Essentia / Devices / Vitrectomy System

Device Lab 32

Vitrectomy System

A jet of compressed gas through a restriction pulls a vacuum on the collection chamber, and the eye is connected to that chamber through the probe. The surgeon commands a vacuum with the pedal; the flow is then whatever the port, the needle and the fluid in front of it allow. Nothing in the machine measures or controls the flow, and nothing needs to: the pressure difference is the setting and the flow is the consequence.

Also called: Vitrectomy Machine. Arabic: نظام استئصال الزجاجية. Device Lab 32 of 69 in BMEssentia Medical City, 2 configurations.

Overview: the configurations

How it works: the main parts

What each part does, from the Vitrectomy System lessons in the 3D Device Lab.

Console enclosure, chassis, mast and castors

A cabinet about a metre high on four castors, with a screen on a swivel arm above it, a bay in the front face for a cassette, and a tall mast off the back corner carrying a bottle of saline. Two brakes on the front castors and none behind.

Touch fascia, fluidics display and pressure readouts

A wide glass fascia on a swivel arm, split into a fluidics window and a narrower cutter window, with four hard keys under the glass and a mechanical vacuum gauge beside it. The fluidics window carries pressures and flow on one axis.

Dual-linear foot pedal and its side switches

A treadle on a base with a guard hoop over it, a raised heel pad behind, and a switch on each flank. The treadle moves in two directions, down, and side to side, and the two axes do different things.

Compressed-gas supply, regulator and accumulator

Low in the cabinet: a small compressor on rubber mounts, a steel accumulator beside it, a regulator with a relief port on top, a clear water trap and a connector on the back panel for the theatre’s own air pipeline. It is noisy, it is the heaviest thing in the machine, and it is the single source for everything pneumatic, the cutter’s drive, the forced infusion if the machine has one, and the vacuum jet if it has one.

Infusion pressure source and irrigation bottle

A half-litre bottle of balanced salt solution hanging inverted from the mast, and, depending on the configuration, either a pinch clamp and a graduated mast, or a regulated air line into the bottle’s own vent with a transducer beside it. This is the side of the balance that holds the eye up.

Infusion tubing, drip chamber and pinch valve

A spike into the bottle, a clear chamber below it with fluid standing in the bottom, then about two metres of wide-bore tubing down the mast, through a pinch valve on the console, and away across the floor to the eye. A stopcock on the console body.

Valved trocar cannulae and the infusion cannula

Three short metal tubes through the white of the eye, each with a flange lying flat on the surface and a soft valve inside it. One carries the infusion, one the light probe, one the instrument.

Vitrectomy probe, outer needle and guillotine port

A moulded handpiece the size of a thick pen with a steel needle half a millimetre across projecting from it, two thin gas lines and one fluid line leaving the back. The tip of the needle is CLOSED.

Explore it in the Device Lab

• The balance, and the pressure nothing measures: Set the applied infusion pressure, then sweep the aspiration and watch the eye. The relationship is a straight line with a slope, and the slope is the resistance of the infusion path.
• Raising the rate to lower the flow: The one idea, on the bench. Fix everything else and sweep the cut rate, then read the mean flow.
• Occlusion break, on each configuration: Occlude the port, let the vacuum build, then release it, and read what comes out and what happens to the pressure.
• A loop closed on an estimate: Turn the pressure compensation on and off while sweeping the flow, then lie to it about the gauge in use.
• A dose with no display: Sweep the working distance and read the irradiance, then compute how long a given radiant exposure takes at each distance.

Common faults and what to check

Most reported device problems (FDA MAUDE)

Raw counts of adverse event reports for this device type (FDA product code HQE), all years. Not adjusted for the number of units in use, so they show what gets reported, not failure rates. Report text is never copied.

Planned maintenance checks

From the BMEssentia procedure library: every 12 months, about 60 minutes, electrical class I, applied part type BF.

Test instruments: Electrical safety analyser; The manufacturer's test chamber and cassette.

Recent FDA recalls

From the FDA recall database (openFDA), newest first, imported 2026-10-22. 37 recalls on record for this device type. Recall text is the FDA's public text; each recall links to the official record.

Learn it, see it in 3D, ask about it

• Ask Essentia about the Vitrectomy System: answers from named sources, with the device open in its 3D Device Lab beside the answer.
• The Vitrectomy System on the BMEssentia Platform: the Device Library course, 13 sections from physics to maintenance.
• BMEssentia Medical City: Device Lab 32, the Vitrectomy System fully assembled in 3D, with lab tasks and the simulations.

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