CN110236614A

CN110236614A - Cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function

Info

Publication number: CN110236614A
Application number: CN201910535432.5A
Authority: CN
Inventors: 柏建峰; 余晴晴
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-20
Filing date: 2019-06-20
Publication date: 2019-09-17

Abstract

The invention discloses cranium operations after a kind of neurosurgery with microscopic function with strutting drainage device, including transverse slat, microscope, miniature webcam, mini-medical pump and telescopic cylinder, the inside left and right ends of the transverse slat, which are run through, screw rod, the outside screw of the screw rod is connected with vertical bar, bearing rod is fixed with below the vertical bar, the microscope inlays the inside for being mounted on mounting structure, and the miniature webcam is fixedly mounted on the lower section of mounting rack.Cranium operation is with strutting drainage device after the neurosurgery with microscopic function, it is convenient that expanded support block is positioned, and the operating surface above expanded support block can be expanded, the inner case of cranium after facilitating under medical worker's viewing microscope, convenient for adjusting microscopical position, and then the rear cranium of patient can be comprehensively observed using microscope, facilitate placement conduction hose, it can be avoided the residue inside conduction hose disorderly to spread, cause surgical environments contaminated.

Description

Cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function

Technical field

It performs the operation correlative technology field the present invention relates to rear cranium, cranium hand after specially a kind of neurosurgery with microscopic function Art is with strutting drainage device.

Background technique

Medical worker needs that dilator and flow diverter is used to handle the rear cranium of patient in cranium surgical procedure after neurosurgery, In order to facilitate medical worker's operation, dilator and flow diverter are applied in combination, and add microscope on the medical apparatus, thus Increase microscopic function, the medical worker of neurosurgery is facilitated to handle the nerve of patient, but it is existing with micro- function With drainage device is strutted, there are still certain defects for cranium operation after the neurosurgery of energy, such as:

1. inconvenient position expanded support block, needs medical worker to hold expanded support block always, the behaviour above expanded support block can not be expanded Make face；

2. usually 2 groups of expanded support blocks are connected by hinged mode, so that the space above expanded support block and expanded support block forms triangle Shape, the space that can be operated are less, it has not been convenient to medical worker's operation；

3. being not easy to adjust microscopical position, the inner case of cranium after patient can not be comprehensively observed；

4. after draining work, it has not been convenient to place conduction hose, cause the residue inside conduction hose disorderly to spread, surgical environments It is contaminated；

Therefore the purpose of the present invention is to provide cranium operations after a kind of neurosurgery with microscopic function with strutting drainage device, Cranium operation is filled with drainage is strutted after the neurosurgery with microscopic function currently on the market to solve above-mentioned background technique proposition The problem of setting.

Summary of the invention

The purpose of the present invention is to provide cranium operations after a kind of neurosurgery with microscopic function with strutting drainage device, To solve after the existing neurosurgery with microscopic function mentioned above in the background art cranium operation with strutting drainage device Inconvenience positions expanded support block, can not expand the operating surface above expanded support block, medical worker is on the rear cranium of distracted patient The space that side can operate is less, it has not been convenient to which medical worker's operation is not easy to adjust microscopical position, can not comprehensively see The inner case of cranium after patient is examined, after draining work, it has not been convenient to place conduction hose, lead to the residual inside conduction hose Object is disorderly spread, the contaminated problem of surgical environments.

To achieve the above object, the invention provides the following technical scheme: cranium after a kind of neurosurgery with microscopic function Operation is with strutting drainage device, including transverse slat, microscope, miniature webcam, mini-medical pump and telescopic cylinder, the transverse slat Internal left and right ends, which are run through, screw rod, and the right side of screw rod is welded with operation panel, and the left side of screw rod is fixed with surely Fixed board, the right end of the transverse slat offers ring rail, and the inside front and rear sides of transverse slat offer traverse rod, the outside of the screw rod It is threaded with vertical bar, and the front and rear sides of vertical bar are respectively and fixedly provided with link block, and link block is fastened on the inside of traverse rod, it is described The bottom end of vertical bar offers the holding groove of cross section structure in a ring, and mounting structure is provided on the outside of vertical bar, the vertical bar Lower section be fixed with bearing rod, and expanded support block is welded with below bearing rod, the microscope, which is inlayed, is mounted on mounting structure Inside, and mounting rack is provided with above mounting structure, the miniature webcam is fixedly mounted on the lower section of mounting rack；

The upper surface of the transverse slat is welded with restriction box, and the top engaging for limiting box is equipped with the bottom end of foul water tank, the dirt The top of water tank is equipped with case lid, and the inside front and rear sides of case lid offer perforation, the right side welding of the foul water tank There is frame plate, and the front end of frame plate offers placing groove, the mini-medical pump is mounted on the left side of foul water tank, and mini-medical pumps Output end be connected with outlet pipe, and the input terminal of mini-medical pump is connected with conduction hose, and the telescopic cylinder is in transverse slat Lower surface at left and right sides of have installation, and the lower surface of telescopic cylinder is fixed with backing plate.

Preferably, the steadying plate includes outside plate, connecting rod and connected ball, and the medial surface of outside plate is angularly fixed with connection Bar, and the right side of connecting rod is fixed with connected ball.

Preferably, the formula that is internally embedded of the ring rail is equipped with connected ball, and the depth of connected ball embedded rings rail is greater than company The radius size received.

Preferably, center line symmetrical setting of the vertical bar about screw rod, and vertical bar is made up of screw rod and transverse slat and slides Structure, and the hand of spiral of screw rod left and right ends is opposite.

Preferably, the mounting structure includes stop block, the first side plate, telescopic rod, second side and plate, stop block Lateral surface is welded with the first side plate, and the outside upper and lower ends of the first side plate are mounted on telescopic rod, the output end connection of telescopic rod There is second side, the outside vertical of second side is fixed with plate.

Preferably, the longitudinal section of the stop block is in " convex " font structure, and stop block is fastened on the inside of holding groove.

Preferably, the medial surface of second side shape structure in curved surface, and the medial surface of second side and vertical bar are constituted Rotational structure.

Preferably, the connection type of the mounting rack and plate is card slot connection, and the vertical centerline of mounting rack and aobvious The vertical centerline of micro mirror overlaps.

Preferably, the longitudinal section of the expanded support block is in half elliptic structure, and the inside of the medial surface of expanded support block and vertical bar Face is located in same level.

Preferably, the connection type of the conduction hose and frame plate be card slot connection, and the diameter dimension of conduction hose and The diameter dimension of outlet pipe is equal to the internal diameter of perforation.

Compared with prior art, the beneficial effects of the present invention are: there is cranium operation after the neurosurgery of microscopic function to use for this Drainage device is strutted, it is convenient that expanded support block is positioned, and the operating surface above expanded support block can be expanded, it is convenient using miniature webcam The inner case of cranium after under medical worker's viewing microscope, by the length of rotational installation structure and adjusting telescopic rod, convenient for adjusting Microscopical position is saved, and then can comprehensively observe the rear cranium of patient using microscope, facilitates placement conduction hose, can keep away Exempt from the residue inside conduction hose disorderly to spread, causes surgical environments contaminated；

1. being provided with screw rod, vertical bar and expanded support block, since screw rod is threadedly coupled with vertical bar, vertical bar is symmetrical about the center line of screw rod 2 groups are provided with, on the contrary, by rotating clockwise screw rod, 2 groups of vertical bars are opposite on screw rod to be moved the hand of spiral of screw rod left and right ends Dynamic, so that the expanded support block below vertical bar is mobile, and then 2 groups of expanded support blocks strut the rear cranium of patient, conveniently strut the rear cranium of patient, When screw rod is static, expanded support block is static, consequently facilitating fixed expanded support block, convenient to position to expanded support block, and can expand on expanded support block The operating surface of side；

2. being provided with microscope and miniature webcam, miniature webcam is mounted on microscopical lower section by mounting rack, miniature to take the photograph As the display screen of head and outer machine is of coupled connections, the inside feelings of cranium after being facilitated under medical worker's viewing microscope using miniature webcam Condition, and miniature webcam is mounted on mounting rack, mounting rack is connect with mounting structure card slot, conveniently removes miniature webcam, is made Miniature webcam is obtained flexibly to be used；

3. being provided with mounting structure and microscope, the stop block inside mounting structure is engaged and installed in the cross section inside vertical bar and is in In the holding groove of ring structure, so that mounting structure and vertical bar constitute rotational structure, it is convenient that peace is rotated above the rear cranium of patient Microscope on mounting structure, and the length by adjusting telescopic rod convenient for adjusting microscopical position, and then utilize aobvious Micro mirror can comprehensively observe the rear cranium of patient；

4. it is provided with foul water tank and conduction hose, after completing drainage work using mini-medical pump, outlet pipe and conduction hose, The inside that the end of conduction hose is passed through to perforation insertion foul water tank, facilitates placement conduction hose, can be avoided in conduction hose The residue in portion is disorderly spread, and causes surgical environments contaminated.

Detailed description of the invention

Fig. 1 is that the present invention faces cutting structural schematic diagram；

Fig. 2 is enlarged structure schematic diagram at A in Fig. 1 of the present invention；

Fig. 3 is transverse slat side structure schematic view of the present invention；

Fig. 4 is enlarged structure schematic diagram at B in Fig. 1 of the present invention；

Fig. 5 connect overlooking structure diagram with mounting structure for vertical bar of the present invention；

Fig. 6 is vertical bar schematic diagram of internal structure of the present invention；

Fig. 7 is expanded support block transportable state structure schematic diagram of the present invention；

Fig. 8 is that the present invention limits box and foul water tank side view attachment structure schematic diagram；

Fig. 9 is foul water tank overlooking structure diagram of the present invention.

In figure: 1, transverse slat；2, screw rod；3, operation panel；4, steadying plate；401, outside plate；402, connecting rod；403, connected ball； 5, ring rail；6, vertical bar；7, link block；8, traverse rod；9, holding groove；10, mounting structure；1001, stop block；1002, the first side plate； 1003, telescopic rod；1004, second side；1005, plate；11, microscope；12, mounting rack；13, miniature webcam；14, it accepts Bar；15, expanded support block；16, box is limited；17, foul water tank；18, case lid；19, it perforates；20, frame plate；21, placing groove；22, miniature doctor Treat pump；23, outlet pipe；24, conduction hose；25, telescopic cylinder；26, backing plate.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.

Please refer to Fig. 1-9, the present invention provides a kind of technical solution: cranium is performed the operation after a kind of neurosurgery with microscopic function With strutting drainage device, including transverse slat 1, screw rod 2, operation panel 3, steadying plate 4, ring rail 5, vertical bar 6, link block 7, traverse rod 8, accept Slot 9, microscope 11, mounting rack 12, miniature webcam 13, bearing rod 14, expanded support block 15, limits box 16, sewage at mounting structure 10 Case 17, case lid 18, perforation 19, frame plate 20, placing groove 21, mini-medical pump 22, outlet pipe 23, conduction hose 24, telescopic cylinder 25 and backing plate 26, the inside left and right ends of transverse slat 1, which are run through, screw rod 2, and the right side of screw rod 2 is welded with operation panel 3, and The left side of screw rod 2 is fixed with steadying plate 4, and the right end of transverse slat 1 offers ring rail 5, and the inside front and rear sides of transverse slat 1 open up There is traverse rod 8, the outside screw of screw rod 2 is connected with vertical bar 6, and the front and rear sides of vertical bar 6 are respectively and fixedly provided with link block 7, and connect Block 7 is fastened on the inside of traverse rod 8, and the bottom end of vertical bar 6 offers the holding groove 9 of cross section structure in a ring, and the outside of vertical bar 6 It is provided with mounting structure 10, the lower section of vertical bar 6 is fixed with bearing rod 14, and the lower section of bearing rod 14 is welded with expanded support block 15, shows Micro mirror 11 inlays the inside for being mounted on mounting structure 10, and the top of mounting structure 10 is provided with mounting rack 12, miniature webcam 13 are fixedly mounted on the lower section of mounting rack 12；

The top engaging that the upper surface of transverse slat 1, which is welded with, to be limited box 16, and limit box 16 is equipped with the bottom end of foul water tank 17, sewage The top of case 17 is equipped with case lid 18, and the inside front and rear sides of case lid 18 offer perforation 19, the right side of foul water tank 17 It being welded with frame plate 20, and the front end of frame plate 20 offers placing groove 21, mini-medical pump 22 is mounted on the left side of foul water tank 17, and The output end of mini-medical pump 22 is connected with outlet pipe 23, and the input terminal of mini-medical pump 22 is connected with conduction hose 24, Telescopic cylinder 25 has installation at left and right sides of the lower surface of transverse slat 1, and the lower surface of telescopic cylinder 25 is fixed with backing plate 26；

Steadying plate 4 includes outside plate 401, connecting rod 402 and connected ball 403, the medial surface etc. of outside plate 401 as shown in Figure 1, Figure 2 and in Fig. 3 Angle is fixed with connecting rod 402, and the right side of connecting rod 402 is fixed with connected ball 403, and connecting rod 402 passes through connected ball 403 It is rotatablely connected with transverse slat 1, the formula that is internally embedded of ring rail 5 is equipped with connected ball 403, and the depth of 403 embedded rings rail 5 of connected ball is big In the radius size of connected ball 403, so that the screw rod 2 being fixedly connected with steadying plate 4 is rotated in the internal stability of transverse slat 1, vertical bar 6 About the center line symmetrical setting of screw rod 2, and vertical bar 6 constitutes slide construction, and screw rod 2 or so two by screw rod 2 and transverse slat 1 The hand of spiral at end is on the contrary, the rotation of screw rod 2 drives vertical bar 6 to move, to drive expanded support block 15 mobile, and then utilization expanded support block The rear cranium of 15 expanded support patients, the longitudinal section of expanded support block 15 are in half elliptic structure, and the medial surface of expanded support block 15 and vertical bar 6 is interior Side is located in same level, longitudinal section in half elliptic structure expanded support block 15 can after further expansion patient cranium place Reason face；

As mounting structure 10 includes stop block 1001, the first side plate 1002, telescopic rod 1003, second in Fig. 4, Fig. 5, Fig. 6 and Fig. 7 Side 1004 and plate 1005, the lateral surface of stop block 1001 are welded with the first side plate 1002, on the outside of the first side plate 1002 Lower both ends are mounted on telescopic rod 1003, and the output end of telescopic rod 1003 is connected with second side 1004, second side 1004 Outside vertical is fixed with plate 1005, adjusts the telescopic rod 1003 inside mounting structure 10 and is convenient for adjusting the position of microscope 11, Consequently facilitating comprehensively observing the rear cranium of patient, the longitudinal section of stop block 1001 is in " convex " font structure, and stop block 1001 is blocked It closes in the inside of holding groove 9, so that mounting structure 10 is stably connected with vertical bar 6, the medial surface of second side 1004 shape in curved surface Structure, and the medial surface of second side 1004 and vertical bar 6 constitute rotational structure, facilitate the operating angle for adjusting microscope 11, peace Shelve 12 and with the connection type of plate 1005 be that card slot connect, and the vertical centerline of mounting rack 12 and microscope 11 it is vertical in Heart line overlaps, and is amplified cranium after the brain of patient using microscope 11, facilitate by the miniature webcam 13 on mounting rack 12 from It is removed on microscope 11, flexibly uses miniature webcam 13, conduction hose 24 is connect with the connection type of frame plate 20 for card slot, and The diameter dimension of conduction hose 24 and the diameter dimension of outlet pipe 23 be equal to perforation 19 internal diameter, facilitate processing work it Conduction hose 24 afterwards avoids the residue contaminated operation environment inside conduction hose 24.

Working principle: when cranium operation is with drainage device is strutted after using the neurosurgery with microscopic function, first Telescopic rod 1003, microscope 11, miniature webcam 13, mini-medical pump 22 and the working principle of telescopic cylinder 25 are existing back Mature technology under scape, as shown in Figure 1, backing plate 26 is placed on operating bed by medical worker, so that transverse slat 1 is located at patient's brain Top, when cranium struts after needing patient, the position of regulating device, under the action of telescopic cylinder 25, adjust expanded support block 15 height, so that expanded support block 15 is located at the opening of patient's brain, then medical worker rotates clockwise the operation panel in Fig. 1 3, since operation panel 3 is fixedly connected with screw rod 2, screw rod 2 is threadedly coupled with vertical bar 6, and vertical bar 6 is symmetrical about the center line of screw rod 2 2 groups are provided with, and the hand of spiral of 2 left and right ends of screw rod is on the contrary, rotating clockwise with the screw rod 2 in Fig. 1, in Fig. 2 Connected ball 403 is rotated clockwise in the inside of ring rail 5, and 2 groups of vertical bars 6 relatively move, 2 groups of expanded support blocks being indirectly connected with vertical bar 6 15 relative movements, are strutted the opening of cranium after patient using the movement of 2 groups of expanded support blocks 15；

When medical worker needs to observe the rear cranium of patient using microscope 11, as shown in figure 4, since stop block 1001 is fastened on The inside of holding groove 9, structure, stop block 1001 and vertical bar 6 constitute rotational structure in a ring for the cross section of holding groove 9, thus the Two side faces 1004 can rotate in the outside of vertical bar 6, by rotating the mounting structure 10 in Fig. 7, will install on mounting structure 10 Microscope 11 turn to the top of cranium after patient, the display screen in miniature webcam 13 and the external world is of coupled connections, miniature webcam 13 are transmitted to the rear cranium image observed by microscope 11 extraneous display screen, observe for medical worker, see when needs are comprehensive When examining the rear cranium of patient, the fastening bolt on telescopic rod 1003 is removed manually, then adjusts the length of telescopic rod 1003, thus The first side plate 1002 is adjusted at a distance from second side 1004, and then adjusts position of the microscope 11 after patient on cranium, thus The rear cranium of patient is comprehensively observed；

After needing patient when the sewage discharge of intracranial part, the conduction hose 24 in Fig. 1 is put into the rear encephalic of patient, is opened Sewage is arranged the inside to foul water tank 17 by outlet pipe 23, works as dirt by mini-medical pump 22 under the action of mini-medical pump 22 After water extraction work comes to an end, the conduction hose 24 in Fig. 7 is passed through to the inside of 19 insertion foul water tanks 17 of perforation, due to drawing Stream hose 24 is plastic products, has certain plasticity, conduction hose 24 is caught in frame plate 20 from the front end of placing groove 21 Inside, frame plate 20 play the role of positioning to conduction hose 24, after operation is completed, when needing to clear up foul water tank 17, by outlet pipe 23 and conduction hose 24 from the inside of case lid 18 extract, then by foul water tank 17 from limit box 16 on remove, then from foul water tank Case lid 18 is removed on 17, can clear up foul water tank 17, the above cranium operation use after just completing the neurosurgery with microscopic function The sequence of operations of drainage device is strutted, the content being not described in detail in this explanation belongs to known in professional and technical personnel in the field The prior art.

The standardized element that the present invention uses can commercially, and shaped piece is according to specification and attached drawing note Load can carry out customized, and the specific connection type of each part is all made of in the prior art mature bolt, rivet, welding etc. Conventional means, mechanical, part and equipment are all made of in the prior art, conventional model, in addition circuit connection uses the prior art Middle conventional connection type, this will not be detailed here.

Although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the art, It is still possible to modify the technical solutions described in the foregoing embodiments, or part of technical characteristic is carried out etc. With replacement, all within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should be included in this Within the protection scope of invention.

Claims

1. cranium operation is with strutting drainage device, including transverse slat (1), microscope after a kind of neurosurgery with microscopic function (11), miniature webcam (13), mini-medical pump (22) and telescopic cylinder (25), it is characterised in that: the inside of the transverse slat (1) Left and right ends, which are run through, to be had screw rod (2), and the right side of screw rod (2) is welded with operation panel (3), and the left side of screw rod (2) It is fixed with steadying plate (4), the right end of the transverse slat (1) offers ring rail (5), and the inside front and rear sides of transverse slat (1) open up Have traverse rod (8), the outside screw of the screw rod (2) is connected with vertical bar (6), and the front and rear sides of vertical bar (6) are respectively and fixedly provided with connection Block (7), and link block (7) is fastened on the inside of traverse rod (8), and the bottom end of the vertical bar (6) offers cross section and ties in a ring The holding groove (9) of structure, and mounting structure (10) are provided on the outside of vertical bar (6), bearing rod is fixed with below the vertical bar (6) (14), it and below bearing rod (14) is welded with expanded support block (15), the microscope (11), which is inlayed, is mounted on mounting structure (10) Inside, and mounting rack (12) are provided with above mounting structure (10), the miniature webcam (13) is fixedly mounted on installation The lower section of frame (12)；

The upper surface of the transverse slat (1), which is welded with, limits box (16), and the top engaging for limiting box (16) is equipped with foul water tank (17) top of bottom end, the foul water tank (17) is equipped with case lid (18), and the inside front and rear sides of case lid (18) open up Have perforation (19), the right side of the foul water tank (17) is welded with frame plate (20), and the front end of frame plate (20) offers placing groove (21), the mini-medical pump (22) is mounted on the left side of foul water tank (17), and the output end of mini-medical pump (22) is connected with Outlet pipe (23), and the input terminal of mini-medical pump (22) is connected with conduction hose (24), and the telescopic cylinder (25) is in cross There is installation at left and right sides of the lower surface of plate (1), and the lower surface of telescopic cylinder (25) is fixed with backing plate (26).

2. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 1, Be characterized in that: the steadying plate (4) includes outside plate (401), connecting rod (402) and connected ball (403), the inside of outside plate (401) Face is angularly fixed with connecting rod (402), and the right side of connecting rod (402) is fixed with connected ball (403).

3. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 2, Be characterized in that: the formula that is internally embedded of the ring rail (5) is equipped with connected ball (403), and connected ball (403) embedded rings rail (5) Depth is greater than the radius size of connected ball (403).

4. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 1, It is characterized in that: center line symmetrical setting of the vertical bar (6) about screw rod (2), and vertical bar (6) passes through screw rod (2) and transverse slat (1) Slide construction is constituted, and the hand of spiral of screw rod (2) left and right ends is opposite.

5. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 1, Be characterized in that: the mounting structure (10) includes stop block (1001), the first side plate (1002), telescopic rod (1003), second side Face (1004) and plate (1005), the lateral surface of stop block (1001) are welded with the first side plate (1002), the first side plate (1002) Outside upper and lower ends be mounted on telescopic rod (1003), the output end of telescopic rod (1003) is connected with second side (1004), The outside vertical of second side (1004) is fixed with plate (1005).

6. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 5, Be characterized in that: the longitudinal section of the stop block (1001) is in " convex " font structure, and stop block (1001) is fastened on holding groove (9) Inside.

7. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 5, It is characterized in that: the medial surface shape structure in curved surface of the second side (1004), and the medial surface of second side (1004) and perpendicular Bar (6) constitutes rotational structure.

8. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 5, Be characterized in that: the mounting rack (12) and the connection type of plate (1005) are that card slot is connect, and mounting rack (12) it is vertical in Heart line and the vertical centerline of microscope (11) overlap.

9. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 1, Be characterized in that: the longitudinal section of the expanded support block (15) is in half elliptic structure, and the medial surface of expanded support block (15) and vertical bar (6) Medial surface is located in same level.

10. cranium operation is with strutting drainage device after a kind of neurosurgery with microscopic function according to claim 1, Be characterized in that: the conduction hose (24) connect with the connection type of frame plate (20) for card slot, and the diameter of conduction hose (24) The diameter dimension of size and outlet pipe (23) is equal to the internal diameter of perforation (19).