# Respiratory flow parameters

## Overview

The SPIRO app considers the peak inspiratory flow rate (PIFR), the peak expiratory flow rate (PEFR), the mean inspiratory flow rate (MIFR)and the mean expiratory flow rate (MEFR). These parameters are can be also normalized with the body weight of the patient.## Details

**Peak inspiratory flow rate (PIFR (L/min))**

PIFR is the highest flow value of an inspiration, see [Rimensberger2015] p.362.

PIFR is detected as the highest flow between an inspiratory- and an expiratory onset.

**Normalized peak inspiratory flow rate ((PIFR normalized) (mL/kg/s))**

PIFR normalized is the PIFR value divided by the patients body weight and normalized to the standard units mL and s.

**Peak expiratory flow rate (PEFR (L/min))**

PEFR is the smallest flow value of an expiration, see [Rimensberger2015] p.362.

PEFR is detected as the smallest flow between an expiratory- and an inspiratory onset.

**Normalized peak expiratory flow rate ((PEFR normalized) (mL/kg/s))**

PEFR normalized is the PEFR value divided by the patients body weight and normalized to the standard units mL and s.

**Mean inspiratory flow rate (MIFR (L/min))**

MIFR is the mean value of the inspiratory flow between an inspiratory- and an expiratory onset.

MIFR is sometimes also called rate of rise (ROR or RofR). The parameter MIFR describes only the average flow during inspiration (mean value). Since this parameter is not a signal of the changes of the flow during inspiration, the name Rate of Rise is misleading from a mathematical point of view.

The name MIFR is chosen according to PIFR.

**Normalized mean inspiratory flow rate (MIFR normalized (mL/kg/s))**

MIFR normalized is the MIFR value divided by the patients body weight and normalized to the standard units mL and s.

**Mean expiratory flow rate (MEFR (L/min))**

MEFR is the mean value of the flow between an expiratory- and an inspiratory onset.

**Normalized mean expiratory flow rate (MEFR normalized (mL/kg/s))**

MEFR normalized is the MEFR value divided by the patients body weight and normalized to the standard units mL and s.