Multi-stage negative pressure adjustment device for a ventilator
The multi-stage negative pressure adjustment device addresses the limitations of constant pressure suction by allowing adjustable power settings and preventing air backflow, ensuring effective obstruction removal across varying conditions.
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-03-26
AI Technical Summary
Existing negative pressure pharyngeal suction devices generate a constant negative pressure, which is insufficient for varying conditions such as obesity, age, and the type of obstruction, and often suffer from air backflow and reverse airflow due to simple check valves.
A multi-stage negative pressure adjustment device with a rotary cap allowing for adjustable suction power in four stages (strong, moderate, weak, minimal) and a specialized check valve flap to prevent air backflow, featuring a safety cap to avoid accidental activation.
Enables tailored suction power adjustment for different individuals and conditions, effectively removing obstructions while preventing air backflow, enhancing safety and ease of use.
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Abstract
Description
BACKGROUND OF THE INVENTION (a) Context of the invention
[0001] The present invention relates to a multi-stage negative pressure adjustment device for a ventilator, in particular a multi-stage negative pressure adjustment device for a ventilator, wherein foreign bodies lodged in the pharynx or esophagus are removed by means of an instantaneous negative pressure force generated in a sealed chamber. The suction force is adjusted according to the conditions by means of a rotary cap, a non-return valve flap is provided to prevent backflow of air and to help prevent reverse airflow, while a safety cap is attached to a release mechanism to prevent accidental contact with a switch. (b) Description of the method of execution according to the state of the art
[0002] If a person eats without chewing their food thoroughly, it can become a sticky bolus that can easily get stuck in the throat. Whether it's an elderly person without teeth swallowing food, an average person eating in a hurry, or a child swallowing a foreign object, the food or object can obstruct the throat and airway, leading to immediate choking. The choking person will be unable to breathe, speak, or even make a sound, which can be fatal if help doesn't arrive quickly. Therefore, medical professionals often teach the Heimlich maneuver, a type of resuscitation technique used to dislodge a foreign object obstructing the upper airway.To perform the abdominal thrust, a person providing first aid must stand behind a patient, apply pressure to the diaphragm with their hands, compress the lungs, and exert pressure on the foreign body, thereby expelling it from the trachea.
[0003] Not everyone knows how to perform the Heimlich maneuver when performing CPR. If someone performs it incorrectly, they will never expel the foreign object from the choking person. Conversely, if the choking person is obese and the person administering first aid is slim and smaller, they may not be able to exert enough force to remove the foreign object from the choking person's windpipe. Excessive force can sometimes damage the diaphragm or lungs. Finally, not everyone is a healthcare professional, and if no one else is around, the choking person must try to save themselves by finding a chair or table to apply pressure to their abdomen and diaphragm to compress their lungs. However, this goal cannot be achieved if the person panics, as they will miss the opportunity to perform CPR.
[0004] There are now industries that manufacture a type of negative pressure aspirator for the throat, which is a useful tool for self-rescue or for ventilating others. The negative pressure aspirator for the throat primarily consists of a suction chamber, inside which are a piston rod, a check valve, and a spring. A pressure switch is located on the outer circumference near the top of the chamber. The bottom of the suction chamber is fitted with a suction tube, the interior of the suction chamber is sealed, and the spring is positioned between the base of the piston rod and the bottom of the suction chamber. The pressure switch releases the spring, allowing it to return from a compressed state to its original shape.The spring instantly returns to its original state, allowing the suction tube to draw a large volume of air into the suction chamber in a short time, creating an immediate vacuum. When using the pharyngeal vacuum suction device, a bag-valve mask (BVM) is used to seal the mouth and nose of the choking person, with the pharyngeal vacuum suction device attached to the BVM. The instantaneous vacuum created in the sealed space is used to suction out the foreign object obstructing the throat and esophagus. The non-return valve prevents backflow of air, allowing others to easily resuscitate the choking person and potentially enabling the choking person to save themselves.
[0005] This ventilator is lightweight and compact and can be positioned for easy visibility, allowing people to use it during ventilation, which is very convenient. However, current models of negative pressure pharyngeal suction devices can only generate a constant negative pressure. As is well known, a choking person may be obese, slender, elderly, or young; whereas the foreign body obstructing the throat and esophagus may be large, small, hard, or soft. Therefore, if current models of negative pressure pharyngeal suction devices can only generate a constant negative pressure, this is insufficient to meet all the aforementioned conditions. If the elasticity of the throat and esophagus of a choking elderly person is weak and the obstruction is significant, a suction device capable of generating a high negative pressure is required.On the other hand, since a child's throat is weak, a suction device with only a slight negative pressure is required to prevent further damage to the throat. In such cases, the prior art negative pressure suction device for the throat, with its single constant negative pressure value, cannot cover all types of choking hazards, which is a major disadvantage. Furthermore, the prior art check valve uses only a simple duckbill diaphragm, which frequently leads to the phenomenon of air backflow and reverse airflow, affecting the negative pressure value and sometimes resisting spring compression. SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention provides a multi-stage negative pressure adjustment device for a ventilator, comprising mainly an outer cylinder, an inner cylinder, a rotating cap, a spring, a suction tube plug, and a bottom cap. An outer ring is attached to the top of the outer cylinder, the outer ring being provided with a release mechanism. A connecting rod is attached to the center of the inner cylinder. The bottom of the outer cylinder has a base wall, which is provided with a large central through-hole and several small outer through-holes. The suction tube plug and the bottom cap are provided on the underside of the base wall.The spring and the inner cylinder are arranged within the outer cylinder. The spring is positioned between the piston connecting rod and the bottom wall of the outer cylinder, with the intake manifold plug allowing the installation of a BVM (Battery Valve Module). The present invention is characterized in that the rotary cap is encased and pivotably arranged on the upper side of the inner cylinder. Several projecting stop walls are arranged on an outer circumference of the rotary cap near its upper side. These several projecting stop walls are located at different heights. A check valve flap is arranged between the underside of the bottom wall and the intake manifold plug. The release mechanism is equipped with a locking claw designed to engage with each of the projecting stop walls on the rotary cap.When the locking claw is released, the rotating cap above the inner cylinder can rotate, allowing the protruding stop walls to engage with the inner cylinder at different heights to adjust the vacuum inside the outer cylinder.
[0007] A main object of the present invention is to create a multi-stage negative pressure adjustment device for a ventilator, wherein the rotary cap is provided for selecting and adjusting the strength of the negative pressure in stages (four stages: strong, moderate, weak and minimal), so that a user can adjust the suction power as needed.
[0008] A second objective of the present invention is to create a multi-stage negative pressure adjustment device for a ventilator, wherein a special non-return valve flap is provided to prevent backflow of air and to help prevent reverse airflow so that the negative pressure can be generated correctly, the suction power is not lost and the spring can be compressed without resistance.
[0009] A third objective of the present invention is to create a multi-stage negative pressure adjustment device for a ventilator, wherein the unlocking mechanism is designed with a safety cap which constitutes a safety device to prevent accidental contact with the locking claw.
[0010] For a better understanding of the stated objectives and the technological methods of the present invention, a detailed description of the preferred embodiments follows the brief description of the accompanying drawings below. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a three-dimensional exploded view of the present invention. Fig. Figure 2 shows a three-dimensional schematic view of the assembly of the present invention, in which a BVM is attached and a rotating cap is released. Fig. Figure 3 shows a three-dimensional exploded view of an outer cylinder, a check valve flap, a suction pipe plug and a bottom cap from a different perspective according to the present invention. Fig. Figure 4 shows a sectional view along line 4-4 in Fig. 2. Fig. Figure 5 shows a partial sectional view along line 5-5 in Fig. 2. Fig. Figure 6 shows a sectional view along line 6-6 in Fig. 2 (an outer ring does not lock the rotating cap). Fig. Figure 7 shows a three-dimensional schematic view of the present invention, with the rotating cap pressed downwards. Fig. Figure 8 shows a sectional view along line 8-8 in Fig. 7 (the outer ring locks the rotating cap). Fig. Figure 9 shows a sectional view of the present invention, in which a safety cap is opened and a locking claw releases the rotating cap. Fig. Figure 10 shows a sectional view of the present invention, with the rotating cap pressed downwards. Fig. Figure 11 shows a three-dimensional schematic view of the present invention, in which the rotating cap is rotated by an angle. Fig. Figure 12 shows a three-dimensional schematic view of the present invention, wherein the rotating cap is viewed from bottom to top. Fig. Figure 13 shows a partially cut-away and enlarged view of the present invention, in which the locking claw locks the rotating cap. DETAILED DESCRIPTION OF PREFERRED EXECUTION EXAMPLES
[0011] The Fig. 1, Fig. 2 and Fig. Figure 4 shows that the present invention mainly comprises an outer cylinder 10, an inner cylinder 20, a rotating cap 30, a spring 40, a check valve flap 50, a suction pipe plug 60, and a bottom cap 70. A top surface of the outer cylinder 10 is assembled with an outer ring 80 and provided with a matching internal thread 11; while a bottom surface of the outer ring 80 is provided with a matching external thread 81, and the matching internal thread 11 is connected to the matching external thread 81. A circumference of the outer cylinder 10 is provided with two identical rings with a non-slip surface pattern 12, which increases and facilitates grip when held by a user, allowing the user to hold the outer cylinder 10 practically without slipping.The outer ring 80 has a release mechanism 90 which is provided with two projecting lugs 82 on the outer part of the outer ring 80; whereas a safety cap 91 and a locking claw 92 (see . Fig. 1 and Fig. 9) are pivotably arranged between the two protruding lugs 82. The safety cap 91 is located on the outer part of the locking claw 92 and can be opened and closed. When the safety cap 91 is closed, it prevents the locking claw 92 from being accidentally touched and actuated. Conversely, when the safety cap 91 is opened, the locking claw 92 can be pressed, and an inner surface of the locking claw 92 abuts a horizontal spring 921, which is positioned on an inner surface of the locking claw 92. A front end of the locking claw 92 can penetrate the outer ring 80 to an inner wall, whereby the pressed locking claw 92 is returned to its original state by the elasticity of the horizontal spring 921.A center in the inner cylinder 20 is attached to a piston connecting rod 21; whereas an outer circumference on a lower side of the piston connecting rod 21 is provided with an upper projecting ring 22, a middle projecting ring 23, and a lower projecting ring 24. A top surface of the upper projecting ring 22 is encased by a buffer ring 221, an upper sealing ring 231 is located between the upper projecting ring 22 and the middle projecting ring 23, and a lower sealing ring 241 is located between the middle projecting ring 23 and the lower projecting ring 24. A bottom of the outer cylinder 10 is provided with a bottom wall 13 (see . Fig. 3), whereas the bottom wall 13 has a large central through-hole 131 and several small outer through-holes 132. An underside of the bottom wall 13 is equipped with a check valve flap 50 and a suction pipe plug 60 and is assembled with the bottom cap 70. The check valve flap 50 is a soft silicone cushion that can oscillate slightly vertically with the airflow. The center of the check valve flap 50 is provided with a large, downwardly projecting sphere 51 (hemisphere), the circumference of which has a large gap 511. The large gap 511 is further opened by the upward air pressure, thus enabling the upward oscillation of the large, downwardly projecting sphere 51.An outer circumference of the large, downwardly projecting sphere 51 is provided with two small, upwardly projecting spheres 52 (hemispheres), while the circumference of each small, upwardly projecting sphere 52 has a small gap 521. The small gap 521 is opened wider by the downward air pressure and causes the downward oscillation of the small, upwardly projecting sphere 52. Accordingly, the intake manifold plug 60 is provided with a large central cutout 61 and two small outer cutouts 62. The bottom cap 70 has a large central through-hole 71 and several small outer through-holes 72, while an inner wall at the bottom of the outer cylinder 10 is provided with two positioning ribs 14.Two positioning grooves 53 are arranged accordingly on an outer circumference of the check valve flap 50, with one outer circumference on the top of the intake manifold plug 60 being provided with two positioning notches 63. The positioning rib 14 is embedded in the positioning groove 53 and the positioning notch 63 to correctly position the angle of the check valve flap 50 and the angle of the intake manifold plug 60. A base of the outer cylinder 10 is provided with an external thread 15, while an inner wall of the base cap 70 is provided with an internal thread 73 (see ). Fig. 1); whereas the internal thread 73 is attached to the external thread 15, allowing the bottom cap 70 to mount and position the check valve flap 50 and the suction pipe plug 60 on the bottom of the outer cylinder 10. The suction pipe plug 60 enables the assembly of a BVM 100 (see Fig. 2), wherein the BVM 100 is a state-of-the-art device made of silicone.
[0012] The spring 40 and the inner cylinder 20 are inserted into the outer cylinder 10 in a top-to-bottom order, with the spring 40 positioned between the underside of the piston connecting rod 21 and the bottom wall 13 of the outer cylinder 10. An outer circumference of the inner cylinder 20 is provided with several double projecting ribs 25 and several elongated sliding slots 251, each elongated sliding slot 251 being located between two double projecting ribs 25. The double projecting ribs 25 consist of two vertical ribs with a height of [missing value] and do not extend to the top of the inner cylinder 20, but are set back from the top by a distance [missing value]. The rotating cap 30 is provided with several elongated grooves 32, which are set back from the top and correspond to the elongated sliding slots 251. An inner wall of the outer ring 80 is provided with several projecting tabs 83 (see [missing value]). Fig. 6 and Fig. 8), while the projecting tabs 83 slide into the elongated grooves 32 of the rotary cap 30 and the elongated sliding slots 251 of the inner cylinder 20, allowing the rotary cap 30 and the inner cylinder 20 to move upwards and downwards in a defined direction relative to the outer ring 80. When the rotary cap 30 and the inner cylinder 20 are lifted, the elongated grooves 32 of the rotary cap 30 disengage from the projecting tabs 83 of the outer ring 80 (see Fig. 2 and Fig. 6) and at this point the rotating cap 30 can rotate. On the other hand, the rotating cap 30 can only rotate if the rotating cap 30 and the inner cylinder 20 lower themselves sufficiently so that the projecting tabs 83 of the outer ring 80 can engage through the elongated grooves 32 in the rotating cap 30 (see Fig. 7 and Fig. 8), whereby the rotating cap 30 cannot rotate at this point. A top side of the inner cylinder 20 has four positioning slots 26 (see Fig. 5) open, while inside the positioning slot 26 a small spring 261 and a roller element 262 (ball) are housed. An inner upper surface of the rotating cap 30 is provided with four concave recesses 34 and four curved ribs 341 (see Fig. 12), while the rolling element 262 contacts the concave recess 34 on the inner upper surface of the rotary cap 30, thus providing the rotary cap 30 with a four-stage rotational positioning. The four curved ribs 341 define the upper surface of the inner cylinder 20, while the rotary cap 30 is mounted on the inner cylinder 20 and can pivot. A top surface of the piston connecting rod 21 has a screw hole 211, with a perforation 31 arranged relative to the upper surface of the rotary cap 30. A screw 311 is screwed into a washer 312 and the perforation 31, thus also securing the screw hole 211 of the inner cylinder 20. The rotary cap 30 is rotatable against the screw 311, so that the rotary cap 30 can rotate above the inner cylinder 20. Several projecting stop walls 33 are arranged around the circumference of the rotary cap 30 and near its upper surface.The several projecting stop walls 33 are all located at different heights and are formed by separately cutting the circumference of the rotary cap 30 into a small area, which is subdivided into a first projecting stop wall 331, a second projecting stop wall 332, a third projecting stop wall 333 and a fourth projecting stop wall 334 (see . Fig. 1, Fig. 2, Fig. 4, Fig. 5 and Fig. 11), which gradually move away from the top to have a different height. The locking claw 92 of the unlocking mechanism 90 can be engaged with the third projecting stop wall 333 of the rotating cap 30 (see Fig. 13) or be stopped at the first projecting stop wall 331, the second projecting stop wall 332, or the fourth projecting stop wall 334. The multiple projecting stop walls 33 at different heights are adjusted to correspond to the locking claw 92, thereby adjusting the magnitude of the vacuum of the outer cylinder 10. The present invention is based on four projecting stop walls 33 for a four-stage force adjustment (strong, moderate, weak, and minimal); the lower the projecting stop wall 33, the more the spring 40 is compressed, the longer the stroke, and the stronger the suction force; conversely, the higher the projecting stop wall 33, the less the spring 40 is compressed, the shorter the stroke, and the weaker the suction force.This allows the suction power of the ventilator to be adjusted according to the condition of the suffocating person, which is also a feature of the present invention.
[0013] Due to the structures mentioned above, the safety cap 91 is first opened during use (see Fig. 9) and a lower part of the locking claw 92 is pressed, allowing an upper part of the locking claw 92 to unlock the lock on the third projecting stop wall 333. At this point, the rotating cap 30 and the inner cylinder 20 are no longer held back and quickly rise due to the elastic force of the spring 40 to protrude a portion from the outer ring 80 (see Fig. 2 and Fig. 4) Next, the elongated grooves 32 in the rotating cap 30 are disengaged from the projecting tabs 83 (see Fig. 6) Next, the rotating cap 30 is turned to the required angle (see Fig. 11) (also known as selecting a strong, moderate, weak, or minimal force of the spring 40). For example, the angle of the fourth projecting stop wall 334 relative to the locking claw 92 is selected, after which the rotating cap 30 is pressed downwards until the locking claw 92 engages the fourth projecting stop wall 334. The spring 40 is compressed again, after which the suction tube plug 60 and the BVM 100 are assembled. The BVM 100 covers the nose and mouth of the choking person (the choking person should open their mouth, with an interior of the BVM 100 provided with a branch tube that can push the tongue downwards), and after the nose and mouth of the choking person have been sealed by the BVM 100, the locking claw 92 is pressed again, thereby releasing the locking claw 92 from the lock on the fourth projecting stop wall 334.The rotating cap 30 and the inner cylinder 20 are instantly lifted by the elastic force of the spring 40 and protrude a distance from the outer ring 80. Simultaneously, the piston connecting rod 21 rises rapidly, instantly creating a negative pressure force at the bottom of the outer cylinder 10, which forces the foreign body in the throat from the esophagus into the mouth to facilitate ventilation.
[0014] When the rotary cap 30, the inner cylinder 20 and the piston connecting rod 21 are rapidly lifted by the elastic force of the spring 40, and when the check valve flap 50 and the piston connecting rod 21 are lifted (see Fig. 4) The airflow enters the BVM 100 from the throat through the intake tube plug 60. At this point, the large central cutout 61, the large space 511, and the large central through-hole 131 remain open under the influence of the airflow; whereas the airflow in the intake tube plug 60 is concentrated at the bottom of the outer cylinder 10, resulting in a strong negative pressure force that immediately transports the foreign body in the throat from the esophagus into the mouth. Conversely, when the rotating cap 30 is pressed downwards by hand to effect rotation (the reverse airflow compared to normal use), the inner cylinder 20 and the piston connecting rod 21 are lowered (see Fig.10) and the spring 40 is gradually compressed. Under the influence of the airflow, the large downward-projecting ball 51 blocks the large central cutout 61 of the suction tube plug 60, and the airflow enters the small space 521 through the small outer through-holes 132 and then the small outer cutouts 62, after which it is expelled from the bottom of the outer cylinder 10 through the outer through-holes 72. This ensures that the BVM 100 does not cover the nose and mouth of a choking person while awaiting the next ventilation.
[0015] The present invention relates to a multi-stage negative pressure adjustment device for a ventilator, mainly consisting of an outer cylinder 10 containing a spring 40 and a piston connecting rod 21, wherein a BVM 100 is attached to a base of the outer cylinder 10, so that an immediate negative pressure force is generated in a sealed space to suction out foreign bodies obstructing the pharynx and esophagus. The present invention is characterized in that a top of the outer cylinder 10 is provided with a rotating cap 30 so that a user can adjust the suction force according to the condition of a choking person. A safety cap 91 is provided to prevent accidental contact with a release mechanism 90, while a check valve flap 50 is provided to prevent backflow of air and to help prevent reverse airflow.
[0016] The present invention has the following features: 1. The rotary cap 30 is designed for multi-stage selection of the strength of the negative pressure (four levels: strong, moderate, weak and minimal) to select and adjust the suction power according to the condition of the suffocating person, allowing a user to adjust the suction power according to the condition, and it can be used for an elderly person, a child, an obese person, a slim person as well as a small child. 2. A special check valve flap 50 is intended to prevent air backflow and to help prevent reverse airflow, so that the vacuum can be correctly discharged without losing suction power and without obstruction when the rotary cap 30 is pressed downwards. 3. The unlocking mechanism 90 is designed with the safety cap 91, which is a safety device to prevent a user from accidentally touching the locking claw 92 and having to press and turn the rotating cap 30 again, which delays the ventilation time. 4. An outer circumference of the outer cylinder 10 is provided with two rings with identical non-slip surface pattern 12, thereby increasing the frictional force while a user holds the outer cylinder 10 with their hands, enabling the user to practically hold the outer cylinder 10 without slipping. 5. Other people can easily rescue the suffocating person, and the suffocating person can also rescue themselves. 6. A user can hold the outer cylinder 10 with one hand and turn and press the rotary cap 30 with the other hand, which is ergonomically sound, so that the ventilator can be operated easily and without hindrance. 7. The size is small and therefore takes up hardly any space, while the device can be placed in a clearly visible location, which facilitates access. 8. It is a necessity for use in a family.
[0017] It is understood that the embodiments described herein serve only to illustrate the principles of the present invention and that several modifications can be made by those skilled in the field without deviating from the spirit and scope of the invention as described in the attached claims.
Claims
[1] Multi-stage negative pressure adjustment device for a ventilator, mainly comprising an outer cylinder (10), an inner cylinder (20), a rotating cap (30), a spring (40), a suction tube plug (60) and a bottom cap (70), wherein a top of an outer cylinder (10) is assembled with an outer ring (80), the outer ring (80) is provided with a release mechanism (90), a center in an inner cylinder (20) is attached to a piston connecting rod (21), a bottom of the outer cylinder (10) is provided with a bottom wall, the bottom wall (13) having a large central through-hole (131) and several small outer through-holes (132), a bottom of the bottom wall (13), the suction tube plug (60) and the bottom cap (70), the spring (40) and the inner cylinder (20) are housed separately in the outer cylinder (10), the spring (40) between the piston connecting rod (21) and the bottom wall (13) of the outer cylinder (10) is arranged,wherein the suction pipe plug (60) allows the attachment of a BVM (bag valve mask) (100), the rotary cap (30) is encased and pivotably arranged on a top side of the inner cylinder (20), a location near a top side on a circumference of the rotary cap (30) has several projecting stop walls (33), the several projecting stop walls (33) are all at different heights, and a check valve flap (50) is arranged between a bottom side of the bottom wall (13) and the suction pipe plug (60), the release mechanism (90) is provided with a locking claw (92) that abuts one of the projecting stop walls (33) of the rotary cap (30), and the locking claw (92) is released to rotate the rotary cap (30) over the inner cylinder (20), thereby allowing the several projecting stop walls (33) to engage with the inner cylinder (20) at different heights,to adjust the vacuum inside the outer cylinder (10). [2] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein an outer circumference of the inner cylinder (20) is provided with several double projecting ribs (25) and several elongated sliding slots (251), wherein each elongated sliding slot (251) is arranged between two double projecting ribs (25), the rotating cap (30) has several elongated grooves (32) corresponding to the elongated sliding slots (251), an inner wall of the outer ring (80) is provided with several projecting tabs (83), the projecting tabs (83) slide into the elongated grooves (32) and into the elongated sliding slots (251), a top surface of the inner cylinder (20) is provided with several positioning slots (26), and a small spring (261) and a roller element (262) are located inside the positioning slot (26).an inner top surface of the rotating cap (30) has four concave recesses (34) and four curved ribs (341) and the rolling element (262) enters the concave recess (34) to enable multi-stage positioning. [3] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein the multiple projecting stop walls (33) are formed by separately cutting a circumference of the rotating cap (30) into a small area and are divided into a first projecting stop wall (331), a second projecting stop wall (332), a third projecting stop wall (333) and a fourth projecting stop wall (334) which gradually move away from the top to have different heights. [4] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein an upper side of the piston connecting rod (21) has a screw hole (211), a perforation (31) is arranged relative to an upper side of the rotary cap (30), a screw (311) is anchored in a washer (312) and the perforation (31) is attached to the screw hole (211). [5] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein an outer circumference on a bottom side of the piston connecting rod (21) is provided with an upper projecting ring (22), a middle projecting ring (23) and a lower projecting ring (24), a top side of the upper projecting ring (22) is encased with a buffer ring (221), an upper sealing ring (231) is encased between the upper projecting ring (22) and the middle projecting ring (23), wherein a lower sealing ring (241) is inserted between the middle projecting ring (23) and the lower projecting ring (24). [6] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein a release mechanism (90) with two projecting lugs (82) is provided on an outer part of the outer ring (80), a safety cap (91) and a locking claw (92) are pivotably arranged between the two projecting lugs (82), the safety cap (91) is arranged on the outer part of the locking claw (92) and a horizontal spring (921) is positioned on the inner surface of the locking claw (92). [7] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein a center of a check valve flap (50) is provided with a large downward-projecting ball (51), a circumference of this large downward-projecting ball (51) has a large space (511), two small upward-projecting balls (52) are arranged outside the large space (511), a circumference of each small upward-projecting ball (52) has a small space (521), the suction tube plug (60) is provided with a large central cutout (61) and several small outer cutouts (62) accordingly, the bottom cap (70) has a large central through-hole (71) and several small outer through-holes (72), an inner wall at the bottom of the outer cylinder (10) is provided with two positioning ribs (14), and two positioning grooves (53) are arranged accordingly on an outer circumference of a check valve flap (50). are,an outer circumference on the top of the intake manifold plug (60) is provided with two positioning notches (63) and the positioning rib (14) is embedded in the positioning groove (53) and the positioning notch (63). [8] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein a bottom of the outer cylinder (10) is provided with an external thread (15), an inner wall of the bottom cap (70) has an internal thread (11) and the internal thread (11) is attached to the external thread (81). [9] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein a bottom of the outer ring (80) is provided with a matching external thread (81), a top of the outer cylinder (10) has a matching internal thread (11), wherein the matching internal thread is attached to the matching external thread (81). [10] Multi-stage negative pressure adjustment device for a ventilator according to claim 1, wherein a circumference of the outer cylinder (10) is provided with two rings with a non-slip surface pattern (12).