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==See also==
==See also==
* [[Collaborative COVID-19 initiatives]]
* [[Collaborative COVID-19 initiatives]]
* [[Artificial lung method MOST]]


[[category:MOST methods]]
[[category:MOST methods]]

Revision as of 21:38, 3 April 2020

Over the rest of the semester MOST and well as the MTU Open Source Hardware Enterprise will be documenting, building and testing open source ventilators. If you want to help please do.

Background

Follow literature review protocols from the group here:[1]

How Many are Needed?

See Dave Denkenbergers' spreadsheet

https://www.mdedge.com/rheumatology/article/219591/coronavirus-updates/fda-allow-alternative-respiratory-devices-treat

Existing Designs

MTU Designs

Testing Procedures

MTU Testing Procedure

  • Select on of the four modes using the user interface on the ventilator:
 *Continuous mechanical ventilation (CMV): used when a patient is not breathing on their own
 *Inverse ratio ventilation (IRV): used when a patients inhale lasts longer than their exhales(i.e 2:1 instead of 1:2)
 *Pressure support ventilation (PSV): when a patient has trouble completing a breath thus resulting in negative pressure during a breathing circuit
 *Assist Control (AC): used when a patient needs support for every breath
  • Confirm that the peak inspiratory pressure (PIP), respiratory rate (RR), positive end expiratory pressure (PEEP), inspiratroy:expiratory ration (i:e), and tidal volume (TV) are accurate by using the Michigan Instruments software package that accompanies the lung (downloaded in the MI USB drive).
  • Test the alarms by unplugging the machine, wiring, and appropriate tubing. The accessories that should be tested are:
 *Low Pressure Alarm: Decrease the PIP value using the ventilators user interface to an abnormal value.
 
 *High Pressure Alarm: Increase the PIP value using the ventilators user interface to an abnormal value.
 
 *Oxygen Concentration Alarm: Increase/decrease the percentage of oxygen per breathe to above/below the safety range (19.5-23.5%) by mechanically increasing/decreasing the amount of O2 entering the ventilator and using an O2 sensor. 
 
 *Battery Backup Alarm: Unplug the ventilator's primary battery from the voltage source.

 *Wire Disconnection Alarm: Unplug a wire from the circuit board in the ventilator while it is running. 
 
 *Oxygen Tube Disconnection Alarm: Unplug the oxygen intake tube from the ventilator while the machine is on.
 
 *Mechanical Failure/Fatigue (# of cycles): Leave the machine running for extended periods of time (a few hours, days, weeks) and observe any inaccuracies.
  • Ideal Values that Should be Targeted for a Healthy Patient:

https://www.nursingcenter.com/getattachment/Clinical-Resources/nursing-pocket-cards/Mechanical-Ventilation-Settings-and-Basic-Modes/Mechanical-Ventilation-Settings-and-Basic-Modes-Tip-Card_January-2019.pdf.aspx

 *PIP: 10-14 cm H2O
 
 *RR: 8-12 breathes per minute (BPM)
 *PEEP: 3-10 cm H2O
 *I:E: 1:2
 *TV: 6-8 mL/kg
 *O2 Concentration: 19.5-23.5%
 *FiO2: 1.0 (100%)
 * Mechanical Failure/Fatigue (# of cycles): ideally for as long as the patient requires the use of the ventilation

Regulations

 *COVID-19 activities: https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/covid-19-related-guidance-documents-industry-fda-staff-and-other-stakeholders
 * A ventilator would fall under other medical devices: https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#covidothermeddev

Safety Precautions

  • Confirm that the wiring in the ventilator is correctly set-up (see wiring diagram)
CircuitWiring IGSVent.jpg
  • Make sure that the ventilator is properly connected to the artificial lung with the proper adapter size (see picture below)
Taken from https://www.michiganinstruments.com/wp-content/uploads/2018/11/TTL3OpsManualREV2017-05.pdf
  • Confirm that the artificial lung is set-up correctly BEFORE turning the machine on (see manual below, pg.11)

https://www.michiganinstruments.com/wp-content/uploads/2018/11/TTL3OpsManualREV2017-05.pdf

See also

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