EFFECTS OF A MODIFIED VITRECTOMY PROBE IN SMALL-GAUGE VITRECTOMY: An Experimental Study on the Flow and on the Traction Exerted on the Retina.

Purpose: Thorough this experimental study, the physic features of a modified 23-gauge vitrectomy probe were evaluated in vitro.

Methods: A modified vitrectomy probe to increase vitreous outflow rate with a small-diameter probe, that also minimized tractional forces on the retina, was created and tested. The "new" probe was created by drilling an opening into the inner duct of a traditional 23-gauge probe with electrochemical or electrodischarge micromachining.

INTRAOCULAR PRESSURE CHANGES DURING VITRECTOMY USING CONSTELLATION VISION SYSTEM'S INTRAOCULAR PRESSURE CONTROL FEATURE.

Purpose: To evaluate intraocular pressure (IOP) changes during experimental vitrectomy and the efficacy of Constellation Vision System's IOP control (IOPc) feature in reestablishing baseline pressure.

Methods: Using a pressure transducer in freshly enucleated porcine eyes, a broad range of parameters (baseline pressures, aspiration levels, and cut rates) were tested with 23- and 25-gauge probes and IOPc turned ON versus OFF.

Results: IOPc turned ON was significantly more effective than IOPc turned OFF in controlling IOP drop and stabilizing pressure during vitrectomy using a wide range of baseline pressures (20-70 mmHg).

Comparison of reaction response time between hand and foot controlled devices in simulated microsurgical testing.

Purpose: We hypothesized that reaction times (RTs) for a switch release are faster for hand-controlled than for foot-controlled switches for physiological and anatomical reasons (e.g., nerve conduction speed).

Analysis of a 23-gauge ultra high-speed cutter with duty cycle control.

Purpose: The purpose of the study was to determine the performance of dual pneumatic ultra high-speed 23-gauge cutters operated with variable duty cycle (DC) settings.

Methods: Frame-by-frame analysis of high-speed video was used to determine the DC in core, 50-50, and shave modes. Using three cutters at various cycles per minute and aspiration levels, mass of water or vitreous removed from a vial was measured within a specified time period.

Fluidics in a dual pneumatic ultra high-speed vitreous cutter system.

Background: Dual pneumatic systems use two separate air line tubes to open and close the cutter and can achieve high cut rates. The purpose of this study is to evaluate the influence of gauge size, cut rate and aspiration on the flow rate performance of ultra high-speed cutters operated with a commercially available dual pneumatic vitrectomy system.

Methods: Analysis of a high-speed video was used to determine duty cycle.

Performance analysis of millennium vitreous enhancer™ system.

Background And Objective: This study evaluates water and porcine vitreous flow rates and duty cycle using the Millennium Vitrectomy Enhancer (MVE) system (Bausch & Lomb, St. Louis, MO).

Materials And Methods: A precision balance measured mass of water or vitreous removed from a vial within a certain time by 20-, 23-, and 25-gauge MVE cutters at 800, 1,000, 1,500, 2,000, and 2,500 cuts per minute (CPM) with various aspiration levels was studied.

Novel method to quantify traction in a vitrectomy procedure.

Aim: To report a novel method to quantify traction applied to the retina using vitreous cutters during pars plana vitrectomy.

Methods: Fresh porcine eyes were positioned in a specially developed holder and transfixed to the retinal layers with a wire and the other end fixed to the load cell of a strain gauge. Five separate 20-gauge electrical drive mechanism vitrectors were introduced into the eye at a 45 degrees angle and positioned at a distance of either 3 or 5 mm from the retina.

An experimental protocol of the model to quantify traction applied to the retina by vitreous cutters.

Purpose: The purpose of this study was to use a novel method to quantify the traction applied to the retina during vitrectomy.

Methods: Five 20-gauge electric cutters were used. Fresh porcine eyes were positioned in a specially developed holder and transfixed to the retinal layers with a microwire, and the other end was fixed to the load cell of a strain gauge.

Bio-inspired microsystem for robust genetic assay recognition.

A compact integrated system-on-chip (SoC) architecture solution for robust, real-time, and on-site genetic analysis has been proposed. This microsystem solution is noise-tolerable and suitable for analyzing the weak fluorescence patterns from a PCR prepared dual-labeled DNA microchip assay. In the architecture, a preceding VLSI differential logarithm microchip is designed for effectively computing the logarithm of the normalized input fluorescence signals.