Control device (102) for an ophthalmic surgical
system (100), in which an ophthalmic surgical cassette (4) can be inserted into a cassette receptacle (101) of a console (1) of the ophthalmic surgical
system (100), wherein the cassette (4) has at least one fluid pump (10, 20, 30, 40) for conveying a treatment fluid (3) through the cassette (4), for which purpose the at least one fluid pump (10, 20, 30, 40) has a
pump chamber (11, 21, 31, 41) for the treatment fluid (3) and a drive chamber (13, 23, 33, 43) for a drive fluid, wherein the
pump chamber (11, 21, 31, 41) and the drive chamber (13, 23, 33, 43) are separated by an elastic separating element (12, 22, 32, 42) are fluidically separated from each other, which is designed to be moved between two end positions of the separating element (12, 22, 32, 42) for a pumping
stroke of the fluid pump (10, 20, 30, 40), wherein the drive chamber (13, 23, 33,43) with the
insertion of the cassette (4) into the cassette receptacle can be fluidically coupled to a drive fluid source (17, 27, 37, 47) of the console (1), wherein the drive fluid source (17, 27, 37, 47) is designed to provide the drive fluid depending on a drive
pressure control signal of the control device (102) with a predeterminable drive pressure, which can be detected by means of a drive
pressure sensor (18, 28, 38, 48) of the console (1), wherein with the
insertion of the cassette (4) into the cassette receptacle (101), a first surface of a detection membrane (50) of the cassette (4) can be mechanically contacted by a
force sensor (51) of the console (1), wherein a second surface of the detection membrane (50) contacts the treatment fluid (3) contained in the cassette (4), wherein the control device (102) is designed to receive signals from at least the drive
pressure sensor (18, 28, 38, 48), the
force sensor (51) and a displacement sensor (19, 29, 39,49) of the console (1) for detecting a position of the separating element (12, 22, 32, 42) in the fluid pump (10, 20, 30, 40) and to provide the drive
pressure control signal at least partially depending on the received signals, characterized in that the control device (102) is designed to provide a first drive
pressure control signal for calibrating the
force sensor (51) when the cassette (4) is inserted into the cassette holder (101) depending on the detection of one of the two end positions of the separating element (12, 22, 32, 42), so that the drive fluid source (17, 27, 37, 47) provides the drive fluid with a constant first drive pressure so that the separating element (12, 22, 32, 42) is moved from a first of the end positions to a second of the end positions, a temporal profile of a sensor signal, preferably at least one force signal of the force sensor (51) or one displacement signal of the displacement sensor (19, 29, 39, 49),to detect and evaluate during movement from the first of the end positions to the second of the end positions in order to determine a reference position of the separating element (12, 22, 32, 42) in the fluid pump (10, 20, 30, 40) in which the drive pressure corresponds to the
fluid pressure of the treatment fluid, to determine a displacement signal of the displacement sensor (19, 29, 39, 49) corresponding to the reference position as a reference displacement signal, to detect a first force signal of the force sensor (51) in the reference position, and to calibrate the force sensor (51) depending on the first force signal and the first drive pressure.