Reverse set for a surgical instrument

Abstract

The invention relates inter alia to a reversing set (2) for a surgical instrument (1), in particular an endoscope, with, preferably exclusively, two outer achromats (10, 20), each of which preferably exclusively has two lenses, and with, preferably exclusively, two inner achromats (30, 40) arranged between the outer achromats (10, 20), wherein the inner achromats (30, 40) each have, preferably exclusively, two lenses (31, 32; 41, 42), wherein the pairs with one outer achromat (10, 20) and one inner achromat (30, 40) are arranged symmetrically in relation to each other.

Description

[0001] The present disclosure relates to a reversing set for a surgical instrument, in particular an endoscope. Furthermore, the invention relates to the use of a reversing set. Furthermore, the invention relates to a surgical instrument, in particular an endoscope, and a method for operating a surgical instrument, in particular an endoscope.

[0002] As is known in the art, rigid endoscopes typically comprise an optical system consisting of an objective lens, an eyepiece, and a relay lens system arranged therebetween. The relay lens system comprises multiple reversing lens sets. Typically, an odd number of reversing lens sets is provided, since the objective lens and each reversing lens set produce an inverted image, and a normal endoscope should produce an upright image, with the resulting image being oriented upright. To correct significant aberrations, a symmetrical configuration of the reversing lens sets is provided.

[0003] For example, DE 11 2004 002 220 B4 discloses a reversing set for an optical system of a rigid endoscope. Furthermore, DE 10 2012 200 146 A1 describes a reversing set for an endoscope with a plurality of equivalent reversing sets.

[0004] In addition, it is known that extended endoscopes (e.g., laparoscopes) with additional shorter reversal sets are intended or used as minimally invasive surgical instruments for bariatric surgery.

[0005] It is an object of the invention to provide, in particular, cost-effective optics with a small (outer) diameter and a short length for bariatric surgical instruments, in particular laparoscopes or the like, with increased resolution. Another object of the invention is to provide a surgical instrument for bariatric surgeries with improved optical properties or performance.

[0006] Such objects can be achieved by a reversing set for a surgical instrument, in particular an endoscope, with, preferably exclusively, two outer achromats, each having, preferably exclusively, two lenses, and with, preferably exclusively, two inner achromats arranged between the outer achromats, wherein the inner achromats each have, preferably exclusively, two lenses, wherein the pairs, each with an outer achromat and an inner achromat, are arranged symmetrically with respect to one another, wherein the reversing set satisfies the following condition L∗NA2D2∗(ΦRMS+|PTZ|10)>5, where L is the length of the reverse set / mm (ie divided by the unit mm), NA is the numerical aperture, D is the (outer) diameter of the reversing set / mm (ie divided by the unit mm), Φ RMSthe minimum, especially polychromatic, root mean square of the light spot diameter in the center is / mm (ie divided by the unit mm), |PTZ| is the absolute value of the curvature (third order) of the Petzval surface, where PTZ is given by the formula PTZ=−S4l2, where S4 is the Petzval sum (third order) and I is the Helmholtz-Lagrange invariant.

[0007] The basic idea of ​​the invention is to provide an optical system as a reversing set for a surgical instrument, such as a 5.4 mm laparoscope or the like, which has a small diameter, e.g. < 4 mm, and a short length, wherein the optical quality of the reversing set is increased in the center and especially at the edges. In addition, the reversing set according to the invention also provides high resolution while maintaining high brightness and contrast. The length of the reversing set, the (outer) diameter of the reversing set and the minimum root mean square of the light spot diameter in the center are each given in millimeters (mm). The values ​​for the length of the reversing set, the diameter of the reversing set and the minimum root mean square of the light spot diameter are inserted into the mentioned condition dimensionless, i.e. without units.

[0008] In the converse theorem, the formula mentioned takes into account the quality of the system in the center and at the edge as well as the ratio of total length to brightness.

[0009] Within the scope of the invention, it is provided that the outer achromats and the inner achromats are designed in particular as glued or cemented doublet achromats.

[0010] According to a further embodiment of the reversal theorem, the lenses of the inner achromats and the lenses of the outer achromats have the same diameter, in particular outer diameter.

[0011] Furthermore, according to a further development of the converse theorem, the diameter of the lenses of the inner achromats and the diameter of the lenses of the outer achromats are less than 4.00 mm. For example, the diameter of the lenses is 3.75 mm.

[0012] Preferably, the inner achromats each have a negative lens (diverging lens) and a positive lens (converging lens) and / or the outer achromats each have a negative lens (diverging lens) and a positive lens (converging lens).

[0013] The object is further achieved by using a reversing set as described above for a surgical instrument, in particular an endoscope, for performing a surgical, in particular bariatric, operation. In particular, the surgical instrument is designed with at least one reversing set as described above. To avoid repetition, express reference is made to the above statements.

[0014] Furthermore, the object is also achieved by a surgical instrument, in particular an endoscope, having at least one reversing set, wherein the surgical instrument, in particular an endoscope, is provided with at least one reversing set as described above.

[0015] Additionally, the object is achieved by a method for operating a surgical instrument, in particular an endoscope, for performing a surgical operation, in particular a bariatric operation, wherein the surgical instrument is provided with a reversing set according to the invention. To avoid repetition, express reference is made to the above statements.

[0016] Further features will become apparent from the description of embodiments together with the claims and the accompanying drawings. Embodiments may fulfill individual features or a combination of several features.

[0017] The embodiments are described below without limiting the general inventive concept, whereby express reference is made to the drawings for the disclosure of all details not explained in detail in the text.

[0018] In the drawings: Fig. 1 shows a schematic representation of a reversing set according to the invention for an endoscope, Fig. Figure 2a illustrates a diffraction pattern MTF (Modulation Transfer Function) of an optical system with a reversal set according to the invention and Fig. Figure 2b illustrates an MTF (Modulation Transfer Function) diffraction pattern of an optical system of a bariatric optical system (according to the prior art).

[0019] Fig. Figure 1 schematically illustrates a reversing set 2 for a schematically designated surgical instrument 1. The surgical instrument 1 is preferably provided as a laparoscope or endoscope. Preferably, the surgical instrument 1 is designed as a rigid surgical instrument.

[0020] The reversing set 2 is a component of an optical system of the surgical instrument 1. The optical system of the surgical instrument 1 is arranged in a preferably rigid tube (not shown). The optical system of the surgical instrument 1 can have an objective lens at the distal end, wherein the image generated by the objective lens is transmitted, for example, using a plurality of reversing sets, to an image plane at the proximal end, on which the image can be viewed through an eyepiece. A camera can also be arranged at the eyepiece.

[0021] The Fig. The reversing set 2 of the optical system of the surgical instrument 1 shown in Figure 1 transmits the image from a first image plane 3.1 to a second image plane 3.2. The image present in the image plane 3.1 is displayed in reverse form on or in the image plane 3.2. In this way, the image of the image plane 3.1 is inverted in the image plane 3.2.

[0022] The reversal set 2 has two outer achromats 10, 20, between which two inner achromats 30, 40 are arranged. The outer achromat 10 has a biconcave lens 11 and a biconvex lens 12. Correspondingly, the outer achromat 20 has a biconcave lens 21 and a biconvex lens 22. The lenses 11, 12 of the outer achromat 10 and the lenses 21, 22 of the second outer achromat 20 are circular in cross-section, i.e., perpendicular to the plane of the drawing, and have a constant (outer) diameter D, such as 3.75 mm.

[0023] The inner achromats 30, 40 arranged between the outer achromats 10, 20 each have a convex-concave lens 31, 41 and a biconvex lens 32, respectively 42. The lenses 31, 32 of the inner achromat 30 and the lenses 41, 42 of the second inner achromat 40 are circular in cross-section and have the same diameter D. The reversal set 2 with the two outer achromats 10, 30 and the two inner achromats 20, 40 has a length L that corresponds to the distance between the image planes 3.1 and 3.2.

[0024] The inner achromats 30, 40 or the lenses 31, 32, 41, 42 of the inner achromats 30, 40 are arranged and housed in a sleeve or a shaft (or the like).

[0025] The two outer achromats 10, 30 and the two inner achromats 20, 40 are arranged symmetrically to each other. Thus, the pair with the outer achromat 10 and the inner achromat 30 is arranged symmetrically to the other pair with the outer achromats 20 and the inner achromat 40.

[0026] According to the invention, the reversal sentence satisfies the condition L∗NA2D2∗(ΦRMS+|PTZ|10)>5, where L is the length of the reversal set 2 / mm, NA is the numerical aperture of the inverse theorem 2, D is the (outer) diameter of the reversing set 2 / mm, Φ RMS the minimum, especially polychromatic, root mean square of the light spot diameter in the center is / mm, |PTZ| is the absolute value of the curvature (third order) of the Petzval surface, where PTZ is given by the formula PTZ=−S4l2, where S4 is the Petzval sum (third order) and I is the Helmholtz-Lagrange invariant. The length of the inverse set, the (outer) diameter of the inverse set, and the minimum root mean square of the spot diameter at the center are each given in millimeters (mm), whereby the values ​​are inserted dimensionlessly, i.e., without units, into the above condition.

[0027] Fig. 2a and Fig. 2b show the modulation transfer functions (MTF) of an optical system with an inversion set according to the invention (see Fig. 2a) and a bariatric optical system (according to the state of the art) (see Fig. 2b). The horizontal axis shows the spatial frequency (lp / mm), and the vertical axis shows the MTF, also contrast.

[0028] The MTF describes the optical system in terms of contrast at different spatial frequencies, expressed in line pairs per mm (lp / mm). Higher spatial frequencies correspond to finer details. An MTF value of 1 means perfect contrast; 0 means no contrast at all; white and black lines can no longer be distinguished at all.

[0029] Basically, the solid lines represent the MTF in the tangential direction, and the dashed lines represent the MTF in the sagittal direction. The MTF a / a' represented by dotted lines represent the theoretical ideal case of a diffraction-limited system. As in Fig. As can be seen in Figure 2b, even the theoretical optimum is accompanied by a rapid decrease in MTF towards finer details.

[0030] Lines b and b' indicate the MTF at the center of the image plane, which is equal in the sagittal and tangential directions. Lines c, c' and d, d' indicate the MTF at 80% image height in the tangential and sagittal directions, respectively. Lines e, e' and f, f' indicate the MTF at 100% image height, i.e., at the far edge.

[0031] As in Fig. As can be seen in Figure 2b, the MTF of the bariatric optical system shows worse MTF values, especially the contrast (MTF) at the edges becomes catastrophic.

[0032] In an optical system with the Fig. With the inversion set according to the invention shown in Figure 2a, the values ​​are significantly better not only in the central region but also in the peripheral region. The MTFs are significantly improved overall, especially at high spatial frequencies, resulting in clearer and more detailed images.

[0033] While there have been shown and described what are considered embodiments of the invention, it should be understood that various modifications and changes in form or detail may readily be made without departing from the spirit of the invention. It is therefore intended that the invention not be limited to the precise forms described and illustrated, but should be constructed to cover all modifications which may come within the scope of the appended claims. List of reference symbols 1 surgical instrument 2 Converse sentence 3.1, 3.2 Image plane 10 Achromat 11 Biconcave lens 12 Biconvex lens 20 Achromat 21 Biconcave lens 22 Biconvex lens 30 Inner Achromat 31 Convex-concave lens 32 Biconvex lens 40 Inner Achromat 41 Convex-concave lens 42 Biconvex lens D Diameter L length QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 11 2004 002 220 B4

[0003] DE 10 2012 200 146 A1

[0003]

Claims

[1] Inversion set (2) for a surgical instrument (1), in particular an endoscope, with, preferably exclusively, two outer achromats (10, 20), each having, preferably exclusively, two lenses, and with, preferably exclusively, two inner achromats (30, 40) arranged between the outer achromats (10, 20), wherein the inner achromats (30, 40) each have, preferably exclusively, two lenses (31, 32; 41, 42), wherein the pairs, each with an outer achromat (10, 20) and an inner achromat (30, 40), are arranged symmetrically with respect to one another, wherein the inversion set (2) satisfies the following condition L∗NA2D2∗(ΦRMS+|PTZ|10)>5, where L is the length (L) of the reversal set (2) / mm, NA is the numerical aperture, D is the outer diameter (D) of the reversing set (2) / mm, Φ RMSthe minimum, especially polychromatic, root mean square of the light spot diameter in the center is / mm, |PTZ| is the absolute value of the curvature (third order) of the Petzval surface, where PTZ is given by the formula PTZ=−S4l2, where S4 is the Petzval sum (third order) and I is the Helmholtz-Lagrange invariant. [2] Reversal sentence (2) according to claim 1, characterized by that the lenses (31, 32; 41, 42) of the inner achromats (30, 40) and the lenses (11, 12; 21, 22) of the outer achromats (10, 20) have the same diameter, in particular outer diameter. [3] Reversal sentence (2) according to claim 1 or 2, characterized by that the diameter of the lenses (31, 32; 41, 42) of the inner achromats (30, 40) and the diameter of the lenses (11, 12; 21, 22) of the outer achromats (10, 20) is less than 4.00 mm. [4] Reversal set (2) according to one of claims 1 to 3, characterized bythat the inner achromats (30, 40) each have a negative lens (diverging lens) (31; 41) and a positive lens (converging lens) (32; 42) and / or the outer achromats (10, 20) each have a negative lens (diverging lens) (11; 21) and a positive lens (converging lens) (12; 22). [5] Use of a reversing set (2) according to one of claims 1 to 4 for a surgical instrument (1), in particular an endoscope, for performing a surgical, in particular bariatric, operation. [6] Surgical instrument (1), in particular endoscope, with at least one reversing set (2), wherein the surgical instrument, in particular endoscope, is provided with at least one reversing set (2) according to one of claims 1 to 4. [7] Method for operating a surgical instrument (1), in particular an endoscope, for performing a surgical operation, in particular a bariatric operation, wherein the surgical instrument (1) is provided with a reversing set (2) according to one of claims 1 to 4.

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