Patent RU-2759047-C2 (RU)
Inventor: MCDONELL BRIAN WILLIAM
IPC: A61F9/007
Filed: 2018-05-22
Granted: 2021-11-09
Abstract: FIELD: medical equipment.  
     SUBSTANCE: group of inventions relates to medical equipment, namely to ophthalmic surgical instruments; it can be used for cutting and removing the vitreous body. A vitrectomy probe contains an external cutting tube with a side hole of an external port, an internal cutting tube and a diaphragm. The internal cutting tube is located inside the external cutting tube. The internal cutting tube has an open distal end having a cutting edge. The internal cutting tube additionally contains a distal side port with a cutting edge of the distal side port located on the distal side port so that, when the internal cutting tube is removed into the external cutting tube, tissue entering the side hole of the external port also enters the distal side port of the internal cutting tube to be cut by the cutting edge of the distal side port, when the internal cutting tube is removed in the external cutting tube. The diaphragm is connected to the internal cutting tube. The diaphragm is located inside a drive chamber, and the diaphragm is made with the possibility to move back and forth inside the drive chamber, when air is alternately supplied and released from any side of the diaphragm in the drive chamber. The movement of the diaphragm causes the internal cutting tube to oscillate inside the external cutting tube so that the open distal end of the internal cutting tube moves back and forth through the side hole of the external port to cut tissue entering the side hole of the external port. The diaphragm contains an open stroke side with the first contact surface that contacts an inner wall of the drive chamber, when the internal cutting tube is in a retracted position. The diaphragm contains a closed stroke side with the second contact surface that contacts an opposite wall of the inner drive chamber, when the internal cutting tube is in an extended position; and the first contact surface contains material with lower hardness than that of the second contact surface. In accordance with the second embodiment, the vitrectomy probe contains an external cutting tube with a side hole of an external port and a beveled closed end, and an internal cutting tube contains a flat upper edge, approximately perpendicular to the longitudinal axis of the internal tube, on a part of the internal cutting tube that cuts through the side hole of the external port. According to the third embodiment of the vitrectomy probe, an external cutting tube has a beveled closed end and the distance from a tip of a port edge to the retina (PTRD) that is approximately in the range from 0.004 to 0.009 inches, and the measurement of the distance from the port edge to a distal tip of the probe (PTTD) for the side hole of the external port is approximately in the range from 0.005 to 0.010 inches with a bevel angle of approximately 60 degrees, measured from the beveled closed end to an elongated line of the rear surface of the external cutting tube, which is opposite to the side hole of the external port.  
     EFFECT: inventions provide for the cutting and removal of the vitreous body with great care to avoid tension on the retina, separation of the retina from the vascular membrane of the eye, rupture of the retina or, in the worst case, cutting and removal of the retina itself. 
     20 cl, 19 dwg