IL319230A

IL319230A - Medical instrument

Info

Publication number: IL319230A
Application number: IL319230A
Authority: IL
Inventors: Gerhard Frech; Roland Frech; Thomas Gaiselmann; Dr Siegfried Riek; Karl-Heinz Bachmann; Arnold Getsch
Original assignee: Gerhard Frech; Roland Frech; Thomas Gaiselmann; Dr Siegfried Riek; Bachmann Karl Heinz; Arnold Getsch
Priority date: 2022-08-31
Filing date: 2023-08-22
Publication date: 2025-04-01
Also published as: DE102022121987B3; EP4580720A1; WO2024046810A1

Description

Medical Instrument The invention relates to a medical instrument according to the preamble of patent claim 1.

In many medical interventions a straight hollow needle which is bevelled to a point at the tip, in the following also referred to as cannula, is punctured, for example through the skin, into a blood vessel in order to withdraw blood or to inject pharmaceutical agents. In other interventions the cannula is inserted through the skin into body tissues or organs in order, for example, to administer anesthetics or to aspirate body fluids, for example during a cyst puncture.

During anesthesia of the cervix the posterior vaginal vault is punctured at several sites, for example clockwise at 9, 12, and 3 o'clock paracervically, i.e. next to the cervix, in order to anesthetize the appropriate nerves. These punctures are painful and must be performed multiple times. Furthermore, blood vessels may be injured before the target area has been reached. The puncture out of the cervical canal through the inner wall to the target area can take place free of pain and without the potential of injuring major vessels.

DE10 2005 044 468 A1 discloses a medical instrument with a guide tube which medical instrument can be inserted into a canal of the body of a patient. The lumen of the body canal is conventionally very narrow. The guide tube comprises an open proximal end and a closed distal end as well as, starting at the proximal end, an inner axial guide channel which terminates into an opening disposed laterally on the circumference of the guide tube such that an elastically flexible Page cannula can be introduced through the proximal end into the guide channel, and during its advance in the guide channel, emerges laterally through the opening with a distal tip deflected with respect to the axis of the guide tube, whereby the entrance angle of the cannula into the wall of the body canal can be enlarged.

The guide tube is disposed with its proximal end on a grip part such that it is rotatable about its longitudinal axis in order to be able to generate different puncture points clockwise at identical positioning of the medical instrument.

As a rule, the cannula is fabricated of a hard material such as, for example metal; if the medical instrument is also fabricated of a metal, high fabrication costs are incurred. If the medical instruments, in particular the guide tube, is fabricated of a synthetic material, the guide channel can be damaged through the distal tip during the advancement of the distal tip of the cannula in the guide channel and during its redirection toward the laterally disposed opening. In particular, there is a risk of plastic particles being scraped off by the distal tip, whereby the plastic particles can either clog the distal tip or escape through the lateral opening into the body canal.

The invention therefore addresses the problem of further developing a medical device with a guide tube that can be inserted into a patient's body canal in such a way that the safety during use is improved.

According to the invention, the problem is resolved by a medical device with the characteristics of patent claim 1.

Advantageous embodiments and further developments are specified in the dependent claims.

Page 3 The medical instrument according to the invention with a guide tube that can be introduced into a body canal of a patient, wherein the guide tube comprises an open proximal end and a closed distal end as well as, starting at the proximal end, an inner axial guide channel terminating into an opening disposed laterally on the circumference of the guide tube such that an elastically flexible cannula can be inserted through the proximal end into the guide channel and during its advance in the guide channel emerges laterally through the opening with a distal tip deflected with respect to the longitudinal axis of the guide tube, wherein the guide tube is disposed on a grip part [such that it is] rotatable about its longitudinal axis is distinguished thereby that the guide channel comprises a first segment adjoining the proximal end and a second segment adjoining the opening, wherein a wall of the guide channel in the first, in particular proximal, segment is fabricated of synthetic material and in the second, in particular distal, segment is fabricated of a material which is of greater hardness than the synthetic material of the first segment. The risk of damage through the shaving or scraping of the distal end along the wall of the guide channel is especially high in the segment adjoining the opening. The invention is therefore based on the concept of implementing precisely this segment to be especially abrasion-proof, in particular without fabricating the entire guide tube of a material of appropriate hardness.

The wall can be developed for example by appropriate coating of the interior side of the guide channel. According to an especially preferred embodiment of the invention the guide channel is developed to be straight in the first segment and developed to be oblique or curved in the second segment. The risk of damage due to the scraping or shaving by the distal tip along the wall of the guide channel is especially high in the curved segment in which the guide channel bends away or deflects from the axis of the guide tube toward the lateral opening such that precisely this segment of the guide channel advantageously comprises a wall of a material which is of greater hardness than the synthetic material of the first segment. The wall can, for example, be developed by an appropriate coating of the interior side guide channel. However, the guide tube especially preferably comprises a first guide tube segment and a second guide tube segment, wherein the first guide tube segment encompasses the first segment of the guide channel and the second guide tube segment encompasses the second segment of the guide channel, and wherein the first guide tube segment is fabricated of a synthetic material and the second guide tube segment is fabricated of a material having a greater hardness than the synthetic material of the first guide tube segment. Stated differently, a distal end region of the guide tube, in which is located in particular the lateral opening, is fabricated of the material with greater hardness than the synthetic material of which is fabricated the remaining portion of the guide tube. The guide tube is thereby developed in particular of at least two parts.

The material having a greater hardness than the synthetic material of the first segment is preferably metal, in particular special steel, especially preferred medical grade stainless steel. These materials have been found to be especially abrasion-proof wherein especially medical grade stainless steel is correspondingly suitable for use in a medical instrument.

Page 5 According to an especially preferred embodiment of the invention the synthetic material is a transparent or translucent synthetic material. The view onto the tip, at least disposed section-wise in the guide tube, is thereby enabled for a user whereby operation of the medical instrument can be simplified and safety can be increased.

According to a preferred embodiment of the invention the guide tube comprises at its proximal end a tubular fixing segment which overarches a tubular securement segment rotatably supported on the grip part. Due to such implementation a simple and reliable rotatably supported securement of the guide tube can be enabled.

The grip part preferably comprises a reception for a syringe in which the syringe is axially movable between a proximal position, in which the distal tip of its cannula is in retraction in the guide channel, and a distal position in which the distal tip of the cannula emerges through the opening from the guide tube. Such implementation permits the versatile and especially safe applicability of the instrument. In particular, commercially available syringes can be utilized. In the proximal position of the syringe the distal tip of the cannula is located within the guide channel such that the guide tube can be introduced into the body canal of the patient without the risk of injuring the body canal through the distal tip of the cannula. In the distal position of the syringe the cannula has been advanced so far that its distal tip emerges laterally from the guide tube and can puncture through the wall of the body canal into the surrounding tissue at a defined exit angle and at a defined exit length.

Page 6 The reception advantageously comprises a distal abutment which delimits the axial movement of the syringe in the distal direction, wherein the syringe at its abutment on the distal abutment is disposed in the distal position and in this position is held by means of a first latching mechanism. In this position the user can be assured that the desired target area has been reached.

The reception preferably comprises a proximal abutment which delimits the axial movement of the syringe in the proximal direction, wherein the syringe at its abutment on the proximal abutment is disposed in the proximal position and in this position is held by means of a second latching mechanism. Such abutments enable an especially simple and reproducible handling of the instrument. The distal abutment can in particular define the length by which the distal tip of the cannula emerges from the circumference of the guide tube, respectively the opening, whereby the penetration depth of the cannula into the wall of the body canal of the patient can be defined. In this manner, the applicant can be assured that the patient is not injured when the puncture position is adjusted.

A latching mechanism for holding the syringe in fixed position at its abutment on the distal and/or proximal abutment can provide haptic feedback to the operator of having reached the particular position and can thereby further increase the operational safety.

According to a preferred embodiment of the invention on the reception at least one radially projecting lobe is disposed. Two radially projecting lobes are preferably disposed. One or two such lobes can serve the user Page as a finger contact surface and can simplify handling the instrument. If according to an advantageous further development of the invention a handhold be provided on the grip part, such can further simplify handling the instrument.

Furthermore, according to a preferred embodiment of the invention on the guide tube a slidable adjustment ring can be provided on the guide tube by means of which the penetration depth of the guide tube into the cervical canal, and therewith the injection point, is defined can be made individually adjustable. For this purpose, a gradation of the guide tube can be provided.

An embodiment example of the invention will be explained in detail in conjunction with the following Figures. Therein depict: Figure 1 a perspective view onto an embodiment example of a medical instrument according to the invention with emplaced syringe in a distal position, Figure 2 a longitudinal section through the instrument according to Figure 1, Figure 3 a top view onto the instrument according to Figure 1, Figure 4 a longitudinal section through the instrument according to Figure 1 with the syringe in a proximal position, Figure 5 a top view onto the instrument according to Figure 1 with the syringe in the proximal position, Figure 6 a detail enlargement of a cross section of the distal end of the instrument according to Figure 3, and Figure 7 a detail enlargement of a cross section of the distal end of the instrument according to Figure 5.

Figures 1 to 7 show different views of an embodiment example of a medical instrument according to the invention with a guide tube 20 that is insertable into a body canal of a patient. The guide tube 20 comprises an open proximal end 21 and a closed distal end 22. The closed distal end 22 can herein be implemented to be bluntly rounded and optionally slightly tapering conically. The guide tube 20 comprises a longitudinal axis A and, in particular, is developed to be straight cylindrical. Starting at the proximal end 21 the guide tube 20 comprises an inner axial guide channel 24 which terminates into an opening 26 disposed laterally on the circumference of the guide tube 20. The opening 26 is disposed in particular within the spatial proximity to the closed distal end 22 of the guide tube 20. The guide channel 24 comprises a first segment 25a adjoining the proximal end 21 and a second segment 25b adjoining the opening 26. The guide channel 24 is herein developed in the first segment 25a in particular to be straight while the guide channel 24 is developed in the second segment 25b to be in particular oblique or curved.

The guide channel 24 comprises a wall 25 wherein the wall 25 in the first segment 25a is fabricated of synthetic material and wall 25 in the second segment 25b is fabricated of a material of greater hardness than the synthetic material of the first segment 25a.

Page The guide tube 20 can comprise a first guide tube segment 20a and a second guide tube segment 20b wherein the first guide tube segment 20a can comprise the first segment 25a of the guide channel 24 and the second guide tube segment 20b can comprise the second segment 25b of the guide channel 24 and wherein the first guide tube segment 20a is fabricated of synthetic material and the second guide tube segment 20b is fabricated of a material of greater hardness than the synthetic material of the first guide tube segment 20a. Not only the wall 25 but the corresponding entire segment of the guide tube 20 is thereby fabricated of the corresponding material whereby the fabrication can be simplified.

The material that is of greater hardness than the synthetic material of the first segment 25a can be metal, in particular special steel, especially preferably medical grade stainless steel. The synthetic material can be a transparent or translucent synthetic material.

Due to the laterally disposed opening 26 the guide channel 24 is developed such that an elastically flexible cannula 51 can be inserted through the proximal end 21 into the guide channel 24 and, during its advancement in the guide channel 24, can emerge with a distal tip deflected relative to the longitudinal axis A of the guide tube 20 laterally through the opening (cf. in particular Figures 6 and 7). For this purpose, there can be developed in particular in the guide channel 24 a deflection device 24a, for example in the form of a wedge-shaped slope or a curved or arc-form rounded ramp which preferably forms a stepless transition of the straight first segment 25a into the lateral opening.

Starting at the opening 26 the diameter of the guide channel 24 is in particular dimensioned such that the cannula 51 can be pushed under guidance through the guide channel 24. The guide channel 24 can be conically widened in the distal direction. The length of the portion of the guide channel 24 disposed between the opening 26 and the conical widening 24b can be adapted to the length of the cannula 51 as will be further explained in the following. The conical widening 24b can serve as insertion help for inserting the cannula 51. Following the conical widening 24b the guide channel 24 can comprise a diameter of such size that a syringe 50 can at least sectionally be received at in the guide channel 24.

The guide tube 20 can in particular be disposed with its proximal end 21 on a grip part 30 such that it is rotatable about its longitudinal axis A. The guide tube 20 can for this purpose comprise at its proximal end 21 a tubular fixing segment 27 which overlaps a tubular securement segment rotatably supported on the grip part 30. The axial securement can herein take place, for example, by a latching mechanism 29. The rotatable support can be realized thereby that the latching mechanism 29 is developed such that it encircles the circumference. The guide tube can be detachably disposed on the grip part 30, for example thereby that the latching mechanism 29 is developed to be detachable.

The tubular fixing segment 27 can be formed by that portion of the guide tube 20 in which the syringe 50 can be sectionally received.

[Page 11] An actuation lever 28 can be disposed, in particular radially projecting, on the guide tube 20. By means of the actuation lever 28 the guide tube 20 can be rotated about its longitudinal axis A. The actuation lever 28 is advantageously disposed at the same peripheral angle position as the opening 26 such that the actuation lever 28 can indicate the angular position of the opening relative to the grip part 30.

On the guide tube 20 can be disposed an adjustment ring 53 displaceable on the guide tube by means of which the penetration depth of the guide tube 20 can be defined.

The grip part 30 can comprise a reception 34 for the syringe 50 in which the syringe 50 is axially movable between a proximal position, in which the distal tip 52 is in retraction in its cannula and located in the guide channel 24 (cf. Figures 4, 5, and 7), and a distal position in which the distal tip 52 of the cannula 51 emerges through the opening 26 from the guide tube 20 (cf. Figures 2, 3 and 6). The reception 34 can be developed for example in the form of a semishell and to be upwardly open.

The syringe 50 can be inserted proximally in the axial direction into the reception 34 wherein, in particular, counterholder lobes 50a disposed at the proximal end of the syringe 50 come to rest in the reception 34. Herein in particular the distal end of the syringe 50 at which the cannula is disposed can be received segmentally in the guide tube 20, in particular in the tubular fixing segment 27.

The reception 34 can comprise a distal abutment 35 which delimits the axial movement of the syringe 50 in the distal direction, wherein the syringe 50 when in contact on the distal abutment is disposed in the distal position and is held fixedly in this position by means of a first latching mechanism Page (cf. in particular Figure 2). The first latching mechanism 37 can be developed for example as a projection that engages behind the counterholder lobes 50a or a radially encircling collar at the proximal end of the syringe 50 which transitions into the counterholder lobes 50a and latches in.

The reception 34 [sic: can?] comprise a proximal abutment 36 which delimits the axial movement of the syringe 50 in the proximal direction, wherein the syringe 50 when in contact on the proximal abutment 36 is disposed in the proximal position and is fixedly retained in this position by means of a second latching mechanism 38 (cf. in particular Figure 4). The second latching mechanism 38 can be developed, for example, as a projection which engages behind the counterholder lobes 50a or the radially encircling collar at the proximal end of the syringe 50, which transitions into the counterholder lobes 50a and latches in. When one of the counterholder lobes 50a of the syringe 50 is in contact on the second latching mechanism this [syringe] can be rotated by 90 degrees such that a fill level marking of the syringe becomes visible in the transparent guide tube 20.

The distal abutment 35 and the proximal abutment 36 can be formed for example by edges on the opposing front faces of the reception 34.

On the reception 34 at least one radially projecting lobe 39a can be disposed. In the present embodiment example on the reception 34 two radially projecting lobes 39a, 39b are disposed which can serve as finger contact surface.

On the grip part 30, for example on the underside of the reception 34, a handle 40 can be disposed.

Page The grip part 30 can be fabricated of synthetic material. The grip part 30 including the reception and the handle 40 can in particular be fabricated such that they are unitary. syringe 50 is emplaced If the instrument 10 is utilized for injections, into the instrument 10 is placed initially the syringe 50, for example an appropriate commercially available syringe 50, in particular in the form of a disposable syringe 50 of synthetic material. At the distal end of the syringe 50 the cannula 51 is applied. The cannula 51 is elastically flexible and fabricated, for example, of metal. The syringe comprises an axially displaceable plunger 50b by means of which a fluid disposed in the syringe 50 can be pushed out through the cannula 51 and be injected.

The syringe 50 with the attached cannula 51 is inserted from the proximal end through the reception 34 into the guide tube 20. The cannula 51 arrives herein especially favorably through the conical widening 24b into the distal portion of the guide channel 24. The syringe 50 is received coaxially in the reception [sic: 34] and the proximal portion of the guide channel 24, in particular in the fixing segment 27. The encircling radial [sic] lobes [of] radial collar 50a [sic : radial collar lobes] of the syringe 50 come to lie in particular between the distal abutment 35 and the proximal abutment 36 of the reception 34.

The axial longitudinal dimensions of the instrument 10 are matched to the longitudinal dimensions of the syringe 50 and the longitudinal dimensions of the cannula 51 such that the distal tip 52 of the cannula 51 is located within the guide channel 24 when the radial collar [sic: with lobes]{?} 50a of the syringe 50 is in contact on the proximal abutment 36 and that the distal tip 52 of the cannula 51 projects from the opening 26 by a length defined for injecting when the counterholder lobes 50a [of a radial collar] of the syringe 50 Page are in contact on the distal abutment 35. With the syringe 50 in the proximal position, the [sic : needle of] instrument 10 can be inserted without risk into the body canal of the patient. If the desired position of the [sic : needle of] instrument 10 in the body canal has been reached, the syringe 50 can be moved into the distal position in which the distal tip 52 projects out of the opening 25. The plunger 50b of the syringe [sic: 50] can be moved axially in order to inject the fluid, for example an anesthetic agent. After an injection in a first peripheral angle position, the syringe 50 can be moved into the proximal position, and the guide tube 20 can be turned or twisted by means of the actuation lever 28 about its longitudinal axis A in order to be able to carry out in a further peripheral angle position a further injection after a renewed move of the syringe 50 into the distal position. List of Reference Symbols Instrument Guide tube 20a [First] guide tube segment 20b [Second] guide tube segment Proximal end Distal end Guide channel (inner axial) 24a Deflection device 24b Widening Wall 25a First segment 25b Second segment 26 Opening Fixing segment Actuation lever Latching mechanism Grip part Securement segment Reception Distal abutment Proximal abutment First latching mechanism Second latching mechanism 39a Lobe [of radial collar] 39b Lobe [of radial collar] Hand grip Syringe 50a Counterholder lobe [of radial collar] 50b Plunger Cannula Distal tip Adjustment ring A Longitudinal axis [Not in Figures]

Claims

1. Medical Instrument (10) with a guide tube (20) which is insertable into a body canal of a patient, wherein the guide tube (20) comprises an open proximal end (21) and a closed distal end (22) as well as, starting at the proximal end (21), an inner axial guide channel (24) which terminates into an opening (26) disposed laterally on the circumference of the guide tube (20) such that an elastically flexible cannula (51) can be inserted through the proximal end (21) into the guide channel (24) and when advanced in the guide channel (24) emerges with a distal tip (52) deflected with respect to the longitudinal axis (A) of the guide tube (20) laterally through the opening (26), wherein the guide tube (20) is disposed rotatably about its longitudinal axis (A) on a grip part (30), characterized in that the guide channel (24) comprises a first segment (25a) adjoining the proximal end (21) and a second segment (25b) adjoining the opening (26), wherein a wall (25) of the guide channel (24) in the first segment (25a) is fabricated of synthetic material and in the second segment (25b) of a material with a greater hardness than the synthetic material of the first segment (25a).

2. Instrument as in Claim 1, characterized in that the guide channel (24) in the first segment (25a) is developed to be straight and in the second segment (25b) is developed to be oblique or curved.

3. Instrument as in one of the preceding Claims, characterized in that the guide tube (20) comprises a first guide tube segment (20a) and a second guide tube segment (20b), wherein the first guide tube segment (20a) comprises the first segment (25a) of the guide tube channel (24) and the second guide tube segment (20b) comprises the second segment (25b) of the guide tube channel (24), and wherein the first guide tube segment (20a) is fabricated of synthetic material and the second guide tube segment (20b) is fabricated of a material which has a greater hardness than the synthetic material of the first guide tube segment (20a).

4. Instrument as in one of the preceding Claims, characterized in that the material which has a greater hardness than the synthetic material of the first segment (25a) is metal, in particular special steel, especially preferably medical grade stainless steel.

5. Instrument as in one of the preceding claims, characterized in that the synthetic material is a transparent or translucent synthetic material.

6. Instrument according to one of the preceding Claims, characterized in that the guide tube (20) comprises at its proximal end (21) a tubular fixing segment (27) which engages behind a tubular securement segment (32) rotatably disposed on the grip part (30).

7. Instrument as in one of the preceding Claims, characterized in that the grip part (30) comprises a reception (34) for a syringe (50) in which the syringe (50) is axially movable between a proximal position, in which the distal tip (52) of its cannula (51) is located in retraction in the guide channel (24), and a distal position in which the distal tip (52) of the cannula (51) emerges from the guide tube (20) through the opening (26).

8. Instrument as in Claim 7, characterized in that the reception (34) comprises a distal abutment (35) that delimits the axial movement of the syringe (50) in the distal direction, wherein the syringe (50) when in contact on the distal abutment (35) is disposed in the distal position and in this position is secured by means of a first latching mechanism (37).

9. Instrument as in Claim 7 or 8, characterized in that the reception (34) comprises a proximal abutment (36) that delimits the axial movement of the syringe (50) in the proximal direction, wherein the syringe (50) when in contact on the proximal abutment (36) is disposed in the proximal position and in this position is secured by means of a second latching mechanism (38).

10. Instrument as in one of the Claims 7 to 9, characterized in that in the reception (34) at least one radially projecting lobe (39a) is disposed, preferably two radially projecting lobes (39a, 39b) are disposed.

11. Instrument as in one of the preceding Claims, characterized in that on the grip part (30) one handle (40) is disposed.

12. Instrument as in one of the preceding Claims, characterized in that on the guide tube (20) an adjustment ring (53) displaceable on the guide tube (20) is disposed. For the Applicant WOLFF, BREGMAN AND GOLLER By: