wherein the cassette has at least a part of at least a first fluid pump for supplying a fluid to the eye being treated via the irrigation line and at least a part of at least a second fluid pump for aspirating fluid from the eye being treated via the aspiration line in a suction direction.

[0017] An advantage of the invention is that, for clearing an aspiration line or a hollow needle or similar component of a handpiece fluidically connected to the aspiration line, the fluid reservoir according to the invention, with its movable separating element, provides a large fluid delivery volume of aspiration fluid that can be backflushed against the suction direction, and simultaneously, the backflow preventer in the fluid reservoir prevents the aspiration fluid of a previous patient from mixing with the aspiration fluid of a current patient. The backflow preventer thus forms a contamination barrier, which, for example, enables the multiple use of a cassette.

[0018] Another advantage of the invention is that a reflux function of a medical system, in which an aspiration fluid is conveyed by an aspiration fluid pump against the direction of suction, can be used for rinsing a handpiece during surgical preparation.

[0019] Another advantage of the invention is that, since the reflux volume is defined by the fluid reservoir according to the invention with the backflow preventer, no reflux limitation is required, which is realized by a control system with which a console is provided.

[0020] A further advantage of the invention is that, since the reflux volume per patient does not need to be limited, there is no risk of having to replace lines or tubes during an operation due to an insufficient reflux volume. This is the case, for example, when, as mentioned above, part of an aspiration tube is used as the reflux volume, but this reflux volume is exceeded during an operation and additional reflux volume can only be provided by replacing the aspiration tube.

[0021] A further advantage of the invention is that the length of an aspiration tube can be chosen more freely, since the fluid reservoir provides the reflux volume. Thus, shorter aspiration tubes can also be used, which have less influence on the flow behavior with regard to delay effects and flow resistance.

[0022] Another advantage of the invention is that when a cassette is placed in a receiving area of ​​a console of an ophthalmic surgical system, as in Fig. As shown in Figure 14, when inserted, the console does not need to distinguish between a cassette type intended for multiple use, where a limitation of the reflux volume usually needs to be made, and a cassette type intended for single use, so that the console does not need to have a function for detecting the cassette type.

[0023] Another advantage of the invention is that with the cassette type for multiple use, the reflux volume no longer needs to be monitored and therefore no separate control, for example implemented in the form of firmware, is required.

[0024] The dependent claims contain advantageous further developments and improvements of the fluid reservoir specified in claim 1, the aspiration line specified in claim 7 and the ophthalmic surgical system specified in claim 9.

[0025] According to a preferred embodiment of the fluid reservoir of the invention, the flexible separating element is designed to be movable between a rest state, which occurs when there is the same pressure in the first sub-chamber and the second sub-chamber, or a permeable state, which occurs when a fluid flows through the chamber at a certain first velocity in the suction direction, and a deformed state, which occurs due to the certain positive pressure difference between the first sub-chamber and the second sub-chamber after a certain amount of fluid has flowed into the first sub-chamber in the opposite direction to the suction direction.and to reduce the volume of the second sub-chamber by the specified fluid flow volume during movement between the rest or flow state and the deformed state, and to increase the volume of the second sub-chamber by the specified fluid flow volume during movement between the deformed state and the rest or flow state.

[0026] According to a preferred embodiment of the fluid reservoir of the invention, the flexible separating element has a curved initial shape.

[0027] According to a preferred embodiment of the fluid reservoir of the invention, the determined fluid delivery volume is in a range of 1 to 10 ml and is particularly 5 ml.

[0028] According to a preferred embodiment of the fluid reservoir of the invention, the backflow preventer is a beak valve or a check valve.

[0029] One advantage of this preferred further development of the invention is that the fluid reservoir has a simple design.

[0030] According to a preferred embodiment of the aspiration line of the invention, the first part of the aspiration line has a length such that the fluid reservoir is close to the fluid pump, and in particular a length that is in a range between 5% and 15% of the total length of the aspiration line.

[0031] An advantage of this preferred embodiment of the invention is that the fluid reservoir does not weigh down the external aspiration line near the handpiece or the surgical site, thereby impairing the handling of the handpiece or the external aspiration line by an operator.

[0032] A further advantage of this preferred embodiment of the invention is that the second part of the aspiration line provides a sufficiently large safety volume in case a contaminated aspiration fluid should reach the uncontaminated side of a fluid reservoir due to diffusion or capillary effects or a malfunction of the backflow preventer.

[0033] Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 schematically a cassette-side arrangement of an ophthalmic surgical system according to the invention; Fig. 2 a sectional view of a fluid reservoir according to a first embodiment of the invention in a first state; Fig. 3 a perspective partial section view of the fluid reservoir in Fig. 2 Fig. 4 a further sectional view of the fluid reservoir according to the first embodiment of the invention in a second state; Fig. 5 a sectional view of a fluid reservoir according to a first variant of a second embodiment of the invention in a first state; Fig. 6 a perspective partial section view of the fluid reservoir in Fig. 5; Fig. 7 an enlarged sectional view of a valve element of the fluid reservoir according to the first variant of the second embodiment of the invention; Fig. 8 an enlarged top view of a valve plate of the fluid reservoir according to the second embodiment of the invention; Fig. 9 a sectional view of the fluid reservoir according to the first variant of the second embodiment of the invention in a second state; Fig. 10 a perspective partial section view of the fluid reservoir in Fig. 9; Fig. 11 a sectional view of the fluid reservoir according to the first variant of the second embodiment of the invention in a third state; Fig. 12 a sectional view of a fluid reservoir according to a second variant of the second embodiment of the invention in a first state; Fig. 13 a sectional view of a fluid reservoir according to the second variant of the second embodiment of the invention in a second state; and Fig. 14 a console of an ophthalmic surgical system.

[0034] Fig. Figure 1 schematically shows a cassette-side arrangement of an ophthalmic surgical system according to the invention. However, the invention can also be used with other medical systems. The arrangement 102 comprises a cassette 103 with a cassette-side part 104 of an irrigation fluid pump and a cassette-side part 105 of an aspiration fluid pump. The arrangement 102 further comprises an external irrigation line 106 and an external aspiration line 107, which extend outside the cassette 103, an internal irrigation line 108 and an internal aspiration line 109, which extend inside the cassette 103, and a handpiece 110. A first end of the external irrigation line 106 and a first end of the internal irrigation line 108 are fluidically connected to each other via a first connecting piece 111.A first end of the outer aspiration line 107 and a first end of the inner aspiration line 109 are fluidically connected to each other via a second connector 112. A second end of the inner irrigation line 108 or the inner aspiration line 109 is fluidically connected to the cassette-side part 104 of the irrigation fluid pump or the cassette-side part 105 of the aspiration fluid pump, respectively. A second end of the outer irrigation line 106 or the outer aspiration line 107 is fluidically connected to the handpiece 110. The aspiration line 107 has a fluid reservoir 113 according to the invention between a first part 107a of the outer aspiration line 107 and a second part 107b of the outer aspiration line 107, which is suitably fluidically connected to the first part 107a of the aspiration line 107 and the second part 107b of the aspiration line 107.

[0035] Cassette 103, for example, is a cassette for insertion into the cassette holder 401 of the console 400. Fig. 14. When such a cassette 103 is inserted into the cassette holder 401, the irrigation fluid pump is formed, for example, by the cassette-side part 104 of the irrigation fluid pump and a console-side part of the irrigation fluid pump (not shown and not described in detail). Similarly, the aspiration fluid pump is formed by the cassette-side part 105 of the aspiration fluid pump and a console-side part of the aspiration fluid pump (not shown and not described in detail). To prevent contact between fluids transported by the fluid pumps and the driving parts of the fluid pumps, and to ensure sterility, the driving parts of the fluid pumps are typically located in the console 400, particularly when cassettes 103 are being changed.

[0036] During operation of the ophthalmic surgical system according to the invention during a surgical procedure, treatment fluid or irrigation fluid is supplied, for example, by the irrigation fluid pump from an irrigation fluid container (not shown) via the inner irrigation line 108 and the outer irrigation line 106 to the handpiece 110, and from the handpiece 110 via, for example, a hollow needle (not shown) or through a space between a needle (not shown) and a sleeve (not shown) to the eye of a patient undergoing surgery. The hollow needle or needle is, for example, vibrated in the ultrasonic frequency range by a piezoelectric drive in the handpiece 110 in order to emulsify the lens of the eye. The lens particles produced during emulsification, if applicable,Other particles and fluids and the used irrigation fluid are drawn in as aspiration fluid by means of the aspiration fluid pump through, for example, a suction opening in the hollow needle of the handpiece 110 via the outer aspiration line 107, the fluid reservoir 113 and the inner aspiration line 109 and conveyed to a collection container for the aspiration fluid downstream of the aspiration fluid pump (not shown).

[0037] The external irrigation line 106 and the external aspiration line 107 are preferably tubing. The external irrigation line 106, the external aspiration line 107, and the fluid reservoir 113 preferably form a tubing set or tubing assembly. The tubing set is designed to be interchangeable and fluidically connectable to the handpiece 110 and the first and second connectors 111 and 112. In a medical system, the fluid reservoir 113 is preferably located near the cassette 103 or near the aspiration fluid pump, and the lengths of the first part 107a and the second part 107b of the external aspiration line 107 are selected accordingly.

[0038] Fig. 2 and Fig. Figure 3 shows a sectional view and a perspective partial sectional view of a fluid reservoir 213 according to a first embodiment of the invention in a first state. The fluid reservoir 213 has a radially symmetrical housing 214 and a radially symmetrical flexible partition 215. The housing 214 has, along a longitudinal axis 216 of the fluid reservoir 213, a first shell-shaped housing part 217 and a second shell-shaped housing part 218, which enclose a chamber 219 of the fluid reservoir 213 on their inner surface. The flexible partition 215 divides the chamber 219 into a first sub-chamber 219a, which is defined by the first shell-shaped housing part 217 and the flexible partition 215, and a second sub-chamber 219b, which is defined by the second shell-shaped housing part 218 and the flexible partition 215.The first shell-shaped housing part 217 has, along its longitudinal axis 216, a first fluid connection 220 on the aspiration fluid pump side for connection with, for example, the first part 107a of the in . Fig. The external aspiration line 107 shown in Figure 1 is located on the first fluid connection 220, which is cylindrical and has a circular opening 221 that penetrates the first housing part 217 and fluidically connects the first subchamber 219a to the outside of the housing 214. The second shell-shaped housing part 218 has a second fluid connection 222, on the handpiece side, at a first end along its longitudinal axis 216 for connection to, for example, the second part 107b of the housing 214. Fig. The second fluid connection 222 is cylindrical and has a circular second opening 223 that penetrates the second housing part 218 and fluidically connects the second subchamber 219b to the outside of the housing 214.

[0039] The first shell-shaped housing part 217 has a radial edge section at a second end along its longitudinal axis 216, which features a peripherally extending first groove 224. The second shell-shaped housing part 218 also has a radial edge section at a second end along its longitudinal axis 216, which features a peripherally extending second groove 225. The first and second grooves 224 and 225 are opposite each other and together form an annular cavity. The cavity lies in a plane perpendicular to the longitudinal axis 216 and forms a boundary plane between the first and second shell-shaped housing parts 217 and 218, and surrounds the longitudinal axis 216 in this plane. The first and second grooves 224 and 225 are each radially bounded by an outer wall 226 and an inner wall 227 of the respective radial edge section.The outer walls 226 of the first and second grooves 224 and 225 have a length along the longitudinal axis 216 such that they touch each other at a buttress area 228, while the inner walls 227 have a length along the longitudinal axis 216 that is shorter than the length of the outer walls 226, such that a gap 229 is formed along the longitudinal axis 216 between the inner walls 227.

[0040] The flexible separating element 215 has a hollowed-out or convex shape on the side facing the second opening 223. In a radial edge section, the flexible separating element 215 has a T-shaped bead 230 that transitions radially inward into a radially symmetrical, approximately frustoconical region 231, to which a beak-shaped region 232 extends further radially inward. The beak-shaped region 232 has a first wall 233 and a second wall 234 that converge radially inward in a concave manner and terminate in sealing lips 236. These sealing lips define a slot-shaped opening 237 that can be opened and closed by the sealing lips 236. The beak-shaped region 232 thus forms a beak valve.

[0041] Further referring to Fig. 2 and Fig. Figure 3 shows an unloaded state or rest state of the beak valve or the flexible separating element 215, in which the same pressure exists on both sides of the flexible separating element 215, i.e. in the first sub-chamber 219a and the second sub-chamber 219b, and in which the flexible separating element 215 is therefore not deformed and has its initial state.

[0042] The sealing lips 236 are preferably designed and / or the material of the flexible separating element 215 and / or its dimensions are preferably selected such that the sealing lips 236 in the rest state form the slot-shaped opening 237 in Fig. 3. The chambers are sealed fluid-tight and only open when a fluid flows in a flow direction 238. This prevents fluid exchange between the first subchamber 219a and the second subchamber 219b, even when a medical system is stationary and no fluids are flowing, and avoids contamination of, for example, aspiration fluid in the second subchamber 219b by aspiration fluid in the first subchamber 219a.

[0043] The in Fig. 2 and Fig. 3 The rest state shown in the first embodiment is, due to properties of the separating element 215, preferably similar to a flow state of the nozzle valve or the flexible separating element 215, in which a fluid flows relatively stably, i.e., at a constant velocity, and without exceeding a critical flow velocity in a flow direction 238 through the housing 214, and the separating element 215 is in a different position compared to the rest state. Fig. 2 is only slightly further deformed in the direction of the first opening 221. The critical flow velocity is, for example, a velocity at which the beak-shaped region 232 begins to vibrate strongly and the vibration is transmitted to the separating element 215. In the open state of the beak valve, a fluid, in particular an aspiration fluid, flows in the flow direction 238 through the second and first openings 223 and 221 of the fluid reservoir 213, for example from the one in Fig. The handpiece 110 shown in 1 relates to the cassette 103 also shown there. The fluid, at a certain pressure of the fluid, forces the sealing lips 236 apart and allows the fluid to flow through the slot-shaped opening 237.

[0044] Fig. Figure 4 shows a further sectional view of the fluid reservoir 213 according to the first embodiment of the invention in a second state. This shows a closed state of the nozzle valve or a deformed state of the flexible separating element 215, which occurs when a fluid flows into the housing 214 or the first sub-chamber 219a in a blocking direction 239, or, more generally, when the pressure in the first sub-chamber 219a is greater than the pressure in the second sub-chamber 219b, i.e., when there is a positive pressure difference between the first and second sub-chambers 219a and 219b. The flexible separating element 215 is deformed in the direction of the second opening 223, whereby, due to a contact pressure of the sealing lips 236 against each other caused by the deformation, the sealing lips 236 close the slot-shaped opening 237 in such a way that no fluid can enter the second sub-chamber 219b of the housing 214.Thus, for example, in an ophthalmic surgical system, no contaminated aspiration fluid flows in the blocking direction 239, that is, for example, in a direction from the in . Fig. Cassette 103 shown in 1 to the handpiece 110 also shown there, through the slot-shaped opening 237.

[0045] The flexible separating element 215 is preferably a membrane. The membrane is, for example, made of silicone, while the shell-shaped first and second housing parts 217 and 218 are, for example, made of polycarbonate (PC), polypropylene (PP), or acrylonitrile butadiene styrene copolymer (ABS) by injection molding. The wall thickness and material of the first and second housing parts 217 and 218 are selected such that the first and second housing parts 217 and 218 are dimensionally stable or rigid compared to the flexible separating element 215. The wall thickness is, for example, 0.5 mm. The flexible separating element 215 is in Fig. 2 preferably with the T-shaped bead 230, which is arranged in the first and second grooves 224 and 225, clamped or pressed between the first and second shell-shaped housing parts 217 and 218. The first and second shell-shaped housing parts 217 and 218 are joined to one another at or near the abutment area 228 by welding, gluing, screwing, etc.

[0046] Fig. 5 and Fig. Figure 6 shows a sectional view and a perspective partial sectional view of a fluid reservoir 313 according to a first embodiment of a second embodiment of the invention in a first state. The fluid reservoir 313 has a radially symmetrical housing 314 and a radially symmetrical flexible partition 315. The housing 314 has, along a longitudinal axis 316 of the fluid reservoir 313, a first shell-shaped housing part 317 and a second shell-shaped housing part 318, which enclose a chamber 319 of the fluid reservoir 313 on their inner surface. The flexible partition 315 divides the chamber 319 into a first sub-chamber 319a, which is defined by the first shell-shaped housing part 317 and the flexible partition 315, and a second sub-chamber 319b, which is defined by the second shell-shaped housing part 318 and the flexible partition 315.The first shell-shaped housing part 317 has, along its longitudinal axis 316, a first fluid connection 320 on the aspiration fluid pump side for connection with, for example, the first part 107a of the in . Fig. The external aspiration line 107 shown in Figure 1 is located on the first fluid connection 320, which is cylindrical and has a circular opening 321 perpendicular to the longitudinal axis 316. This opening penetrates the first housing part 317 along the longitudinal axis 316 and fluidically connects the first sub-chamber 319a to the outside of the housing 314. The second shell-shaped housing part 318 has a second fluid connection 322 at a first end along the longitudinal axis 316, for connection with, for example, the second part 107b shown in Figure 1. Fig. The second fluid connection 322 is cylindrical and has a second circular opening 323 perpendicular to the longitudinal axis 316, which penetrates the second housing part 318 along the longitudinal axis 316 and fluidically connects the second subchamber 319b to the outside of the housing 314.

[0047] The first shell-shaped housing part 317 has a radial edge section at a second end along its longitudinal axis 316, which features a peripherally extending first groove 324. The second shell-shaped housing part 318 also has a radial edge section at a second end along its longitudinal axis 316, which features a peripherally extending second groove 325. The first and second grooves 324 and 325 are opposite each other and together form an annular cavity. The cavity lies in a plane perpendicular to the longitudinal axis 316 and forms a boundary plane between the first and second shell-shaped housing parts 317 and 318, and surrounds the longitudinal axis 316 in this plane. The first and second grooves 324 and 325 are each bounded radially by an outer wall 326 and an inner wall 327 of the respective radial edge section.The outer walls 326 of the first and second grooves 324 and 325 have a length along the longitudinal axis 316 such that they touch each other at an abutment area 328, while the inner walls 327 have a length along the longitudinal axis 316 that is shorter than the length of the outer walls 326, such that a gap 329 is formed along the longitudinal axis 316 between the inner walls 327.

[0048] The flexible separating element 315 has a hollow or convex shape on the side facing the second opening 323. The flexible separating element 315 has a T-shaped bead 330 in a radial edge section, which transitions radially inward into a radially symmetrical S-shaped region 340. Further radially inward, a circular opening 341 perpendicular to the longitudinal axis 316 adjoins this S-shaped region. A circular valve plate 342, forming a valve seat of a check valve, is inserted into the circular opening 341. The circular valve plate 342 has a circular opening 343 within it. A valve stem 344 of a radially symmetrical valve element 345, which includes the valve stem 344 and a valve head 346, is arranged in the circular opening 343. The valve head 346 serves as a valve closure.

[0049] Fig. Figure 7 shows an enlarged sectional view of the valve element 345 of the fluid reservoir 313 according to the first variant of the second embodiment of the invention. The valve stem 344 points along the longitudinal axis 316 towards the circular opening 343 of the valve plate 342. Fig. 5, merging into one another, first a cylindrical section 347 with a constant radial diameter perpendicular to the longitudinal axis 316, a bead-shaped second section 348 with a radial diameter that initially rises slowly along the longitudinal axis 316 and then falls sharply, a cylindrical third section 349 with a constant radial diameter perpendicular to the longitudinal axis 316, and a shield-shaped section that forms the valve head 346. In the case of a valve element 345 inserted into the valve plate 342, as in Fig. As shown in Figure 5, the cylindrical third section 349 of the valve element 345 is arranged in the circular opening 343 of the valve plate 342. The cylindrical third section 349 is preferably designed such that it at least partially seals the circular opening 343 of the valve plate 342 in a fluid-tight manner.

[0050] Fig. Figure 8 shows an enlarged top view of the circular valve plate 342 of the fluid reservoir 313 according to the second embodiment of the invention. In addition to the circular opening 343, the circular valve plate 342 has a first annular section 350 surrounding the circular opening 343, four spokes 351 extending radially from the first annular section 350, and a second annular section 352 in which the spokes 351 terminate. Between the spokes 351, four recesses 353 are formed in the valve plate 342 in the polar direction, which are suitable for allowing a fluid to pass through.

[0051] Back to referring to Fig. 5 and Fig. Figure 6 shows an unloaded or resting state of the check valve or the flexible separating element 315, in which the same pressure exists on both sides of the flexible separating element 315, i.e., in the first subchamber 319a and the second subchamber 319b, and in which the flexible separating element 315 is therefore not deformed and is in its initial state. In this resting state, no fluid, in particular aspiration fluid, flows through the valve plate 342 in the flexible separating element 315.

[0052] Fig. 9 and Fig. Figure 10 shows a sectional view and a perspective partial sectional view of the fluid reservoir 313 according to the first variant of the second embodiment of the invention in a second state. This shows a flow state of the check valve or the flexible separating element 315 in which a fluid, in particular an aspiration fluid, flows through the second and first openings 323 and 321 of the fluid reservoir 313 relatively stably, that is, at a constant velocity, and without exceeding a critical flow velocity through the second opening 323 and the first opening 321 in a flow direction 338, for example from the one shown in Fig. The flow from the handpiece 110 shown in Figure 1 to the cassette 103 also shown therein. The critical flow velocity is, for example, a velocity at which the valve head 346 begins to vibrate or flutter strongly and the vibration is transmitted to the separating element 315. The separating element 315 is, compared to the resting state in Fig. 5 and Fig. 6 in the passage state preferably only slightly further deformed in the direction of the first opening 321.

[0053] At the in Fig. 5, Fig. 6, Fig. 9 and Fig. In the first variant of the second embodiment of the invention shown in Figure 10, the dimensions of the valve head 346 are, for example, a thickness profile of the valve head 346 depending on the radial direction in the section of Fig. 7, and / or the material of at least the valve head 346 is selected such that in the Fig. 5 and Fig. 6 shown rest state of the check valve or the flexible separating element 315 a radially outer area 354 of the valve head 346 in a blocking direction 339 against the in Fig. The second annular section 352 shown in Figure 8 is pressed with a restoring force such that the recesses 353 of the valve plate 342 are fluid-tightly sealed against the first subchamber 319a and no fluid can enter the second subchamber 319b of the housing 314. This prevents fluid exchange between the first subchamber 319a and the second subchamber 319b. Fig. 5 is prevented, and contamination of, for example, aspiration fluid in the second subchamber 319b by aspiration fluid in the first subchamber 319a can be avoided. If the longitudinal axis 316 of the fluid reservoir 313 is furthermore aligned parallel to the acceleration due to gravity, at least the pressure exerted by the valve element 345 is additionally caused by gravity. Fig. 7 radial outer area 354 of the valve head 346 shown in the blocking direction 339 against the in Fig. The second annular section 352 shown in Figure 8 is or rests on it, and the recesses 353 of the valve plate 342 are, with a suitable design of the valve element 345, fluid-tightly closed in the rest state with respect to the first sub-chamber 319a, such that no fluid can enter the second sub-chamber 319b of the housing 314.

[0054] At the in Fig. 5, Fig. 6, Fig. 9 and Fig. In the first variant of the second embodiment shown in Figure 10, the dimensions of the valve head 346 and / or the material of at least the valve head 346 are selected such that in the Fig. 9 shown passage condition, in which a fluid flows in the passage direction 338 from the second opening 323 to the first opening 321 under a certain minimum pressure, the radially outer region 354 in Fig. 7 of the valve head 346 bends elastically away from the valve plate 342 against the restoring force and possibly gravity, such that the radially outer area 354 is sufficiently far from the valve plate 342 at a certain distance 355 to open the check valve or to allow a suitable flow of fluid through at least the recesses 353 towards the first opening 321.

[0055] Fig. Figure 11 shows a sectional view of the fluid reservoir according to the first variant of the second embodiment of the invention in a third state. This shows a closed state of the check valve in which the flexible separating element 315 is deformed. This deformation occurs when a fluid flows into the housing 314 or the first sub-chamber 319a in the blocking direction 339, or more generally, when the pressure in the first sub-chamber 319a is greater than the pressure in the second sub-chamber 319b, i.e., when there is a positive pressure difference between the first and second sub-chambers 319a and 319b. The flexible separating element 315 is deformed in the direction of the second opening 323. Furthermore, the valve head 346 of the valve element 345, and in particular its radially outer region 354, is deformed. Fig. 7 is pressed even more tightly against the valve plate 342 than in the resting state, such that no fluid can enter the second subchamber 319b of the housing 314. Thus, contamination of, for example, aspiration fluid in the second subchamber 319b by aspiration fluid in the first subchamber 319a can be avoided.

[0056] Fig. 12 and Fig. Figure 13 shows sectional views of a fluid reservoir 313 according to a second variant of the second embodiment of the invention in a first and a second state. In this variant, the valve head 346 has a slightly modified form compared to Fig. 7 a flat, round-headed shape with one rounded side along the longitudinal axis 316 and one flat side facing the valve plate 342. In this variant, at least the length of the Fig. The cylindrical third section 349 of the valve element 345 shown in Figure 7 is selected along the longitudinal axis 316 such that the valve element 345 can move to such an extent that the valve head 346 is in a Fig. The first state or flow state of the check valve shown in Figure 12 is located at a specific distance 355 from the valve plate 342 along the longitudinal axis 316, sufficiently to allow suitable fluid flow through at least the recesses 353 of the valve plate 342. The bead-shaped second section 348 of the valve stem 344 presses against the Fig. 8 shown first annular section 350 of the valve plate 342, such that further movement of the valve stem 344 is prevented.

[0057] In a Fig. In the second state, or closed state, of the check valve shown in Figure 13, the flexible separating element 315 is in a deformed state. This deformation occurs when a fluid flows into the housing 314 or the first sub-chamber 319a in the blocking direction 339, or, more generally, when the pressure in the first sub-chamber 319a is greater than the pressure in the second sub-chamber 319b, i.e., when there is a positive pressure difference between the first and second sub-chambers 319a and 319b. The valve head 346 of the valve element 345 is pressed more firmly against the valve plate 342 than in a rest state, where only gravity acts on the valve element 345. It should be noted that in the second variant of the second embodiment of the invention, for the check valve to close in the rest state, the longitudinal axis 316 must be aligned with the direction of gravity.The valve element 345 is therefore preferably designed and its material is selected such that no fluid passes through the recesses 353 and the circular opening 343 in the valve plate 342 in either the rest state or the closed state. Fig. 8 can enter the second subchamber 319b of the housing 314. Thus, contamination of, for example, aspiration fluid in the second subchamber 319b by aspiration fluid in the first subchamber 319a can be avoided.

[0058] The flexible separating element 315 is preferably a flexible membrane. The membrane is, for example, made of silicone, while the shell-shaped housing parts 317 and 318 are, for example, made of polycarbonate (PC), polypropylene (PP), or acrylonitrile butadiene styrene copolymer (ABS) by injection molding. The wall thickness and material of the first and second housing parts 317 and 318 are selected such that the first and second housing parts 317 and 318 are dimensionally stable or rigid compared to the flexible separating element 315. The wall thickness is, for example, 0.5 mm. The membrane is preferably connected to the T-shaped bead 330 in Fig. 5, which is arranged in the first and second grooves 324 and 325, is clamped or pressed between the first and second shell-shaped housing parts 317 and 318. The first and second shell-shaped housing parts 317 and 318 are joined to each other at or near the abutment area 328 by welding, gluing, screwing, etc. The valve plate 342 is preferably made of rigid plastic and preferably connected via a Fig. 8 and Fig. Stage 356 shown in Figure 12, which is located in the second annular section 352 on a side facing away from the valve head 346, is in Fig. The valve plate 342 shown in Figure 8 is joined to the flexible separating element 315 by injection molding, gluing or welding.

[0059] When operating a console of an ophthalmic surgical system, such as the console 400 in Fig. 14, a cassette, such as cassette 103 in Fig. 1, inserted into the cassette holder 401. The cassette is intended to be used for several patients to be treated, for example, over the course of a day. The exemplary hose set in the invention, as shown in Fig. As shown in Figure 1, for example, the external irrigation line 106 and the external aspiration line 107 are connected to the fluid reservoir 113, with lines 106 and 107 being designed as tubing. Before the first use of a tubing set, the aspiration line 107 and the fluid reservoir 113 are usually completely pre-filled (primed) with an irrigation fluid or treatment fluid, such as a balanced salt solution (BSS), so that no air bubbles are present in the aspiration path.

[0060] During an operation with the handpiece 110, the aspiration fluid, drawn in by the aspiration fluid pump, flows in a suction direction through the aspiration line 107 and the fluid reservoir 113 towards the cassette 103. When the tubing set is in Fig. The fluid reservoir 213 shown in Figures 2-4 indicates that the aspiration fluid flows into the reservoir shown in Figure 2-4. Fig. 2 shown flow direction 238, which is a flow direction of the beak valve shown therein. Alternatively, if the hose set is the one shown in the Fig. The aspiration fluid flows into the fluid reservoir 313 shown in Figures 5, 6 and 9-13. Fig. 9 and Fig. The flow direction 338 shown in Figure 12 is a flow direction of the check valve depicted therein. Under these conditions, the flexible separating element 215 or 315 assumes a flow state in both fluid reservoir 213 and fluid reservoir 313.

[0061] If the flow direction of the aspiration fluid is reversed during the operation, for example by a control of console 400 (not shown) in Fig. 12 a reflux function of the console 400 is activated, for example to prevent occlusion of a hollow needle of the handpiece 110 in Fig. 1. To remove a large lens particle and / or to push a suctioned capsular bag or suctioned parts of an iris away from the hollow needle, aspiration fluid from the aspiration pump side flows away from the cassette 103 and through the first part 107a of the external aspiration line 107 into the fluid reservoir 113. If the tubing set is in the Fig. The fluid reservoir 213 shown in Figures 2-4 indicates that the aspiration fluid flows into the reservoir shown in Figure 2-4. Fig. 2 and Fig. 4 shown locking direction 239, which is a locking direction of the beak valve shown therein. If, however, the hose set is the one shown in the Fig. The aspiration fluid flows into the fluid reservoir 313 shown in Figures 5, 6 and 9-13. Fig. 5, Fig. 11 and Fig. The blocking direction 339 shown in Figure 13 is a blocking direction of the check valve shown therein. Under these conditions, the flexible separating element 215 or 315 in both fluid reservoir 213 and fluid reservoir 313 assumes a deformed state, as shown in Figure 13. Fig. 4, Fig. 11 and Fig. 13 is shown.

[0062] When the flexible separating element 215 or 315 changes from its resting or open state to its closed or deformed state, the nozzle valve or check valve begins to close, and the aspiration fluid flowing in the opposite direction into the first subchamber 219a or 319a of the fluid reservoir 213 or 313 from the aspiration pump side pushes only aspiration fluid to the handpiece 110 via the separating element 215 or 315. Fig. 1, which is located in the second subchamber 219b or 319b of the respective fluid reservoir 213 or 313 and the in Fig. The second part 107b of the external aspiration line 107 is shown in Figure 1. The flexible separating element 215 or 315, together with the aspiration fluid on the pump side, which presses against the flexible separating element 215 or 315 in the first subchamber 219a or 319a in the blocking direction 239 or 339, acts like a diaphragm pump, which conveys the handpiece-side aspiration fluid in the second subchamber 219b or 319b towards the handpiece 110.

[0063] A control of the console 400 in Fig. As an extension of the invention, paragraph 14 controls the aspiration fluid pump such that, preferably, the aspiration fluid pump only pumps aspiration fluid against the flow direction of the fluid reservoir 213 or 313 until the aspiration fluid contained in the second subchamber 219b or 319b has been completely emptied from the second subchamber 219b or 319b. This provides an additional safety measure to prevent unwanted contamination.

[0064] If, during the operation, the flow direction is subsequently changed back to the suction direction or flow direction 238, 338, the beak valve opens in Fig. 2 or the check valve in Fig. 9 and Fig. 12, the separating element 215 or 315 is returned to the permeable state by the aspiration fluid and its restoring force, the fluid reservoir 113, 213, 313 fills with an aspiration fluid from a current patient, and the aspiration fluid can flow in the permeable direction 238 or 338 towards the cassette 103.

[0065] When switching between patients, it is necessary to change the handpiece 110 in Fig. 1. to be cleaned or replaced. In addition, at least the second part 107b of the external aspiration line 107 and the reservoir 113, 213, 313 must be replaced. Usually, however, the entire external aspiration line 107 and the fluid reservoir 113, 213, 313, and also the external irrigation line 106 are replaced. When changing patients, the second part 107b of the external aspiration line 107 and the second chamber 219b or 319b of the respective fluid reservoir 213 or 313 are also replaced, for example. Fig. 2, Fig. 5 or Fig. 12 is filled with uncontaminated aspiration fluid or aspiration fluid from the new patient. This ensures that, with the reflux function of console 400 activated, no fluid from a previous patient passes through the second subchamber 219b or 319b of the fluid reservoir 213 or 313 into Fig. 2, Fig. 5 or Fig. 12 and the second part 107b of the external aspiration line 107 in Fig. 1 is not transported, but rather the aspirated aspiration fluid of a current patient is merely pumped back from the respective reservoir 113, 213, 313 towards the eye to be treated. The beak valve or the check valve, together with the flexible separating element 215 or 315, forms the barrier between the aspiration fluid of a previous patient and the aspiration fluid of a current patient.

[0066] The volume separated by the flexible separating element 215 or 315 between the rest state or flow state and the blockage state in the second subchamber 219b or 319b of the respective fluid reservoir 213 or 313 in Fig. 2, Fig. 5 or Fig. The volume displaced is referred to herein as the fluid delivery volume. To determine the volume displaced between the rest state or open state and the closed state in the second subchamber 219b or 319b of the respective fluid reservoir 213 or 313, for example... Fig. 2, Fig. To set the displaced fluid flow volumes to 5 or 12, chamber 219 or 319 has a predetermined shape and volume, and the flexible separating element 215 or 315 has a predetermined initial shape. For example, in the Fig. 2, Fig. 5 and Fig. In the hollowed or curved initial shape of the flexible separating element 215 or 315 shown in Figure 12, the second sub-chamber 219b or 319b occupies a significant part of the volume of chamber 219 or 319 in the rest or flow state in order to maximize the fluid delivery volume and thus also the volume for reflux processes, and to optimally utilize the volume of chamber 219 or 319 for providing the fluid delivery volume.

[0067] Fluid reservoir 113 in Fig. 1 is preferably located as close as possible to the cassette 103. This has the advantage that the fluid reservoir 113 does not obstruct the external aspiration line 107 near the handpiece 110 and thus does not impair the handling of the handpiece 110 by an operator. In ophthalmic surgical systems, the external aspiration line 107 typically has a length of approximately 2 m and a volume of 2 ml to 4 ml, and preferably 3.5 ml. The second subchamber 219b or 319b of the respective fluid reservoir 213 or 313 in Fig. 2 and Fig. In an ophthalmic surgical system according to the invention, the flexible separating element 215 or 315 in its initial state preferably has a volume in the range of 1 ml to 10 ml, and preferably 5 ml. This volume corresponds approximately to the fluid delivery volume and is sufficient, for example, to clear the aspiration line 107 or a hollow needle of the handpiece 110 several times by means of a backflushed aspiration fluid. The fluid reservoir 113 according to the invention is supplied by means of a fluid reservoir 113. Fig. The additional volume provided beyond the first section 107a of the external aspiration line 107 significantly increases the available reflux volume and improves the controllability of the aspiration fluid pump. The first section 107a of the external aspiration line 107 provides a safety volume in case contaminated aspiration fluid should enter the uncontaminated side of a fluid reservoir 113 due to diffusion or capillary effects and / or a defect in the nozzle valve or check valve.

[0068] The spring constant or the modulus of elasticity of the flexible separating element 215 or 315, for example, in Fig. 2, Fig. 5 and Fig. 12 is low and suitably chosen to preferably guarantee both sufficient dimensional stability in the initial state and a restoring force that is not too high in the deformed state of the flexible separating element 215 or 315. A lower restoring force is associated with easier deformation and better movement of the separating element, i.e., a lower pressure loss. The flexible separating element 215 or 315 in Fig. 2, Fig. 5 and Fig. 12 can be made from thermoplastic polyurethane (TPU), thermoplastic elastomer (TPE) or ethylene propylene diene monomer (EPDM) rubber, in addition to silicone.

[0069] Although the present invention has been described above with reference to preferred embodiments, it is not limited to these, but can be modified in many different ways.

[0070] The fluid reservoir and aspiration line described herein are suitable for use in any surgical or medical system where fluid, with or without tissue fragments, needs to be aspirated using a handpiece or instrument, or without a handpiece or instrument. Such systems include ophthalmic surgical systems, such as vitrectomy systems, as well as neurosurgical, visceral surgical, oral surgical, and other surgical or non-surgical medical systems in these fields. In ophthalmic surgical systems for vitrectomy, the [specific application] is described in [reference]. Fig. 1 The aspiration line shown is usually fluidically connected to a vitrectomy, while the irrigation line is fluidically connected to an infusion cannula as an infusion line.

[0071] In variations of the invention, the first and second housing parts have a different shape, such as a cuboid or cylindrical shape. Instead of a housing, the reservoir in variations of the invention is a different casing, such as a hose casing.

[0072] In variations of the invention, the flexible separating element is, as an alternative to a membrane, another flexible element with thin walls, such as a flexible film. In such cases, the resting state and the permeable state can differ considerably. In variations of the invention, the flexible separating element has a flat or concave shape.

[0073] The bead 230 or 330 in, for example, Fig. 2, Fig. In variations of the invention, 5 or 12 has a circular or oval cross-section.

[0074] The external aspiration line 107 has a suitable length and volume in other medical systems. The second subchamber 219b or 319b of the respective fluid reservoir 213 or 313 in Fig. 2, Fig. In another medical system, the flexible separating element 215 or 315 has a suitably large volume in its initial state. This volume is sufficient to, for example, clear a blockage from the aspiration line 107 or a hollow needle of the handpiece 110 several times using backflushed aspiration fluid. Reference symbol list 102 Arrangement 103 Cassette 104 cassette-side part of the irrigation fluid pump 105 cassette-side part of the aspiration fluid pump 106 external irrigation line 107 external aspiration line 107a first part of the external aspiration line 107b second part of the external aspiration line 108 internal irrigation line 109 internal aspiration line 110 handpiece 111 first connecting piece 112 second connecting piece 113, 213, 313 Fluid reservoir 214, 314 Housing 215, 315 Separating element 216, 316 Longitudinal axis 217, 317 first housing part 218, 318 second housing part 219, 319 Chamber 219a, 319a first sub-chapter 219b, 319b second sub-chapter 220, 320 first fluid connection 221, 321 first opening 222, 322 second fluid connection 223, 323 second opening 224, 324 first groove 225, 325 second groove 226, 326 Exterior wall 227, 327 Interior wall 228, 328 Kick-off area 229, 329 gap 230, 330 bead 231 frustoconical area 232 beak-shaped area 233 first wall 234 second wall 236 sealing lips 237 slit-shaped opening 238, 338 Direction of passage 239, 339 Blocking direction 340 S-shaped area 341 circular opening 342 Valve plate 343 circular opening 344 Valve stem 345 Valve element 346 Valve head 347 cylindrical first section 348 bead-shaped second section 349 cylindrical third section 350 first ring-shaped section 351 spoke 352 second annular section 353 cutouts 354 radial outer area 355 distance 356th level 400 console 401 cassette recording

Claims

[1] Fluid reservoir (113; 213; 313) for an aspiration line (107) of a medical system, wherein the aspiration line (107) serves to aspirate a fluid from a surgical site on a living being by means of a fluid pump of the medical system in a suction direction, comprising: - a shell (214; 314) enclosing a chamber (219; 319) designed to hold a fluid; - a separating element (215; 315) that divides the chamber (219; 319) into a first sub-chamber (219a; 319a) and a second sub-chamber (219b; 319b); - a first fluid connection (220; 320) designed to fluidically connect the first subchamber (219a; 319a) to an outer surface of the shell (214; 314), and designed to be connected to a first part (107a) of the aspiration line (107) to be connected to the fluid pump; - a second fluid port (222; 322) designed to fluidically connect the second subchamber (219b; 319b) to the outer surface of the shell (214; 314), and designed to be connected to a second part (107b) of the aspiration line (107) to be directed towards the surgical site; and - a backflow preventer that the separating element (215; 315) has to fluidically connect the first subchamber (219a; 319a) with the second subchamber (219b; 319b), wherein the backflow preventer is designed to prevent a flow of fluid from the first subchamber (219a; 319a) into the second subchamber (219b, 319b) in the opposite direction to the suction direction, and wherein the separating element is a flexible separating element (215; 315), and the flexible separating element (215; 315) is designed in such a way as to achieve a pumping effect of the fluid reservoir (113; 213; 313) in the second subchamber (219b; 319b) when the flexible separating element (215; 315) is deformed by a certain positive pressure difference between the first subchamber (219a; 319a) and the second subchamber (219b; 319b), which enables the conveyance of a certain fluid delivery volume, characterized by , that the specific fluid flow volume is chosen depending on the type of operation performed on a living being. [2] Fluid reservoir (113; 213; 313) according to claim 1, characterized by, that the flexible separating element (215; 315) is designed to be movable between a state of rest, which is established at the same pressure in the first sub-chamber (219a; 319a) and the second sub-chamber (219b; 319b), or a state of open passage, which is established when a fluid flows at a certain initial velocity in the suction direction through the chamber (219; 319) and a deformed state, which is established by the certain positive pressure difference between the first sub-chamber (219a; 319a) and the second sub-chamber (219b; 319b) after a certain quantity of fluid flows in the opposite direction to the suction direction into the first sub-chamber (219a; 319a), and to be movable during movement between the state of rest or open passage and the deformed state, the volume of the second sub-chamber (219b;319b) to reduce the specified fluid delivery volume and, during movement between the deformed state and the rest state or flow state, to increase the volume of the second sub-chamber (219b, 319b) by the specified fluid delivery volume.; [3] Fluid reservoir (213, 313) according to one of the preceding claims, characterized by , that the flexible separating element (215; 315) has a curved initial shape. [4] Fluid reservoir (113; 213; 313) according to any one of claims 1 to 3, characterized by that the specified fluid delivery volume is in a range of 1 to 10 ml. [5] Fluid reservoir (113; 213; 313) according to claim 4, characterized by that the specific fluid delivery volume is 5 ml. [6] Fluid reservoir (213; 313) according to any one of the preceding claims, characterized by that the backflow preventer is a beak valve or a check valve. [7] Aspiration line (107) for a medical system, wherein the aspiration line (107) serves to aspirate a fluid from a surgical site on a living being by means of a fluid pump of the medical system in a suction direction, comprising: - a first part (107a) designed to be fluidically connected to the fluid pump, and - a second part (107b) which is to be directed towards the site of the operation, characterized by , that the aspiration line (107) has a fluid reservoir (113; 213; 313) according to one of the preceding claims, which is fluidically connected between the first part (107a) and the second part (107b) of the aspiration line (107). [8] Aspiration line (107) according to claim 7, characterized by , that the first part (107a) of the aspiration line (107) has a length that is in a range between 5% and 15% of the total length of the aspiration line (107). [9] Ophthalmic surgical system for treating an eye of a living being, comprising: - a console (400) that has a cassette recording area; - a cassette (103) designed for insertion into the cassette receiving area; - an irrigation line (106); - an aspiration line (107); and - a handpiece (110) for treating the eye to be treated, wherein the cassette (103) comprises at least a part (104) of at least a first fluid pump for supplying a fluid via the irrigation line (106) to the eye being treated and at least a part (105) of at least a second fluid pump for aspirating fluid from the eye being treated via the aspiration line (107) in a suction direction, characterized by an aspiration line (107) according to claim 7 or 8.

Images