V3 turbine working with Raspberry Pi software

a.tiffen
Posts: 2
Joined: Thu Apr 02, 2020 6:45 pm

V3 turbine working with Raspberry Pi software

Post by a.tiffen »

I have been working with your V3 turbine design and have written both control software and a User Interface in Python so that it can run on a Raspberry Pi. The PI has easy to use Input / Output pins. I am using the speed controller and brushless DC motors from a quadcopter because they are reliable, easy to buy, cheap and can talk directly to the Pi without the need for additional electronics or separate PWM motor controllers.

The software has an option to give patient information, such as Sex and Height so that the correct Tidal Volume can be calculated. There are default settings for Inhalation and Exhalation pressures, Inhalation/ Exhalation ratio, Breaths per minute. All of these setting can be adjusted when setting up a new patient or adjusted when the ventilator is running by clicking on the up / down buttons for each setting. There are automatic warnings for unusually high or low settings and the software stops any attempt to set dangerous settings.

There is an alarm system that sounds an alarm and flashes red on the screen if the Ventilator is stopped or if any required setting is not maintained.

There are two modes of operation, Mandatory Ventilation and Assisted ventilation. In Mandatory mode, the required inhalation and exhalation pressures are met using a pressure sensor in the ventilator output and the breathing rate, I:E ratio are set by the user. System pressure is read by the software using a Analogue to Digital Converter that plugs into the Raspberry Pi (NOTE - I am waiting for new pressure sensors to be delivered tomorrow to fully test this section). This pressure gives feedback to the software to control the motor speed and give more or less air from the turbine to maintain the required pressure.

There is also an assisted Ventilation mode for patients that are able to breath a little on their own. The software monitors the pressure in the ventilator mask and when it sees a drop in pressure, it knows the patient is trying to breath in and it generates a pressure increase by speeding up the turbine to assist the patient breath in. When the patient tries to breath out, there is an increase in pressure in the mask and the system slows the turbine to allow the patient to breath out. PEEP pressure can be maintained by the turbine or via a PEEP valve attached to the mask. In this mode, the patient's own breathing sets the breathing rate and I:E ratio but both are monitored by the software. The software logs information to a .CSV file for analysis if needed. If the patient does not take a breath for a set number of seconds, an alarm sounds and the system goes directly into Mandatory Ventilation mode.

I still have a little bit of work to do to get the pressure sensor feedback right and will be testing different pressure sensors when they arrive tomorrow.

I have attached a screenshot of the Software in operation.

Here is a link to the motor controller that talks to the Raspberry Pi:
https://www.flyingtech.co.uk/electronic ... a-mini-esc

And here is the motor I am using:
https://www.flyingtech.co.uk/electronic ... cing-drone

This is the pressure sensor that can talk to the I/O on the Raspberry Pi:
https://uk.farnell.com/ge-measurement-c ... f-00001000

I hope this is of interest to you. I will send an update when the pressure sensor feedback is fully working.
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dilip
Posts: 14
Joined: Fri Mar 27, 2020 7:47 am

Re: V3 turbine working with Raspberry Pi software

Post by dilip »

Great!!! Is it possible to implement plateau pressure measurement... that may be an important parameter for doctors---

a.tiffen
Posts: 2
Joined: Thu Apr 02, 2020 6:45 pm

Re: V3 turbine working with Raspberry Pi software

Post by a.tiffen »

Yes, Plateau pressure measurement should be possible. I will add that to my list to work on.
Thanks for the input.
Andy

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