---
title: User Defined Parameters
description: "The table below sets out the respiratory parameters that can be set by the user on either the Main Screen or System Set-up Screen respectively. **Main Screen** | Parameter | Description | Default Value | Units | Range | Increments…"
url: "https://lycovent.org/features/user-defined-parameters/"
updated: "2025-07-10"
category: Specifications
---

# User Defined Parameters

The table below sets out the respiratory parameters that can be set by the user on either the Main Screen or System Set-up Screen respectively.

 **Main Screen**

| Parameter | Description | Default Value | Units | Range | Increments |
| --- | --- | --- | --- | --- | --- |
| FIO~2 | Desired FIO~2 used for calculation of required O~2 supply | 50 | % | 21 – 100 | 1 |
| MODE | Operating mode | VCV |  | VCV, ACV, *SX* |  |
| TV | Tidal volume | 500 | mL | 200 – 800 | 10 |
| RR | Respiratory rate | 12 | bpm | 8 – 30 | 1 |
| IE | Inspiration to expiration ratio | 1:2 | Ratio | 5 – 50 | 0.5 |
| PEEP | PEEP set on manual valve | 10 | cmH~2O | -1 – 30 | 1 |
| CV(ACV) | Controlled volume while in ACV mode | 300 | mL | 200 – 800 | 10 |
| AV (ACV) | Assist volume while in ACV mode | 500 | mL | 200 – 800 | 5 |
| TIN (ACV) | Inspiration time while in ACV mode | 1 | s | 0.5 – 2.0 | 0.1 |

 **System Set-Up Screen**

| Parameter | Description | Default Value | Units | Range | Increments |
| --- | --- | --- | --- | --- | --- |
| PMAX | Maximum allowable pressure | 50 | cmH~2O | 0 – 50 | 1 |
| Plat H | Maximum expected plateau pressure | 40 | cmH~2O | *Plat L* – 50 | 1 |
| Plat L | Maximum expected plateau pressure | 10 | cmH~2O | 0 – *Plat H* | 1 |
| TVRange | Allowable delivered tidal volume deviation | 10 | % | 5 – 50 | 1 |
| FiO~2 H | High FiO~2 alarm threshold | 57.5 | % | *FiO~2 L* – 100 | 0.5 |
| FiO~2 L | Low FiO~2 alarm threshold | 42.5 | % | 20 – *FiO~2 H* | 0.5 |
| PTrig | Pressure drop trigger for breath detection while in ACV mode | 2 | cmH~2O | 1 – 20 | 1 |
| FTrig | Volume drawn trigger for breath detection while in ACV mode | 5 | mL | 0 – 100 | 1 |
| Suction | Suction mode duration | 30 | s | 10 – 300 | 1 |
| O~2 Conc | Concentration of O~2 supply used | 100 | % | 0 - 100 | 1 |