Repeatable excitation and manual operation integrated throat negative pressure suction device

Abstract

The utility model discloses a repeatable excitation and manual operation integrated throat part negative pressure suction device, relates to medical instrument related technical field, including lower casing and upper casing, lower casing and upper casing detachable connection, the upper casing is equipped with the upper inner cavity that runs through up and down, the lower casing is slidingly connected with the piston, the piston is equipped with the lower inner cavity that runs through up and down, and the lower inner cavity is equipped with the lower inner cavity that runs through up and down. The piston is connected with a piston push rod connected with the upper shell, a trigger block is slidably installed in the upper inner cavity and extends out of the upper shell, the trigger block is provided with a vertically-through penetrating groove, the piston push rod is provided with a stepped groove at the position of the penetrating groove, and when the piston push rod is locked, the piston push rod is locked in the stepped groove. The bottom wall of the trigger block abuts against the bottom wall of the stepped groove. The locking effect on the piston push rod is achieved through the triggering block, the negative pressure suction effect can be achieved through the cooperation with the piston, meanwhile, the piston push rod is connected to the piston, and the piston push rod can be manually controlled to reciprocate by moving the position of the triggering block.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a reusable and manually operated integrated negative pressure suction device for the throat. Background Technology

[0002] Foreign objects blocking the airway are a common occurrence in our lives, with thousands dying from suffocation globally each year, a significant proportion of whom are children. If someone chokes on a foreign object, the optimal rescue time is generally no more than 4 minutes. Beyond this time, death can result from oxygen deprivation and cardiac arrest. Even with successful resuscitation, prolonged oxygen deprivation to the brain can lead to long-term consequences such as aphasia, intellectual disability, and paralysis. In China, the Heimlich maneuver is typically used in such situations. However, a choking person may not be able to perform the Heimlich maneuver on themselves. Another person (if present) may lack the strength, be untrained, or be too afraid to perform the Heimlich maneuver. This invention patent provides an integrated device that can be charged, activated, and manually pressed. Simply connect a mask, place the mask over the face of the person with the foreign object blocking their airway, and then activate the pull-out device. This instantly creates a negative pressure environment at the mask, drawing out the foreign object stuck in the airway using the principle of atmospheric pressure difference. If the foreign object in the airway is not removed after one use of the trigger, the method of reloading and triggering can be flexibly chosen according to the situation, or the manual pressing and suction method can be switched. Existing products in the domestic market include two types: those with continuous pulling and those with repeated loading after triggering. The amount of negative pressure generated by the manual pulling product depends on the force applied by the user; for users with less strength, the effect is not optimal. Although the triggering product can instantly generate a large negative pressure difference by simply pressing a button, if multiple uses are required, the repeated loading consumes time, prolonging the rescue time and risking missing the optimal rescue window. This invention patent provides an integrated device that can store and trigger the airway and can be manually pressed, allowing the user to choose the desired method according to the specific usage environment after one use. Utility Model Content

[0003] Purpose of the invention: The purpose of this utility model is to provide a reusable and manually operated integrated negative pressure suction device for the throat, which solves the problem of the cumbersome reusability of existing negative pressure suction devices.

[0004] Technical solution:

[0005] A reusable and manually operated integrated negative pressure suction device for the throat includes a lower outer shell and an upper outer shell, which are detachably connected. The upper outer shell has an upper inner cavity that extends vertically. A piston is slidably connected inside the lower outer shell, and a piston push rod connected to the upper outer shell is attached to the piston. A trigger block is slidably installed inside the upper inner cavity, and the trigger block extends out of the upper outer shell. The trigger block has a through groove that extends vertically, through which the piston push rod passes. The piston push rod has a stepped groove at the through groove. When the piston push rod is locked, the bottom wall of the trigger block abuts against the bottom wall of the stepped groove.

[0006] Preferably, the trigger block and the inner wall of the upper inner cavity are horizontally slidably connected, one end of the trigger block penetrates the upper outer shell, and a reset spring is connected between the other end of the trigger block and the inner wall of the upper inner cavity.

[0007] Preferably, the trigger block is connected to a locking structure, which is used to restrict the sliding of the trigger block.

[0008] Preferably, the locking structure includes a locking block that is slidably connected to the inner wall of the upper inner cavity. One end of the locking block penetrates the inner wall of the upper inner cavity, and the other end of the locking block is connected to a locking rod, which is inserted into the trigger block.

[0009] Preferably, the bottom wall of the trigger block is provided with a slot, and when the locking structure is working, the locking rod is inserted into the slot.

[0010] Preferably, the locking structure includes a fixed cylinder fixed to the upper inner cavity, an adjusting cylinder rotatably mounted on the fixed cylinder, an insert fixedly connected inside the adjusting cylinder, the fixed cylinder and the adjusting cylinder being located above the trigger block, the trigger block having an upward-opening movable groove, and the lower end of the insert extending into the movable groove.

[0011] Preferably, the fixing cylinder has a through slot for inserting pieces, and the inserting pieces pass through the slot.

[0012] Preferably, the upper inner cavity is provided with an upper cover above the trigger block, and a pressing cover is slidably connected to the upper cover. The piston push rod and the upper cover are slidably connected in the vertical direction, and the piston push rod passes through the upper cover and the pressing cover upward and is fixedly connected.

[0013] Preferably, the lower outer shell has a lower inner cavity that extends vertically, and the piston and the inner wall of the lower inner cavity are slidably connected vertically.

[0014] Preferably, the lower end face of the piston is provided with a positioning groove, and a lower spring is connected between the piston and the bottom wall of the lower inner cavity. The upper end of the lower spring is embedded in the positioning groove, and the lower end of the lower spring abuts against the bottom wall of the lower inner cavity.

[0015] Beneficial effects: This application achieves the locking effect of the piston push rod through the trigger block, which can work with the piston to achieve the effect of negative pressure suction. At the same time, the piston push rod is connected to the piston. By moving the position of the trigger block, the piston push rod can be manually controlled to move back and forth, which is convenient for users to repeat the work of negative pressure suction. The locking device connected to the trigger block can then control the state of the trigger block, thereby adjusting the piston push rod to switch between manual reciprocating and automatic triggering states, so as to meet the user's needs for adjustment in different states. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a partial cross-sectional view of the lower outer shell of this utility model.

[0018] Figure 3 This is a schematic diagram of the piston structure of this utility model;

[0019] Figure 4 This is a schematic diagram of the piston structure of this utility model;

[0020] Figure 5 This is a schematic diagram of the upper outer shell structure of this utility model;

[0021] Figure 6 for Figure 5 Enlarged structural diagram at point A in the middle;

[0022] Figure 7 This is a schematic diagram of the locking structure of this utility model;

[0023] Figure 8 This is a schematic diagram of the cross-sectional structure of the outer shell in another embodiment of the present invention;

[0024] Figure 9 This is a schematic diagram of a locking structure according to another embodiment of the present invention.

[0025] Reference numerals: 11. Outer shell; 12. Face mask; 13. Upper outer shell; 14. Press cover; 21. Lower inner cavity; 22. Outer spring; 23. Fixed one-way valve; 24. Connection port; 31. Piston push rod; 32. Piston; 33. Movable one-way valve; 34. Sealing ring; 35. Positioning groove; 36. Air hole; 37. Notch; 41. Guide block; 42. Upper cover; 43. Guide groove; 44. Upper inner cavity; 45. Limiting groove; 46. Return spring; 51. Trigger block; 52. Locking block; 53. Locking rod; 54. Slot; 55. Through slot; 56. Receiving slot; 57. Movable slot; 61. Movable cylinder; 62. Adjusting cylinder; 63. Insert plate; 64. Toggle block; 65. Insert plate slot. Detailed Implementation

[0026] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] like Figure 1-7 As shown, a reusable and manually operated integrated negative pressure suction device for the throat includes a lower outer shell 11 and an upper outer shell 13. The lower outer shell 11 and the upper outer shell 13 are detachably connected and are threaded together for easy disassembly and installation.

[0029] The lower end of the lower outer shell 11 is connected to a face mask 12. The face mask 12 and the lower outer shell 11 are connected by a plug-in connection. The lower end of the lower outer shell 11 is provided with an extended connection port 24. The connection port 24 and the face mask 12 are plugged in. A rubber ring is provided at the connection between the face mask 12 and the connection port 24 to improve the sealing effect. The face mask 12 is used to cover the user's mouth to ensure a tight seal.

[0030] The lower outer shell 11 has a lower inner cavity 21 that runs vertically through it. The connection port 24 has a through hole that runs through the lower outer shell 11. The lower outer shell 11 has a fixed one-way valve 23 at the connection port 24. The fixed one-way valve 23 seals the through hole. The fixed one-way valve 23 can control the air to enter the lower inner cavity 21 in one direction, which can help to perform air extraction.

[0031] Meanwhile, a piston 32 is slidably connected to the inner wall of the lower inner cavity 21. An annular groove is provided on the side wall of the piston 32, and a sealing ring 34 is installed on the piston 32 at the annular groove. The sealing ring 34 can improve the sealing effect between the piston 32 and the lower inner cavity 21, making it easier to form a suitable sealing space between the piston 32 and the lower inner cavity 21, thereby creating a pressure difference and achieving the effect of negative pressure suction.

[0032] The piston 32 is provided with a movable one-way valve 33. After the piston 32 abuts against the inner wall of the lower inner cavity 21 through the sealing ring 34, the air is discharged through the movable one-way valve 33, which facilitates the abutment between the piston 32 and the bottom wall of the lower inner cavity 21 and discharges the air between the piston 32 and the lower inner cavity 21. In this application, there are two movable one-way valves 33.

[0033] Furthermore, a lower spring 22 is provided between the piston 32 and the lower inner cavity 21. The lower spring 22 is always in a compressed state. The lower end face of the piston 32 is provided with a positioning groove 35, which is annular. One end of the lower spring 22 is connected to the inner wall of the positioning groove 35, and the other end of the lower spring 22 is connected to the bottom wall of the lower inner cavity 21. The lower inner cavity 21 is provided with a corresponding annular baffle on the periphery of the connection port 24 to facilitate the connection and fixation of the lower spring 22. Through the elastic force of the lower spring 22, the piston 32 is moved away from the bottom wall of the lower inner cavity 21 to achieve the effect of negative pressure suction.

[0034] The piston 32 is connected to a piston rod 31 that is connected to the upper outer shell 13. The piston rod 31 extends upward and extends upward out of the lower inner cavity 21. The upper outer shell 13 is provided with an upper inner cavity 44 that runs through it from top to bottom. The piston rod 31 passes through the upper inner cavity 44.

[0035] A trigger block 51 is slidably installed inside the upper inner cavity 44. The trigger block 51 is horizontally positioned and slides along the radial direction of the upper inner cavity 44. A through hole is provided on one side wall of the upper inner cavity 44, through which the trigger block 51 can pass and extend out of the upper inner cavity 44. A button is provided on the outer side of the upper outer shell 13 for easy pressing and pushing of the trigger block 51 to slide. One end of the trigger block 51 extends out of the upper outer shell 13, and the other end of the trigger block 51 is located inside the upper inner cavity 44. The end of the trigger block 51 has an extended groove, and a return spring 46 is connected to the groove. The inner wall of the upper inner cavity 44 has a limiting groove 45 in the groove. The outer wall of the groove extends into the limiting groove 45 and is slidably connected to the inner wall of the limiting groove 45. The return spring 46 is located in the limiting groove 45. One end of the return spring 46 is connected to the inner wall of the limiting groove 45, and the other end of the return spring 46 is connected to the inner wall of the groove. The return spring 46 is always in a compressed state, which facilitates control of the horizontal movement of the trigger block 51.

[0036] The trigger block 51 is used to control the up and down movement of the piston push rod 31. The trigger block 51 has a through groove 55 that runs vertically through the middle. The piston push rod 31 passes through the through hole. At the same time, the piston push rod 31 has a stepped groove 37 below the trigger block 51. The bottom wall of the stepped groove 37 can contact the bottom wall of the trigger block 51. When the piston push rod 31 completely passes through the through groove 55, the device is in a negative pressure extraction state. When the bottom wall of the stepped groove 37 abuts against the bottom wall of the trigger block 51, the piston push rod 31 cannot slide upward. The piston 32 is located at the bottom of the lower inner cavity 21. Horizontally pushing the trigger block 51 can make the piston push rod 31 contact and lock the sliding.

[0037] Furthermore, to prevent triggering during storage, the trigger block 51 is also connected to a locking structure, which restricts the sliding of the trigger block 51.

[0038] The locking structure includes a locking block 52, which slides up and down along the inner wall of the upper inner cavity 44. The locking block 52 can be located above or below the trigger block 51. In this application, the locking block 52 is located below the trigger block 51. One end of the locking block 52 extends through the upper outer shell 13. A push button is connected to the outer side of the upper outer shell 13. The push button controls the locking block 52 to slide up and down. A locking rod 53 is connected to the locking block 52 in the upper cavity 44. The trigger block 51 is provided with an upper and lower through slot 54. When the locking rod 53 is inserted into the slot 54, the trigger block 51 cannot move in the horizontal direction.

[0039] Furthermore, there are two slots 54. When the locking rod 53 is inserted into two different slots 54, the trigger 51 can be controlled to lock in different positions, so that the piston push rod 31 is in a free-moving or locked state, which is convenient for adjustment.

[0040] The shape of the locking lever 53 is not limited. In this application, the locking lever 53 is in the form of a multi-grid design for easy insertion.

[0041] The upper inner cavity 44 is provided with an upper cover 10 above the trigger block 51. A pressing cover 14 is slidably connected to the upper cover 10. The piston push rod 31 is slidably connected to the upper cover 10 in the vertical direction. The piston push rod 31 passes through the upper cover 10 and the pressing cover 14 and is fixedly connected, so that the user can control the piston push rod 31 to slide through the pressing cover 14.

[0042] Furthermore, the upper cover 10 is provided with a guide groove 43 that runs vertically through the top and bottom, and a guide block 41 is fixedly connected to the lower end of the pressing cover 14. The guide block 41 and the guide groove 43 are slidably connected vertically.

[0043] Example 2

[0044] A reusable and manually operated integrated negative pressure suction device for the throat includes a lower outer shell 11 and an upper outer shell 13. The lower outer shell 11 and the upper outer shell 13 are detachably connected and are threaded together for easy disassembly and installation.

[0045] The lower end of the lower outer shell 11 is connected to a face mask 12. The face mask 12 and the lower outer shell 11 are connected by a plug-in connection. The lower end of the lower outer shell 11 is provided with an extended connection port 24. The connection port 24 and the face mask 12 are plugged in. A rubber ring is provided at the connection between the face mask 12 and the connection port 24 to improve the sealing effect. The face mask 12 is used to cover the user's mouth to ensure a tight seal.

[0046] The lower outer shell 11 has a lower inner cavity 21 that runs vertically through it. The connection port 24 has a through hole that runs through the lower outer shell 11. The lower outer shell 11 has a fixed one-way valve 23 at the connection port 24. The fixed one-way valve 23 seals the through hole. The fixed one-way valve 23 can control the air to enter the lower inner cavity 21 in one direction, which can help to perform air extraction.

[0047] Meanwhile, a piston 32 is slidably connected to the inner wall of the lower inner cavity 21. An annular groove is provided on the side wall of the piston 32, and a sealing ring 34 is installed on the piston 32 at the annular groove. The sealing ring 34 can improve the sealing effect between the piston 32 and the lower inner cavity 21, making it easier to form a suitable sealing space between the piston 32 and the lower inner cavity 21, thereby creating a pressure difference and achieving the effect of negative pressure suction.

[0048] The piston 32 is provided with a movable one-way valve 33. After the piston 32 abuts against the inner wall of the lower inner cavity 21 through the sealing ring 34, the air is discharged through the movable one-way valve 33, which facilitates the abutment between the piston 32 and the bottom wall of the lower inner cavity 21 and discharges the air between the piston 32 and the lower inner cavity 21. In this application, there are two movable one-way valves 33.

[0049] Furthermore, a lower spring 22 is provided between the piston 32 and the lower inner cavity 21. The lower spring 22 is always in a compressed state. The lower end face of the piston 32 is provided with a positioning groove 35, which is annular. One end of the lower spring 22 is connected to the inner wall of the positioning groove 35, and the other end of the lower spring 22 is connected to the bottom wall of the lower inner cavity 21. The lower inner cavity 21 is provided with a corresponding annular baffle on the periphery of the connection port 24 to facilitate the connection and fixation of the lower spring 22. Through the elastic force of the lower spring 22, the piston 32 is moved away from the bottom wall of the lower inner cavity 21 to achieve the effect of negative pressure suction.

[0050] The piston 32 is connected to a piston rod 31 that is connected to the upper outer shell 13. The piston rod 31 extends upward and extends upward out of the lower inner cavity 21. The upper outer shell 13 is provided with an upper inner cavity 44 that runs through it from top to bottom. The piston rod 31 passes through the upper inner cavity 44.

[0051] A trigger block 51 is slidably installed inside the upper inner cavity 44. The trigger block 51 is horizontally positioned and slides along the radial direction of the upper inner cavity 44. A through hole is provided on one side wall of the upper inner cavity 44, through which the trigger block 51 can pass and extend out of the upper inner cavity 44. A button is provided on the outer side of the upper outer shell 13 for easy pressing and pushing of the trigger block 51 to slide. One end of the trigger block 51 extends out of the upper outer shell 13, and the other end of the trigger block 51 is located inside the upper inner cavity 44. The end of the trigger block 51 has an extended groove, and a return spring 46 is connected to the groove. The inner wall of the upper inner cavity 44 has a limiting groove 45 in the groove. The outer wall of the groove extends into the limiting groove 45 and is slidably connected to the inner wall of the limiting groove 45. The return spring 46 is located in the limiting groove 45. One end of the return spring 46 is connected to the inner wall of the limiting groove 45, and the other end of the return spring 46 is connected to the inner wall of the groove. The return spring 46 is always in a compressed state, which facilitates control of the horizontal movement of the trigger block 51.

[0052] The trigger block 51 is used to control the up and down movement of the piston push rod 31. The trigger block 51 has a through groove 55 that runs vertically through the middle. The piston push rod 31 passes through the through hole. At the same time, the piston push rod 31 has a stepped groove 37 below the trigger block 51. The bottom wall of the stepped groove 37 can contact the bottom wall of the trigger block 51. When the piston push rod 31 completely passes through the through groove 55, the device is in a negative pressure extraction state. When the bottom wall of the stepped groove 37 abuts against the bottom wall of the trigger block 51, the piston push rod 31 cannot slide upward. The piston 32 is located at the bottom of the lower inner cavity 21. Horizontally pushing the trigger block 51 can make the piston push rod 31 contact and lock the sliding.

[0053] Furthermore, to prevent triggering during storage, the trigger block 51 is also connected to a locking structure, which restricts the sliding of the trigger block 51.

[0054] like Figure 8-9 As shown, the locking structure includes a fixed cylinder 61 fixed to the upper inner cavity 44. The upper outer shell 13 has a conical structure, with its lower diameter smaller than its upper diameter. The lower part of the fixed cylinder 61 is connected to the inner wall of the upper inner cavity 44. An adjusting cylinder 62 is rotatably mounted on the fixed cylinder 61. An insert 63 is fixedly connected inside the adjusting cylinder 62. The fixed cylinder 61 and the adjusting cylinder 62 are located above the trigger block 51. The trigger block 51 has an upward-opening movable groove 57, and the lower end of the insert 63 extends into the movable groove 57.

[0055] The fixed cylinder 61 has a through slot 65 that extends vertically. The insert 63 passes through the slot 65. When the adjusting cylinder 62 rotates, the adjusting cylinder 62 can abut against the side wall of the movable slot 57, thereby restricting the sliding of the trigger block 51.

[0056] The upper inner cavity 44 is provided with an upper cover 10 above the trigger block 51. A pressing cover 14 is slidably connected to the upper cover 10. The piston push rod 31 is slidably connected to the upper cover 10 in the vertical direction. The piston push rod 31 passes through the upper cover 10 and the pressing cover 14 and is fixedly connected, so that the user can control the piston push rod 31 to slide through the pressing cover 14.

[0057] Furthermore, the upper cover 10 is provided with a guide groove 43 that runs vertically through the top and bottom, and a guide block 41 is fixedly connected to the lower end of the pressing cover 14. The guide block 41 and the guide groove 43 are slidably connected vertically.

[0058] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A reusable and manually operated integrated negative pressure suction device for the pharynx, comprising a lower outer shell (11) and an upper outer shell (13), wherein the lower outer shell (11) and the upper outer shell (13) are detachably connected, and the upper outer shell (13) has an upper inner cavity (44) extending vertically, characterized in that: A piston (32) is slidably connected inside the lower outer shell (11). A piston push rod (31) connected to the upper outer shell (13) is connected to the piston (32). A trigger block (51) is slidably installed inside the upper inner cavity (44). The trigger block (51) extends out of the upper outer shell (13). The trigger block (51) is provided with a through groove (55) that runs vertically through the upper and lower parts. The piston push rod (31) passes through the through groove (55). The piston push rod (31) is provided with a stepped groove (37) at the through groove (55). When the piston push rod (31) is locked, the bottom wall of the trigger block (51) and the bottom wall of the stepped groove (37) abut against each other.

2. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 1, characterized in that, The trigger block (51) and the inner wall of the upper inner cavity (44) are horizontally slidably connected. One end of the trigger block (51) passes through the upper outer shell (13), and a reset spring (46) is connected between the other end of the trigger block (51) and the inner wall of the upper inner cavity (44).

3. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 1, characterized in that, The trigger block (51) is connected to a locking structure, which is used to restrict the sliding of the trigger block (51).

4. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 3, characterized in that, The locking structure includes a locking block (52), which is slidably connected to the inner wall of the upper inner cavity (44). One end of the locking block (52) penetrates the inner wall of the upper inner cavity (44), and the other end of the locking block (52) is connected to a locking rod (53). The locking rod (53) is inserted into the trigger block (51).

5. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 4, characterized in that, The bottom wall of the trigger block (51) is provided with a slot (54). When the locking structure is working, the locking rod (53) is inserted into the slot (54).

6. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 3, characterized in that, The locking structure includes a fixed cylinder (61) fixed to the upper inner cavity (44), an adjusting cylinder (62) rotatably mounted on the fixed cylinder (61), and an insert (63) fixedly connected inside the adjusting cylinder (62). The fixed cylinder (61) and the adjusting cylinder (62) are located above the trigger block (51). The trigger block (51) is provided with an upward-opening movable groove (57), and the lower end of the insert (63) extends into the movable groove (57).

7. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 6, characterized in that, The fixed cylinder (61) is provided with a through slot (65) for inserting pieces, and the insert (63) passes through the slot (65).

8. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 1, characterized in that, The upper inner cavity (44) is provided with an upper cover (10) above the trigger block (51). A pressing cover (14) is slidably connected to the upper cover (10). The piston push rod (31) and the upper cover (10) are slidably connected in the vertical direction. The piston push rod (31) passes through the upper cover (10) and the pressing cover (14) and is fixedly connected.

9. The reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 1, characterized in that, The lower outer shell (11) has a lower inner cavity (21) that runs vertically through it, and the piston (32) and the inner wall of the lower inner cavity (21) are slidably connected vertically.

10. A reusable and manually operated integrated negative pressure suction device for the pharynx according to claim 9, characterized in that, The piston (32) has a positioning groove (35) on its lower end face. A lower spring (22) is connected between the piston (32) and the bottom wall of the lower inner cavity (21). The upper end of the lower spring (22) is embedded in the positioning groove (35), and the lower end of the lower spring (22) abuts against the bottom wall of the lower inner cavity (21).

Images