PROBE FOR VITRECTOMY WITH REGULATED SIZE OF CUTTING TOOL CHANNEL Russian patent published in 2017 - IPC A61B17/32 A61F9/07 A61B17/00 

FIELD: medicine.

SUBSTANCE: probe for the vitrectomy comprises: a housing, a cutting tool extending longitudinally from the first end of the housing. The cutting tool comprises an external cutting member coupled to the housing; an internal cutting member; a regulated channel; an oscillator adapted to reciprocatingly move the internal cutting member; a stroke limiter adapted to limit the size of the regulated channel; and a biasing member disposed between the part of the stroke limiter and the part of the housing. The internal cutting member is adapted to slide within the external cutting member. The internal cutting member can slide between the retracted position and the extended position. The size of the regulated channel is defined by the edge of the opening formed in the external cutting member and the end surface of the internal cutting member, when the internal cutting member is in the fully retracted position. The stroke limiter is moved along the longitudinal probe axis for the vitrectomy in response to the fluid medium pressure. According to the second probe embodiment for the vitrectomy, the cutting tool comprises: a hollow external cutting member coupled to the housing, wherein the external cutting member comprises an open end and a closed end; a hollow internal cutting member adapted to slide in the external cutting member, the internal cutting member comprises opposing open ends and the first cutting surface on its first end; an opening formed in the external cutting member proximally to its end; the first and the second pneumatic chambers formed in the housing; the first and the second membranes; a stroke limiter coupled to the second membrane and moving with it; a biasing member disposed in the third chamber part; the third through opening. The opening formed in the external cutting member, has the second cutting surface combined with the first cutting member for dissecting materials included in the opening. The opening and the first cutting surface determine a channel, the size of which is determined by the location of the first cutting surface against the opening, when the internal cutting member is in the fully retracted position. The first membrane is coupled to the internal cutting member and divides the first pneumatic chamber into the first and the second parts of the chamber. The first part of the chamber is in fluid communication with the first through opening, and the second part of the chamber is in fluid communication with the second through opening. The first and the second through openings are adapted to transmit the first pneumatic pressure of the first chamber part and the second chamber part, respectively, in an alternating sequence to cause oscillations of the first membrane and the internal cutting member between the fully retracted position and the fully extended position. The second membrane divides the second pneumatic chamber into the third chamber part and the fourth chamber part. The third through opening is communicated with the fourth chamber part and is adapted to transmit the second pneumatic pressure of the fourth chamber part to bias the second membrane to the extent proportional to the second pneumatic pressure. The method for limiting the size of the cutting tool channel of the probe for the vitrectomy, contains oscillating the internal cutting member between the fully extended position and the fully retracted position against the external cutting member; changing the position of the stroke limiter against the internal cutting member; and contacting the part of the internal cutting member with the part of the stroke limiter to define the fully retracted position of the internal cutting member. The position of the internal cutting member in the fully retracted position against the external cutting member, defines the size of the cutting tool channel.

EFFECT: invention can control the size of the probe channel in order to maximize the efficiency of the cutting process and tissue turnover.

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