WO2010146159A1

WO2010146159A1 - Apparatus and method for sucking a fluid to be sucked

Info

Publication number: WO2010146159A1
Application number: PCT/EP2010/058645
Authority: WO
Inventors: Dietmar Mattes; Monika Mayer; Edah Silajdzic
Original assignee: Medizinische Universität Graz
Priority date: 2009-06-18
Filing date: 2010-06-18
Publication date: 2010-12-23

Abstract

An apparatus (10) for sucking a fluid to be sucked (12) is provided, the apparatus (10) comprising a sucking tube (14) through which the fluid to be sucked (12) is suckable and a feeding unit (16) adapted for feeding a sucking aid liquid (18) to a portion (20) of the sucking tube (14) for supporting the sucking of the fluid to be sucked (12) through the sucking tube (14).

Description

Apparatus and method for sucking a fluid to be sucked

The invention relates to an apparatus for sucking a fluid to be sucked.

Further, the invention relates to a method for sucking a fluid to be sucked.

During minimally invasive surgery, it may be desirable to suck fluids from an operating field, e.g. a body cavity of a patient, in order to remove smoke and liquids generated in the surgical procedure.

DE 39 22 746 Cl discloses an insufflation apparatus comprising a sucking tube of an endoscope whose distal ending portion is arranged within an operating field. A sucking pump, conduits and valves are accordingly arranged for sucking smoke and liquids from the operating field away through the sucking tube. These fluids have been generated in the surgical procedure upon e.g. ablating tissue. Further, gas can be fed through the sucking tube to regulate the environmental pressure within the operating field. US 2007/0249990 Al discloses an automatic smoke evacuation and insufflation system for surgical procedures comprising a vacuum pump for removing gas, smoke and debris from an operating field through a sucking tube and an insufflator for supplying gas to the operating field. JP 11-318909 A discloses a smoke removal system used for surgical procedures at the human body. The system comprises a pneunoperitoneum device which sucks fluids from the operating field through a sucking tube and which feeds gas to the operating field, in order to regulate the pressure at the operating field. However, during sucking fluids from the operating field the sucking tube may get choked due to debris deposited at the inner surface of the sucking tube, since the fumes and liquids to be sucked may comprise solid particles. Thus the cross section of the sucking tube and thus the flow rate through the sucking tube may be reduced. In this context, the term "flow rate" may denote the fluid volume passing through the sucking tube per time unit. Accordingly, there may be a need for efficiently preventing the debris depositing at the inner surface of the sucking tube, in order to maintain a constant flow rate through the sucking tube in case of stable sucking conditions such as pressure conditions within the sucking tube. In the following, the term "constant flow rate" through the sucking tube may denote such a flow rate through the sucking tube which occurs under stable sucking conditions of the sucking tube, in particular under stable pressure conditions in the sucking tube.

It is an object of the invention to provide an apparatus for sucking a fluid to be sucked which enables sucking the fluid to be sucked at a constant flow rate. Further, it is an object of the invention to provide a method for sucking a fluid to be sucked at a constant flow rate.

In order to achieve the object defined above, an apparatus for sucking a fluid to be sucked and a method for sucking a fluid to be sucked are provided. According to an exemplary embodiment of the invention, an apparatus for sucking a fluid to be sucked is provided, the apparatus comprising a sucking tube through which the fluid to be sucked is suckable and a feeding unit adapted for feeding a sucking aid liquid to a portion of the sucking tube for supporting the sucking of the fluid to be sucked through the sucking tube.

According to another exemplary embodiment of the invention, a method for sucking a fluid to be sucked is provided, the method comprising sucking a fluid to be sucked through a sucking tube, and feeding a sucking aid liquid to a portion of the sucking tube for supporting the sucking of the fluid to be sucked through the sucking tube.

In the context of this application, the term "fluid" may particularly denote any gaseous or liquid medium. The fluid may comprise solid particles. More particularly, a fluid may be a burning condensate, e.g. smoke, generated during any kind of burning process or combustion process which may occur e.g. during ablation of human tissue in a surgical procedure or in an industrial system, a vehicle, etc. In particular, during an incomplete burning process a fluid to be sucked such as smoke may be generated which may comprise a high fraction of soot and unburned hydrocarbon.

In the context of the application, the term "portion of the sucking tube" may denote an ending portion of the sucking tube, any intermediate portion of the sucking tube or the total sucking tube. In medical applications, the portion of the sucking tube may be a distal ending portion of the sucking tube which may be introduced into a body cavity and placed within an operating field.

In the context of the application, "feeding the sucking aid liquid to the portion of the sucking tube" may comprise the fact that the sucking aid liquid is fed to the interior of the sucking tube as well as to a region outside of the sucking tube, but in close proximity of an opening of the sucking tube. The opening of the sucking tube may be arranged at the face side of the sucking tube or at any portion of the sucking tube.

According to the exemplary embodiments of the invention, an apparatus for sucking a fluid to be sucked and a method for sucking a fluid to be sucked are provided which enable sucking a fluid to be sucked through a sucking tube at a constant and in particular high flow rate.

A pressure gradient may be provided within the sucking tube such that the fluid to be sucked may be sucked through the sucking tube, in order to accomplish a sucking process in an operational state of the apparatus. For this purpose, the apparatus may comprise a sucking pump adapted for sucking the fluid to be sucked through the sucking tube. The sucking pump may be arranged at e.g. an ending portion of the sucking tube. The pump may generate a lower pressure within the sucking tube such that a fluid to be sucked is sucked from a more distant portion of the sucking tube comprising a higher pressure to the lower pressure environment. Further, a pressure gradient may be naturally provided in an operational state of the apparatus in that e.g. an ending portion of the sucking tube may be arranged in a high pressure area, whereas another ending portion of the sucking tube may be arranged in a low pressure area. In case of medical applications the high pressure area may be provided by a body cavity into which the sucking tube is inserted, and the low pressure area may coincide with an environmental area with the other ending portion of the sucking tube being open to the environment. The low pressure area may also coincide with the central vacuum system of the hospital with the other ending portion of the sucking tube being connected to the central vacuum system.

If the fluid to be sucked is a burning condensate, fractions of the fluid to be sucked may deposit at an inner surface of the sucking tube such that the cross-section of the sucking tube may be reduced. These undesired fractions may be solid, liquid or gaseous. In order to prevent this choking effect of the sucking tube, a sucking aid liquid may be fed to the particular portion of the sucking tube where these undesired fractions of the fluid to be sucked may be precipitated or deposited at the inner surface of the sucking tube. The sucking aid liquid may also be fed to a portion of the sucking tube upstream of the portion of the sucking tube, where fractions may be deposited at the inner surface of the sucking tube. The sucking aid liquid may be mixed with the fluid to be sucked, and the undesired fractions of the fluid to be sucked may be incorporated into the sucking aid liquid. Due to this scrubbing effect the mixed fluid to be sucked and the sucking aid liquid may be transported through the sucking tube without forming any undesired deposition at the inner surface of the sucking tube. Further, already deposited fractions of the fluid to be sucked which may have formed agglomerations of particles, e.g. tar or soot, may be removed from the inner surface of the sucking tube and may be transported downstream through the sucking tube. Thus the cross- section of the sucking tube may be kept almost constant in the sucking process such that the fluid to be sucked may be transported through the sucking tube at a high and in particular constant flow rate.

Consequently, maintenance costs of the apparatus for sucking a fluid to be sucked as well as time delays occurring upon exchanging a choked sucking tube may be significantly reduced.

In the following, further exemplary embodiments of the apparatus will be explained. However, these embodiments also apply to the method.

The feeding unit may comprise a feeding tube through which the sucking aid liquid is feedable. Thus, a compact and stable design of the apparatus for sucking a fluid to be sucked is provided. The feeding tube may be a thin-walled tube which may be designed flexible upon bending.

The feeding unit may comprise at least two feeding tubes, with a number of feeding tubes eventually varying according to a dimension of an inner diameter of the sucking tube, in order to continuously support a complete mixture of the sucking aid liquid provided by the feeding tubes and the fluid to be sucked. A larger diameter of the sucking tube may require more than one feeding tubes emptying into or near the portion of the sucking tube.

An opening of the feeding unit may face an opening of the portion of the sucking tube. This measure causes a better mixing of the sucking aid liquid with the fluid to be sucked, since the sucking aid liquid can be directly supplied to the sucking tube for an enhanced mixing of the sucking aid liquid and the fluid to be sucked.

A cross-section of the opening of the feeding tube may vary according to the need of supplying the sucking aid liquid to the fluid to be sucked. The cross-section of the opening may be slit-like or circular. In particular, cross-sections of two openings may be different to one another.

An opening of the feeding tube may be filled with a fluid permeable material, whereby a contamination of the feeding tube by fractions of the fluid to be sucked may be prevented. The fluid permeable material may be a porous material through which e.g. solid particles of the fluid to be sucked may not pass.

In particular, one feeding tube may comprise at least two openings, whereby a very small and compact design of the feeding unit is accomplished.

An ending portion of the feeding tube may be formed in a needle- like way. This allows for precisely directing a flow of the sucking aid liquid to a desired position.

At least an ending portion of the sucking tube and/or the feeding tube may be designed flexible upon bending, thus allowing for a three dimensional bending of the tubes. Therefore inserting and properly placing the tubes at a desired location are significantly improved.

Further, the feeding unit may comprise a feeding pump for feeding the sucking aid liquid to the portion of the sucking tube. The feeding unit may comprise an ejection nozzle through which the sucking aid liquid is ejectable to the fluid to be sucked, whereby a homogenous distribution of the sucking aid liquid in a region around the nozzle may be provided. Therefore, the mixing of the fluid to be sucked and the sucking aid liquid may be enhanced. This measure may be particular useful, if the flow through the sucking tube is laminary, since the mixing of the fluid to be sucked and the sucking aid liquid may happen across the total cross-section of the sucking tube.

If the flow through the sucking tube is turbulent, the feeding unit may not comprise an ejection nozzle, but only an injection tube with the sucking aid fluid being ejected to the fluid to be sucked through the opening of the injection tube. Here, the injection tube may be identical to the feeding tube. Mixing of the fluid to be sucked and the sucking aid liquid may automatically occur in the sucking tube, since a turbulent flow may have turbulences and transverse flows favouring the mixing process. The feeding unit may comprise at least two ejection nozzles with the number of ejection nozzles depending on the desired degree of mixing and a dimension of a diameter of the sucking tube. An apparatus comprising at least two ejection nozzles may be particular useful in case of a sucking tube comprising a larger diameter, since a better mixing of the sucking aid liquid and the fluid to be sucked may be achievable.

The ejection nozzle may be provided at an ending portion of the feeding tube with the feeding tube emptying into or outside of the sucking tube.

Openings of the feeding tubes and/or ejection nozzles may be arranged along an at least partial circumference of the portion of the sucking tube, whereby a homogenous mixture of the fluid to be sucked and the sucking aid liquid may be provided. In particular, the openings of the feeding tubes and/or the ejection nozzles may be equally distantly displaced to one another seen along a longitudinal axis of the portion of the sucking tube. Thus a still more homogeneous mixture of the fluid to be sucked and the sucking aid liquid is provided. In particular, the openings and/or the ejection nozzles may empty into or direct the sucking aid liquid into an interior of the sucking tube or to a position in close proximity to an opening of the sucking tube. In particular, the openings of the feeding tubes and/or the ejection nozzles may be arranged in at least two circumferential lines or in at least one circumferential area of the sucking tube depending on a desired degree of mixing of the fluid to be sucked and the sucking aid liquid. In particular, the openings of the feeding tube and/or the ejection nozzles may be arranged along the same circumferential line of the portion of the sucking tube. This measure may be particularly useful, if the sucking tube comprises a larger inner diameter or a flow of the fluid to be sucked through the sucking tube is laminary.

The feeding tube may be arranged outside of the sucking tube, whereby the apparatus comprises a flexible design in that the position of the feeding tube may be adapted according to the space available for the apparatus.

Alternatively, the feeding tube may be received in the sucking tube. In particular, the feeding tube may be surrounded by the sucking tube or incorporated into the sucking tube. This measure enables a particularly compact design of the apparatus. If the apparatus is used in the medical field as part of e.g. an endoscope, only a single cut into the tissue of a patient may be required for inserting both tubes into a body of the patient, whereby a risk of injuring the patient may be significantly reduced.

The feeding tube and the sucking tube may be spatially separated tubes. Thus manufacturing of the apparatus may be facilitated, since lesser manufacturing steps are required compared to an apparatus comprising tubes being connecting to one another. Further, if one of the tubes is damaged, only the damaged tube may have to be exchanged, whereby repairing costs of the apparatus may be reduced.

A wall of the sucking tube may comprise an elongated hole which at least partially forms the feeding tube, whereby the feeding tube may be incorporated in a very space-saving and cost-effective way into the sucking tube. In particular, the hole may be axially arranged with respect to a longitudinal axis of the sucking tube. Further, the hole may be transversely arranged with respect to a longitudinal axis of the sucking tube.

The feeding unit may comprise a sucking aid liquid reservoir which is in fluid-tight connection with the sucking tube, wherein a passage may be provided from the elongated hole to the sucking aid liquid reservoir. This mechanism allows for supplying the sucking aid liquid to a portion of the sucking tube.

The sucking aid liquid reservoir may be formed by a ring-element of an axial U-shaped cross-section, wherein arms of the ring-element are fluid-tightly connected to the sucking tube.

The sucking aid liquid reservoir may be formed by an at least partially circumferential hole within a wall of the sucking tube. In particular, the circumferential hole may be a ring nut within a wall of the sucking tube.

These measures represent two configurations of a sucking aid liquid reservoir which can be easily incorporated into the apparatus.

It may be also possible that the sucking tube is surrounded by the feeding tube. An ending portion of the feeding tube may project from an ending portion of the sucking tube, whereby the sucking aid liquid and the fluid to be sucked may mix outside of the sucking tube. Therefore the already mixed fluid to be sucked is sucked through the complete length of the sucking tube such that choking of any portion of the sucking tube may be prevented at a very early stage. If the apparatus is used in the medical field, the ending portion of the sucking tube and the feeding tubes may be the distal ending portions.

At least a portion of the feeding tube may be formed in a fluid permeable way. This measure causes the sucking aid liquid not only to empty from an opening of the ending portion of the feeding tube, but also from any portion of the feeding tube through its side wall. If the feeding tube is surrounded by the sucking tube, the fluid to be sucked and the sucking aid liquid may be also mixed inside the sucking tube such that the amount of sucking aid liquid which is fed to the portion of the sucking tube may be enhanced. Thus the degree of mixing both the fluid to be sucked and the sucking aid liquid is improved, and, in turn, choking of the sucking tube may be prevented in a very efficient way.

At least the portion of the feeding tube may be formed by a fluid permeable material. At least the portion of the feeding tube may comprise perforations.

Both measures represent possibilities of designing the portion of the feeding tube in a fluid permeable way which may be individually or simultaneously applied. Designing the portion of the feeding tube using a fluid permeable material represents a very simple and cost-effective measure, in order to achieve a laterally leaking from at least the portion of the feeding tube. Perforations arranged at the portion of the feeding tube may enable tuning the amount of the sucking aid liquid to be fed, since the number and size of the perforations may be adapted accordingly. The perforations may be formed as holes of any suitable cross-section, e.g. of a circular of elliptic cross-section, or may be formed as circumferential slits. If the feeding tube is received in the sucking tube and be placed next to an inner surface of a sucking tube wall, the perforations may only cover a portion of the feeding tube facing towards the interior of the sucking tube. An ending portion of the sucking tube may be formed in a needle like way, whereby the sucking process may be precisely performed, since the pointed tip of the needle may be placed at a desired place. In a medical application of the apparatus, the ending portion of the sucking tube may be the distal ending portion of the sucking tube. Further, the ending portion of the sucking tube may be slanted under an angle of between approximately 10° and approximately 75° measured from a longitudinal axis of the (not bended) sucking tube. Therefore a front side of the ending portion of the sucking tube may be enlarged such that the amount of the fluid to be sucked may be increased.

The feeding tube may be axially arranged with respect to the sucking tube and in line with a tip of the distal ending portion of the sucking tube. In particular, an "in line" arrangement of the feeding tube with a tip of the sucking tube may denote an arrangement of the feeding tube in prolongation of the tip of the sucking tube. Thus mixing of the sucking aid liquid with the fluid to be sucked occurs outside of the sucking tube such that any sticking of undesired fractions of the fluid to be sucked to an inner surface of the sucking tube is prevented at an early stage. In particular, choking of the sucking tube needle portion comprising the largest (radial) distance from the feeding tube is prevented, since the fluid to be sucked and the sucking aid liquid have already been mixed before entering the sucking tube despite a timely later mixing event at such a position compared to positions (radial) closer to the feeding tube.

An inner cross-section of the sucking tube may taper seen along a longitudinal axis of the sucking tube in a direction away from the portion of the sucking tube. A tapered ending portion of the sucking tube seen along a flow direction of the fluid to be sucked through the sucking tube may be useful, since the inner surface of the distal ending portion of the sucking tube may be designed in a fluidic favorable way. In particular, the inner diameter of the sucking tube may be constant in portions except for the ending portion of the sucking tube comprising the tapering cross-sections. In particular, the outer diameter of the sucking tube may be kept constant, whereby a wall thickness of the ending portion of the sucking tube may increase from the opening of the ending portion. In particular, a wall thickness of the sucking tube may linearly increase forming a pointed edge along the outer circumference of the sucking tube. In particular, a wall thickness of the sucking tube may exponentially increase from the opening of the sucking tube towards the other ending portion of the sucking tube. In particular, if the apparatus comprises two ejection nozzles within a wall of the sucking tube at diametrically opposed positions along a circumference of the sucking tube, the ending portion of the sucking tube may comprise a V-shaped axial cross-section with the ejection nozzles being arranged at the most distant ending points of the distal ending portion of the sucking tube.

An inner surface of at least a portion of the sucking tube may be covered by a fluid repellent coating, whereby deposition of fractions of the mixture of the fluid to be sucked and the sucking aid liquid at the inner surface of this portion of the sucking tube may be prevented or at least significantly reduced. The fluid repellent coating may comprise suitable nano particles. The portion of the sucking tube covered with the fluid repellent coating may be the portion of the sucking tube to which the sucking aid liquid is fed or the portion of the sucking tube which is designed in a fluid permeable way. The fluid repellent coating may be applied to the sucking tube along the total length of the sucking tube.

An inner surface of at least a portion of the sucking tube may be designed in a flat way, whereby deposition of the mixed fluid to be sucked and, in particular the fractions of the mixed fluid to be sucked, is reduced in that the sucking tube is designed in a fluidic favorable way. This flat portion of the sucking tube may coincide with the portion of the sucking tube covered with the fluid repellent coating.

The feeding unit may be adapted such that the sucking aid liquid is continuously feedable to the portion of the sucking tube. This measure causes a continuous mixing of the fluid to be sucked and the sucking aid liquid such that the sucking process is permanently supported.

The feeding unit may be adapted such that the sucking aid liquid is feedable to the portion of the sucking tube in a sequence of pulses. The feeding process of the sucking aid liquid to the fluid to be sucked may be adapted according to the amount of the undesired fractions of the fluid to be sucked which shall be incorporated in the sucking aid liquid. In particular, a length of the pulses and a time interval between two subsequent pulses may be accordingly adapted. The feeding unit may further comprise a feeding controller for controlling the feeding process in terms of controlling the feeding mode, the feeding velocity of the sucking aid liquid, the volume of the fed sucking aid liquid, etc.

The apparatus may comprise a sucking aid liquid container which comprises the sucking aid liquid. The sucking aid liquid may be fed from the sucking aid liquid container to the portion of the sucking tube. In particular, an adapter tube may be provided between the sucking aid liquid reservoir and the sucking aid liquid container. In particular, the sucking aid liquid reservoir and the sucking aid liquid container may be identical or comprise one another.

The sucking aid liquid may comprise at least one of the group consisting of water, an isotonic fluid, an infusion solution, an organic or inorganic solution, a Ringer solution, a physiological sodium chloride solution, an alcoholic solution, a solution comprising hydrocarbons, and a medical fluid approved for surgical use. In particular, the solution comprising hydrocarbons may comprise a contact oil. The kind of the sucking aid liquid used may depend on the purpose of its use, in particular on the (undesired fractions of the) fluid to be sucked. In case of medical applications the sucking aid liquid can be any medical fluid approved for surgical use. Further, the sucking aid liquid may comprise additives adapted to reduce a surface tension of the sucking aid liquid such that fractions of the fluid to be sucked may be incorporated into the sucking aid liquid in an improved way. These additives may reduce the surface tension of the fluid to be sucked such that the undesired fractions of the fluid to be sucked, e.g. solid particles, may be incorporated in the fluid to be sucked in a more efficient way and does not deposit at the inner surface of the sucking tube.

The apparatus may comprise a coalescing filter for separating fractions of the mixture of the fluid to be sucked and the sucking aid liquid. In particular, the sucking aid liquid including the incorporated fractions of the fluid to be sucked or only the undesired fractions of the fluid to be sucked may be filtered out. Thus, the fluid to be sucked may be cleaned before a subsequent discharge. In particular, e.g. toxic or harmful fractions of the fluid to be sucked may be filtered out, such that these fractions can be separately disposed.

The apparatus may comprise a tank for receiving filtered fractions of the mixture of the fluid to be sucked and the sucking aid liquid. The tank may be used for storing the filtered fractions of the fluid to be sucked before their further disposal.

The apparatus may comprise a pressure regulating unit for regulating an environmental pressure of the fluid to be sucked. This measure may enable an almost constant pressure outside of or in the sucking tube, since a pressure decrease due to the sucking process may be compensated. In particular, the pressure regulating unit may be adapted to feed any suitable medium, e.g. gas, to a region outside of or in the sucking tube. The pressure regulation unit may comprise a further tube and/or a further pump for feeding the suitable medium to the region where the fluid to be sucked is. This measure may be particularly desirable when using the apparatus during a surgical procedure with an ending portion of the sucking tube being placed inside the body, where a constant pressure at the operating field may be indispensible.

An inner diameter of the sucking tube may be less than 2.5 mm, particularly less than 2.0 mm, further particularly less than 1.5 mm. In particular, the inner diameter of the sucking tube may be dimensioned to be between approximately 0.6 mm and approximately 0.9 mm. The smaller the cross-section of the sucking tube is, the more necessary may be the need of keeping the cross-section of the sucking tube constant, since an already small choking of the sucking tube significantly reduces the cross-section of the sucking tube and turns the sucking tube being not usable any more. An apparatus with such a thin sucking tube may be particular desirable in the field of minimally invasive surgery, since a very small cut into a tissue of a patient upon inserting the sucking tube into the human body of the patient may be highly desired due to security- relevant and aesthetic aspects. Further, a small inner diameter of the sucking tube may cause a turbulent flow through the sucking tube which may enhance the mixing of the fluid to be sucked and the sucking aid liquid.

The sucking tube may be widened upstream of the portion of the sucking tube to which the sucking aid liquid is fed. If the apparatus is used in the medical field, the sucking tube may be widened outside of the human body.

A flow rate through the sucking tube may be approximately 2 l/min, when a 0.9 mm diameter sucking tube is used. Further flow rates through the sucking tube may also be possible for further sucking tubes of different shape.

A sucking power through the sucking tube may be approximately 0.8 bar. An outer diameter of the feeding tube may be approximately 0.3 mm, particularly approximately 0.2 mm, further particularly approximately 0.1 mm.

The apparatus may comprise a body tissue ablation element for ablating body tissue. Designing the apparatus with a further body tissue ablation element offers a very compact design of the apparatus. The fluid to be sucked may be generated during the ablation process and may be smoke comprising soot and/or tissue particles to be removed from the operating field. The body tissue ablation element may be a laser, a mechanical cutter or an electrical cutter supplied with a high frequency voltage. The body tissue ablation element may be used for removing tissue and/or coagulate the tissue at the operating field. Further, the body tissue ablation element may be received in the sucking tube and/or the feeding tube. The body tissue ablation element may be received in a further tube which may be received in the sucking tube and/or in the feeding tube or may be spatially arranged from the sucking tube and/or feeding tube.

The apparatus may comprise an instrument tube through which a medical instrument is insertable towards a distal ending portion of the sucking tube. The medical instrument may be permanently installed within the instrument tube or may be inserted in the course of the surgical procedure. The medical instrument may be or form part of the body tissue ablation instrument. The instrument tube may be received in the sucking tube and/or the feeding tube and/or the further tube of the body tissue ablation element or may be a spatially separated tube.

The apparatus may form part of an endoscope. The fluid to be sucked may in this case comprise blood, smoke, tissue particles or any other gaseous or liquid medium generated in a surgical procedure. The apparatus may be used e.g. in the field of aesthetic surgery for (transcutaneous) fat reduction or reduction mammoplasty, in the field of ear/nose/throat surgery for removing nasal obstructions, polyps, synechia, in the field of neurosurgery for removing brain, head or neck tumours, in the field of abdominal surgery for removing obstructive neoplasmay in the colon and for laparascopic procedures with smaller incisions, in the field of urology for removing bladder tumours, urethral and ureteral tumours, in the field of thoracic/pulmonary surgery for soft tissue incision, excision, ablation and coagulation and for removing obstructive tumours of the airway and tracheobroncheal tree and mediastinal tumours, and in the field of orthopedics for conturing/sculpting of articular surfaces, plica removal, lateral release, ligament/tendon release, meniscectomy and removal of osteoarthritic lesion.

Alternatively, the apparatus may be part of an industrial tube system, wherein the sucking tube is a tube of the industrial tube system. The fluid to be sucked may comprise a burning condensate such as smoke or any gaseous or liquid medium comprising e.g. soot or tar from an incomplete burning process.

The apparatus may also form part of a vehicle tube system, where the fluid to be sucked may comprise smoke. The apparatus may also form part of an emergency smoke evacuation system for the cabin of an aeroplane or a submarine.

The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.

The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited. Fig. 1 illustrates a schematic cross-sectional partial view of an apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig.2A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig. 2B illustrates a schematic cross-sectional view of the apparatus in Fig. 2A, taken along lines A-A in Fig. 2A.

Fig. 3A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig. 3B illustrates a schematic cross-sectional view of the apparatus in Fig. 3A, taken along lines A-A in Fig. 3A.

Fig. 4A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig. 4B illustrates a schematic cross-sectional view of the apparatus in Fig. 4A, taken along lines A-A in Fig. 4A.

Fig. 5A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention. Fig . 5B illustrates a schematic cross-sectional view of the apparatus in Fig. 5A, taken along lines A-A in Fig . 5A.

Fig. 6A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig . 6B illustrates a schematic cross-sectional view of the apparatus in Fig. 6A, taken along lines A-A in Fig . 6A.

Fig. 7A illustrates a schematic cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig . 7B illustrates a schematic top view of the apparatus in Fig . 7A, taken along lines A-A in Fig. 7A.

Fig . 8A illustrates a schematic view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig . 8B illustrates a schematic view of the apparatus in Fig . 8A, taken along lines B-B in Fig. 8A.

Fig. 8C illustrates a schematic view of the apparatus in Fig. 8A, taken along lines C-C in Fig. 8B.

Fig . 9 illustrates a schematic cross-sectional partial view of a pressure regulating unit of the apparatus in Fig. 8A - 8C. Fig . 10 illustrates a schematic cross-sectional partial view of a further pressure regulating unit in Fig. 8A - 8C

Fig. HA illustrates a cross-sectional partial view of a further apparatus for sucking a fluid to be sucked according to an exemplary embodiment of the invention.

Fig. HB illustrates a perspective partial view of the apparatus in Fig . H B.

The illustration in the drawing is schematically. In different drawings, similar or identical elements are provided with the same reference signs.

Referring to Fig. 1, an apparatus 10 for sucking a fluid to be sucked 12 is shown. The apparatus 10 can be used in the medical field or in industrial applications where the fluid to be sucked 12 comprises fractions which may choke part of a sucking tube 14 of the apparatus 10 due to their precipitation or deposition within the sucking tube 14.

In this embodiment, the apparatus 10 is used in a surgical procedure with the sucking tube 14 being introduced into a body cavity of a patient. The fluid to be sucked 12 comprises blood and solid particles of removed tissue of the patient.

The sucking tube 14 of the apparatus 10 is designed as a thin walled rigid tube. The apparatus 10 further comprises a feeding unit 16 for feeding a sucking aid liquid 18 to a distal ending portion 20 of the sucking tube 14. The feeding unit 16 comprises two feeding tubes 24a, b which are spatially separated from the sucking tube 14 and from one another. Longitudinal axes 26a, b of the feeding tubes 24a, b coincide with one another and vertically run compared to a longitudinal axis 28 of the sucking tube 14. Distal ending portions 30a, b of the feeding tubes 24a, b are arranged in close proximity of an opening 32 of the distal ending portion 20 of the sucking tube 14. Further, the distal ending portions 30a, b of the feeding tubes 24a, b are formed as ejection nozzles 34a, b such that the sucking aid liquid 18 is homogeneously spread over a broad region.

The feeding unit 16 further comprises a sucking aid liquid container (not shown) which is arranged at proximal portions of the feeding tubes 24a, b. The sucking aid liquid container comprises the sucking aid liquid 18 which is water having additives. A feeding pump (not shown) is arranged at the feeding tubes 24a, b adapted to feed the sucking aid liquid 18 to the distal ending portion 20 of the sucking tube 14.

The apparatus 10 further comprises a sucking pump (not shown) which enables the fluid to be sucked 12 to be sucked through the sucking tube 14.

A filter 36 is inserted within the sucking tube 14 for filtering undesired fractions of the fluid transported through the sucking tube 14. In particular, filter 36 is adapted to separate the sucking aid liquid 18 and solid fractions of the fluid to be sucked 12 from the remaining fractions of the fluid to be sucked 12. The remaining fractions of the fluid to be sucked may be of a gaseous form. The portion of the sucking tube 14 comprising the filter 36 is arranged outside of the body of the patient.

A drain line 38 connects the sucking tube 14 at the location of the filter 36 and a storage tank (not shown). In operation of the apparatus 10, the fluid to be sucked 12 is generated outside the sucking tube 14 close to the distal ending portion 20 of the sucking tube 14. The sucking aid liquid 18 is continuously fed to the region close to the distal ending portion 20 of the sucking tube 14. The fluid to be sucked 12 and the sucking aid liquid 18 are mixed outside of the sucking tube 14, and the mixed fluid is sucked through the opening 32 of the sucking tube 14 in a downstream direction indicated by an arrow 40. The sucking aid liquid 18 prevents undesired fractions of the fluid to be sucked 12 to deposit at an inner surface 41 of the sucking tube 14, since the undesired fractions are incorporated into the sucking aid liquid 18. The additives of the sucking aid liquid 18 further support the sucking process in terms of reducing the surface tension of the sucking aid liquid 18 such that the fractions of the fluid to be sucked 12 are more easily incorporated into the sucking aid liquid 18 and do not deposit at an inner surface 41 of the sucking tube 14. The mixed fluid is then filtered by the filter 36 such that the sucking aid liquid 18 including the undesired fractions of the fluid to be sucked 12 and the fluid to be sucked 12 are separated from one another. The undesired fractions of the fluid to be sucked 12 and the sucking aid liquid 18 are thus filtered out, drained away along the drain line 38 and stored in the storage tank to be discharged afterwards.

As shown in Fig. 2A, B, a further apparatus 10 for sucking a fluid to be sucked 12 comprises a sucking tube 14 whose distal ending portion 20 is formed needle-like. The most distal ending portion of the sucking tube 14 forms a tip 42. The distal ending portion 20 of the sucking tube 14 is thus slanted under an angle α of 65° measured from the longitudinal axis 28 of the sucking tube 14 in a counter clockwise way. The feeding unit 14 comprises a single feeding tube 24 which is axially attached to an outer surface of a wall 43 of the sucking tube 14 in line with the tip 42 of the needle-like distal ending portion 20 of the sucking tube 14. The attachment of the feeding tube 24 to the sucking tube wall 43 is accomplished using an adhesive. Further, a distal ending portion 30 of the feeding tube 24 is designed flexibly and encompasses the distal ending portion 20 of the sucking tube 14 in that the distal ending portion 30 of the feeding tube 24 is vertically arranged respecting the distal ending portion 20 of the sucking tube 14. Thus, a longitudinal axis 26 of the distal ending portion 30 of the feeding tube 16 vertically runs to a longitudinal axis 26 of the feeding tube 24. The longitudinal axis 26 of the remaining portions of the feeding tube 24 runs parallelly compared to the longitudinal axis 28 of the sucking tube 14. The distal ending portion 20 of the feeding tube 24 slightly projects into the opening 32 of the sucking tube 14. A distal ending portion 30 of the feeding tube 24 is formed needle-like with a slanting angle δ of the distal ending portion 30 of the feeding tube 24 being about 30° measured from a plane perpendicular to the axial extent of the distal ending portion 30 of the feeding tube 24. An opening 44 of the feeding tube 24 faces the opening 32 of the sucking tube 14.

An outer diameter d of the feeding tube 24 is by a factor of approximately six smaller than an outer diameter D of the sucking tube 14 (Fig. 2B). The operation of the apparatus 10 in Fig. 2A, B is similar to the operation of the apparatus 10 in Fig. 1.

Fig. 3A shows a further apparatus 10 for sucking a fluid to be sucked 12. The apparatus 10 comprises a sucking tube 14 whose distal ending portion 20 comprises a flat front side being arranged perpendicular to a longitudinal axis 26 of the sucking tube 14.

A feeding unit 16 comprises four identical feeding tubes 24a-d which are axially arranged respecting the sucking tube 14 and are attached to the outer surface of the wall 43 of the sucking tube 14. The feeding tubes 24a-d are arranged in a displaced way of about 90° when viewing along the longitudinal axis 28 of the sucking tube 14. Distal ending portions 30a-d of the feeding tubes 24a-d are flexibly designed and encompass the distal ending portion 20 of the sucking tube 14 in that an outer surface of the wall of the distal ending portion 20 of the feeding tubes 24a-d butt against the front side of the wall 43 of the sucking tube 14. The distal ending portions 30a-d of the feeding tubes 24a-d are formed in a needle-like way with a slanting angle δ of the front side of the feeding tubes 24a-d of about 30° measured from a plane perpendicular to the longitudinal axis 26a-d of the distal ending portions 30a-d of the feeding tubes 24a-d. A cross-section of the openings 32a-d of the feeding tubes 24a-d comprises an elliptical shape.

As shown in Fig. 3B, the outer diameter D of the sucking tube 14 is by a factor of six larger than an outer diameter d of the feeding tubes 24a-d. For instance, the outer diameter D of the sucking tube 14 measures 0.8 mm, whereas the outer diameter d of the feeding tubes 24a-d is dimensioned to be 0.1 mm. The sucking tube 14 is made of a transparent plastic material, whereas the feeding tubes 24a-d are made of surgical steel.

The operation of the apparatus 10 in Fig. 3A, B is similar to the operation of the apparatus 10 in Fig. 1 - 2B. Fig. 4A, B illustrates a further apparatus 10 of sucking a fluid to be sucked 12. A sucking tube 14 of the apparatus 10 is rigidly formed and comprises a needle-like tip 42 with a distal ending portion 20 of the sucking tube 14 being slanted under an angle α of 65° measured from a longitudinal axis 28 of the sucking tube 14 in a counter clockwise direction.

A feeding tube 24 of a feeding unit 16 of the apparatus 10 is formed as a rigid tube and is axially arranged in contact to an inner surface 41 of the sucking tube 14 in line with the needle tip 42. The feeding tube 24 is not fixed to the inner surface 41 of the sucking tube 14, but freely movably arranged within the sucking tube 14. The feeding tube 24 projects from the front side of the distal ending portion 20 of the sucking tube 14 and is also formed in a needle like way in that it is slanted under an angle β of 60° measured from the longitudinal axes 26, 28 of the feeding tube 24 and the sucking tube 14 in a counter clockwise way. In operation of the apparatus 10, the fluid to be sucked 12 is sucked through the opening 32 of the sucking tube 14. A sucking aid liquid 18 is fed to a region adjacent to the opening 32 of the sucking tube 14 and mixes with the fluid to be sucked 12 outside of the sucking tube 14. As the feeding tube 24 is axially arranged in line with the tip 42 of the sucking tube 14 and its opening 44 faces the opening 32 of the sucking tube 14, the sucking aid liquid 18 mixes with the fluid to be sucked 12 before the fluid to be sucked 12 contacts the inner surface 41 of the sucking tube 12. As shown in Fig. 5A, B, a further apparatus 10 for sucking a fluid to be sucked 12 comprises a rigid sucking tube 12 and a feeding unit 16.

The feeding unit 16 comprises a feeding tube 24 which is formed as an axial elongated hole 45 arranged within a wall 43 of the distal ending portion 20 of the sucking tube 14. Thus the feeding tube 24 is realized by the walls 43 of the sucking tube 14. The feeding tube 24 is formed needle-like with a front side of the feeding tube 24 and a front side of the sucking tube 14 coinciding. A radial slit 46 is realized within the wall 43 of the sucking tube 14 ranging from an outer surface of the wall 43 of the sucking tube 14 into the wall 43 of the sucking tube 14. A ring element 47 is fluid-tightly placed around the sucking tube 12 with a centre of the ring element 47 and the sucking tube 14 coinciding. The ring element 47 comprises an axial U-shape cross-section such that a circumferential reservoir 48 for the sucking aid liquid 18 is provided between the ring-element 47 and the outer surface of the sucking tube 14. A terminal adapter 49 passes through the ring element 47 providing a passage for the sucking aid liquid 18 into the ring element 47. The terminal adapter 49 is designed as a thin walled bushing and is arranged radial outward of the slit 46.

An inner surface 41 of the sucking tube 14 is further coated with a fluid repellent material forming a coating layer 50. This coating layer 50 prevents solid fractions of the fluid to be sucked 12 to deposit at the inner surface 41 of the sucking tube 14.

The distal ending portion 30 of the feeding tube 24, i.e. the inner part of the wall 43 of the distal ending portion 20 of the sucking tube 14, is formed in a fluid permeable way in that the distal ending portion 30 of the feeding tube 24 comprises perforations 51 in the form of circular holes 52. The holes 52 are formed in a feeding tube wall 54 facing towards to an interior of the sucking tube 14. A hole diameter increases towards the opening 44 of the feeding tube 24 such that the amount of the sucking aid liquid 18 pouring out from the feeding tube 24 is increased towards the opening 44 of the feeding tube 24. Thus mixing of the fluid to be sucked 12 and the sucking aid liquid 18 is enhanced in a region close to the distal ending portions 20, 30 of the sucking tube 14 and the feeding tube 24. Further, a portion 55 of the feeding tube wall 54 is made of a fluid permeable material such as a ceramic comprising an open pore structure. Thus feeding of the sucking aid liquid 18 along the length of the portion 55 of the feeding tube 24 can be achieved ensuring that no choking of the sucking tube 14 may occur along this length. The apparatus 10 shown in Fig. 5A, B similarly operates to the apparatus 10 in Fig. 1 - 4B.

Fig. 6A, B shows a further apparatus 10 for sucking a fluid to be sucked 12. The apparatus 10 is similarly designed compared to the apparatus 10 in Fig. 5A, B in that a feeding tube 24a is formed within a wall of the sucking tube 14. However, in this embodiment, the feeding unit 16 comprises four feeding tubes 24a-d of such type displaced by about 90° to one another seen along a longitudinal axis 28 of the sucking tube 14.

Radial slits 46a-d are accordingly realized in a wall 43 of the sucking tube 14 providing a passage from the feeding tube 24a-d to a sucking aid liquid reservoir 48. A terminal adapter 49 is arranged radial outwardly of the slit 46a.

A distal ending portion 24 of the wall of the sucking tube 14 tapers inwardly such that the distal ending portion 20 of the sucking tube 14 forms a pointed edge at its outer circumference. A front side of the feeding tubes 24a-d is slanted under an angle y of about 50° measured from the longitudinal axis 26, 28 of the sucking tube 14 and the feeding tubes 24a-d in a counter clockwise direction.

The operation of the apparatus shown in Fig. 6A, B is similar to the operation of the apparatus shown in Fig. 1 to 5B.

Fig. 7 A, B shows a further apparatus 10 for sucking a fluid to be sucked 12.

A sucking tube 14 of the apparatus 10 is formed as a thick walled rigid tube. An inner cross-section of the sucking tube 14 tapers when seen along the longitudinal axis 28 of the sucking tube 14 away from the opening 32 of the sucking tube 14. An inner diameter of the distal ending portion 20 of the sucking tube 14 enlarges such that an inner part of the distal ending portion 20 of the sucking tube 14 is shaped in a rounded way. An outer diameter of the sucking tube 14 is kept constant. Thus the interior of the distal ending portion 20 of the sucking tube 14 is formed in a fluidic favourable way.

The feeding unit 16 of the apparatus 10 comprises a terminal adapter 49 designed as a bushing. The terminal adapter 49 is radially inserted into a wall 43 of the sucking tube 14 with an opening of the terminal adapter 49 connecting the terminal adapter 49 to a reservoir 48 for a sucking aid liquid 18. The reservoir 48 is realized as a centric circumferential ring nut of a rectangular cross-section within the wall 43 of the distal ending portion 20 of the sucking tube 14. Feeding tubes 24a- h are arranged within the wall 43 of the sucking tube 14 and run from an radial outer distal ending portion of the reservoir 48 to an inner surface 41 of the distal ending portion 20 of the sucking tube 14. Openings 44 of the feeding tubes 24a-h are placed along a circumferential line of the inner surface 41 of the sucking tube 14 in that the openings 44 are arranged at positions comprising an identical radial distance from the longitudinal axis 28 of the sucking tube 14 as an radial inner distal ending portion of the reservoir 48. Further, the openings 44 are displaced to one another by about 45° seen along the longitudinal axis 28 of the sucking tube 14 and are placed on a circle whose centre is located on the longitudinal axis 28 of the sucking tube 14. Instead of the openings 44, ejection nozzles 34 can be placed at the distal ending portions 30a-h of the feeding tubes 24a-h.

Fig. 8A - 8C illustrate a further apparatus 10 for sucking a fluid to be sucked 12 which is used in an ophthalmologic surgical procedure of removing an eye tumour. The apparatus 10 comprises a sucking tube 14 which is introduced into an eye cavity 56 of an eye 58 of a patient through a sclera 59 of the eye 58. The distal ending portion 20 of the sucking tube 14 is arranged next to the cornea 60 and the lens 61 of the eye 58. A coalescing filter 36 is arranged within the sucking tube 14. A feeding unit 16 of the apparatus 10 comprises a feeding pump

62 and a feeding tube 24, wherein an ejection nozzle 34 is arranged at a distal ending portion 30 of the feeding tube 24. The feeding tube 24 is spatially separated from the sucking tube 14, with both distal ending portions 20, 30 are placed close to one another. The apparatus 10 further comprises a pressure regulating unit 64 which regulates a pressure p, within the eye cavity 56. The pressure regulating unit 64 comprises a gas feeding tube 66 for feeding a pressure regulating gas to the eye cavity 56, in which a fine filter 68 is placed. A liquid feeding tube 70 empties into the gas feeding tube 66. An injection pump 72 is arranged at the liquid feeding tube 70. A heating device 73 for warming or heating the pressure regulating gas is arranged at the gas feeding tube 66 downstream of the liquid feeding tube 70 emptying into the gas feeding tube 66, but upstream of the gas feeding tube 66 passing through the sclera 59. The heating device 73 is circumferentially located at the gas feeding tube 66 and is in direct contact with an outer wall of the gas feeding tube 66 such that the heating efficiency is increased. Pressure sensors 74, 76 are arranged outside of the eye cavity 56 and within the eye cavity 56 close to the sclera 59. The pressure sensor 74 measures an environmental pressure p₀ outside of the eye cavity 56, whereas the pressure sensor 76 measures a pressure p, within the eye cavity 56.

A pressure controller 78 receives the pressure values p₀, p, measured by the pressure sensors 74, 76 and outputs signals to inlet and outlet valves 80, 82 placed in the gas feeding tube 66 and the sucking tube 14 upstream and downstream of the filters 68, 36, respectively. The pressure controller 78 is a state controller adapted to control the pressure p, within the eye cavity 56 using state variables such as the pressure and or the mass flow/volume flow within the gas feeding tube 66 downstream of the inlet valve 80, within the gas feeding tube 66 upstream of the inlet valve 80, within the eye cavity 56, within the sucking tube 14 upstream of the outlet valve 82 and/or within the sucking tube 14 downstream of the outlet valve 82. Further pressure sensors and/or flow meters can be integrated into the pressure regulating unit 64. Alternatively, the pressure controller 78 may be a Pi-controller, a

PID -controller or a fuzzy controller.

It may be also possible to use a further gas diverting tube for draining the pressure regulating gas off the eye cavity 56.

In the surgical procedure, tissue of an eye tumour 84 is ablated by means of a body tissue ablation element 86, here by means of a laser probe 88. For this purpose the laser probe 88 is inserted into the eye cavity 56 with its tip being located close to the tissue of the eye tumour 84 to be removed. A distal ending portion 90 of a shaft 92 of an endoscope 94 is also inserted into the eye cavity 56 such that a surgeon may monitor the operating field. The endoscope 94 also provides an endoscopic light source which is used for illuminating the operating field. In the embodiment of Fig. 8A - 8C, the distal ending portion 90 of the endoscope shaft 92 is placed close of the pressure sensor 76, but can be placed also elsewhere in the sclera 59. Alternatively, the medical procedure can be monitored through the cornea 60 and the lens 61 using a surgical microscope, since these parts of the eye 58 are transparent. In this case an endoscopic light source (not shown) instead of the endoscope 94 can be used whose distal ending portion is inserted into the eye 58 close to the pressure sensor 76. The distal ending portion of the endoscopic light source may be placed at any suitable position in the sclera 59.

A fluid to be sucked 12 arises from the ablation process in that smoke is generated during burning the abnormal tissue away. In order to prevent the soot of the smoke to stick as tar to the inner surface 42 of the sucking tube 14, the sucking aid liquid 18 is fed to the operating field. The sucking aid liquid 18 mixes with the smoke, and the mixed fluid is sucked through the sucking tube 14. The coalescing filter 36 filters out the fraction of solid particles of the smoke as well as the sucking aid liquid 18 which are discharged via a drain line 38 to a disposal tank. The remaining fractions of the fluid to be sucked 12 and the sucking aid liquid 18 are transported through the outlet valve 82 to a further tank for subsequent storage.

In sucking the fluid to be sucked 12 from the eye cavity 56, the pressure p, within the eye cavity 56 decreases. This pressure difference I Po - PiI is measured by the pressure sensors 74, 76. The pressure controller 78 accordingly activates a flow of the pressure regulating gas to the eye cavity 56 via the gas feeding tube 66 for compensating this effect. The pressure regulation gas is a medically compatible gas which is approved in surgical procedures. The pressure regulating gas passes the inlet valve 80 and is filtered by the fine filter 68 such that bacterial contamination of the gas is eliminated. A humidifying liquid is fed to the filtered gas to humidify the gas, as this being conventionally delivered in a dry form. The relative humidity of the gas almost reaches the saturation level (90 to 100 % relative humidity), in order to avoid drying out of the biological tissue within the eye cavity 56. The humidifying liquid may be any liquid medically approved such as purified water, a physiological solution of sodium chloride, a Ringer lactate etc. For an improved dosing of the humidifying liquid to the gas fed to the eye cavity 56 injection nozzles may be incorporated at the mouth of the tubes 66 and 70. The pressure controller 78 may also control the amount of humidified liquid fed to the gas via controlling the injection pump 72. The gas is additionally warmed up to approximately 32 to 37°C by the heating device 73 to be better tolerated by the human body. The humidified and warmed up gas is then introduced into the eye cavity 56 such that the pressure p, within the eye cavity 56 increases, in order to keep the pressure p, almost constant in the surgical procedure.

Fig. 9 illustrates an alternative arrangement of the pressure sensor 76 in the eye cavity 56. A pressure transferring tube 95 is inserted into the eye cavity 56 through the sclera 59. The pressure sensor 76 is connected to the pressure transferring tube 95 such that the pressure p, within the eye cavity 56 is transferred to the pressure sensor 76.

Fig. 10 illustrates a further arrangement of the pressure sensor 76 in the eye cavity 56. A distal ending portion 96 of the gas feeding tube 66 passes through the sclera 59 of the eye 58. A distal ending portion 98 of the pressure transfer tube 95 is arranged within a distal ending portion 96 the gas feeding tube 66. The remaining pressure transfer tube 95 is located outside of the gas feeding tube 66 in that the pressure transfer tube 95 passes through the wall of the gas feeding tube 66. This arrangement enables that a further opening of the body cavity 56 for the pressure transfer tube 95 is omitted, since the pressure transfer tube 95 is received in the gas feeding tube 66. Further, the pressure transfer tube 95 is kept free from impurities, since the gas flow through the gas feeding tube 66 provides a continuous cleaning process for the pressure transfer tube 95. Further, the pressure transfer tube 95 can be designed very thin, as it is shown in Fig. 10.

The distal ending portion 98 of the pressure transfer tube 95 projects from the distal ending portion 96 of the gas feeding tube 66 such that an opening of the pressure transfer tube 95 is displaced from an opening of the gas feeding tube 66 by a distance a. This relative arrangement of the pressure transfer tube 95 and the gas feeding tube 66 allows for a precise pressure measurement, whereas a contamination sensitivity of the pressure transfer tube 95 is increased. Further, the opening of the pressure transfer tube 95 may lie in the opening of the gas feeding tube 66 such that front sides of the pressure transfer tube 95 and the gas feeding tube 66 coincide. Further, the opening of the pressure transfer tube 95 may be displaced from the opening of the gas feeding tube 66 into the distal ending portion of the gas feeding tube 66 (negative displacement distance a) such that the pressure transfer tube 95 ends in the interior of the gas feeding tube 66. This relative arrangement of the pressure transfer tube 95 and the gas feeding tube 66 reduces the contamination sensitivity of the pressure transfer tube 95. However, the measurement accurateness is decreased. The distal ending portion 98 of the pressure transfer tube 95 may be slanted forming a needle like tip. The opening of the pressure transfer tube 95 may face to or away from the gas feeding tube 66 depending on the area of application of the apparatus 10. Alternatively, the distal ending portion 98 of the pressure transfer tube 95 may run within the wall of the gas feeding tube 66 or adjacent to the gas feeding tube 66 outside of the gas feeding tube 66. The opening of the pressure transfer tube 95 may be arranged within the gas flow provided by the gas feeding tube 66 such that the opening of the pressure transfer tube 95 may be kept open.

The pressure regulating unit 64 further comprises a monitoring unit 100 for monitoring the pressure within the pressure transfer tube 95. For this purpose, the monitoring unit 100 comprises a gas injection pump 102 arranged at a feeding line 104. The gas injection pump 102 is adapted for feeding pulses of small gas volumes to the pressure transfer tube 95. The feeding line 104 empties outside of the gas feeding tube 66 into the pressure transfer tube 95.

The pressure monitoring unit 100 is particularly adapted for sensing whether choking of the distal ending portion 98 of the pressure transfer tube 95 is existent. In operation of the pressure monitoring unit 100 small gas volumes are fed to the pressure transfer tube 95 in a sequence of pulses. The pressure sensor 76 senses the induced time- dependent pressure distribution within the pressure transfer tube 95, in particular, a hysteresis of the pressure within the pressure transfer tube 95. The pressure controller 78 analyses the recorded pressure distribution.

If the pressure transfer tube 95 is not choked by any undesired fluids, the gas fed by the feeding line 104 will leak from the distal ending portion 98 of the pressure transfer tube 95 into the body cavity 56. If the distal ending portion 98 of the pressure transfer tube 95 is choked, the pressure within the pressure transfer tube 95 will increase, since the gas fed to the pressure transfer tube 95 cannot leak. Further, a pulse of the gas volume fed by the gas injection pump 102 may blow a tissue particle choking the distal ending portion 98 of the pressure transfer tube 95 out of the pressure transfer tube 95.

The pressure monitoring unit 100 may not interfere with the sucking and pressure regulating process, since only very small gas volumes are fed to the pressure transfer tube 95 and thus to the body cavity 56 under investigation. The monitoring routines may be regularly performed in intervals of 0.1s to 100s or in case of any malfunctions. Fig. HA, B illustrate a further apparatus 10 used in a surgical procedure. The apparatus 10 comprises a simple embodiment whose design may change according to the manufacturing process of the apparatus 10, in particular according to the availability of the used apparatus components. In particular, the design of the apparatus 10 is similar to the design of the apparatus 10 in Fig. 4A, B.

The apparatus 10 comprises a sucking tube 14 of a small size. The sucking tube 14 comprises a 6 mm long distal ending portion 20 made of surgical steel (outer diameter of 0.9 mm) and a silicon hose arranged adjacent to the distal ending portion 20. The most distal ending portion of the sucking tube 14 is designed as a needle. A feeding tube 24 (diameter 0.3 mm - 30G) is inserted into the distal ending portion 20 of the sucking tube 14, in order to allow for a sucking aid liquid injection. The feeding tube 24 comprises a distal ending portion 30 in the form of a 30 G - 0.3 mm DM needle or syringe made of surgical steel. Further, the feeding tube 24 comprises a portion in the form of a rubber hose connected to the distal ending portion 30 of the feeding tube 24. The needle of the feeding tube 24 penetrates through the rubber hose of the sucking tube 14 at a position adjacent to the surgical steel/silicone interface of the sucking tube 14 under an angle of about 40° measured to a longitudinal axis 28 of the sucking tube 14 in a clockwise direction. The needle of the feeding tube 24 is further bended into the longitudinal axis 28 of the sucking tube 14, penetrates through the distal ending potion 20 of the sucking tube 14, and projects from the needle-type distal ending portion 20 of the sucking tube 14. The feeding tube 24 is axially arranged in line with a tip 42 of the needle-type distal ending portion 20 of the sucking tube 14 and is in direct contact to, but not fixed to an inner surface 41 of the distal ending portion 20 of the sucking tube 14. A proximal ending portion of the feeding tube 24 is connected to an infusion line and a motor infusion pump (not shown), which supplies the sucking aid liquid 18. The sucking aid liquid 18 comprises BSS (balanced saline solution).

In operation of the apparatus 10, the sucking aid liquid 18 is pumped in the small feeding tube 24, which penetrates the wall 43 of the sucking tube 14 to the front side of the sucking tube 14, where the sucking aid liquid 18 is continuously ejected. The sucking aid liquid 18 absorbs and incorporates the fluid to be sucked 12, here smoke particles. The smoke and the sucking aid liquid 18 are transported through the sucking tube 14 without forming undesired deposition at the inner surface 41 of the sucking tube 14.

It should be noted that the term "comprising" does not exclude other elements or features and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

C l a i m s

1. An apparatus (10) for sucking a fluid to be sucked (12), the apparatus (10) comprising a sucking tube (24) through which the fluid to be sucked (10) is suckable; and a feeding unit (16) adapted for feeding a sucking aid liquid (18) to a portion (20) of the sucking tube (14) for supporting the sucking of the fluid to be sucked (12) through the sucking tube (14).

2. The apparatus of claim 1, wherein the feeding unit (16) comprises a feeding tube (24) through which the sucking aid liquid (18) is feedable.

3. The apparatus of claim 2, wherein an opening (44) of the feeding tube (24) faces an opening (32) of the portion (20) of the sucking tube (14).

4. The apparatus of claim 2 or 3, wherein an ending portion (30) of the feeding tube (24) is formed in a needle-like way.

5. The apparatus of anyone of claims 1 to 4, wherein the feeding unit (16) comprises an ejection nozzle (34) through which the sucking aid liquid (18) is ejectable to the fluid to be sucked (12).

6. The apparatus of anyone of claims 2 to 5, wherein openings (44) of the feeding tubes (24) and/or ejection nozzles (34) are arranged along an at least partial circumference of the portion (20) of the sucking tube (14).

7. The apparatus of anyone of claims claim 2 to 6, wherein the feeding tube (24; 24a, b) is arranged outside of the sucking tube (14).

8. The apparatus of anyone of claims 2 to 6, wherein the feeding tube (24) is received in the sucking tube (14).

9. The apparatus of anyone of claims claim 2 to 7, wherein the feeding tube (24) and the sucking tube (14) are spatially separated tubes.

10. The apparatus of anyone of claims 2 to 8, wherein a wall (43) of the sucking tube (24) comprises an elongated hole (45) which at least partially forms the feeding tube (24).

11. The apparatus of claim 10, wherein the feeding unit (16) comprises a sucking aid liquid reservoir (47) which is in fluid-tight connection with the sucking tube (14), wherein a passage is provided from the elongated hole (45) to the sucking aid liquid reservoir (47).

12. The apparatus of claim 11, wherein the sucking aid liquid reservoir (48) is formed by a ring- element (49) of an axial U-shaped cross-section, wherein arms of the ring-element (48) are fluid-tightly connected to the sucking tube (14).

13. The apparatus of claim 11, wherein the sucking aid liquid reservoir (48) is formed by an at least partially circumferential hole within a wall (43) of the sucking tube (14).

14. The apparatus of anyone of claims 2 to 13, wherein an ending portion (30) of the feeding tube (24) projects from an ending portion (20) of the sucking tube (14).

15. The apparatus of anyone of claims 2 to 14, wherein at least a portion (30) of the feeding tube (24) is formed in a fluid permeable way.

16. The apparatus of claim 15, wherein at least the portion (30) of the feeding tube (24) is formed by a fluid permeable material.

17. The apparatus of claim 15 or 16, wherein at least the portion (30) of the feeding tube (24) comprises perforations (50).

18. The apparatus of anyone of claims 1 to 17, wherein an ending portion (20) of the sucking tube (14) is formed in a needle-like way.

19. The apparatus of claim 18, wherein the feeding tube (24) is axially arranged with respect to the sucking tube (14) and in line with a tip (42) of the ending portion (20) of the sucking tube (14).

20. The apparatus of anyone of claims 1 to 19, wherein an inner cross-section of the sucking tube (14) tapers seen along a longitudinal axis (28) of the sucking tube (14) in a direction away from the portion (20) of the sucking tube (14).

21. The apparatus of anyone of claims 1 to 20, wherein an inner surface (41) of at least a portion (20) of the sucking tube (14) is covered by a fluid repellent coating (49).

22. The apparatus of anyone of claims 1 to 21, wherein the feeding unit (16) is adapted such that the sucking aid liquid (18) is continuously feedable to the portion (20) of the sucking tube (14).

23. The apparatus of anyone of claims 1 to 22, wherein the feeding unit (16) is adapted such that the sucking aid liquid (18) is feedable to the portion (20) of the sucking tube (14) in a sequence of pulses.

24. The apparatus of anyone of claims 1 to 23, wherein the apparatus (10) comprises a sucking aid liquid container which comprises the sucking aid liquid (18).

25. The apparatus of anyone of claims 1 to 24, wherein the sucking aid liquid (18) comprises at least one of the group consisting of water, an isotonic fluid, an infusion solution, an organic or inorganic solution, a Ringer solution, a physiological sodium chloride solution, an alcoholic solution, a solution comprising hydrocarbons and a medical fluid approved for surgical use.

26. The apparatus of anyone of claims 1 to 25, wherein the sucking aid liquid (18) comprises additives adapted for reducing a surface tension of the sucking aid liquid (18).

27. The apparatus of anyone of claims 1 to 26, wherein the apparatus (10) comprises a coalescing filter (36) for separating fractions of the mixture of the fluid to be sucked (12) and the sucking aid liquid (18).

28. The apparatus of claim 27, wherein the apparatus (10) comprises a tank for receiving filtered fractions of the mixture of the fluid to be sucked (12) and the sucking aid liquid (18).

29. The apparatus of anyone of claims 1 to 28, wherein the apparatus (10) comprises a pressure regulating unit (64) for regulating an environmental pressure of the fluid to be sucked (12).

30. The apparatus of anyone of claims 1 to 29, wherein an inner diameter of the sucking tube (14) is less than 2.5 mm, particularly less than 2.0 mm, further particularly less than 1.5 mm.

31. The apparatus of anyone of claims 1 to 30, wherein the apparatus (10) comprises a body tissue ablation element (86) for ablating body tissue.

32. The apparatus of anyone of claims 1 to 31, wherein the apparatus (10) comprises an instrument tube through which a medical instrument is insertable towards a distal ending portion (20) of the sucking tube (14).

33. The apparatus of anyone of claims 1 to 32, wherein the apparatus (10) forms part of an endoscope (94).

34. The apparatus of anyone of claims 1 to 33, wherein the apparatus (10) is part of an industrial tube system, and wherein the sucking tube (14) is a tube of the industrial tube system.

35. A method for sucking a fluid to be sucked (12), the method comprises sucking a fluid to be sucked (12) through a sucking tube (14); and feeding a sucking aid liquid (12) to a portion (20) of the sucking tube (14) for supporting the sucking of the fluid to be sucked (12) through the sucking tube (14).