An ophthalmic vitreous cutting bit

Abstract

The application provides an ophthalmic vitreous cutting head with a composite outer tube structure, which comprises a cutter sleeve, a cutter core and a composite outer tube. The composite outer tube is arranged on the outer side of the cutter sleeve, and an auxiliary gas channel is arranged in the composite outer tube and connected with an auxiliary gas chamber a. The other end of the auxiliary gas channel is arranged on the upper side of a cutter edge. The cutter core is sleeved in the cutter sleeve, and the inner end of the cutter core is fixedly connected with a reversing valve. A connecting channel is arranged in the cutting head, and the cutter edge is connected with a drainage channel through the connecting channel. Compared with the original glass cutter, the glass cutter provided by the application pushes the sealed gas to the position of the cutter edge through the auxiliary gas channel during the reciprocating movement, provides a bidirectional action for the cutting of the diseased tissue, and provides a new positive pressure supplement through the original negative pressure action of the drainage channel and the gas discharged by the auxiliary gas channel, so that the diseased tissue is tightly attached to the cutter edge, and the diseased tissue is prevented from being separated during the cutting process.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and in particular to a novel vitrectomy head for ophthalmic vitrectomy. Background Art

[0002] The vitreous is a colorless, transparent, semisolid, gel-like substance that fills the space between the retina and the lens, providing refraction and retinal fixation. As a refractive medium, the vitreous also fills the interior of the eye, maintaining its shape. Bleeding, inflammation, trauma, and degenerative diseases such as tumors can easily cause vitreous lesions, which are typically categorized as vitreous opacity, vitreous hemorrhage, and vitreous proliferation. Vitreous lesions generally require surgical treatment, such as vitrectomy.

[0003] Vitrectomy refers to the surgical removal of cloudy or diseased vitreous to restore light permeability, or to remove the vitreous to reduce or alleviate the vitreous's pull on the retina, thereby treating retinal diseases and restoring the patient's visual function. Vitrectomy is widely used in clinical practice, and the surgical scope almost covers the entire eyeball. The vitreous head used in existing vitreous cutters is generally reciprocating, and the diseased vitreous is cut through the relative movement of the inner and outer tubes and then sucked away for treatment. However, this is often inefficient. At the same time, it is difficult to suck some lens nuclei that are adhered to tissues such as organized membranes and blood clots into the lumen of the vitreous head, resulting in incomplete treatment and poor recovery. There are also double-tube and high-frequency vitreous heads, but their clinical usage rate is low due to their complex design, large size, inability to perform micro-cutting, and the high-frequency vibration that easily causes contusion to the vitreous.

[0004] The invention patent with patent publication number CN110996864A provides a vitrectomy probe, which moves back and forth in the drive chamber by alternately supplying and exhausting air on either side of the diaphragm in the drive chamber, causing the cutting inner tube to oscillate in the cutting outer tube, so that the open distal end of the cutting inner tube moves back and forth across the outer port side opening to cut tissue entering the outer port side opening.

[0005] Among them, a cavity where gas gathers is formed on the lower side of the driving chamber. This part of the gas needs to be continuously compressed or stretched during the reciprocating motion, resulting in poor overall efficiency of the reciprocating motion and requiring more energy consumption; at the same time, the vitreous body is filled with liquid tissue. When cutting is performed by negative pressure suction, the suction intensity of the negative pressure is strictly limited. Excessive negative pressure can easily cause tissue to be sucked too quickly, affecting the imbalance of pressure in the vitreous body and causing more serious consequences. Weaker negative pressure has a smaller suction force on the diseased tissue. The diseased tissue in the vitreous body is mostly flexible tissue. The cutting effect of relying solely on the suction provided by the negative pressure and the biting of the inner and outer tubes of the vitrectomy is not ideal. It is not easy to cut off the flexible diseased tissue, resulting in unsatisfactory surgical results and low surgical efficiency. Summary of the Invention

[0006] The reciprocating motion requires compression and stretching of the gas in the lower cavity of the driving chamber, resulting in poor overall efficiency and high energy consumption of the reciprocating motion, as well as unsatisfactory cutting effects due to the suction provided by negative pressure alone and the interlocking of the inner and outer tubes of the glass cutter.

[0007] The present invention provides a vitrectomy head for ophthalmic vitreous cutting, the cutting head having a composite outer tube structure, comprising a handle and a cutting head, wherein the cutting head is sleeved on the handle, wherein a sleeve for mounting the cutting head is fixed at the front end of the handle.

[0008] A sealed cavity is provided inside the handle, in which a group of parallel sealing rings are installed. The sealed cavity is divided into three sections by the sealing rings. The front section close to the cutting head is the auxiliary air chamber a, the middle section is the piston cavity b, and the rear section close to the tail of the handle is the negative pressure connecting cavity c. The size of the piston cavity b is larger than that of the auxiliary air chamber a and the negative pressure connecting cavity c.

[0009] A reversing valve is installed in the sealed chamber, and the reversing valve is installed in the piston chamber b. At the same time, the reversing valve has extension sections to the auxiliary air chamber a and the negative pressure connecting chamber c at both ends. The reversing valve and its extension section match the sealed chamber. The extension section of the reversing valve and the sealing ring form a sealing structure to isolate the gas flow between the auxiliary air chamber a, the piston chamber b and the negative pressure connecting chamber c.

[0010] The handle is also provided with a knife return air path and a knife feed air path. The knife return air path is connected to the lower side of the piston chamber b, and the knife feed air path is connected to the upper side of the piston chamber b.

[0011] A drainage channel is provided in the middle of the reversing valve, one end of the drainage channel is connected to the cutting head, and the other end is connected to the negative pressure connection chamber c.

[0012] The handle also includes a negative pressure interface, which is connected to the negative pressure connection cavity c.

[0013] The cutting head includes a knife sleeve, a knife core and a composite outer tube, wherein a knife edge is provided at the front end of the knife sleeve, a composite outer tube is provided on the outside of the knife sleeve, an auxiliary air channel is provided in the composite outer tube to connect to the auxiliary air chamber a, and the other end of the auxiliary air channel is provided on the upper side of the knife edge. The knife core sleeve is installed in the knife sleeve, and the inner end of the knife core is connected and fixed to the reversing valve. A connecting channel is provided in the cutting head, and the knife edge is connected to the excretion channel through the connecting channel.

[0014] The present invention further provides a vitreous cutting head for vitreous body cutting, wherein the air outlet of the auxiliary air channel is located above the blade provided on the blade sleeve, and the air outlet of the auxiliary air channel is tilted downward toward the blade.

[0015] The present invention further provides a vitreous cutting head for vitreous cutting, wherein a group of tracheal interfaces are provided at the rear end of the handle, which are respectively connected to the return air path and the feed air path. The air source is connected through the tracheal interfaces to provide an alternating positive pressure air source for the return air path and the feed air path.

[0016] The present invention further provides a vitreous cutting head for vitreous cutting, wherein the blade core is an annular blade cylinder, and an oblique cutting surface is provided on the inner side of the blade head of the annular blade cylinder.

[0017] The present invention further provides a vitreous cutting head for vitreous cutting, wherein the downward extension section of the reversing valve is provided with a sleeve, and the blade core is fixed on the reversing valve through the sleeve.

[0018] The present invention further provides a vitrectomy head for vitreous body cutting, wherein the blade sleeve has an outer port side opening and a beveled closed end.

[0019] The present invention further provides a vitrectomy head for vitreous cutting, wherein the length of the cutting head is at least cm.

[0020] The present invention further provides a vitreous cutting head for vitreous cutting, wherein the sealed cavity is T-shaped, the reversing valve matches the sealed cavity, one side of the reversing valve extends to the auxiliary air chamber a and the negative pressure connecting cavity c at both ends of the sealed cavity, an excretion channel is arranged inside the extended part of the reversing valve, the return air path and the feed air path are arranged on the same side of the excretion channel, and the return air path and the feed air path are located at the air outlets on both sides of the piston cavity b corresponding to each other.

[0021] The present invention further provides a vitreous cutting head for vitreous body cutting, wherein the outer ends of the return air path and the feed air path are connected to an alternating positive pressure air source through an air pipe joint with a parallel interface.

[0022] The present invention further provides a vitreous cutting head for vitreous cutting, wherein the composite outer tube of the cutting head is sleeved in the sleeve, and the contact surfaces of the composite outer tube and the sleeve are provided with an anti-slip coating.

[0023] Beneficial effects of the present invention

[0024] Through the above technical solution, the present invention provides a cutting edge on the cutting head of the device, which is in communication with the inner cavity of the tissue being cut. The cutting head can move forward and backward, or rotate under the power supply or human operation of the device, accurately controlling the cutting position to perform miniaturized cutting of the vitreous body. When the external negative pressure device is working, a negative pressure environment is formed in the inner cavity of the cutting tissue. The vitreous body and the lens nucleus adhered to the organized membrane or blood clot are shredded and, under the action of surface tension and negative pressure suction, are sucked into the cutting edge and then into the storage compartment of the device. The device has high cutting efficiency and can perform miniaturized and precise operations, greatly increasing the suction effect of the diseased tissue, improving the success rate of clinical surgery and having good prognosis.

[0025] Compared with the original vitrectomy knife, the vitrectomy knife provided by the present invention discharges and absorbs the accumulated gas through the auxiliary gas channel at the lower end of the reciprocating mechanism during the reciprocating motion, avoiding the need to overcome the reverse force of the enclosed gas on the reciprocating mechanism when the reciprocating mechanism moves in a sealed state, thereby improving the operating efficiency of the vitrectomy knife and reducing energy consumption; at the same time, the auxiliary gas channel is used to push the sealed gas to the position of the blade, providing a two-way effect for the cutting of the diseased tissue, the excretion channel is acted upon by the original negative pressure, and the gas discharged from the auxiliary gas channel provides a new positive pressure supplement, providing positive pressure to the diseased tissue, so that the diseased tissue is close to the blade, preventing the diseased tissue from detaching during the resection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the appearance structure of the present invention.

[0027] Figure 2 It is a schematic cross-sectional structural diagram of the handle of the present invention.

[0028] Figure 3 It is a schematic diagram of the overall cross-sectional structure of the present invention.

[0029] Figure 4 It is a partial cross-sectional view of the connection portion between the cutting head and the handle of the present invention.

[0030] Figure 5 It is a schematic cross-sectional structural diagram of the cutting head of the present invention.

[0031] Figure 6 It is a cross-sectional view of another embodiment of the cutting head end portion of the present invention.

[0032] Figure 7 It is a schematic diagram of the appearance structure of the reversing valve of the present invention.

[0033] Figure 8 It is a cross-sectional view of a handle according to another embodiment of the present invention.

[0034] Figure 9 It is a structural diagram of installing a balancing buffer mechanism.

[0035] Figure 10 It is a schematic diagram of the cross-sectional structure of the balance buffer mechanism.

[0036] Figure 11 It is a cross-sectional structural schematic diagram of another embodiment.

[0037] Numbers in the figure: handle 1, cutting head 2, sealing chamber 101, auxiliary air chamber a, piston chamber b, negative pressure connecting chamber c, sleeve 102, sealing ring 103, return air path 104, feed air path 105, negative pressure interface 106, reversing valve 107, discharge channel 108, knife sleeve 201, knife core 202, composite outer tube 203, auxiliary air channel 204, ball 301, spiral groove 302, balance buffer mechanism 401, connecting sleeve 402, movable kit 403, elastic part 404. DETAILED DESCRIPTION

[0038] Example 1: Vitrectomy refers to the surgical removal of cloudy or diseased vitreous to restore light permeability, or to remove the vitreous to reduce or alleviate the vitreous's pull on the retina, thereby treating retinal diseases and restoring the patient's visual function. Vitrectomy is widely used in clinical practice, and the surgical scope almost covers the entire eyeball. The vitreous head used in existing vitreous cutters is generally reciprocating, and the diseased vitreous is cut and then aspirated for treatment through the relative movement of the inner and outer tubes. However, this is often inefficient. At the same time, it is difficult to aspirate some lens nuclei that are adhered to tissues such as organized membranes and blood clots into the lumen of the vitreous head, resulting in incomplete treatment and poor recovery. There are also double-tube and high-frequency vitreous heads, but their clinical usage is low due to their complex design, large size, inability to perform micro-cutting, and the high-frequency vibration that can easily cause contusion to the vitreous.

[0039] Moreover, existing reciprocating vitrectomy heads usually use positive air pressure to push the piston to reciprocate. Since the vitrectomy head generally adopts a closed structure, a part of gas accumulation or cavity will be formed at the lower end of the piston. During the reciprocating motion of the piston, it is necessary to continuously compress or stretch this part of the gas or cavity, resulting in poor overall efficiency of the reciprocating motion and requiring more energy consumption. If an open structure is adopted, the continuous reciprocating motion of the piston causes the gas at the lower end of the piston to be continuously blown and sucked to generate a reciprocating airflow, which is similar to the operation of the surgical procedure.

[0040] The vitreous body is filled with liquid tissue. When cutting by negative pressure suction, the suction strength of the negative pressure is strictly limited. Excessive negative pressure can easily cause tissue to be sucked too quickly, affecting the imbalance of pressure in the vitreous body and causing more serious consequences. Weaker negative pressure has a smaller suction force on the diseased tissue. The diseased tissue in the vitreous body is mostly flexible tissue. The cutting effect of relying solely on the suction provided by the negative pressure and the biting of the inner and outer tubes of the vitrectomy knife is not ideal. It is not easy to cut off the flexible diseased tissue, resulting in unsatisfactory surgical results and low surgical efficiency.

[0041] In view of the above problems, the present invention provides a vitreous cutting head for ophthalmic vitrectomy with a composite outer tube structure, such as Figure 1 As shown, the vitrectomy head includes a handle 1 as the main body of the vitrectomy head and a cutting head 2 as a tissue cutting head. The cutting head 2 is arranged at the front end of the handle 1 as the main body. The cutting head 2 and the inside of the handle 1 of the main body are provided with a channel connected to each other for sucking and collecting the cut diseased tissue.

[0042] like Figure 2 and Figure 3 As shown, the handle 1 includes a sleeve 102 and a reversing valve 107, wherein the sleeve 102 is installed at the front end of the handle, and the cutting head 2 is installed on the handle through the sleeve 102. At the same time, a sealed cavity 101 is provided inside the handle 1 for installing the reversing valve 107, and the reversing valve 107 is matched and fitted in the sealed cavity 101.

[0043] A group of parallel annular grooves are provided in the sealing chamber 101, through which an annular sealing ring 103 is installed. At the same time, the sealing chamber 101 is divided into three sections with the sealing ring 103 as the boundary. The front section close to the cutting head 2 is the auxiliary air chamber a, the middle section is the piston chamber b, and the rear section close to the tail of the handle is the negative pressure connecting chamber c. The size of the piston chamber b is larger than that of the auxiliary air chamber a and the negative pressure connecting chamber c.

[0044] The reversing valve 107 is mounted in the piston chamber b and moves up and down along the piston chamber b. The handle 1 is also provided with a return air path 104 and a feed air path 105 which are respectively connected to the piston chamber b, wherein the return air path 104 is connected to the lower side of the piston chamber b, and the feed air path 105 is connected to the upper side of the piston chamber b. By alternately introducing positive air pressure into the return air path 104 and the feed air path 105, the reversing valve 107 is pushed to reciprocate along the piston chamber b.

[0045] The switching valve 107 extends symmetrically to the auxiliary air chamber a and the negative pressure connecting chamber c on both sides of the piston chamber b, and forms an extension section matched with the auxiliary air chamber a and the negative pressure connecting chamber c, respectively. The extension section is in abutment with the sealing ring 103 installed in parallel in the sealing chamber to form a sealing structure, so as to isolate the auxiliary air chamber a, the piston chamber b and the negative pressure connecting chamber c into three separate chambers with different air flows. The matching extension sections provide a limit for the switching valve 107, and ensure that the switching valve performs linear reciprocating motion.

[0046] The tail end of the handle 1 is provided with a negative pressure connector 106 which is communicated with the negative pressure connecting chamber c. The negative pressure equipment is connected through the negative pressure connector 106 to provide negative pressure for the cutting head, so that the cutting head 2 can suck the lesion tissue for cutting.

[0047] The switching valve 107 is provided with a drainage passage 108 penetrating through the middle. One end of the drainage passage 108 is communicated with the cutting head 2 installed at the front end of the handle, and the other end is communicated with the negative pressure connecting chamber c. The negative pressure is transmitted to the cutting head 2 through the drainage passage 108, and the cut lesion tissue is sucked through the drainage passage and discharged into the storage bin of the equipment through the negative pressure.

[0048] As shown in Figure 4 and Figure 5 , the cutting head 2 comprises a cutter sleeve 201, a cutter core 202 and a composite outer tube 203. The front end of the cutter sleeve 201 is provided with a cutter opening. The cutter core 202 is installed in the cutter sleeve 201 of the cutting head. The cutter core 202 moves axially relative to the cutter sleeve 201. The inner end of the cutter core 202 is fixed on the switching valve 107. The cutter core 202 moves reciprocatingly with the switching valve 107. The cutting edge of the cutter core 202 is in close contact with the cutter opening of the cutter sleeve. During the reciprocating movement, the cutting edge quickly passes through the cutter opening to perform shearing. The cutter core 202 is in tubular structure. The tubular inner cavity of the cutter core 202 is communicated with the drainage passage 108. The outer side of the cutter sleeve 201 is provided with the composite outer tube 203. The composite outer tube 203 is provided with an auxiliary air passage 204 communicated with the auxiliary air chamber a. The other end of the auxiliary air passage 204 is arranged on the upper side of the cutter opening.

[0049] The drainage passage is connected with a negative pressure passage. The switching valve and the cutter core structure are fixed. When the drainage passage is connected with the negative pressure, the back cutting air passage 104 and the forward cutting air passage 105 are connected with the alternating positive pressure air source. At this time, the cutter core and the cutter sleeve form a shearing action. The cutter opening is close to the tissue to be removed. The tissue is sucked into the cutter opening at the instant of the cutter core back-off. The tissue is cut and removed when the cutter core advances. The removed tissue is sucked into the tubular inner cavity of the cutter core, and then is sucked into the drainage passage by the negative pressure, and then is discharged into the storage bin of the equipment.

[0050] During the cutting process, the reversing valve 107 extends into the extension section of the auxiliary air chamber a and simultaneously pushes and sucks the gas in the auxiliary air chamber a. When the reversing valve pushes the knife core forward for cutting, the extension section pushes the gas in the auxiliary air chamber a to be discharged through the auxiliary air channel 204. The discharged gas generates pressure to press the diseased tissue against the side wall of the blade, making it easier to cut the diseased tissue during the forward movement of the knife core; when the reversing valve pushes the knife core backward to absorb the diseased tissue, the extension section simultaneously suctions in the auxiliary air chamber a to suck the discharged gas back.

[0051] Compared with the existing vitrectomy knife, the vitrectomy knife provided by the present invention discharges and absorbs the accumulated gas through the auxiliary gas channel 204 at the lower end of the reciprocating mechanism during the reciprocating motion, avoiding the need to overcome the reverse force of the enclosed gas on the reciprocating mechanism when the reciprocating mechanism moves in a sealed state, thereby improving the operating efficiency of the vitrectomy knife and reducing energy consumption; at the same time, the auxiliary gas channel 204 is used to push the sealed gas to the position of the blade, providing a two-way effect for the cutting of the diseased tissue, the excretion channel 108 is acted upon by the original negative pressure, and the gas discharged from the auxiliary gas channel 204 provides a new positive pressure supplement, providing positive pressure to the diseased tissue, so that the diseased tissue is close to the blade, and the diseased tissue is prevented from detaching during the resection process.

[0052] Example 2: Figure 11 As shown, the sealed chamber 101 is T-shaped, and the reversing valve 107 is matched with the sealed chamber 101. One side of the reversing valve 107 extends to the auxiliary air chamber a and the negative pressure connecting chamber c at both ends of the sealed chamber 101. A discharge channel 108 is arranged inside the extended part of the reversing valve 107, and the return knife air path 104 and the feed knife air path 105 are arranged on the same side of the discharge channel 108, and the return knife air path 104 and the feed knife air path 105 are located at the air outlets on both sides of the piston chamber b. At the same time, the outer ends of the return knife air path 104 and the feed knife air path 105 are connected to the alternating positive pressure air source through an air pipe joint with a parallel interface.

[0053] The return air path 104 and the feed air path 105 are located at the air outlets on both sides of the piston chamber b corresponding to each other. In the process of the alternating positive pressure air source alternately pushing the reversing valve, the driving force exerted on the reversing valve forms a symmetrical structure, thereby avoiding the situation where the reversing valve is unidirectionally tilted by the alternating thrust, reducing the wear between the reversing valve and the sealing chamber, and improving the durability of the device.

[0054] Example 3: When a circular cutter head is used for cutting, pressure is fully utilized to cut. The blade of the circular cutter head may contact the front wall of the tube, which may cause damage to the blade after long-term use, affecting the sharpness. It is often only a disposable tool and cannot be reused, resulting in high costs.

[0055] like Figure 6-8As shown, the circular cutter head of the cutter core 202 is provided with spiral teeth along the circumference, the outer wall of the sealing chamber 101 has a small span spiral groove 302, and a ball groove is provided at the corresponding position on the reversing valve 107, and a ball 301 is matched in the ball groove, and the ball 301 is matched and located in the spiral groove 302.

[0056] When the reversing valve 107 is pushed to perform reciprocating motion by the positive airflow alternately provided by the return air path 104 and the feed air path 105, the ball 301 slides along the spiral groove 302. Since the spiral groove 302 has a small span, the ball 301 will drive the reversing valve 107 to rotate back and forth during the sliding process, thereby driving the knife core 202 fixedly connected to the reversing valve 107 to rotate back and forth. At this time, the linear reciprocating motion provides pressure cutting, and the reciprocating rotation drives the spiral tooth blade to perform transverse shear cutting. The dual-action cutting improves the reliability of cutting diseased tissue. At the same time, the rotating transverse cutting avoids damage to the blade of the knife core under long-term pressure cutting, so that the blade can maintain sharpness for a longer time, improve reusability and reduce costs.

[0057] Example 4: The return air path 104 and the feed air path 105 pass through the positive air pressure alternately. When the reversing valve 107 moves back and forth with the alternating positive air pressure, it will impact the front and rear walls of the piston chamber b. This impact will cause slight vibration of the handle, which is not conducive to surgical operation.

[0058] In order to prevent the reversing valve 107 from impacting the front and rear walls of the piston chamber b and reduce the vibration of the handle, as shown in FIG. Figure 9-10 As shown, a balancing buffer mechanism 401 is connected between the air pipes that provide positive air pressure for the return air path 104 and the feed air path 105. The balancing buffer mechanism includes a connecting sleeve 402, a movable kit 403 and an elastic member 404, wherein the connecting sleeve 402 includes parallel connecting tubes, and the connecting tubes are connected by a piston tube. The movable kit 403 is matched in the piston tube, and the elastic members 404 are symmetrically installed on both sides of the movable kit 403. Limit stops are set at both ends of the piston tube, and the elastic member 404 is installed between the movable kit 403 and the limit stop.

[0059] The connecting pipes on both sides of the connecting sleeve 402 are respectively installed on the air pipes that provide positive air pressure to the return air path 104 and the feed air path 105. When the air source provides positive air pressure to one side of the return air path 104 and the feed air path 105, the excessive air pressure will enter the piston tube when passing through the balancing buffer mechanism 401, and push the movable kit 403 to compress the spring on the opposite side, thereby reducing the pressure of the passing air flow; when the air is supplied alternately, the balancing buffer mechanism 401 moves in the opposite direction, thereby achieving a buffering effect of pressure reduction balance, thereby avoiding the alternating air pressure directly impacting the reversing valve and causing the handle to vibrate.

[0060] It should be understood that the above-described specific embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and are not intended to limit the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A vitreous cutting head for ophthalmic vitreous cutting, comprising a handle (1) and a cutting head (2), wherein the cutting head (2) is mounted on the handle (1), wherein a sleeve (102) for mounting the cutting head (2) is fixed to the front end of the handle (1); characterized in that: A sealing chamber (101) is provided inside the handle (1), and a set of parallel sealing rings (103) are installed in the sealing chamber (101). The sealing chamber (101) is divided into three sections with the sealing ring (103) as the boundary, wherein the front section close to the cutting head is the auxiliary air chamber a, the middle section is the piston chamber b, and the rear section close to the tail of the handle is the negative pressure connection chamber c. The size of the piston chamber b is larger than the size of the auxiliary air chamber a and the negative pressure connection chamber c. A reversing valve (107) is installed in the sealing chamber (101), and the reversing valve (107) is installed in the piston chamber b. At the same time, the reversing valve (107) ) has an extension section to the auxiliary air chamber a and the negative pressure connecting chamber c at both ends, the reversing valve (107) and its extension section match the sealing chamber (101), and the extension section of the reversing valve (107) and the sealing ring (103) form a sealing structure to isolate the gas flow of the auxiliary air chamber a, the piston chamber b and the negative pressure connecting chamber c; the handle (1) is also provided with a return knife air path (104) and a feed knife air path (105), the return knife air path (104) is connected to the lower side of the piston chamber b, and the feed knife air path (105) is connected to the upper side of the piston chamber b; a discharge passage is provided in the middle of the reversing valve (107) The excretion channel (108) is connected to the cutting head (2) at one end and to the negative pressure connection chamber c at the other end; the handle (1) further comprises a negative pressure interface (106), the negative pressure interface (106) being connected to the negative pressure connection chamber c; the cutting head (2) comprises a knife sheath (201), a knife core (202) and a composite outer tube (203), wherein a knife edge is provided at the front end of the knife sheath (201), a composite outer tube (203) is provided on the outside of the knife sheath (201), an auxiliary gas channel (204) is provided in the composite outer tube (203) and is connected to the auxiliary gas chamber a, and the auxiliary gas The other end of the channel (204) is arranged on the upper side of the blade, the blade core (202) is sleeved in the blade sleeve (201), the inner end of the blade core (202) is connected and fixed on the reversing valve (107), a connecting channel is arranged in the cutting head (2), the blade is connected to the discharge channel (108) through the connecting channel, the air outlet of the auxiliary air channel (204) is located on the upper side of the blade arranged on the blade sleeve (201), the air outlet of the auxiliary air channel (204) is tilted downward toward the blade, the blade core (202) is an annular blade cylinder, and an oblique cutting surface is arranged on the inner side of the blade head of the annular blade cylinder.

2. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The rear end of the handle (1) is provided with a set of tracheal interfaces, which are respectively connected to the return knife air path (104) and the feed knife air path (105), and the air source is connected through the tracheal interfaces to provide an alternating positive pressure air source for the return knife air path (104) and the feed knife air path (105).

3. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The downward extension section of the reversing valve (107) is provided with a sleeve, and the blade core (202) is fixed on the reversing valve (107) through the sleeve.

4. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The knife sleeve (201) has an outer port side opening and a beveled closed end.

5. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The length of the cutting head (2) is at least 8 cm.

6. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The sealing chamber (101) is T-shaped, and the reversing valve (107) matches the sealing chamber (101). One side of the reversing valve (107) extends toward the auxiliary air chamber a and the negative pressure connecting chamber c at both ends of the sealing chamber (101). An exhaust channel (108) is provided inside the extended portion of the reversing valve (107). The return air path (104) and the feed air path (105) are provided on the same side of the exhaust channel (108), and the return air path (104) and the feed air path (105) are located at the air outlets on both sides of the piston chamber b, corresponding to each other.

7. A vitrectomy head for ophthalmic vitrectomy according to claim 6, characterized in that: The outer ends of the return knife air path (104) and the feed knife air path (105) are connected to an alternating positive pressure air source via an air pipe joint with a parallel interface.

8. The vitrectomy head for ophthalmic vitrectomy according to claim 1, characterized in that: The composite outer tube (203) of the cutting head (2) is sleeved in the sleeve (102), and a non-slip coating is provided on the contact surfaces of the composite outer tube (203) and the sleeve (102).

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