Liberate Medical VentFree User manual

Document #:
MAN-006
Version
01
Document Title:
VentFree User’s Manual EUA
Approval Date:
28-Apr-2020
Effective Date:
28-Apr-2020
CHANGE SUMMARY
Rev # Date Description CO#
00 21-Apr-2020
EUA requirements
CO-2020-348
01 28-Apr-2020
Liberate Medical Electrodes
CO-2020-382

DOCUMENT: MAN-006-01
Effective: 28-Apr-2020
CONTROL NUMBER: CO-2020-382
Respiratory Muscle Stimulator
User Manual
VentFree has not been FDA cleared or approved.
VentFree has been authorized by FDA under an Emergency Use
Authorization (EUA).
VentFree is authorized only for the duration of the declaration that
circumstances exist justifying the authorization of the emergency use
under section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless
the authorization is terminated or revoked sooner.

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1 Product Description 6
1.1 Principles of Operation 6
1.2 VentFree Features 7
1.3 VentFree Indications for Use 8
1.4 VentFree Contraindications 9
1.5 VentFree Warnings 9
1.6 VentFree Dangers 11
1.7 Cautions 11
1.8 Electrode Cautions 13
1.9 Flow Sensor Cautions 13
1.10 Stimulator Adverse Effects 14
1.11 Glossary of Symbols 15
2VentFree Directions for Use 17
2.1 Getting Started 17
2.2 External Power 17
2.3 Electrode Setup 18
2.4 Electrode Cautions 21
2.5 Electrode Warnings 22
2.6 Re-Application and Storage of Electrodes 23
2.7 User Interface 24
2.8 Connections 25
2.9 Connecting the System 26
3Setting up the System 30
3.1 Stimulation Levels 36
3.2 Begin treatment 37
3.3 Treatment Pause 38

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3.4 Treatment Discontinuation 38
3.5 Power Removal and Device Disconnection 39
3.6 MAIN MENU 40
3.6.1 Brightness 40
3.6.2 Key Volume 41
3.6.3 Session Length 41
3.6.4 Date/time menu 42
3.6.5 Stim Settings 42
3.6.6 About 42
4Error Messages and Troubleshooting 43
5Technical Data 44
5.1 Power Source 44
5.1.1 Battery 44
5.1.2 AC/DC Converter (Power Supply) 44
5.2 Standard Measurement Conditions 45
5.3 Outputs 45
5.4 Typical Waveforms 46
5.5 Treatment Duration 47
5.6 Output Signal Indication 47
5.7 Physical Characteristics 47
5.8 Accessories 47
5.8.1 Electrodes 48
5.8.2 Flow Sensor 49
5.8.3External AC/DC Converter 50
5.9 Environmental Conditions 50
5.10 EN 60601-1 Classification 50
5.11 Electromagnetic Compatibility (EMC) Tables 51
6Disinfection and Cleaning 55
6.1 Agents 55
6.2 VentFree and AC/DC Converter Cleaning and Disinfection Methods 55

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6.3 Electrodes Cleaning and Disinfection Methods 57
6.4 Cleaning and Disinfection of the Flow Sensor 59
7Battery Replacement 62
7.1 Battery Disposal 68
8Calibration and Maintenance 68
8.1 Repairable Parts 68
8.2 Equipment Disposal 68
9Manufacturer Information 68

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1 Product Description
Figure 1: VentFree
VentFree is an electrotherapy device that monitors the patient’s breathing activity using an airflow
sensor, and during the expiratory phase of breathing, applies transcutaneous neuromuscular
electrical stimulation (NMES) to the abdominal wall muscles over two stimulation channels.
Figure 2 Illustration of the VentFree muscle stimulator setup
1.1 Principles of Operation
NMES elicits muscle contractions through the delivery of small electrical pulses to the motor nerve
endings that supply a muscle. When NMES is applied to the abdominal wall muscles in synchrony

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with exhalation, the effect on ventilation is similar to a physiological contraction of the abdominal
wall muscles. An important advantage of using NMES in critically ill respiratory patients is that it
can be used to recruit the abdominal wall muscles inthe absence of patients’ voluntary or automatic
recruitment of those muscles.
1.2 VentFree Features
•Does not depend on patient participation.
•Non-invasive NMES.
•Stimulator protected against defibrillation potentials.
•Audible and visual notifications when the electrodes are not connected or if the flow
sensor is not functional.
•Simple user interface for navigating menus and manipulating settings.
•Real time graphical display of patient’s respiration.
•Two independent digital intensity controls.
•Timed therapy sessions with customizable length.
•Manual control of stimulation.
•Touch Screen operation of non-critical functions.
•Illuminated backlight display.
•Easy to clean surface.
•End of treatment review that displays the session length, starting intensity, average
intensity, and disposables information.
•Displayed battery charge level.
•Powered from rechargeable smart battery source that indicates if the remaining
charge will suffice for at least one treatment.
•Consumables tagged to ensure they are not used for more than the prescribed number
of times or used past their expiration date.
•High Impedance monitor
•Charged balance stimulation
•Current Control stimulation
•Maximum Conformance voltage monitoring
•Battery status indicator
•Battery health monitoring
•Easy to Pause Treatment button

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1.3 VentFree Indications for Use
The VentFree muscle stimulator applies transcutaneous neuromuscular electrical stimulation to
the abdominal wall muscles during the expiratory phase of breathing in conjunction with a
mechanical ventilator.
The VentFree muscle stimulator is for treatment of patients on mechanical ventilation adults
who require mechanical ventilation, including patients with COVID-19, over the duration of the
emergency use authorization. The VentFree muscle stimulator may prevent or retard disuse
atrophy of the abdominal wall muscles and reduce the number of days of ventilator support in
adults who require mechanical ventilation.
The VentFree muscle stimulator is intended to be used by healthcare professions in a healthcare
facility. It is recommended to be used for two 30 minute sessions per day (one in the morning
and one in the afternoon / evening), five days per week, for six weeks or until successful
weaning, whichever occurs sooner.
VentFree has not been FDA cleared or approved.
VentFree has been authorized by FDA under an Emergency Use
Authorization (EUA).
VentFree is authorized only for the duration of the declaration that
circumstances exist justifying the authorization of the emergency use
under section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless
the authorization is terminated or revoked sooner.

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1.4 VentFree Contraindications
VentFree should NOT be used for the following situations or patients with:
●Do not use with demand type implanted pacemaker or defibrillator.
●Do not use electrical stimulation over pregnant uterus.
●Do not use on a patient with recent abdominal surgery with open abdominal wounds.
●Do not use on open or damaged skin.
●Do not use on patients under 18 years of age.
1.5 VentFree Warnings
Regional Use – ALWAYS use the AC/DC converter with the corresponding regional AC Inlet
plug .
Use Setting- This device should only be used in a hospital ICU setting.
Cleaning -Clean device with disinfectant wipe between uses (after use-before storage and
before use). Only use approved chemicals for cleaning/disinfection (refer to Section 6).
Patient Supervision - Clinicians should regularly monitor patient for adequate stimulation level
throughout the treatment.
Multiple Patient Use -If the device is used on more than one patient, the operator should follow
facility infection control procedures.
Prescription and Use – This device should only be prescribed and operated by a clinician that is
familiar with the precautionary measures and operational functions associated with the unit.
Electrode Placement- Electrodes should only be placed on the abdomen in compliance with the
directions for use (refer to Section 2)
Cutting Electrodes - Electrodes should not be cut other than as indicated by the dotted lines in
the back of the electrodes.
Reposition of Electrodes- Electrodes should not be repositioned during treatment sessions.
Throat Stimulation – Severe spasm of the laryngeal and pharyngeal muscles may occur when
the electrodes are placed across the throat or mouth. This may be strong enough to close off the
airway or cause breathing difficulty.
Transthoracic Stimulation – Do not apply electrical stimulation transthoracically (through the
chest area) in that the introduction of electrical current into the heart may cause cardiac
arrhythmias.
Other Electrode Placement -Stimulation should not be applied across or through the head,
directly on the eyes, covering the mouth, on the front of the neck(especially the carotid sinus), or
placed on the chest, upper back or crossing over the heart.
Electrical Shock – To prevent electrical shock, disconnect the unit from the power source and
remove the battery before attempting any maintenance procedures.
Accessories – Use only accessories that are specifically designed for this device. Do not use this
device with accessories manufactured by companies other than Liberate Medical. Liberate
Medical, LLC is not responsible for any consequence resulting from using products
manufactured by other companies. The use of accessories, transducers, or cables other than those
specified by the manufacturer, may result in increased emissions or decreased immunity of the
VentFree muscle stimulator.

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Defibrillation Signals – In certain circumstances, there can be risk of burns under the electrode
sites during the defibrillation.
Safety – The safety and efficacy of the VentFree system depends on the proper use and handling
of the device and accessories. If used improperly, VentFree has a potentially hazardous electrical
output. It must be used only as prescribed.
Electrode Safety-Electrode burns may result from misuse. Electrodes should be securely
adhered to the patient to prevent disconnection. Check accessories regularly as they may show
signs of wear over time and replace if needed.
Electrode Uses- Electrodes should not be shared between patients but may be reused on the
same patient.
Flow Sensor – The Flow Sensor should not be shared between patients but may be reused on the
same patient.
Mechanical Ventilation- VentFree should not be used as a replacement for a mechanical
ventilator.
Intended Use – VentFree should not be used as a replacement of any medical treatment not
specified in VentFree’s Intended Use.
Mechanical Damage (Casing/LCD) – Do not disconnect VentFree from power if casing or
LCD display becomes compromised.
Mechanical Damage (Electrode leads) –Do not touch device electronics or electrode leads if
casing or insulation becomes compromised.
Mechanical Damage (AC/DC converter) – Do not use VentFree if external AC/DC converter
enclosure is damaged.
Battery Safety – Care should be taken if signs of hazardous gaseous or liquid chemicals are
leaking from the battery.
Environment –Do not use device outside of specified environmental conditions.
Repair –Only authorized personnel can open / repair the device.
Modifications – Modifications to the VentFree device or its AC/DC converter are prohibited.
Skin Infection –Care should be taken when using electrodes on patients with skin infections
and the clinician should determine when to change the electrodes.
Network / Data Couplings – USB / DATA Ports in the connector panel of VentFree are for
Factory Use ONLY or as authorized by Liberate Medical, LLC. Any other use is strictly
prohibited.
Proximity to other Equipment –Use of this equipment adjacent to or stacked with other
equipment such as RFID equipment , Diathermy, Electrocautery and Electrosurgical Equipment
or others should be avoided because it could result in improper operation. If such use is
necessary, this equipment and the other equipment should be observed to verify that they are
operating normally.
Surgery – Discontinue the use of VentFree if high-frequency surgical equipment are to be used
during a stimulation session.
Diathermy treatment - Discontinue the use of VentFree if Diathermy treatment is to be
conducted during a stimulation session.
Electrocautery treatment - Discontinue the use of VentFree if Electrocautery treatment is to be
conducted during a stimulation session.