Table 1.
Summary of previous studies on insertion force and intraocular pressure (IOP) changes during intravitreal injection.
Fig 1.
The automatic IVI device and experimental setup.
A: A porcine eye, 17-gauge needle for IOP measurement, syringe for maintaining initial IOP, and a pressure transducer, B: an automatic injection device with a motor and ball screw, and 3-axis stage for insertion, and C: a schematic explanation of the system.
Fig 2.
Typical intraocular pressure and insertion force profiles during intravitreal injection.
The needle contacts the eye (a), penetrates the sclera (b), and stops (c). The injection is initiated (d) and ended (e). The needle extraction is initiated (f) and ended (g).
Fig 3.
Pressure elevation and peak force in the insertion stage.
According to A: needle gauge and B, C: insertion speed. Each subgroup contains 30 samples in A, and 10 samples in B and C.
Fig 4.
Relationship between pressure and force.
A: Linear relationship between pressure elevation and insertion force, and B: slope values according to needle size. Each subgroup contains 30 samples.
Fig 5.
Kinetic friction according to needle size and static friction when the needle stopped.
Each subgroup contains 30 samples.
Fig 6.
Pressure elevation and relaxation according to injection rate.
The maximum pressure values were also represented by a Whisker plot. Each subgroup contains 30 samples.
Fig 7.
Pressure elevation after ending intravitreal injection.
Each subgroup contains 30 samples.