Experiments & Results

Updated 21 May 2020

Porcine Studies

We are working with certified animal testing labs to conduct studies in animal models under IACUC (Institutional Animal Care and Use Committee) approved protocols. A porcine model was chosen as pigs have a respiratory systems that is most similar to human beings. This is essential in order to evaluate system performance and safety. We would like to anonymously acknowledge the laboratory staff for their tireless efforts, and the donors who are enabling this rapid scale-up of animal testing.

Study #1 – 20 March 2020
Study #2 – 24 March 2020
Study #3 – 26 March 2020
Study #4 – 1 April 2020

Benchtop Testing

We conducted testing and experimentation on the benchtop in order to validate system operation under load, investigate calibration of the arm position to volume delivered and understand the actual volume delivered as a function of physiological and breathing circuit parameters.

Bench Testing

Modelling & Waveform Analysis

This work is a model-based and experimental analysis of the flow profiles of the MIT Emergency Ventilator for different patient conditions, incorporating ISO standards.

Modeling & Waveform Analysis

39 Replies to “Experiments & Results”

  1. Saroj Shrestha

    We are also working to develop it for Nepal and mass produce it. The crisis might result to some problems but trying best to get it done and working not just for present but future use as well. Hope for the support from around the globe.
    Thank You

    • Artem Iurkovskiy

      Hi Saroj,
      I am from Ukraine, we are 40 million population and have only 1000 Artificial Ventilators of lungs!
      We’re also looking to build scalable manufacturing of Ventilators. Would you be open to sharing experience on a short call? Or just sharing your jorney via email artem@gt-hq.com – mine.

    • Satish Jadhav

      We’re working out of Mumbai, would love to collaborate wrt research. Please find our contact details on our profile.

  2. Robert Weinberg

    I think that we should consider thinking outside the box. One of the greatest challenges involves the small number of current working ventilators available versus the anticipated spike in the number of patients requiring ventilator support for respiratory failure.

    Some hospitals have considered having 2 different patients sharing a single ventilator. My concept is to design a central air compessor unit with a number of individual cartridge units which could be “plug and play” inserted into the central unit and arranged radially about it.

    Each separate cartridge would be an autonomous respiratory ventilator – lacking only the power, oxygen and air compressor. Each cartridge could have the appropriate ventilatory settings of inspiratory volume, pressure, frequency dialed in and would run separately from adjacent cartridges which could be independently plugged in to the central compressor, and such an arrangement may be able to provide ventilatory support to up to 5 – 8 patients per unit.

    The challenge in producing such a multi-unit ventilator concerns regulating the ventilatory settings of each cartridge separately while still providing for the full panoply of respiratory settings needed to provide ventilatory support to each patient. This type of multi-unit ventilator has never been designed or built before – to the best of my knowledge – but if we can send a man to the moon, I don’t think that such a multi-unit ventilator with plug-and-play cartridges to provide ventilatory support for 6 – 8 patients simultaneously is impossible or even too challenging to design and build in the next 3 – 4 weeks.

    • Parallel Logic

      Note that designing for 2+ patients also requires some logistics on top of the technical challenges. Any system would need to consider how to connect/disconnect one patient at a time, ex in the case of death, without affecting the others.

    • keith kropf

      Possible problems with this design:

      Patients must be in close proximity to each other or long runs of tubing would be needed. Keeping this clean may be a problem.

      Regulating flow and pressure may be more complicated.

    • Sundaram Venkatapathy

      Hi Robert,
      I have been working on an air operated model which would use a centralised compressor. I have designed most of the controls using pneumatics such as pressure, tidal volume, flow rate, I/E ratio and alarm for any mall function. I am yet to understand the assist mode as to how to sense the patient while he starts breathing and how to reverse when he starts expiration and at same time we need to understand his comfortable volume and pressure and there should be a machine learning program to automatically alter the I/E ratio and flow rate. This would be the biggest challenge and if this is done I am sure the pneumatic model would be the most reliable and cost effective and we could produce huge quantities in a very short time.

      • Matthieu Mubikayi

        Salut sundaram,
        La détection de l’aspiration et de l’expiration chez le patient pourrait se faire à l’aide d’un capteur de pression.
        C.à. d le capteur détectera la variation positive ou négatif de la variation de pression.

      • Sonu Kumar

        Hi Sundaram
        This is regarding assist mode ,
        It is detected through flow trigger and pressure trigger .
        A negative flow/pressure will be trigger in the circuit once patient start spontaneous breathing.
        and flow Sensor detect this breathing effort made by patient .
        and accordingly , ventilator synchronizes the Respiration rate with the patient effort .

        Sonu kumar

  3. Jaco Fourie

    Hi. I had a look at the design and was wondering why a mechanical actuator is beging used with a bag. Could a scuba tank with a regulator and solenoid vales not do the same job with less moving parts ?

  4. Carlos Enrique Gutierrez

    Yes , why not yo use an air compressor to supply the air insteed of the bag ?

    • Hairol Aquino

      The ambú or manual respirator provide a safety Volumen un case of a system error. The maximum Volumen of the ambú, if it would’ve been completely compressed, and the system stop, has low risk to damage the lung of the patient.

  5. John Stone

    The hyper-link to studies #2 and #3 don’t work. Last night’s post claims they are now available. Is this a mistake on the page?

  6. Larry Boyer

    I’d love an update on the FDA approval as well.

    Also, does anyone yet have details on the electronics (what microcontroller and what motors, for example) so we can start gearing up for when the full plans are released.

    • Larry Boyer

      Never mind. I found the controls and electronics page. Glad it is Arduino. Simple, RT microcontroller.

    • Abdulsamad Ebrahim

      As mentioned in the electric hardware The microcontroller is the Arduino UNO and the motor is PK51 DC Gearmotor the motor driver is Solarbotics® motor driver (L298 motor driver)

    • Matthieu Mubikayi

      Bonjour à tous,
      Je pense que la conception de l’aspirateur artificiel proposée sur base du microcontroleur Arduino pourrait être facile à réaliser étant donné la simplicité de programmation avec ce type des microcontroleurs.

  7. Rune Kongshaug

    Hi, all thanks for the comments.
    It seems like 1:2 and even 1:3 breathing ratios may be required. Especially asthma patients may need a longer exhale cycle to avoid asphyxiation (breathing in their own air), thus with more time to exhale. Starting lower pressure and then increase compression by reading the spirometer seems safer as too much pressure too fast can create unintended negative consequences, ok I got it. However, in an environment that is crisis-driven, chaotic, with lack in PPE and in a short supply of qualified staff, we may want to consider pre-settings for infant, young, and adult settings for different lung size, breathing ratios and compression rates. These pre-settings may save time, assure mistake-proofing, and quicker adoption, and thus save more lives. Thoughts?

    • N H

      Because settings vary greatly as a function of each person’s pathology clinicians really need to be able to adjust parameters. We feel that the risk of a device where the decision is automated would be high. A safer solution would be, perhaps, working with your clinical team to create a simple guide to the best recommended settings. And this would need to be updated. We are hearing of I:E of up to 1:4 at 40 BPM with smaller tidal volumes being used with some COVID patients.

  8. keith kropf

    Has anyone looked at a design using cams and roller followers instead of gears? I think cams would be less prone to wear and changes in torque due to wear, making it more reliable? Also cams are easier and faster to manufacture. They can be designed to give a constant flow rate for a given motor rpm.

    Is anyone working on a design using cams?

    • Abdulsamad Ebrahim

      Cams are good ideas as well even silent in operation but needs a mechanical engineer to find out the parameters power, the torque needed and so on.

    • Rory Berger

      Hello, yes, we did a design with a cam to provide smooth non-linear acceleration but it does not seem that is as important as we first thought as we do not need to protect any motor gears because we are using a compressed air cylinder to drive the paddles.

  9. Juan Pablo Gonzalez Correa

    Hi, In the “motor selection” section, it is indicated that the torque must be 15N-m, looking for NEMA stepper motors, some reach 8 N-m, what is the actual minimum required torque?

  10. Yueh Lee

    E-vent team – do you have access to ASL-5000 for testing? We have tested our unit on an ASL-5000; contact me directly (I also emailed) for my specific concerns if you haven’t. Thanks.

  11. Julián Montes

    E-Vent Team:
    We have knowledge that some researchers in Spain have had problems with CO2 release. How have you done concerning the CO2 in the tests with the porcine?

  12. Mustakim ikbal Ahmed

    we the students of assam engineering college of INDIA had designed a prototype of our own.we are also trying to design an app so as to monitor and regulate the bpm without physical contact……Can we collaborate to make it possible??

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