IL147954A - Method and apparatus for modeling of the intra-and extravascular operations on the different sections of the circulation system and for testing of the intravascular devices therefor - Google Patents

Description

|l7D γι ηη ι ηιτα) □■n'pipoi-rrmopNi π'η^ψοι-κΊθΐ'κ □■n m1. *7 y nnAin i prm i n o 'iy D ' n^ipoi-NiD.'Nn D '3|7n n mj?^! nnio^DTon rmynn "IVJ Q'lwu D' p^ni (Din . IT JOiyn nm1? D'OiDnn METHOD AND APPARATUS FOR MODELLING OF THE INTRA- AND EXTRAVASCULAR OPERATIONS ON THE DIFFERENT SECTIONS OF THE CIRCULATION SYSTEM AND FOR TESTING OF THE INTRAVASCULAR DEVICES THEREFOR Inventors: Edward G. SHIFRIN, 64, Hashahar St., 43565 Raanana, Israel; Gennady S. NICKELSHPUR, 9-D, Habastiliya St., Apt. 9, 35597 Haifa, Israel.

Arkady S. NICKELSHPUR 24, Ziso St., Apt.32, 46230 Herzeliya, Israel; Nachman KUDLIK, , Korazim St., Neve-Sharet, Tel-Aviv, Israel; Wesley S. MOORE 11467 W. Sunset Blvd, Los Angeles, CA, USA; Peter RF BELL 22, Powys Ave., Oadby, Lecester LE22DP, UK.

Applicant: Ruby Hill Ltd, PO Box 34, 12/13 Hill Rt , Douglas, Isle of Man EVI99 1BW, British Isles. 1 147,954/2 BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to medicine and more particularly, to stands applied for modeling intra- and extravascular surgical operations on circulation system sections, for testing the performance and efficacy of new intravascular devices and instruments, developed for use in these operations on the basis of minimally invasive surgery techniques, as well as for methods of training, on the basis of such stands, surgeons and medical personnel in performing operations using these new intravascular instruments.

Background of the Invention There is known a model to show the blood circulation system suggested by H. Wolf, see German Patent DE 19818618 "Educational model to simulate the blood circulation system". The model bears a front plate of transparent material whereto there are attached a simulated heart and tubes of transparent materials simulating the main blood vessels. The model is provided with a color light filter to simulate changes in blood color in the blood circulation system during circulation with changing oxygen content therein. An additional lighting source illuminates white floating particles which may be displayed through the front plate in a neutral color. The color of lighting may change from red through violet to blue to show the decreasing oxygen level in blood during its circulation. The illumination for the observer is through lamps covered by light filters. There is at least one simulated blood vessel with pressure equilization to demonstrate the elasticity of an aorta wall.

The medical stimulator suggested by K. Amplatz, see U.S. Patent No. 4,726,772 "Medical simulator", enables demonstration and trial of inserting torquable elongated members into small body passages, such as blood vessels. The simulator comprises a rectangular rigid frame closed on opposite sides by 2 147,954/2 sheets of transparent material. Between the sheets there is located a curved passage replicating a blood vessel that is also formed of transparent material. The passage has an open inlet and outlet disposed on opposite sides of the frame. The torqueable elongated members are guide wires or catheters constructed so as to cause their distal tip to turn or twist in response to corresponding motion applied by the operator to a proximal portion of the device.

Finally, I. Bentov, see U.S. No. Patent 3,579,858, suggested an "Anatomical Model" which comprises a simulated main blood vessel (aorta) having a predetermined curvature at its main portion an formed yieldable plastic material. At least one simulated secondary blood vessel is connected with the main blood vessel at its curved portion. The model substantially simulates the aorta and attached arteries.

The principal drawback of all these models is that they provide no systems for circulaton of liquid imitating blood.

J. Niiranen et al., in U.S. Patent No. 2,871,579 "Surgical Body-Member Simulacrum for Teaching First Aid" describes a device for teaching surgeons and medical personnel. The dervice comprises a simulate human body inside whereof there is disposed a hydraulic circuit of eladstec pipelines with a liquid imitating human blood. A reservoir is provided for this liquid connected with a pump and hydraulic cylinder - sources of pulsing pressure. From outside the hydraulic surface is covered by one or several layers simulating skin and hypodermic tissues. Pressure pulsation in the circuit is performed by periodical switching on/off the pump or via a valve built into the hydraulic circuit between its elastic pipelines and reservoir for the liquid.

The teaching device allows to imitate, on its elastic pipelines, subjected to pulsating pressure of liquid, surgical operations of plasty and shunting blood 3 147,954/2 vessels using appropriate medical instruments. The device, however, does not allow to imitate surgical operations inside blood vessels.

A medical model for teching and demonstrating a minimally invasive medical procedure, such as angioplasty, is described by J. Prom in U.S. Patent No. 6,062,866 "Medical Angioplasty Model". The model is a three-dimensional, anatomically correct representation of at least a part of the vascular system and includes the aorta and several arteries. An access port is provided for insertion inside the model of medical devices, such as guides, catheters, as inside narrovings and blockages simulated in the model. Fluid may also be introduced into the model to realistically simulate the conditions of introducing the instrument. Simulated heart chambers or a model of similar construction may also be attached to the aortal valve of the model to further enhance the representation of invasive procedures.

The method for modelling a pathological section of a patient's blood circulation system suggested by A. Ryazanov et al, see WO 9105320 «Method and Model for Modelling a Pathological Section of the Circulatory System of a Patient and Method for Simulating Endovascular Operations)) includes generating a three-dimensional image of the pathological section and attached vessels and making, on the basis of this image, a three-dimensional element model of an optically transparent material. Then the model is combined with a previously obtained angiogram on the basis of which the model was created. The method for imitating an endovascular operation on the basis of obtained model is performed by passing a certain surgical instrument through the obtained three-dimensional model of a pathological section with simultaneously passing through the model a flow of liquid, the hydrodynamic properties whereof imitate hydrodynamic properties of a patient's blood flow in corresponding blood vessels. , By means of such a device and method there are practiced operation techniques of a future operation as well as tested the construction of devices applied therefor. 4 147,954/2 However, these models provide no medium to surround them and imitate tissues surrounding the aorta and other arteries, so it is impossible to authentically simulate surgical operations inside the blood circulation system.

A method and device for testing artificial or natural venous valves is suggested by T. Nguyen et al, see U.S. Patent No. 5,272,909 "Method and Device for Testing Venous Valves". The device comprises a bearing plate, whereon there is attached a chamber for mounting the sample valve fluidly connectd with a path for a liquid simulating blood. There is further provided a number of devices for delivering liquid to the tested valve, such as a muscle pump component in the form of pneumatic pulsating drive, respiratory pump component with a diaphragm responsing to air pressure, capacitance receptacle shaped as a reservoir and a vertical hydrostatic column. All these devices are fluidly connected with a liquid flow path to mimic the muscular hydraulic pressure, respiratory hydraulic pressure, capacitance and hydrostatic liquid pressure, which act on the pulsating liquid flow circulating through the tested valve. On the basis of this device there is performed the method for testing venous valves with mimicking known hemodynamic flow conditions within a mammalian body.

This device, however, does not permit to simulate surgical operations within blood circulation system and test instruments necessary for these operations.

A simulation device is known for measuring compliance conditions of a prosthesis, such as stents and stent-grafts under simulated loading conditions suggested by K. Vilendrer, see U.S. Patent No. 5,670,708 "High Frequency Intravascular Prosthesis Fatigue Tester". Prostheses are positioned within a fluid conduit of the fatigue tester attached to a computer. The fluid conduit is willed with a saline solution or other fluid approximating the liquid medium wherein the tested prostheses are located. The fluid is delivered into the fluid conduit from both sides via two hydraulic pumps in pulsation fashion at a high frequency 147,954/2 simulating thereby systolic and diastolic pressure. The fluid temperature approximates 37° G and is operated by a control system include in the fluid conduit. The fluid is pulsated by a pulse generating system comprising a voice coil drive motor connected with a following unit, having a linear motor with an increasable number of cycles per minute, which may be generated and applied to the tested prostheses. A microprocessor-based computer operates the pulse generating system at a frequency level from 0 to 6000 cycles per minute under closed loop. The microprocessor based computer may be servocontrolled, utilizing feedback from a compliance transducer system, linear displacement trancducers and pressure transducers.

The apparatus for simulating blood circulation in the human body, see M. Takashima, U.S. Patent No. 5,396,895 "Apparatus for Simulating Blood Circulation" has a hydraulic system and sections of this hydraulic system simulating corresponding blood vessels (arteries) of the left and right hand with simulated arterial pulse. These sections of hydraulic system are of rubber resin made of silicon and natural rubber with wall thickness and other parmeters corresponding to certain portions of natural arteries of the human body. Sphygmic diagnosis is thereby simulated in measuring arterial pulse in three spots of hands corresponding to those known in Oriental medicine as "shun", "khan" and "shakn". To detect the simulated pulses and blood circulation in these spots there are apllied three pressure sensors secured in appropriate positions of the above portions of hydraulic system. Simultaneously, from these spots information may be obtained on blood viscosity and elasticity of arterial walls.

Finally, the model disclosed by D. Saloner and J. Rapp in U.S. Patent No. 6,205,871 "Vascular Phantoms" includes a panel of anatomically accurate vascular phantom, such as phantom of carotid artery, renal artery, phantom of aneurysm of end portion of cerebral artery or phantom of aneurysm of abdominal aorta which contain simulated stenosis and other geometric variations of vessels. 6 147,954/2 The panel comprises a range for measuring stenosis dimensions, as well as dimensions of aneurysm or level and width of its neck reltive to the diameter. In all, this panel allows to make five different kinds of measurements. The method of making an anatomically accurate vascular phantom includes stereolithography with an input data set which represents a natural vascular surface for designing an anatomically accurate vascular phantom with a surface corresponding to physical properties of a natural surface. The input data set is the information obtained from images of excited sclerotic portions of corresponding vessels via methods of magnetic resonance with high resolution. These methods include Dopplar Ultrasound (DUS), Magnetic Resonance Angiography (MRA), Catheter-Injected X-ray Angiography (CA).

All these devices cannot, in principle, be applied for modelling intravascular surgical operations and training surgeons and medical personnel on pathological sections of circulation system, as well as for testing the performance and efficacy of new intravascular devices developed for application in minimally invasive surgery techniques.

THE PRIOR ART Training apparatus suggested by H. Hasson in U.S. Patent No. 5,873,732 and U.S. Patent No. 5,947,743 " Apparatus for Training for the Performance of a Medical Procedure" have a frame defining a working space simulating a body cavity. At the bottom of the frame there are secured guides over which holders are movable by their lower part, these holders having on their upper surface supports whereon simulated body organs are located. The supports may be spring-loaded to imitate the elasticity of body organs at contact therewith. At the apparatus operation the holders may move to change their spatial position. The upper part of the apparatus is covered by membrane layers simulating the skin and external body integument whereon there is located a sheet of transparent plastic material with openings to introduce surgical instrument. Surgical instrument is introduced 7 147,954/2 into these openings under an optical control of a monotor, it punches the membrane layers and is directed towards simulated body organs to perform, together with the latter, necessary manipulations. Fluorescent bright-up lamps are built into the apparatus, and beside the apparatus there is mounted a video camera to transmit the image onto the monitor screen in such a way the operator watching the procedure on the monitor screen becomes, on the whole a sufficiently complete illusion of reality of it. The training may be recorded on a video taperecorder for repeted viewing. The apparatus allows to simulate a medical procedure and practice movements which may be encountered in performing a medical procedure. The trainings are performed on fruits, such as oranges, or on artificial objects simulating different body organs, also including blood vessels wherethrough it is necessary to pass the medical instrument. On blood vessel models the operator practises in their cutting, suturing and removing thrombi.

The training apparatus described in U.S. Patent No. 5,947,743 differs from the first in that it has a support assembly including support surface in the form of a flexible sheet changing its configuration. This surface can move along guides (rails) mounted along the frame bottom changing its form from horizontal to vertical. The supports moving together with this surface are secured on the support surface by its lower part. On blood vessel models the operator can practise in their cutting, suturing and removing thrombi.

Apparatus and method for simulating human body cavities for learning and improving eye-hand coordination in surgical endoscopy techniques are described by L. Tuason in U.S. Patent No. 5,403,191 "Laparoscopic Surgery Simulator and Method of Use". The apparatus has open sides for free access to cavities for placement of objects simulating human organs, the objects being mounted and anchored inside these cavities practice simulation in instrument manipulation. The surgical instrument is inserted into these objects through pre-established aperrtures in a transparent plastic panel secured on top of the apparatus, and then 8 147,954/2 manipulations are performed repeating real procedures, but without the benefit of direct binocular vision on the object simulations. Instead, for training there is used viewing of actions in cavities via a video monitor system or a similar indirect viewing via reflecting mirrors of the two mirror concept imitating a real life operative conditions. For objects of training there are used models of organs made of foam rubber.

The common drawbacks of all these apparatus consist in the absence of simulated concrete sections of circulation system, absence of fluid simulating blood and systems providing its circulation. In general, these training apparatus are far shortin dresign and applied modelling method from what is required for practising and improving the methods of intravascular and extravascular operations and for testing surgical instrument being developed therefor.

Closest to the claimed method and apparatus are "Surgical Training Apparatus and Method", disclosed by G. Szinicz in U.S. Patent No. 5,425,644, as well as "The Endovascular Training Model for Continuing Medical Education Courses", suggested by Samuel S. Ann, Wesley S. Moore et al., see "The Journal of Continuing Education in the Health Professions", volume 13, pp. 215-220.

"Surgical Training Apparatus and Method", suggested by G. Szinicz in U.S. Patent No. 5,425,644 describes an apparatus having a body with transparent walls and frame, wherein there are disposed organs of non-living animals (chiefly cows), a peristelsic pump, reservoir with fluid, tubing between the pump and reservoir and between them and animal organs to simulate blood circulation. An elastic non-transparent medium is provided asoociated with the frame, imitating body walls, wherethrough surgical instrument is passed in non-invasive surgery. As this medium "Goetz" or "pelvic" material may be used. The reservoir is filled with a liquid simulating blood. The pump outlet tube may may have a built-in interrupter to create, if necessary, a pulsating flow. There are valves to ajust the flow rate (on the outlet from the organs and on exhaust pipe). In the body there 9 147,954/2 are valves for passing surgical instruments (trocars, endoscopes, holders, dissectors, clamp staplers etc.).

With this apparatus it is impossible to simulate methods of performing intravascular surgical operations on circulaton system sections, as well as to test performance and efficacy of new intravascular instruments designed for application in these operations.

"The Endovascular Training Model for Continuing Medical Educatrion Courses", Samuel S. Ann, Wesley S. Moore et al., see "The Journal of Continuing Education in the Health Professions", volume 13, pp. 215-220, describes a model for training surgeons and medical personnel. The model simulates a patient's left leg from the pelvis to ancle and represents normal arterial anatomy, abnormal pathology of blood vessels and circulatory hemodynamics. The model body is formed as a receptacle of transparent material, wherein simulated skeleton bones are disposed of foam urethane, simulated muscles shaped as a red band of neoprene rubber and isimulated blood circulation system with bifurcation, renal arteries and iliac arteries. The pipe of the right iliac artery is clamped. The pipe of the left iliac artery is made of several parts linked via connectors which allows to replace its parts to simulate various pathologies. The input and output of the model "blood circulation system" are attached to the reservoir simulating blood (mixture of tomato juice and water) and to the pump. A pipe is provided to deliver possible fluid leakages from the model body to the reservoir. In the model there is simulated circular blood circulation by delivering fluid simulating blood. The fluid flow is adjusted by Robert's clamps. The model design allows to build into any place of the simulated blood circulation system portions of arteries taken from a corpse and properly treated. This model demonstrates the techniques of intravascular surgery, such as angiography, angioscopy, atherectomy, balloon angioplasty, laser angioplasty and the placement of stents. 147,954/2 Being somewhat similar to the claimed object, this model does not allow to reliably model intravascular surgucal operations on all sections of the circulation system except leg arteries. Particularly circulation of fluid simulating blood, is carried out in complete circuit, there is air in the liquid, such parameters of circulating fluid as density, viscosity, pressure, flow rate, temperature are not considered. There is no imitation of the medium response, i.e., of a patient's body tissues immediately surrounding the model of thested section of the circulation system, such as imitation elasticity and density of these tissues, enclosing this section when deploying or locating therein a stent or stent-graft. Besides, this model does not permit to test performance and efficacy of new intravascular instruments developed for application in minimally invasive surgery techniques to treat diseases of other sections of the circulation system, such as aortal aneurysm, such instruments, as a stent-graft or intra-aortal stapler.

An object of the claimed invention is the development of an apparatus the construction whereof provides the modelling of methods for performing intravascular and extravascular surgical operations on any sections of circulation system being in conditions that most closely resemble real life conditions of location functioning of these sections.

Another object of the invention is testing, on the basis of this apparatus, the performance and efficacy of new intravascular instruments developed for application in minimally invasive surgery techniques.

A third object of the invention is to provide, on the basis of this apparatus, training of surgeons and medical personnel in performing surgical operations using new intravascilar instruments.

SUMMARY OF THE INVENTION The above objects of the present invention are achieved by a new and improved stand and methods for modelling intravascular and extravascular 11 147,954/2 operations on sections of circulation system and for testing intravascular apparatus developed for these operations.

The claimed stand comprises a supporting structure, at least one peristelsic pump with a working head, reservoir with fluid imitating blood, models of circulation system sections as well as tubing to connect the peristelsic pump with the reservoir and with models of circulation system sections. In this stand, the supporting structure has a bearing surface, and at least one peristelsic pump which serves for providing circulation of fluid imitating blood, for which purpose it is provided with a system of adjusting fluid circulation rate and direction of its circulation. The stand tubing passes through the working head of at least one peristelsic pump and includes at least one closed tube made substantially of transparent material. At least a part of the closed tube disposed in the area of the working head of peristelsic pump is made of flexible material.

The stand has an hermetically sealed chamber of transparent material mounted on the bearing surface of supporting structure, at least a part of the closed tube is disposed within this hermetically sealed chamber and is detachable.

In the stand there is used at least one model of circulation system section mounted within the hermetically sealed chamber, between detachable ends of the closed tube, in such a way that this section creates, together with the closed tube, a single unit to imitate circulation system. The model is provided with an axial passage for introducing medical instrument therein, and this axial passage has an input port, disposed outside the hermetically sealed chamber and provided with a back valve. The stand also has a means for filling the simulated blood supply system with a fluid taken from a special reservoir and imitating blood. The stand further includes a means for filling the hermetically sealed chamber with transparent fluid under pressure to imitate the density of tissues surrounding outside the section of circulation system and a means for removing air from the fluid circulating over the unit for imitation of blood circulation system. Finally, 12 147,954/2 there is a means for detecting leakages of fluid imitating blood, from the section of circulation system in modelling a surgical opertion inside this section.

Owing to such construction, the stand makes it possible to model intravascular and extravascular surgical operations performed by minimally invasive surgery techniques inside the sections of circulation system, such as operation on inserting inside the aorta with aneurysm a stent-graft and anchoring it inside to the aorta walls via special staplers. Besides, there are tested the performance and efficacy of new intravascular instruments developed for application in minimally invasive surgery techniques.

The stand, according to the present invention, additionally comprises a receptacle for tinting fluid, a feeding means for filling the single unit of imitating the blood circulation system with tinting fluid, device for measuring fluid pressure, as well as a device for measuring flow rate inside this single unit.

The supporting structure is substantially a table with perforated bearing surface and receptacle to collect possible fluid leakages. The fluid used in the stand to simulate blood is substantially a 0,9% solution of NaCl. There may be also used natural animal blood, taken from a slaughter, such as bull's blood. The means for detecting leakages of fluid imitating blood, from a section of circulation system, in modelling inside this section a surgical operation, is a tinting fluid added to the fluid imitating blood. The tinting fluid may be fluorescent.

The means for filling the unit of imitating circulation system with fluid imitating blood is a feeding device. The feeding device includes a device for forcing fluid and valve attached via flexible pipelines to the closed tube and with reservoir with fluid imitating blood. There is also a valve whereby the feeding device is attached via flexible pipelines also to the receptacle with tinting fluid.

The stand is provided with a single feeding device comprising a built-in device for forcing fluid and valves connected via transparent pipelines both to the 13 147,954/2 reservoir for fluid imitating blood, and to the receptacle for tinting liquid. The built-in device for forcing fluid is a hydraulic pump. This pump may be also a syringe.

The single unit of the stand for circulation system imitation is additionally provided with a safety system for pressure release of circulating fluid, the system comprising a back valve with a hydraulic drain line connecting this valve to the single feeding device.

The means for removing air from fluid circulating over the unit for circulation system imitation includes a cardiotomy reservoir with filter, whereby the reservoir with fluid imitating blood is connected to the closed tube of the unit for circulation system imitation.

The means for removing air from fluid circulating over the unit of imitating circulation system includes a vacuum pump attached to the closed tube and vacuum receptacle.

The stand is also provided with a device for measuring fluid pressure inside the single unit of imitating circulation system, the unit including a sphygmomanometer attached via T-joint to the closed tube. There is also a device for measuring flow rate inside the single unit of imitating circulation system including a flowmeter attached via T-joint to the closed tube.

The closed tube of the stand is provided with a device of imitating stenosis or occlusion in blood circulation system, such as a hydraulic resistance disposed outside the hermetically sealed chamber.

The means for filling the hermetically sealed chamber with transparent fluid under pressure to imitate the density of tissues surrounding outside the model of a circulation system section includes an auxiliary pump with a manual or electrical drive, a receptacle for transparent fluid, device for draining the fluid from the 14 147,954/2 hermetically sealed chamber and at least one safety valve, which are attached via pipelines to the hermetically sealed chamber.

At the detachment spot of the closed tube of the single unit of imitating circulation system there is placed at least one section model or internal organ model with an attached section of circulation system. One of the models may be a model of a circulation system section, and the second a model of an internal organ with an attached section of circulation system, these models being attached to this closed tube in parallel relationship and linked together via additional valves imitating collaterals. At least one of the models may be provided with a discharge system shaped as shunting collateral connecting the inner cavity of this model and the following element of the unit of imitating circulation system, whereby there is prevented increased fluid resistance inside the model when instrument is inserted therein. Finally, one of the models may be a simulated internal organ , such as a kidney.

At least one of the models of circulation system or internal organ is a natural internal organ of an animal or a section of its circulation system taken from a slaughter. One of the models may be a natural aorta of an animal taken from a slaughter, such as pig's aorta. The aorta is secured by its ends on the first and second tube reducers, each of them being hermetically attachable to a corresponding end of the closed tube, the tube reducers having devices for fixating and tensioning the aorta. At least one, the first or second tube' reducer, is provided with an axial passage for introducing surgical instrument inside the aorta, and the axial passage is provided with a device preventing fluid leakages and device preventing air ingress inside the closed tube.

The hermetically sealed chamber is provided at least with one standby set of tube reducers having different outer diameters and length to attach thereto section models of different sizes, the tube reducers having axial valves of different net section. The hermetically sealed chamber has a body and a detachable 147,954/2 sealable lid of transparent material to mount and replace the corresponding model of circulation system section. The body and lid of hermetically sealed chamber have ports with back valves. These ports serve to insert inside the hermetically sealed chamber surgical instrument, such as trocars, endoscopes, holders, dissectors, clamps, staplers, light guides necessary in modelling surgical operations outside at least one model of circulation system section.

Part of ports in the body and lid of hermetically sealed chamber are associated, via tubes, with the inner cavity of one of the models disposed inside the hermetically sealed chamber, whereby there is provided laporoscopic insertion inside this model additional instrument, such as light guide and stapler to prevent fluid leakages from inside a model with a damaged wall.

The model of circulaton system section may be a thansparent three-dimensional, anatomically correct image of at least a part of blood circulation system and comprises the aorta and a number of arteries, such as the coronary artery, subclavian artery, pulmonary artery and renal artery, and has imitators of narrowings or thrombi, the model having at least one additional port to insert inside the model intravenous guides and catheters.

The model of a pathological section of the circulation system may have a curved main section, substantially the aorta and at least one secondary section attached to the main section in its curved part, as well as means for changing the position of this secondary section relative to the main section according to any variants of age or pathologically abnormal location of this secondary section, encountered in real medical practice. The model of circulation system section may be made of plastic and have a wall thickness, Young's modulus, allowed tension, dimensions and stability cooresponding to certain portions of natural sections of circulation system. 16 147,954/2 In another embodiment of the stand, connection tubes pass successively through working heads of at least two peristelsic pumps and include at least one closed tube made substantially of transparent material. In this case at least two portions of the closed tube disposed in the area of working heads of these peristelsic pumps are made of flexible material. The peristelsic pumps are synchronized with one another in antiphase, so that one of these peristelsic pumps provides forcing of fluid, and the second - suction of fluid, whereby the circulation system imitates the work of heart.

The stand may additionally comprise a control system to operate means and systems of the stand and control preset parameters, including fluid temperature in the stand closed tube which is approximately 37°.

The stand additionally comprises fluorescent bright-up lamps mounted next to the hermetically sealed chamber, and a video camera for regular image transmission to the screen of an attached monitor, the monitor having a video tape recorder to record modelled operations and repeated viewing thereof. The stand as well comprises light filters to imitate changing oxygen content in the liquid imitating blood and circulating in the unit of circulation system imitation, as well as to detect and distinguish in color fluid leakages from the model of a corresponding section during the modelling thereon a surgical operation.

There is also claimed a method for modelling intravascular and extravascular operations on models of circulation system sections. The method comprises several successive steps. First the stand is brought into operative position by attaching its hermetically sealed chamber at least to one peristelsic pump via the closed tube extending through the working area of this pump. Then, the model of a circulation system section, such as the aorta of an animal taken from a slaughter, is prepared for placing in the hermetically sealed chamber, for which purpose this aorta is secured by its ends at corresponding ends of tube reducers and hermetically sealed thereat. Then the prepared model of a circulation 17 147,954/2 system section, such as an animal aorta taken from a slaughter, is placed in the hermetically sealed chamber. In this case, the free ends of tube reducers are connected to free ends of the closed tube and hermetically sealed thereon, the fixated aorta is tensioned via tensioners on tube reducers and is connected collaterally to the following element of the unit for circular system imitation. The axial passage free end and tubes extending from the aorta are fixated in the wall of hermetically sealed chamber and hermetically sealed, to provide access to the aorta inner cavity outside the hermetucally sealed chamber. The single unit for circulation system imitation formed by the closed tube and attached model of pathologic section and thus assembled, is filled with fluid imitating blood and taken from a corresponding reservoir by a feeding device. If necessary, the single unit for circulation system imitation formed by the closed tube and attached model of a pathologic section is filled by tinting fluid taken from a corresponding recertacle by the same feeding device.

Then air is removed from fluid circulating over the unit for circulation system imitation, via a means including a vacuum pump connected to the closed tube and to the vacuum receptacle.

Thereupon, a sphygmomanometer and flowmeter are attached to the closed tube of the unit for circulation system imitation for measuring pressure and flow rate of fluid drawn therethrough.

Next, the hermetically sealed chamber is closed by the lid and filled under pressure with transparent fluid to imitate density of tissues surrounding from outside the model of a circulation system section. Then, by means of a peristelsic pump, fluid circulation is generated in the single unit for circulaton system imitation. 18 147,954/2 The control of preset parameters of the stand operation, including temperature of fluid imitating blood, rate and direction of its circulation is performed by a computer control system.

Necessary surgical instruments and devices, such as guides, devices for mounting stent-grafts and special staplers are introduced inside the aorta model through the axial passage. This occurs with simultaneously engaging the device for preventing fluid leakages and device for preventing air ingress into the single unit for circulation system imitation.

Then modelling of an intravascular operation is performed by means of surgical instruments and devices introduced inside the aorta model, such as operations for placement of a stent-graft and its fixation to the aorta model walls via intravascular staplers.

Simultaneously, via computer control system, preset parameters of the stand operation are controlled, such as the transparent fluid pressure in the hermetically sealed chamber and fluid pressure and flow rate in the closed tube. At the same time, there are visually detected, through the walls and lid of the hermetically sealed chamber and through a layer of transparent fluid it is filled with, leakages of fluid imitating blood, in a mixture with tinting fluid, resulting from the application of intravascular staplers, as well as location, quantity and volume of these leakages.

Then, if necessary, there is modelled an auxiliary intravascular operation by means of surgical instruments and devices introduced inside the aorta model through tubes connected with ports on the walls and lid of the hermetically sealed chamber. In particular, in this way the operation for eliminating leakages from the aorta with a damaged wall is modelled.

In the course of a modelled surgical operation video shooting is performed (including the occuring leakages) on a video camera with simultaneous 19 147,954/2 transmission of the image to the monitor and its recording on a videocorder for following repeated viewing and analysis of the modelled operation. Shooting and recording may be performed automatically under control of a computer control system.

The suggested method for modelling intravascular and extravascular operations on circulation system sections may additionally comprise changing the conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of hydraulic resistance on the closed tube outside the hermetically sealed chamber. Thereafter, repeated modelling is performed of a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model, with simultaneous control, via computer control system, of preset parameters of the stand operation, defining position, quantity and volume of these leakages and shooting the modelled surgical operation, including the shooting of occurring leakages on a video camera with transmitting the image to the monitor and its recording on a video taperecorder.

The claimed method may as well additionally comprise the following steps: - changing the conditions of modelling a surgical operation by replacing the circulation system model with a model having other parameters, or by additionally introducing inside the hermetically sealed chamber a model of an internal organ, such as a kidney; - changing the conditions of modelling a surgical operation by including into the circulation system a second peristelsic pump imitating the work of heart and operating in suction mode, whereas the first peristelsic pump operates in forcing mode; - modelling on a model of a circulation system section a surgical operation performed simultaneously inside and outside this section, using auxiliary surgical instrument, such as trocars, endoscopes, holders, dissectors, 147,954/2 staplers, light guides, introduced inside the hermetically sealed chamber through ports in its lid and walls.

After each of these additional steps there is performed repeated modelling of a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model, with simultaneous control, via computer control system, preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, detecting position, quantity and volume of these leakages and shooting the modelled surgical operation, including the shooting of occurring leakages, on a video camera with trasmitting the image to a monitor and its recording on a video taperecorder.

Finally, there is suggested a method for testing intravascular devices for performing intravascular operations on circulation system sections. The method comprises several successive steps. First, the stand is brought into operative position by connecting its hermetically sealed chamber at least with one peristelsic pump via a closed tube extending through the working area of this pump working head. Then the model of circulation system section, such as the aorta of an animal taken from a slaughter, is prepared for mounting in the hermetically sealed chamber, for which purpose this aorta is secured by its ends at corresponding ends of tube reducers and hermetically sealed thereat. Next, the prepared model of pathological section of blood circulation system, such as the aorta of an animal, taken from a slaughter, is placed in the hermetically sealed chamber, the free ends of tube reducers being connected to the free ends of closed tube and hermetically sealed thereat, the secured aorta is tightened by tensioners on tube reducers and attached collaterally to the following element of unit for circulation system imitation. The free end of the axial passage and tubes extending from the aorta are fixated in the wall of the hermetically sealed chamber and hermetically sealed to provide access from outside the hermetically sealed chamber to the aorta inner cavity. Then the single unit for circulation system imitation formed by the closed 21 147,954/2 tube and attached model of a pathological section is filled with a fluid imitating blood, this fluid being taken from a reservoir via feeding device.

If necessary, the single unit of circulation system imitation formed by the closed tube and attached model of a pathological section is filled with tinting fluid taken from a receptacle via feeding device. Then air is removed from the liquid circulating over the unit for imitation of blood circulation system, by a means including a vacuum pump, associated with the closed tube and vacuum receptacle. Then the sphygmomanometer for measuring fluid pressure and flowmeter for measuring flow rate are connected to the closed tube of the single unit for circulation system imitation.

The hermetically sealed chamber prapared in this way is covered with the lid and filled with transparent fluid under pressure to imitate the density of tissues surrounding the model of a circulation system section outside. Then, via a peristelsic pump, fluid is forced to circulate in the single unit for circulation system imitation. Simultaneously, via said computer control system, the preset parameters of the stand operation are controlled, including temperature of fluid imitating blood, rate and direction of its circulation.

The testing of intravascular devices is performed in the following order. First, through said axial valve, there is introduced inside the aorta model a guide with an intravascular device, such as stent or stent-graft, located at the free end of said guide in a compressed state. This intravascular device is then positioned and deployed in a preset place inside the aorta model. Thereafter the tested intravascular device, such as an intravascular stapler, is introduced inside the aorta model through the axial passage. Simultaneously, there are actuated the device for preventing fluid leakages and device for preventing air ingress inside the single unit for circulation system imitation. Thereafter, there starts the modelling itself of a intravascular operation using surgical instrument introduced inside the aorta model, in particular, there is modelled the operation for mounting a stent-graft and 22 147,954/2 fixating it to the walls of aorta model via an intravascular stapler. In the course of modelling the operation, there are controlled, via a computer control system, preset parameters of the stand operation, such as pressure of transparent fluid in the hermetically sealed chamber, pressure and flow rate in the closed tube. Simultaneously, there are visually detected, through the walls and lid of hermetically sealed chamber and through a layer of transparent fluid the chamber is filled with, leakages of fluid imitating blood, mixed with tinting fluid, the leakages resulting from the application of the intravascular stapler. The location, quantity and volume of these leakages are as well detected visually. In the course of testing shooting is performed of the modelled surgical operation, including the occurring leakages, on a video camera with simultaneous transmission of the image to the monitor and recording it on a video tape recorder for following repeated viewing and analysis of the modelled operation. Shooting and recording may be performed in automatic mode under the control of a computer control system. With the testing completed, performance of the tested intravascular device is estimated on the basis of visual observations, parameters recorded by the computer control system, as well as on the basis of video shooting and video recording.

The claimed method for testing intravascular devices for performing intravascular operations on circulation system sections may additionally include the following steps: - changing conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of a hydraulic resistance on the closed tube outside the hermetically sealed chamber; - changing conditions of modelling a surgical operation through replacing the model of circulaton system by a model with different parameters.

After each of additional steps described above there is performed a repeated modelling of the surgical intravascular operation via tested intravascular device 23 147,954/2 introduced inside the aorta model, with simultaneous control, by a computer control system, of preset parameters of the stand operation, detecting leakages of fluid imitating blood, mixed with tinting fluid, quantity and volume of these leakages and shooting the modelled surgical operation, including the occurring leakages, on a video camera and transmitting the image to the monitor and recording it on a video tape recorder, as well as following estimation of performance of the tested intravascular device on the basis of visual observations, parameters recorded by the computer control system, and on the basis of video shooting video recording.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the drawings: FIG. 1 shows a basic diagram of the stand; FIG. 2 shows the hermetically sealed chamber of the stand with model of a circulation system section, as well as systems and devices for modelling a surgical operation on the basis of this model; 24 147,954/2 FIG. 3 shows the hermetically sealed chamber of the stand with a model of circulation system section and model of an internal organ ; FIG. 4 shows the testing of an intravascular device inside a model of a circulation system section with a stent located therein, the model being mounted and fixated in the hermetically sealed chamber, and FIG. 5 shows a complete model of the aorta used for modelling a surgical operation on the stand.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In the most preferred embodiment of the invention, the claimed stand 1 (see FIG.l) comprises a supporting structure 10, at least one peristelsic pump 12 with a working head 14, reservoir 16 with liquid imitating blood, models 18, 20 of circulation system sections as well as tubing 22 to connect the peristelsic pump 12 with the reservoir 16 and with models 18, 20 of circulation system sections. In stand 1 the supporting structure 10 has a bearing surface 24 (FIGs. 1, 2), a peristelsic pump 12 serves for providing circulation of liquid imitating blood, for which purpose it is provided with a system of adjusting liquid circulation rate and direction (not shown in the drawings). The stand 1 tubing 22 passes through the working head 14 of peristelsic pump 12 and includes at least one closed tube 26 made substantially of transparenr material. At least a part 28 of the closed tube 26 disposed in the area of working head 14 of peristelsic pump 12 is made of flexible material.

Stand 1 has a hermetically sealed chamber 30 (FIGs. 1, 2) of transparent material mounted on the bearing surface 24 of supporting structure 10, at least a part of closed tube 26 being disposed within this hermetically sealed chamber 30 and detachable.

Within the hermetically sealed chamber 30 of stand 1 there is located one, two or more circulation system sections (FIG. 3). Models 32, 34 are placed in 147,954/2 parallel or in succession with each other within hermetically sealed chamber 30, between detachable ends of the closed tube 26, in such a way that theses models create, together with closed tube 26, a single unit 40 (FIG.l) for circulation system imitation. The drawing (FIG. 3) shows the location within hermetically sealed chamber 30 of two models, one of these models, in this case 32, is the model of circulation system section, in this case, the aorta model, and the second model 34 is a model of an internal organ, in this case, a kidney model. The aorta model 32 is provided with an axial passage 42 (FIG. 3) for itroducing surgical instrument therein, and this axial passage 42 has an input port 44 disposed outside the hermetically sealed chamber 30 and provided with a back valve 46. Stand 1 also has a feeding means 48 (FIG. l) for filling the unit 40 for imitating blood supply system with a fluid taken from a reservoir 16 and imitating blood.

The single unit of the stand for circulation system imitation is additionally provided with a system for releasing pressure of circulating fluid (FIG. 1), the system including a back valve 49 with hydraulic drain line 49' connecting this valve to the single feeding device 48.

The stand further includes a means 50 for filling the hermetically sealed chamber 30 (FIG. 1) with transparent fluid under pressure to imitate the density of tissues surrounding outside the section of circulation system. This fluid is delivered from reservoir 52. Besides, there is a means for removing air from the fluid circulating over the unit 40 for imitation of blood circulation system - a cardiotomy reservoir 53 with filter, whereby the reservoir with fluid imitating blood is attached to the closed tube of the unit for circulation system imitation. The means for removing air from fluid circulating over the unit for circulation system imitation also includes a vacuum pump 54 connected to the closed tube and with a vacuum receptacle 56 (FIG. 1). Finally, there is a means for detecting leakages of fluid imitating blood, from models 32, 34 of the sections of circulation system in modelling a surgical opertion inside this section, this is a tinting fluid 26 147,954/2 added from receptacle 58 to the liquid circulating over closed tube 26 (FIG. 1). The tinting fluid may also be fluorescent. Feeding device 48 of stand 1, according to the present invention, serving to fill unit 40 for the circulation system imitation, with fluid taken from reservoir 16 and imitating blood (FIG. 1) simultaneously serves as a feeding device to fill this unit 40 with tinting fluid from receptacle 58. Feeding device 48 includes a means for forcing fluid and valve 60 connected by flexible pipelines 62 to closed tube 26 and reservoir 16 with fluid imitating blood. Owing to valve 60 feeding device 48 is connected by a flexible pipeline 62 also with receptacle 58 with tinting fluid. The common feeding device 48 may be a hydraulic pump (FIG. 1). This pump may also be a syringe (FIG. 2).

Finally, stand 1 has a device for measuring fluid pressure-sphygmomanometer 64, as well as a device for measuring flow rate -flowmeter 66, inside unit 40 for circulation unit imitation. Manometer 68 (FIGS. 1, 2) serves to control liquid pressure inside chamber 30.

As shown in the FIG. 2, the supporting structure of stand 1 is substantially a table 70 with bearing surface 24 having a perforation 72, and receptacle 74 to collect possible fluid leakages. The fluid used in stand 1 to simulate blood is substantially a 0,9% solution of NaCl. There may be also used natural animal blood, taken from a slaughter, such as bull's blood.

The means 50 for filling the hermetically sealed chamber 30 with transparent fluid under pressure (FIGS. 1, 2) includes, besides reservoir 52, an auxiliary pump 80 with a manual or electrical drive, device 82 for draining the fluid from the hermetically sealed chamber 30 and at least one safety valve 84, which are attached via pipelines 86 to the hermetically sealed chamber 30. The closed tube 26 of stand 1 is provided with a device of imitating stenosis or occlusion in blood circulation system, such as a hydraulic resistance 90 disposed outside the hermetically sealed chamber 30 (FIGS. 1, 2). 27 147,954/2 In the most preferred embodiment of the claimed stand 1, at the detachment spot of the closed tube 26 of the single unit of circulation system imitation there are placed at least one model of circulation system section 32 and one model 34 of an internal organ with an attached section of circulation system (FIGS. 1, 3). These models 32 and 34 are attached to the closed tube 26 in parallel relationship and linked together via additional passages 92 imitating collaterals. In this embodiment one of the models - 32 is also provided with a discharge system shaped as shunting collateral 94 connecting the inner cavity of this model 32 and the following element of the unit 40 for circulation system imitation, whereby there is prevented increased fluid resistance inside the model 32 when instrument is inserted therein. The second model 34 is shaped as an internal organ, in this case a kidney.

In the most preferred embodiment, one of the models 32 of circulation system may be a natural aorta of an animal taken from a slaughter, such as pig's aorta 96 (FIG. 3, 4). The aorta 96 is secured by its ends on the first 98 and second 100 tube reducers (FIG. 4), each of them being hermetically attachable to a corresponding end of aorta 96 and corresponding end of the closed tube 26. The tube reducers 98 and 100 have devices for fixating and tensioning the aorta, 102 and 104, respectively. At least one, the first 98 or second 100 tube reducer, is provided with an axial passage 106 for introducing surgical instrument inside the aorta 96. The axial passage 106 is provided with a device preventing fluid leakages 108 (FIG. 1), as well as with above-mentioned device preventing air ingress inside the closed tube - cardiotomy reservoir 53 with filter, as well as with a vacuum pump 54 with vacuum receptacle 56.

The hermetically sealed chamber 30 is provided at least with one standby set of tube reducers 98, 100 having different outer diameters and length to attach thereto section models of different sizes, the tube reducers 98, 100 having axial passages 106 of different net section, and the sets of tube reducers are detachable 28 147,954/2 interchangeable cartridges. The hermetically sealed chamber 30 has a body 109 and a detachable sealable lid 1 10 (FIG. 2) of transparent material to mount and replace the corresponding model 32 or 34 of circulation system section. The body 109 and lid 110 of hermetically sealed chamber 30 have ports, 112 and 1 14 respectively (FIG. 2), with back valves. These ports 1 12 and 114 serve to insert inside the hermetically sealed chamber 30 surgical instrument, such as trocars, endoscopes, holders, dissectors, clapms, staplers, light guides necessary in modelling surgical operations outside at least one model 32 and 34 of circulation system section.

Part of ports 112 and 114 in the body 109 and lid 1 10 of hermetically sealed chamber 30 are associated, via tubes 116 (FIG. 2), with the inner cavity of one of the models, such as aorta model 32, disposed inside the hermetically sealed chamber 30. Thereby there is provided laporoscopic insertion inside this model of additional instrument, such as light guide and stapler to eliminate fluid leakages from inside the aorta model 32 with a damaged wall.

The model of circulaton system section, such as aorta model 32 may be a thansparent three-dimensional, anatomically correct image of at least a part of blood circulation system and comprises the aorta and a number of arteries, such as the coronary artery, subclavian artery, pulmonary artery and renal artery, and has imitators of narrowings or thrombi (FIG. 5). Model 32 has at least one additional port 118 to insert inside the model intravenous guides and catheters.

The model of a pathological section of the circulation system - the aorta 32 (FIG. 5) may have a curved main section 120 and at least one secondary section 122 attached to the main section 120 in its curved part, as well as means for changing the position of this secondary section relative to the main section according to any variants of age or pathologically abnormal location of this secondary section, encountered in real medical practice. All other branches 126 of aorta 32 are hermetically sealed (FIG. 5). Flexible tubes 128 and 130 connect this 29 147,954/2 aorta model 32 to the tube reducers. The model of circulation system section 32 may be made of plastic and have a wall thickness, Young's modulus, allowed tension, dimensions and stability corresponding to certain portions of natural sections of circulation system.

In another embodiment of the stand 1 (FIGS. 1, 2), connection tubes 32 pass successively through working heads of two peristelsic pumps 12 and 13 and includes at least one closed tube 26 made substantially of transparent material. In this case at least two portions of the closed tube 26 disposed in the area of working heads of these peristelsic pumps 12 and 13 are made of flexible material. The peristelsic pumps 12 and 13 are synchronized with one another in antiphase, so that one of these peristelsic pamps, such as 12 provides forcing of fluid during its circulation in closed tube 26, and the second 13 - suction of fluid, whereby the circulation system imitates the work of heart.

The stand 1 may additionally comprise a computer control system-computer 140 (FIG. 1) to operate means and systems and control preset parameters, including fluid temperature in the stand 1 closed tube 26 which must be approximately 37° C.

Stand 1 additionally comprises fluorescent bright-up lamps 152 (FIG.l) mounted next to the hermetically sealed chamber, and a video camera 150 for regular image transmission to the screen of an attached monitor - computer 140, the computer 140 having a video tape recorder 142 to record modelled operations and repeated viewing thereof. Stand 1 as well comprises additionally light filters 154 (FIG. 2) to imitate changing oxygen content in the fluid imitating blood and circulating in the unit 40 for circulation system imitation, as well as to detect and distinguish in color fluid leakages from model 32 or 34 of a corresponding section during the modelling thereon a surgical operation. Owing to such a construction, it is possible to model on stand 1 intravascular and extravascular surgical operations performed by minimally invasive surgery techniques inside 147,954/2 circulation system sections, such as operation for mounting inside aorta 32 with aneurysm, a stent-graft and its fixation inside to the walls of aorta 32 via special staplers (FIG. 1). Besides, there are tested the performance and efficacy of new intravascular instruments developed for application in minimally invasive surgery techniques.

There is also claimed a method for modelling intravascular and extravascular operations on models of circulation system sections. The method comprises several successive steps (FIG. 1-5). First stand 1 is brought into operative position (FIG. 1) by attaching its hermetically sealed chamber 30 to one peristelsic pump 12 via the closed tube 26 extending through the working area of working head of this pump 12. Then, the model of a circulation system section, such as the aorta 32 of an animal taken from a slaughter, is prepared for placing in the hermetically sealed chamber 30, for which purpose this aorta 32 is secured by its ends at corresponding ends of tube reducers 98, 100 and hermetically sealed thereat. The prepared model 32 is then placed in the hermetically sealed chamber 30. In this case, the free ends of tube reducers 98 and 100 are connected to free ends of the closed tube 26 and is hermetically sealed thereon. The fixated aorta 32 is tensioned via tensioners 102 and 104 on tube reducers 98 and 100 and is connected via collateral 94 to the following element of the unit 40 for circular system imitation. The axial passage 42 free end and tubes 116 extending from the aorta 32 are fixated in the wall of hermetically sealed chamber 30 and hermetically sealed, to provide access to the aorta 32 inner cavity outside the hermetically sealed chamber 30. The single unit 40 for circulation system imitation assembled in this way, formed by the closed tube 26 and attached aorta model 32 is filled with fluid imitating blood and taken from a corresponding reservoir 16 by a feeding device - syringe 48 (FIG. 2). If necessary, the single unit 40 for circulation system imitation formed by the closed tube 26 and attached aorta model 32 is filled with tinting fluid taken from a corresponding receptacle 58 by the same feeding device - syringe 48. Theair is then removed from fluid 31 147,954/2 circulating over the unit for circulation system imitatation, via a means including a vacuum pump 54 connected to the closed tube 26 and to vacuum receptacle 56. Thereupon, a sphygmomanometer 64 and flowmeter 66 for measuring pressure and flow rate of fluid drawn therethrough are attached to closed tube 26 of unit 40 for circulation system imitation.

Next, the hermetically sealed chamber 30 is closed by lid 110 and filled under pressure with transparent fluid to imitate density of tissues surrounding from outside the model 32 of a circulation system section. The pressure of transparent fluid is controlled by manometer 68. Then, by means of peristelsic pump 12, fluid circulation is generated in the single unit 40 for circulaton system imitation.

The control of preset parameters of stand 1 operation, including temperature of fluid imitating blood, rate and direction of its circulation is performed by a computer 140.

Necessary surgical instruments and devices, such as guides, devices for mounting stent-grafts and special staplers are introduced inside the aorta model 32 through axial passage 42. This occurs with simultaneously engaging the device for preventing fluid leakages 108 and device for preventing air ingress into the single unit for circulation system imitation - cardiotomy reservoir 53 with filter and vacuum pump 54. When pressure of fluid circulating in the single unit 40 for circulation system imitation is exceeded, back valve 39 actuates to discharge part of fluid via hydraulic drain line 39' again to the single feeding device 48.

Then modelling of an intravascular operation is performed by means of surgical instruments and devices introduced inside the aorta model 32, such as operations for placement of a stent-graft and its fixation to the aorta model 32 walls via intravascular staplers. 32 147,954/2 Simultaneously, via computer 140, preset parameters of stand 1 operation are controlled, such as the transparent fluid pressure in the hermetically sealed chamber 30 and fluid pressure and flow rate in the closed tube 26. At the same time, there are visually detected, through the body walls 109 and lid 1 10 of the hermetically sealed chamber 30 and through a layer of transparent fluid it is filled with, leakages of fluid imitating blood, in a mixture with tinting fluid, resulting from the application of intravascular staplers, as well as location, quantity and volume of these leakages.

Then, if necessary, there is modelled an auxiliary intravascular operation by means of surgical instruments and devices introduced inside the aorta model 32 through tubes 116 connected with ports 112, 114 on the walls 109 and lid 110 of the hermetically sealed chamber 30. In particular, in this way the operation for eliminating leakages from the aorta with a damaged wall is modelled.

In the course of a modelled surgical operation video shooting is performed ( including the occuring leakages) on a video camera 150 with simultaneous transmission of image to the monitor of computer 140 and its recording on a videocorder 142 for following repeated viewing and analysis of the modelled operation. Shooting and recording may be performed automatically under control of computer 140.

The suggested method for modelling intravascular and extravascular operations on circulation system sections may additionally comprise changing the conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of hydraulic resistance 90 on the closed tube 26 outside the hermetically sealed chamber 30. Thereafter, repeated modelling is performed of a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model 32, with simultaneous control, via computer 140, of preset parameters of the stand 1 operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, position, quantity 33 147,954/2 and volume of these leakages and shooting the modelled surgical operation, including the shooting of occurring leakages on a video camera 150 with transmitting the image to the monitor of computer 140 and its recirding on a video tape recorder 142.

The claimed method may as well additionally comprise the following steps: - changing the conditions of modelling a surgical operation by replacing model 18 of a circulation system section with a model having other parameters, or by additionally introducing inside the hermetically sealed chamber 30 a model of an internal organ, such as a kidney; - changing the conditions of modelling a surgical operation by including into the circulation system a second peristelsic pump 13 imitating the work of heart and operating in suction mode, whereas the first peristelsic pump 12 operates in forcing mode; - modelling on a model of a circulation system section a surgical operation performed simultaneously inside and outside this section, using auxiliary surgical instrument, such as trocars, endoscopes, holders, dissectors, staplers, light guides, introduced inside the hermetically sealed chamber 30 through ports 112 and 114 in its lid 110 and body walls 109.

After each of these additional steps there is performed repeated modelling of the surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model 32, with simultaneous control, via computer 140, of preset parameters of the stand 1 operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, detecting position, quantity and volume of these leakages and shooting the modelled surgical operation, including the shooting of occurring leakages, on a video camera 150 with transmitting the image to the monitor of computer 140 and its recording on a video taperecorder 142. 34 147,954/2 Finally, there is suggested a method for testing intravascular devices for performing intravascular operations on circulation system sections. The method comprises several successive steps (FIGS. 1 - 5). First, stand 1 is brought into operative position by connecting its hermetically sealed chamber 30 at least with one peristelsic pump 12 via a closed tube 26 extending through the working area of this pump 12 working head. Then the model of circulation system section, such as the aorta 32 of an animal taken from a slaughter, is prepared for mounting in the hermetically sealed chamber 30, for which purpose this aorta 32 is secured by its ends at corresponding ends of tube reducers 98, 100 and hermetically sealed thereat. Next, the prepared model 32 of the aorta of an animal taken from a slaughter, is placed in the hermetically sealed chamber 30, the free ends of tube reducers 98, 100 being connected to the free ends of closed tube 26 and hermetically sealed thereat. The secured aorta 32 is tightened by tensioners 102, 104 on tube reducers 98, 100 and attached via collateral 94 to the following element of unit 40 for circulation system imitation. The free end of axial passage 42 and tubes 116 extending from the aorta are fixated in the wall of the hermetically sealed chamber 30 and hermetically sealed to provide access from outside the hermetically sealed chamber 30 to the aorta 32 inner cavity. Then the single unit 40 for circulation system imitation formed by the closed tube 26 and attached aorta model 32 is filled with a fluid imitating blood, this fluid being taken from a reservoir 16 via a feeding device - syringe 48.

If necessary, the single unit 40 of circulation system imitation formed by the closed tube 26 and attached aorta model 32 is filled with tinting fluid taken from a receptacle 58 via feeding device - the same syringe 48. Air is then removed from the fluid circulating over the unit 40 for imitation of blood circulation system, by a means including a vacuum pump 54, associated with the closed tube 26 and vacuum receptacle 56. Then the sphygmomanometer 64 for measuring fluid pressure and flowmeter 66 for measuring flow rate are connected to the closed tube 26 of the single unit 40 for circulation system imitation. 147,954/2 The hermetically sealed chamber 30 prepared in this way is covered with the lid 110 and filled with transparent fluid under pressure to imitate the density of tissues surrounding the model 32 of a circulation system section outside. The pressure of transparent fluid is controlled by manometer 68. Then, via a peristelsic pump 12, fluid is forced to circulate in the single unit 40 for circulation system imitation. Simultaneously, via said computer 140, the preset parameters of the stand 1 operation are controlled, including temperature of fluid imitating blood, rate and direction of its circulation.

The testing of intravascular devices is performed in the following order. First, through said axial passage 42, there is introduced inside the aorta model 32 a guide with an intravascular device, such as stent or stent-graft, located at the free end of said guide in a compressed state. Then this intravascular device is positioned and deployed in a preset place inside the aorta model 32. Thereafter the tested intravascular device, such as an intravascular stapler, is introduced inside the aorta model 32 through the axial passage 42. Simultaneously, there are actuated the device 108 for preventing fluid leakages and device for preventing air ingress inside the single unit 40 for circulation system imitation - vacuum pump 54. Thereafter, there starts the modelling itself of a intravascular operation using surgical instrument introduced inside tha aorta model 32, in particular, there is modelled the operation for mounting a stent-graft and fixating it to the walls of aorta model 32 via an intravascular stapler. In the course of modelling the operation, there are controlled, via a computer 140, preset parameters of the stand 1 operation, such as pressure of transparent fluid in the hermetically sealed chamber 30, pressure and flow rate in the closed tube 26. Simultaneously, there are visually detected, through the body walls 109 and lid 110 of hermetically sealed chamber 30 and through a layer of transparent fluid the chamber is filled with, leakages of fluid imitating blood, mixed with tinting fluid, the leakages resulting from the application of the intravascular stapler. The location, quantity and volume of these leakages are as well detected visually. In the course of 36 147,954/2 testing shooting is performed of the modelled surgical operation, including the occurring leakages, on a video camera 150 with simultaneous transmission of the image to the monitor of computer 140 and recording it on a video tape recorder 142 for following repeated viewing and analysis of the modelled operation. Shooting and recording may be performed in automatic mode under control of a computer 140. With the testing completed, performance of the tested intravascular device is estimated on the basis of visual observations, parameters recorded by the computer 140, as well as on the basis of video shooting and video recording.

The claimed method for testing intravascular devices for performing intravascular operations on circulation system sections may additionally include the following steps: - changing conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of a hydraulic resistance 90 on the closed tube 26 outside the hermetically sealed chamber 30; - changing conditions of modelling a surgical operation through replacing the aorta model 32 by a model with different parameters.

After each of additional steps described above there is performed a repeated modelling of the surgical intravascular operation via tested intravascular device introduced inside the aorta model 32, with simultaneous control, by a computer 140, of preset parameters of the stand 1 operation, detecting leakages of fluid imitating blood, mixed with tinting fluid, detecting the location, quantity and volume of these leakages and shooting the modelled surgical operation, including the occurring leakages, on a video camera 150 and transmitting the image to the monitor of computer 140 and recording it on a video tape recorder 142, as well as following estimation of performance of the tested intravascular device on the basis of visual observations, parameters recorded by the computer 140, and on the basis of video shooting video recording. 37 147,954/2 Application of the claimed invention makes it possible to manufacture apparatus which, owing to their design and methods of application, provide modelling of methods for performing intravascular and extravascular surgical operations on any circulation system sections, in conditions most similar to real life conditions of location and functioning of these sections. On the basis of this apparatus and method for its application, it is possible to perform tests of performance and efficacy of new intravascular instruments developed for use in minimally invasive surgery techniques of circular system. Besides, application of the claimed apparatus and method allows to carry out regular training of surgeons and medical personnel in performing surgical operations using new intravascular instruments.

While this invention has been described in conjunction with specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims (51)

38 147,954/2

1. A stand for modelling intravascular and extravascular operations on circulation system sections and for testing intravascular devices for these operations, including a supporting structure, peristelsic pump with a working head, reservoir with fluid imitating blood, models of internal organs or some circulation system section, as well as tubing to connect the peristelsic pump with the reservoir and with models of internal organs or of circulation system sections, wherein the improvement comprises: a) a supporting structure with a bearing surface, and at least one peristelsic pump serving for providing circulation of liquid imitating blood and it is provided with a system for adjusting fluid circulation rate and direction of circulation; b) a tubing passing through the working head of at least one peristelsic pump and including at least one closed tube^made substantially of transparent material, and at least a part of the closed tube disposed in the area of the working head of peristelsic pump is made of flexible material; c) a hermetically sealed chamber of transparent material mounted on the bearing surface of supporting structure, at least a part of said closed tube being disposed within said hermetically sealed chamber and detachable; d) at least one model of a circulation system section mounted within the hermetically sealed chamber, between detachable ends of said closed tube, in such a way that said model forms, together with the closed tube, a single unit for circulation system imitation, the model being provided with an axial passage for itroducing medical instrument therein, and said axial passage has an input port, disposed outside the hermetically sealed chamber and provided with a back valve; e) means for filling the unit for circulation system imitation with a fluid imitating blood and taken from said reservoir; f) means for filling the hermetically sealed chamber with transparent fluid under pressure to imitate the density of tissues surrounding outside the circulation system section; 39 147,954/2 g) means for detecting leakages of fluid imitating blood from the circulation system section in modelling a surgical operation within said section; h) means for removing air from the fluid circulating over the unit for imitation of blood circulation system, whereby there are modelled intravascular and extravascular surgical operations performed by minimally invasive surgery techniques inside circulation system sections, such as operation for placing within the aorta with an aneurysn a stent-graft and fixating it from inside to the aorta walls by means of special staplers, as well there are tested the performance and efficacy of new intravascular instruments developed for application in minimally invasive surgery techniques.

2. The stand according to claim 1, further comprising: j) a receptacle for tinting fluid; k) feeding means for filling said single unit for circulation system imitation with tinting fluid; 1) a device for measuring fluid pressure inside the single unit for circulation system imitation, and m) a device for measuring flow rate inside the single unit for circulation system imitation.

3. The stand according to claim 1, wherein said supporting structure with a bearing structure is a table-like structure with a perforated bearing surface and a receptacle for collecting fluid leakages.

4. The stand according to claim 1, wherein said fluid imitating blood is substantially a 0,9% solution of NaCl.

5. The stand according to claim 1, wherein said fluid imitating blood is substantially natural animal blood, taken from a slaughter, such as bull's blood. 40 147,954/2

6. The stand according to claim 1, wherein said means for detecting leakages of fluid imitating blood, from a circulation system section, in modelling inside said section a surgical operation, is a tinting fluid added to the fluid imitating blood.

7. The stand according to claim 6, wherein said tinting fluid added to the fluid imitating blood is fluorescent.

8. The stand according to claim 1, wherein said means for filling the unit for circulation system imitation with fluid imitating blood is a feeding device, including a device for forcing fluid and a valve attached via flexible pipelines to said closed tube and to a reservoir with fluid imitating blood.

9. The stand according to claim 8, wherein said feeding device for filling the single unit for circulation system imitation with a tinting fluid, is a feeding device, including a device for forcing fluid and a valve, attached via flexible pipelines to said closed tube and to said receptacle with a tinting fluid.

10. The stand according to claim 8 and 9, wherein said means for filling the single unit for circulation system imitation with fluid imitating blood, as well as a feeding device for filling said single unit for filling this single unit for circulation system imitation with a tinting fluid, is a single feeding device including a built-in device for forcing fluid and valves connected via transparent pipelines both to the reservoir for fluid imitating blood, and to said receptacle for tinting liquid.

11. The stand according to claim 10, wherein said built-in device for forcing fluid is a hydraulic pump.

12. The stand according to claim 11, wherein said built-in device for forcing fluid is a manual hydraulic pump, such as a syringe.

13. The stand according to claim 1, wherein said single unit for circulation system imitation is additionally provided with a safety system for releasing pressure of circulating fluid, the system including a back valve with a hydraulic drain line connecting the valve to said single feeding device. 41 147,954/2

14. The stand according to claim 1, wherein said means for removing air from fluid circulating over the unit for circulation system imitation, includes a cardiotomy reservoir with a filter, whereby said reservoir with fluid imitating blood is attached to the closed tube of the unit for circulation system initation.

15. 1 . The stand according to claim 1, wherein said means for removing air from fluid circulating over the unit for circulation system imitation, includes a vacuum pump attached to the closed tube and vacuum receptacle.

16. The stand according to claim 2, wherein said device for measuring fluid pressure inside the single unit for circulation system imitation, includes a sphygmomanometer attached via a T-joint to said closed tube.

17. The stand according to claim 2, wherein said device for measuring flow rate inside the single unit for circulation system imitation, includes a flowmeter attached via a T-joint to said closed tube.

18. The stand according to claim 1, wherein said closed tube is provided with a device for imitating stenosis or occlusion in a circulation system, such as a hydraulic resistance disposed in the closed tube outside the hermetically sealed chamber.

19. The stand according to claim 1, wherein the means for filling the hermetically sealed chamber with transparent fluid under pressure, to imitate the density of tissues, surrounding outside the model of a circulation system section includes an auxiliary pump with a manual or electrical drive, a receptacle for transparent fluid, a device for draining the fluid from the hermetically sealed chamber and at least one safety valve attached via pipelines to the hermetically sealed chamber.

20. The stand according to claim 1, wherein said hermetically sealed chamber is adapted for placing, at the detachment location of said closed tube, at least one model of a circulation system section, or an internal organ model with an attached section of a circulation system. 42 147,954/2

21. The stand according to claim 20, wherein said hermetically sealed chamber is adapted for placing, at the detachment location of said closed tube, at least two models, one of which is a model of a circulation system section, and the second, a model of an internal organ with an attached circulation system section, said models being attached to the closed tube in parallel relationship and linked together via additional passages imitating collaterals.

22. The stand according to claim 21, wherein at least one of said models is provided with a discharge system shaped as shunting collateral connecting the inner cavity of this model and the following element of the unit for circulation system imitation, whereby there is prevented increased fluid resistance inside the model when instrument is inserted therein.

23. The stand according to claim 21, wherein at least one of said models is a model of an internal organ , such as a kidney.

24. The stand according to claim 23, wherein at least one of said models of circulation system section or internal organ is a natural internal organ of an animal or a section of its circulation system taken from a slaughter.

25. The stand according to claim 24, wherein at least one of said models, such as the model of a circulation system section, is a natural aorta of an animal taken from a slaughter, such as pig's aorta.

26. The stand according to claim 25, wherein said natural aorta of an animal, such as pig's aorta, is secured by its ends on the first and second tube reducers, each of which being hermetically attachable with a corresponding end of said closed tube, the tube reducers having devices for affixing and tensioning the aorta.

27. The stand according to claim 26, wherein at least one, the first or second tube reducer, is provided with an axial passage for introducing a surgical instrument inside the aorta, and the axial passage is provided with a device preventing fluid leakages and a device preventing air ingress inside the closed tube. 43 147,954/2

28. The stand according to claim 26, wherein said hermetically sealed chamber is provided at least with one standby set of tube reducers having different outer diameters and length to attach to said aortas of different sizes, the tube reducers having axial passages of different net section, and the sets of tube reducers are detachable interchangeable cartridges.

29. The stand according to claim 1, wherein said hermetically sealed chamber has a body and a detachable sealable lid of transparent material to mount and replace the corresponding model of a circulation system section.

30. The stand according to claim 29, wherein the body and the lid of said hermetically sealed chamber have ports with back valves serving to insert inside the hermetically sealed chamber a surgical instrument, such as trocars, endoscopes, holders, dissectors, clamps, staplers, light guides used in modelling surgical operations outside at least one model of circulation system section.

31. The stand according to claim 30, wherein the body and the lid of said hermetically sealed chamber are provided with ports and back valves, part of which are associated via tubes with the inner cavity of at least one of the models, disposed within this hermetically sealed chamber, whereby there is provided laporoscopic insertion inside this model of additional instrument, such as a light guide and stapler to eliminate fluid leakages from inside a model with a damaged wall.

32. The stand according to claim 1, wherein said model of a circulation section model is a thansparent three-dimensional, anatomically correct image of at least a part of circulation system and includes the aorta and a number of arteries, such as the coronary artery, subclavian artery, pulmonary artery and renal artery, and has imitators of narrowings or thrombi, the model having at least one additional port to insert inside the model intravascular guides and catheters.

33. The stand according to claim 1, wherein said model of a circulation system section has a curved main section, substantially the aorta and at least one secondary section attached to the main section in its curved part, as well as means for changing 44 147,954/2 the position of the secondary section relative to the main section according to any variants of age or pathologically abnormal location of this secondary section, encountered in real medical practice.

34. The stand according to claim 1, wherein said model of a circulation system section is made of plastic and have a wall thickness, Young's modulus, allowed tension, dimensions and stability corresponding to certain portions of natural circulation system sections.

35. The stand according to claim 1, wherein said tubing passes successively through working heads of at least two peristelsic pumps, and includes at least one closed tube made substantially of transparent material, at least two portions of the closed tube disposed in the area of working heads of said peristelsic pumps are made of flexible material.

36. The stand according to claim 35, wherein said at least two peristelsic pumps are synchronised with one another in antiphase, so that one of said peristelsic pumps forces fluid during its circulation in said closed tube, and the second sucks fluid, whereby said circulation system imitates the work of heart.

37. The stand according to claim 1, further including a computer control system for operation of means and devices of the stand and control of preset parameters.

38. The stand according to claim 37, wherein the temperature of fluid imitating blood in the stand closed tube is approximately 37° C and is controlled by the computer control system.

39. The stand according to claim 1, further including fluorescent bright-up lamps mounted next to said hermetically sealed chamber, and a video camera for regular image transmission to the screen of an attached monitor, the monitor having a video tape recorder to record modelled operations and for repeated viewing thereof.

40. The stand according to claim 1, further including light filters to imitate changing oxygen content in the fluid imitating blood, and circulating in the unit for 45 147,954/2 circulation system imitation, as well as to detect and distinguish in color fluid leakages from models of circulation system sections in modelling thereon a surgical operation.

41. A method for modelling intravascular and extravascular operations on models of circulation system sections, comprising the following steps: a) bringing the stand into operative position by attaching its hermetically sealed chamber at least to one peristelsic pump via the closed tube extending through the working area of the pump; b) preparing the model of a circulation system section, such as the aorta of an animal taken from a slaughter, for placing in the hermetically sealed chamber, securing the aorta at its ends to corresponding ends of tube reducers and hermetically sealing said ends; c) placing the prapared model of a circulation system section, such as an animal aorta taken from a slaughter, in the hermetically sealed chamber, the free ends of tube reducers being connected to free ends of the closed tube and hermetically sealed thereon, the affixed aorta is tensioned via tensioners on tube reducers and is connected collaterally to the following element of the unit for circular system imitation, and the free end of the axial passage and tubes extending from the aorta are affixed in the wall of a hermetically sealed chamber and hermetically sealed, to provide access to the aorta inner cavity from the outside of the hermetucally sealed chamber; d) filling the single unit for circulation system imitation formed by the closed tube and attached section model, with fluid imitating blood and taken from the reservoir by said feeding device; e) filling, if necessary, the single unit for circulation system imitation formed by the closed tube and attached section mode, with tinting fluid taken from the receptacle by said feeding device; f) removing air from fluid circulating over the unit for circulation system imitatation, via said means including a vacuum pump connected to the closed tube and to the vacuum receptacle; 46 147,954/2 g) attaching to the closed tube of the single unit for circulation system imitation, a sphygmomanometer for measuring fluid pressure and a flowmeter for measuring and flow rate of fluid drawn therethrough; h) closing the hermetically sealed chamber by the lid and filling it under pressure with transparent fluid, to imitate density of tissues surrounding from the outside of the model of a circulation system section; i) generating, by means of at least one peristelcic pump, fluid circulation in the single unit for circulaton system imitation; j) controlling preset parameters of the stand operation, including temperature of fluid imitating blood, rate and direction of its circulation by a computer control system. k) introdicing surgical instruments and devices, such as guides, devices for mounting stent-grafts or special staplers, inside the aorta model through axial passage, with simultaneously engaging said devices for preventing fluid leakages and for preventing air ingress into the single unit for circulation system imitation; 1) modelling an intravascular operation by means of surgical instruments and devices introduced inside the aorta model, such as operations for placement of a stent-graft and its fixation to the aorta model walls via intravascular staplers; m) controlling, via said computer control system, preset parameters of the stand operation , such as the transparent fluid pressure in the hermetically sealed chamber and fluid pressure and flow rate in the closed tube; n) visually detecting, through the walls and lid of the hermetically sealed chamber and through a layer of transparent fluid it is filled with, leakages of fluid imitating blood, in a mixture with tinting fluid, resulting from the application of intravascular staplers, as well as location, quantity and volume of these leakages; o) modelling an auxiliary intravascular operation by means of surgical instruments and devices introduced inside the aorta model through tubes connected to ports on the walls and lid of the hermetically sealed chamber, in particular, such as the operation for eliminating leakages from the aorta with a damaged wall, and 47 147,954/2 p) filming the modelled surgical operation, including the occuring leakages, on a video camera with simultaneous transmission of image to the monitor and its recording on a videorecorder for repeated viewing and analysis of the modelled operation, the filming and recording may be performed automatically under control of said computer control system.

42. The method for modelling according to claim 41, further including the following steps: q) changing the conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of said hydraulic resistance on the closed tube outsade the hermetically sealed chamber, and r) repeatedly modelling a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model, with simultaneous control, via said computer control system, of preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, defining location, quantity and volume of the leakages and filming the modelled surgical operation, including the filming of occurring leakages on a video camera with transmitting the image to the monitor and its recording on a video-taperecorder.

43. The method according to claim 41, further comprising the following steps: s) changing the conditions of modelling a surgical operation by replacing the model of a circulation system section with a model having other parameters, and t) repeatedly modelling a surgical intravascular operation by means of surgical instruments and devices inserted inside the aorta model, with simultaneous control, via said computer control system, preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, defining location, quantity and volume of these leakages and filming the modelled surgical operation, including the ocurring leakages, on a video camera with transmiiting the image to the monitor and its recording on a video taperecorder. 48 147,954/2

44. The method for modelling according to claim 41, further including the following steps: u) changing the conditions of modelling a surgical operation by adding an introducing inside the hermetically sealed chamber, a model of an internal organ, such as a kidney, to the model of a circulation system section, and v) repeatedly modelling a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model, with simultaneous control, via said computer control system, of preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, defining location, quantity and volume of these leakages and filming the modelled surgical operation, including the filming of occurring leakages on a video camera while transmitting the image to the monitor and its recording on a video-taperecorder.

45. The method for modelling according to claim 41, further including the following steps: w) changing the conditions of modelling a surgical operation by inserting into the circulation system a second peristelsic pump imitating the work of heart and operating in suction mode, whereas the first peristelsic pump operates in forcing mode, and x) repeatedly modelling a surgical intravascular operation by means of surgical instruments and devices introduced inside the aorta model, with simultaneous control, via said computer control system, of preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, defining location, quantity and volume of these leakages and filming the modelled surgical operation, including the filming of occurring leakages on a video camera while transmitting the image to the monitor and its recording on a video-taperecorder. 49 147,954/2

46. The method for modelling according to claim 41, further including following steps: i) modelling on a model of a circulation system section, a surgical operation performed simultaneously inside and outside this section, using auxiliary surgical instrument, such as trocars, endoscopes, holders, dissectors, clamps, staplers, light guides, introduced inside the hermetically sealed chamber through said ports in its lid and walls, and ii) simultaneously controlling via said computer control system, of preset parameters of the stand operation, visually detecting leakages of fluid imitating blood, in a mixture with tinting fluid, visually defining location, quantity and volume of these leakages and filming the modelled surgical operation, including the filming of occurring leakages on a video camera with transmitting the image to the monitor and its recording on a video-taperecorder.

47. The method for testing intravascular devices for performing intravascular operations on circulation system sections, including the following steps: a) bringing the stand into operative position by connecting its hermetically sealed chamber to at least one peristelsic pump via a closed tube passing through the operation area of this pump's working head; b) preparing a model of a circulation system section, such as the aorta of an animal taken from a slaughter, for placement in a hermetically sealed chamber, for which chamber this aorta is secured by its ends at corresponding ends of tube reducers and sealed thereat; c) placing in a hermetically sealed chamber the prepared model of a circulation system section, such as the aorta of an animal taken from a slaughter, the free ends of tube reducers being connected to free ends of the closed tube and sealed thereon, the secured aorta is tightened via tensioners on tube reducers and connected collaterally to the following element of the unit for circulation system imitation, and the free end of axial passage and tubes extending from the aorta are affixed in the 50 147,954/2 wall of a hermetically sealed chamber and sealed, to provide access from outside the hermetically sealed chamber to the aorta inner cavity; d) filling the single unit for circulation system imitation formed by a closed tube and attached section model with fluid imitating blood, taken from said reservoir via said feeding device; e) filling, if necessary, the single unit for circulation system imitation, formed by a closed tube and attached model of a pathological section, with tinting fluid taken from the receptacle via said feeding device; f) removing air from fluid circulating over the unit for circulation system imitation, via said means including a vacuum pump associated with the closed tube and vacuum receptacle; g) attaching to the closed tube of the single unit for circulation system imitation a sphygmomanometer for measuring fluid pressure and flowmeter for measuring flow rate; h) closing the hermetically sealed chamber with the lid and filling it with transparent fluid under pressure to imitate density of tissues surrounding outside the model of a circulation system section; i) generating, at least by one peristelsic pump, fluid circulation in the single unit for circulation system imitation; j) controlling, via said computer control system, preset parameters of stand operation, including the temperature of fluid imitating blood, rate and direction of its circulation; k) inserting through said axial passage inside the aorta model a guide with an intravascular device, in particular, a stent or stent-graft disposed at the free end of said guide in compressed state, positioning and deploying this intravascular device at the required spot inside the aorta model; 1) inserting through said axial passage inside the aorta model a tested intravascular device, such as intravascular stapler and simultaneously engaging said device for preventing fluid leakages and said device for preventing air ingress inside the single unit for circulation system imitation; 51 147,954/2 m) modelling an intravascular operation by means of surgical instrument inserted inside the aorta model, such as operation for mounting a stent-graft and its fixation to the walls of aorta model via an intravascular stapler; n) controlling, via said computer control system, preset parameters of stand operation, such as pressure of transparent fluid in the hermetically sealed chamber and and fluid pressure in the closed tube; o) visually detecting, through the walls and lid of the hermetically sealed chamber and through a layer of transparent fluid it is filled with, leakages of fluid imitating blood, in a mixture with tinting fluid, resulting from the application of an intravascular stapler, visually defining the location, quantity and volume of these leakages; p) filming the modelled surgical operation, including occurring leakages, on a video camera with simultaneous transmitting of the image to a monitor and recording it on a video tape recorder for following repeated viewing and analysis of the modelled operation, and filming and recording may be performed automatically under the control of said computer control system, and q) estimating the performance of the tested intravascular device on the basis of visual observations, parameters, recorded by the computer control system, as well as on the basis of video filming and video recording.

48. The method for testing intravascular devices according to claim 47, further including following steps: r) changing the conditions of modelling a surgical operation by imitating stenosis or occlusion through changing the inner section of said hydraulic resistance on the closed tube outside the hermetically sealed chamber; s) repeated modelling of a surgical intravascular operation by means of the tested intravascular device inserted inside the aorta model, with simultaneous control, via said computer control system, preset parameters of stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, defining location, quantity and volume of these lekages and filming the modelled surgical operation, including the occurring leakages, on a video camera with transmitting the 52 147,954/2 image to a monitor and recording it on a video taperecorder, as well as with following estimating of performance of the tested intravascular device on the basis of visual observations, parameters recorded by a computer control system, and on the basis of video filming and video recording.

49. The method for testing intravascular devices according to claim 47, further including following steps: t) changing the conditions of modelling a surgical operation by replacing a model of a circulation system section with a model having different parameters, and u) repeated modelling of a surgical intravascular operation by means of the tested intravascular device introduced inside the aorta model, with simultaneous control, via said computer control system, preset parameters of the stand operation, detecting leakages of fluid imitating blood, in a mixture with tinting fluid, detecting position, quantity and volume of these leakages and filming the modelled surgical operation, including the filming of occurring leakages, on a video camera with trasmitting the image to a monitor and its recording on a video taperecorder, as well as following estimating of performance of the tested intravascular device on the basis of visual observations, parameters recorded by the computer control system and on the basis of video filming and video recording.

50. A stand for modelling intravascular and extravascular operations on circulation system sections and for testing intravascular devices for these operations according to claim 1, substantially as hereinbefore described and with reference to the accompanying drawings.

51. A method for modelling intravascular and extravascular operations on models of circulation system sections according to claim 41, substantially as hereinbefore described and with reference to the accompanying drawings. for the Applicant: WOLFF, BREGMAN AND GOLLER