DE102006037533A1 - Holding device for e.g. stent, has drive provided for moving flexible band along longitudinal direction of band such that object is rotated along its longitudinal direction during moving of object - Google Patents

Abstract

The holding device (100) has a roller (110b) arranged at a distance form another roller (110a). A flexible band (115) is stretched transverse across the rollers, such that the band forms a recess between the rollers. A cylindrical object e.g. stent (120), is inserted into the recess. A drive is provided for moving the band along a longitudinal direction of the band such that the object is rotated along its longitudinal direction during moving of the object.

Description

The The invention relates to a holding device for a cylindrical object, especially for a tube constructed of a grid for the purpose of surface inspection of the article with an optical sensor.

The The invention further relates to an optical measuring arrangement for three-dimensional Measuring the surface structure a cylindrical article with an optical sensor.

vascular diseases, which in particular in today's affluent society far are common under certain circumstances to a complete close lead a blood vessel. The The tissue to be supplied by the respective bloodstream can be irreversible be damaged. If this tissue for the human organism is vital, such a vascular occlusion even lead to the death of the patient.

Around in excellent places vasoconstriction To prevent it, medicine has developed endoluminal vascular prostheses which by surgery in those threatened by a narrowing Position of the blood vessel inserted become. The endoluminal vascular prostheses are usually stretchy, metallic tubes constructed of a lattice structure, as a vascular support to Serve for improved keeping open of a blood vessel. The vascular prostheses usually a certain flexibility so they are also used in places of the human body can be where the respective blood vessel has a curvature. This curvature can be dependent from the respective posture be different. An endoluminal vascular prosthesis becomes common referred to as a stent.

There with faulty stents the life of patients is endangered, will go to the quality control Stents made very high demands. Mistakes like material weakening, Material breaks, bumps in the grid material and the like must be reliably detected.

to Inspection of stents, for example, optical measuring systems used, which is the outer surface of the Stents by means of a two-dimensional image recording and / or a Check three-dimensional detection of the outer surface.

For the highly accurate three-dimensional measurement of small objects is from the DE 196 084 68 C2 an optical distance sensor is known, which is based on the confocal optical imaging principle. Such a distance sensor, for example, in 7 the cited document comprises a punctiform light source and a point-shaped receiver. The point light source is imaged on a surface of a measurement object. The point-shaped receiver is arranged confocally to the point-shaped light source in the image-side measuring range. The distance sensor is distinguished on the object side by a coaxial guidance of illumination and measuring light. The optical path between the point-shaped receiver and the measurement object can be varied by the use of a vibrating mirror system. By determining the maximum light intensity measured by the receiver as a function of the position of the oscillating mirror system, the altitude of the respective measuring point on the surface of the measuring object can be determined.

Of the Invention is based on the object, a holding device for Holding and simultaneously rotating a cylindrical object in a precise spatial Able to create. The invention is also based on the object, a optical measuring arrangement for to create a cylindrical object.

These Tasks are solved through the objects the independent one Claims. Advantageous embodiments The present invention is described in the dependent claims.

With the independent one Claim 1 is a holding device for rotating a cylindrical object around its longitudinal axis described. The holding device is particularly suitable for turning a grid-like tube for the purpose of optical surface inspection the latticed tube. The holding device according to the invention comprises (a) a first support element, (b) a second support element, which is spaced from the first support element is arranged and (c) a flexible band extending across the two support members so tense is that the flexible band between the two Support elements forms a recess into which the cylindrical Object is inserted. The holding device according to the invention comprises and (d) a drive for displacing the flexible belt its longitudinal direction, so that when a shift of the tape into the depression inserted cylindrical object rotates about its longitudinal axis.

The invention is based on the finding that a cylindrical object, such as a grid-like tube made of a flexible material, can be gently rotated about its longitudinal axis by being supported in a recess or bagging of a flexible film. The Aussackung is located between the two support elements over which the flexible belt is moved in a smooth and jerk-free movement.

The flexible band is applied to the two support elements, that a so-called support surface is created on each support element, within which the flexible band touches the respective support element. The curvature the bearing surfaces depends in particular of the surface profile of both support elements as well as the tension of the flexible band from. The bearing surfaces are preferably parallel to the longitudinal axis aligned with the cylindrical object, so that advantageous Way a largely symmetrical structure of the holding device realized is.

The described holding device allows in an advantageous manner a precise one Rotation of the cylindrical object about its longitudinal or symmetry axis, so that by sequential scanning the entire surface of the cylindrical object can be measured. By means of the described Holding device can thus be a particularly gentle pivot bearing also of mechanically sensitive cylindrical objects such as Stents are realized. This allows a simple way precise optical inspection of the cylindrical objects from all sides.

According to claim 2, the flexible band is a transparent foil. This can be on Advantageously, a measurement of the cylindrical object in particular take place in the visible spectral range.

According to claim 3 is the distance between the two support elements between an insertion position and a measuring position variable. In the insertion position the distance between the two support elements can be so great that the cylindrical object in a simple manner, for example, manually in the recess formed between two support elements can be inserted. After inserting can for measuring the cylindrical Object the two support elements are then brought closer together so that the recess a possible defined defined between the two support elements defined Pocket forms. The cylindrical object can only separated by the flexible band directly abut the two support elements.

According to claim 4 is the drive with the flexible band and / or with at least coupled to one of the two support elements. This has the advantage that the flexible band on diverse Way directly and / or indirectly, in particular by a Rotary movement to be driven by at least one support element can. The drive can also without major design difficulties be designed so that always a constant voltage of the flexible Bandes and thus a spatial ensures solid position of the recess is.

According to claim 5, the first support element is rotatable in a first axis of rotation mounted first roller and / or the second support element is a in a second axis of rotation rotatably mounted second roller. This has the advantage that the displacement of the flexible band largely can be done without friction, so that with a corresponding storage the rollers a particularly smooth movement is realized.

At However, this point is explicitly stated noted that a shift of the flexible band even without a rotatable mounting of the support elements is possible. A gentle and jerk-free Relative movement between the flexible band and the respective support element can then be achieved for example by a corresponding lubricant which is between the band and the rigid support elements is introduced and which the sliding friction between support element and Band reduced. However, the sliding friction can also by a suitable choice of the materials of the flexible band and / or the Support elements are reduced.

According to claim 6, a preferred measuring position is provided in which the two Rollers are spaced apart from each other and the flexible band is so curious that a pickled in the recess cylindrical object (a) below one through the two axes of rotation defined connection level and (b) of the flexible Band is at least so far enclosed that the cylindrical object only separated by the flexible band both on the first as well as abutting against the second support element. A pivot bearing of the cylindrical article in the preferred measuring position the advantage that the cylindrical object at least as far enclosed by the flexible band is that the recess a parallel to the axes of rotation aligned pocket forms, in which the cylindrical object is received. This allows the position of the cylindrical object to be measured particularly accurately determined become. This is true even if the cylindrical object is made is made of an elastic material and has a slight curvature, by gently pulling the object against the undersides the two roles can be eliminated.

In such a concern of cylindri rule object on the undersides of the two rollers, the object from the bottom of the holding device can be better visible than from the top of the holding device. For this reason, an optical measurement of the cylindrical object can preferably be made from below.

With the independent one Claim 7 is an optical measuring arrangement for a cylindrical object described. The optical measuring arrangement is particularly suitable for one latticed tube like for example, an endoluminal vascular prosthesis. The optical measuring arrangement comprises (a) an optical sensor and (b) a holding device according to one the above embodiments. The Holding device is arranged relative to the optical sensor such that at least a portion of the cylindrical object within a Detection range of the optical sensor can be positioned.

Of the The invention is based on the finding that the above-described Holding device with a corresponding rotation of the cylindrical Subject of a sequential three-dimensional surface inspection from all points along a circumferential circle of the cylindrical Object allows. The gentle and spatial precise storage the rotating cylindrical object allows it a very precise surface measurement by means of a suitable optical sensor.

According to claim 8, the optical measuring arrangement additionally has a positioning device, by means of which the holding device relative to the optical sensor along the longitudinal axis slidably inserted in the recess cylindrical object is. By such a longitudinal method of the to be measured Item may be in connection with the rotational movement of the item every point on the surface of the object and thus the complete surface structure the cylindrical object inspected and optionally existing defects are checked.

According to claim 9, the optical sensor is based on the confocal optical imaging principle confocal distance sensor. The use of a so-called confocal Distance sensor allows advantageously a particularly accurate distance measurement with a high resolution of only a few microns. This allows the surface texture a cylindrical object received by the holding device be inspected with high accuracy. From the measured surface profile can be a complete three-dimensional model of the cylindrical object be calculated.

According to claim 10, the confocal distance sensor (a) comprises a point-shaped optical transmission element, arranged for emitting illumination light, (b) imaging optics for focusing the illumination light into an object area and (c) a punctiform optical receiving element. In this case, the point-shaped optical receiving element with respect to the imaging optics confocal to the optical transmitting element arranged. Further, the point-shaped optical receiving element set up for the reception of measuring light, which differs from the cylindrical one Object at least partially scattered back and over the Imaging optics is directed to the receiving element. The confocal Distance sensor further comprises (d) a displacement device for Varying the optical path between the imaging optics and the optical transmission element.

According to the confocal Illustration principle results in the height or distance position of the respective Measuring point by an evaluation of the by the receiving element measured intensity curve as a function of the distance between the imaging optics and the optical transmitting element, in which the intensity maximum is measured.

It It should be noted that the transmitting element and the receiving element by means of a single optical element, for example the end a light-conducting fiber can be realized, so that the transmitting element and the receiving element is effectively located at the same location are. An optical coupling with a light source as well as with a Light detector is done in a known manner by a splitting the other end of the light-conducting fiber in two different Dividing ends or through a beam splitter, over which both a light source as well as a light detector with the other end of the light conducting Fiber is optically coupled.

The Displacement device, the lens, the optical transmitting or Receiving element and / or between lens and optical transmitter or receiving element arranged reflector move. To a high Scanning speed, the displacement device should a preferably allow rapid variation of the optical path. For example, the displacement device be a tuning fork driven at a given frequency, at the legs of the movable components of the confocal distance sensor are attached. this makes possible a particularly fast periodic variation of the optical path between imaging optics and optical transmitting element and allowed Thus, a particularly fast data acquisition of each to be measured Distance or height values.

According to claim 11, the confocal distance sensor is a multi-channel distance sensor, with several parallel measuring points on a measuring line can be measured. The transmitting element is in this case preferably one of several Point light sources existing light line and the receiving element is preferably a line sensor, each point light source respectively a pixel of the line sensor is assigned. This way a can particularly fast measurement of the surface structure of the cylindrical Object can be realized without affecting the accuracy of each Measured values is reduced. Of course, the point light sources can and / or the punctiform receiving elements also by a pinhole or by the end of light conductive fibers are realized.

According to claim 12, the optical measuring arrangement is used to measure a grid-like tube, for example, an endoluminal vascular prosthesis (stent). It is the holding device relative to the confocal distance sensor such arranged that (a) a first portion of the wall of the grid-like Tube of the illumination light is at least partially penetrable and that (b) a second portion of the wall of the grid-like tube within of the object area is positionable. It should be noted that the two mentioned portions of the tube wall typically in Reference to the central axis of the tube on opposite Pages are located. Thus, with a corresponding focus of the illumination light on the inner wall of the second portion the tube wall the internal structure of the tube be measured. Thus, advantageously, not only the external structure the latticed tube, but also the surface structure be measured on the inside of the grid-like tube.

By a full review of the Topography of the latticed tube on cracks, sharp edges, burrs etc. and a corresponding rejection From faulty stents can be a high quality of endoluminal vascular prostheses and thus a high level of patient safety is ensured.

Of course you can to inspect a stent not just the inner surface but also the outer surface of the Stents are measured, so that from the obtained distance values a Three-dimensional model can be calculated which the stent Completely describes.

It It is noted that a partial scattering of the illumination light through the first portion of the grid-like tube at the entrance of the illumination light in the interior of the tube to be measured, the measurement accuracy is not or only in negligible Way impaired. This is because when entering the inside of the tube through the first part of the illumination light is not yet strongly focused is and thus the illumination beam still has a larger cross-section. Thus, a scattered light scattering on the grid-like tube wall only one negligible Influence on the for the confocal measurement effectively used light intensity.

Further Advantages and features of the present invention will become apparent the following exemplary description of presently preferred embodiments.

In the drawing show in schematic representations

1 a perspective view of a holding device for rotatably supporting a stent,

2 an optical measuring arrangement with a confocal distance sensor and the in 1 shown holding device,

3a a perspective view of the holding device in a loading position,

3b a perspective view of the holding device in a measuring position,

3c a perspective view of the bottom of in

3b shown holding device,

4a a stent which is in a pocket of an untensioned foil, and

4b a stent which is located in a pocket of a tensioned foil.

At It should be noted that in the drawing the Reference signs of identical or corresponding components differ only in their first digit.

1 shows according to an embodiment of the invention, a holding device 100 for a stent 120 , which is rotatably mounted in a well-defined spatial position. The holding device 100 includes a first role 110a which are in a first axis of rotation 111 is rotatably mounted. The holding device 100 further includes a second roller 110b , which in a second axis of rotation 111b is rotatably mounted. About the two roles 110a and 110b is a flexible band 115 placed, which according to the embodiment described here, a thin and highly flexible transparent film 115 is. The foil 115 is so excited that between between the two roles 110a and 110b forms a depression into which a stent 120 can be inserted. In the case of the film tension shown here, the film lies within a contact area 112a on the roll 110a and within a circulation area 112b on the roll 110b at.

A rotation of the inserted stent 120 counterclockwise about its axis of symmetry is achieved by the fact that the film 115 along a direction of movement 116 is moved to the right. The movement of the slide 115 is achieved by a drive mechanism, not shown for reasons of clarity, directly or indirectly with the film 115 is coupled.

The drive mechanism is preferably a roller drive in which the film 115 is guided over a drive roller. Unless the foil 115 is a closed band, the roller drive can be a so-called endless drive. However, the roller drive may also have a driven take-up roll, so that by changing directions of movement of the film 115 between two take-up rolls is moved back and forth.

In addition, the film can 115 also be a so-called disposable tape, which depends on the role 110a unwound and off the roll 110b is wound up. After the slide 115 at least almost completely off the role 110a has been settled, the role may 110a be exchanged for a new role, on which there is a new disposable tape. In order to avoid too large effective roll diameters as a result of a wound film, it is advisable to replace the roll 110a also the role 110b exchange.

The use of a disposable band has the advantage that the pivotal mounting of the stent 120 can be realized completely sterile. Furthermore, the use of a disposable tape has 115 the advantage of having an if necessary on the stent 120 located coating material which is partially transferred to the disposable belt during the pivot bearing, can not be transferred to other stents. In other words, this means that the use of a disposable band a completely contamination-free pivotal mounting of the stent 120 guaranteed.

It should be noted that when unwinding the film 115 from the role 110a and upon winding the film 115 on the role 110b to change the effective roll diameter continuously. Nevertheless, always a precise pivot bearing of the stents 120 To ensure in a predetermined rotational position, the spatial positions of the axes of rotation 111 respectively. 111b the roles 110a respectively. 110b be suitably changed so that the changes of the effective roll diameter are compensated accordingly.

To the speed of the slide 115 To keep constant, at least one separate driven pinch roller (not shown) may be used, attached to the film 115 is applied. In this case, the supply rolls 110a and 110b not driven directly. The pressure roller, for example, directly to the role 110b and / or the role 110a issue. This principle, which is used for example in conventional cassette recorders, can be ensured in a simple manner that the tangential speed of the film 115 regardless of the supply of transparencies on the rolls 110a and 110b remains constant. The at least one pinch roller can be placed so that it only covers the side of the foil 115 touch which side does not come in contact with the stent.

Of course, the film 115 also by a rotary movement of the roll 110a and / or the role 110b are driven. In this case, the stiction should be between the film 115 and the two roles 110a and 110b be as large as possible to prevent accidental slippage of the film 115 to prevent. To a constant film tension, especially in the area between the two rollers 110a and 110b To obtain the rotational movements of the two rollers should be actively coordinated by means of a suitable control or passive, for example by means of a so-called slip clutch. Of course, this also applies when using a not directly with the film 115 coupled drive.

For optical measurement of the stent 120 is the holding device 100 above a tube 190 a confocal optical distance sensor arranged. In contrast to distance sensors based on the principle of triangulation, in the case of a confocal distance sensor, the object axes are the optical axes of the illumination light 192 and the measuring light 192 identical.

2 shows an optical measuring device, which is a confocal distance sensor 270 and a holding device 200 for a stent 220 having. The holding device 200 as well as the in 1 illustrated holding device 100 two roles 210a and 210b on, across which transverse to the longitudinal direction of the rollers 210a and 210b a slide 215 is laid. Between the two roles 210a and 210b is from the slide 215 formed a depression into which a stent 220 or another cylindrical object can be inserted. The role 210a which are in a rotation axis 211 is rotatably supported by a rotary drive 213a driven. The role 210b which are in a rotation axis 211b is rotatably supported by a rotary drive 213b is exaggerated. The holding device 200 also has a chassis 205 in which the described components of the holding device 200 are arranged. For optical measurement of the stent 220 is in the chassis 205 a measurement window 206 intended.

The following is the confocal distance sensor 270 briefly explained. More details about the confocal distance sensor 270 can be found in the known from the prior art document DE 196 084 68 C2 ,

The confocal distance sensor 270 has an at least approximately punctiform light source 275 on. The small areal extent of the light source 275 can also be realized by a correspondingly large aperture in front of the light source. That of the punctiform light source 275 emitted light meets an optic 276 , which illuminate the illumination light as a parallel beam onto a beam splitter 280 directed. At the beam splitter 280 the illumination light is reflected and via an optic 281 , a retro reflector 285 and a deflecting mirror 287 on an object-side lens 291 directed. The objective 291 preferably has a very small focal length, so that the illumination light 292 with a large numerical aperture in an optical region of the confocal distance sensor 270 is focused.

The holding device 200 can relative to the distance sensor 270 by means of a positioning device 240 be positioned. The positioning is preferably carried out automatically by means of a drive 242 , A ball bearing 241 between the positioning device 240 and the chassis 205 allows a precise spatial adjustment of the holding device 200 ,

According to the embodiment illustrated here, the positioning device allows 240 a three-dimensional displacement of the holding device 200 namely a displacement along a horizontal x direction, along a vertical z direction and along a y direction perpendicular to the z direction and the x direction.

As further out 2 can be seen, is the holding device 200 relative to the confocal distance sensor 270 adjusted along the z-direction such that the illumination light 292 on the inner surface of the stent 220 is focused. The illumination light penetrates 292 the lower part of the stent 220 , due to the in the lower area of the stent 220 expanded cross-section of the illumination light 292 the lattice-like structure of the stent 220 the illumination light 292 weakens only slightly. The objective 291 the confocal distance sensor 270 is located in a tube 290 , which is the upper limit of the confocal distance sensor 270 represents.

The on the surface of the upper portion of the stent 220 at least partially backscattered light, which is referred to as measuring light in the following, is from the lens 291 collected and over the deflection mirror 287 , the retro reflector 285 and the optics 281 on the beam splitter 280 directed. The measuring light is transmitted through the beam splitter 280 at least partially transmitted, so it has an optic 296 on the dot-shaped light detector 295 meets. The point-shaped light detector 295 can also be realized by means of a small pinhole, which is located in front of an optionally flat light detector.

The confocal measuring principle for the determination of height positions now consists in that of the point-shaped light detector 295 measured intensity depends on which focus diameter the illumination light 292 on the surface of the stent to be measured 220 is focused. For this purpose is the retroreflector 285 via a displacement device 285a along a direction of displacement 285b periodically displaceable, so that the focus diameter on the lower portion of the stent 220 with a periodic movement of the retroreflector 285 can be varied. The of the punctiform light detector 292 detected backscatter intensity is then maximum when the illumination light 295 on the surface of the stent to be measured 220 with a minimum focus diameter. If the surface to be measured has unevenness, it can be determined from the respective position of the retroreflector 285 in which the light detector 295 measures a maximum intensity, the respective height position of a measuring point located on the unevenness are determined.

The following is the adjustment and operation of the holding device 200 discussed in more detail. How out 2 can be seen, is the holding device 200 by means of the positioning device 240 adjusted so that the upper portion of the stent 220 just in that by the focus position of the illumination light 292 excellent object area lies. By a rotation of the stent 220 about its axis of symmetry, which is parallel to the two rollers 210a and 210b Thus, the inner wall of the stent can be oriented 220 be sequentially scanned along a circumferential circle on the lateral surface of the stent.

A complete scan of the internal structure of the stent 220 requires in addition to the rotation of the stent 220 also a displacement of the stent 220 relative to the confocal distance sensor 270 along the longitudinal axis of the stent 220 , For this reason, the positioning device 240 set up such that the holding device 200 also can be moved perpendicular to the plane of the drawing along a y-axis which is perpendicular to both the in 2 shown z-axis and perpendicular to the in 2 oriented x-axis is oriented. Thus, by a superimposition of a displacement movement along the y-axis and a rotational movement, a full-surface scan of the internal structure of the stent 220 possible.

The 3a shows a perspective view of the holding device 100 in a loading position. The holding device, which now with the reference numeral 300 is located immediately above a tube 390 a confocal distance sensor. In the loading position are the two axes of rotation 311 and 311b the two roles 310a and 310b spaced so far apart that a stent to be measured 320 easily from the top into the recess of the film 315 can be inserted.

How out 3b can be seen after inserting the stent 320 the two roles 310a and 310b pushed together so that the film 315 forming a pocket in which the stent 320 is included. When moving the slide 315 along the direction of movement 316 will be in the in 3b not shown bag stent rotated about its longitudinal axis.

How out 3c which shows a perspective view of the underside of the in 3b shown holding device, the stent lies 320 , separated only by the film, not shown, on the lateral surfaces of the two rollers 310a and 310b at. Thus, the position of the stent 320 Set exactly perpendicular to its longitudinal axis. In the 3b displayed direction of movement 316 The foil causes the stent to rotate 320 along the direction of rotation 321 , The measurement of the rotatably mounted stent 320 is done by the reference numeral 392 characterized illumination light and measuring light.

The 4a and 4b show cross-sectional views of the holding device 300 , which now with the reference numeral 400 is provided. The foil 415 runs over two rollers 410a and 410b , each about a rotation axis 411a respectively. 411b are rotatably mounted. Between the two roles 410a and 410b describes the foil 415 a loop in which a stent to be measured 420 located. The measurement or optical inspection of the stent 420 takes place by means of a lighting or measuring light 492 ,

4a shows the foil 415 in an unstressed state. The stent located in the foil pocket 420 is in an unstable position. When shifting the film 415 along the direction of movement 416 is to be expected that the foil bag in the form of a swing-like movement between the two rollers 410a and 410b swinging back and forth.

4b shows the foil 415 in a tense state. The stent 420 is located in a foil bag whose spatial position through the lateral surfaces of the two rollers 410a and 410b exactly defined. The foil flap thus represents a pocket formed directly between the two support elements, so that the stent 420 , only through the film 415 separated, immediately at the two rolls 410a and 410b is applied. By the concern of the stent 420 on the two rollers 410a and 410b Thus, a well-defined spatial location of the stent 420 guaranteed. Will the film 415 perpendicular to the cylinder axis of the stent 420 moved, so the stent turns 420 without slippage around its longitudinal axis. This axis has a well-defined spatial position.

It It should be noted that the embodiments described herein only a limited Choice of possible variants represent the invention. So it is possible the characteristics of individual embodiments suitably combine with each other, so for the skilled person with the explicit variants here a variety of different embodiments as obvious to be disclosed.

100

holder

110a / b

role

111a / b

axis of rotation

112a / b

support area

115

flexible Tape / foil

116

movement direction

120

stent

190

tube

192

Illumination / measuring light

200

holder

205

chassis

206

measurement window

210a / b

role

213a / b

rotary drive

215

flexible Tape / foil

220

stent

240

positioning

241

ball-bearing

242

drive

270

confocal distance sensor

275

punctiform light source

276

optics

280

beamsplitter

281

optics

285

retroreflector

285a

shifter

285b

displacement direction

287

deflecting

290

tube

291

lens

292

Illumination / measuring light

295

punctiform light detector

296

optics

300

holder

310a / b

role

311a / b

axis of rotation

315

flexible Tape / foil

316

movement direction

320

stent

321

direction of rotation

390

tube

392

Illumination / measuring light

400

holder

410a / b

role

411a / b

axis of rotation

415

flexible Tape / foil

416

movement direction

420

stent

492

Illumination / measuring light

Claims (12)

Holding device ( 200 ) for rotating a cylindrical object ( 220 ) about its longitudinal axis, in particular for rotating a grid-like tube ( 220 ) for the purpose of optical surface inspection of the grid-like tube ( 220 ), the holding device ( 200 ) comprising • a first support element ( 210a ), • a second support element ( 210b ) which is spaced from the first support element ( 210a ), • a flexible band ( 215 ), which transversely over the two support elements ( 210a . 210b ) is stretched so that the flexible band ( 215 ) between the two support elements ( 210a . 210b ) forms a depression into which the cylindrical object ( 215 ), and • a drive ( 213a . 213b ) for moving the flexible band ( 215 ) along its longitudinal direction, so that during a displacement of the band ( 215 ) a cylindrical object inserted in the recess ( 220 ) rotates about its longitudinal axis. Holding device according to claim 1, wherein the flexible band comprises a transparent film ( 215 ). Holding device according to one of claims 1 to 2, wherein the distance between the two support elements ( 210a . 210b ) is variable between an insertion position and a measuring position. Holding device according to one of claims 1 to 3, wherein the drive ( 213a . 213b ) with the flexible band ( 215 ) and / or with at least one of the two support elements ( 210a . 210b ) is coupled. Holding device according to one of claims 1 to 4, wherein the first support element in a first axis of rotation ( 211 ) rotatably mounted first roller ( 210a ) and / or the second support element one in a second axis of rotation ( 211b ) rotatably mounted second roller ( 210b ). Holding device according to claim 5, wherein in a preferred measuring position the two rollers ( 410a . 410b ) are spaced apart from each other and the flexible band ( 415 ) is tensioned such that a cylindrical object ( 420 ) - below one through the two axes of rotation ( 411a . 411b ) defined connection level and - of the flexible band ( 415 ) is enclosed at least so far that the cylindrical object ( 420 ) only by the flexible band ( 415 ) separated on both the first and on the second support element ( 410a . 410b ) is present. Optical measuring arrangement for a cylindrical object ( 220 ), in particular for a grid-like tube ( 220 ), the optical measuring arrangement comprising • an optical sensor ( 270 ) and • a holding device ( 200 ) according to one of claims 1 to 6, which relative to the optical sensor ( 270 ) is arranged such that at least a portion of the cylindrical object ( 220 ) within a detection range of the optical sensor ( 270 ) is positionable. Optical measuring arrangement according to claim 7, additionally comprising a positioning device ( 240 ), by means of which the holding device ( 200 ) relative to the optical sensor ( 270 ) along the longitudinal axis of a cylindrical object inserted into the depression ( 220 ) is displaceable. Optical measuring arrangement according to one of Claims 7 to 8, in which the optical sensor is a confocal distance sensor based on the confocal optical imaging principle ( 270 ). Optical measuring arrangement according to Claim 9, in which the confocal distance sensor ( 270 ) • a point-shaped optical transmitting element ( 275 ) arranged for emitting illumination light ( 292 ), • an imaging optics ( 291 ) for focusing the illumination light ( 292 ) into an object area, • a point-shaped optical receiving element ( 295 ), Which - in relation to the imaging optics ( 291 ) confocal to the optical transmitting element ( 275 ) at is arranged and - which is adapted to receive measuring light, the cylindrical object ( 220 ) at least partially scattered back and about the imaging optics ( 291 ) on the receiving element ( 295 ), and • a displacement device ( 285a ) for varying the optical path between the imaging optics ( 291 ) and the optical transmitting element ( 275 ). Optical measuring arrangement according to one of claims 9 to 10, wherein the confocal distance sensor ( 270 ) is a multi-channel distance sensor, with the parallel several measuring points lying on a measuring line can be measured. Optical measuring arrangement according to one of Claims 9 to 11, used for measuring a grid-like tube ( 220 ), wherein the holding device ( 200 ) relative to the confocal distance sensor ( 270 ) is arranged such that a first portion of the wall of the grid-like tube ( 220 ) of the illumination light ( 292 ) is at least partially penetrable and that a second portion of the wall of the grid-like tube ( 220 ) is positionable within the object area.