Electronic calibration shield for ArmeeVent v1 pneumatic oscillator

[olemis]

Shield overview
This shield operates upon pneumatic oscillator screws and control switches so as to modify oscillation parameters.

Describe the solution you'd like

This shield is strictly dedicated to actuate upon pneumatic oscillator. It should be possible to remove it after calibrating the device up to a well known variables set point.

Mechanical specifications

This shield should be placed immediately on top of the oscillator so as to have direct access to its surface. It should consist of a set of actuators for operating control switches/screws and a second set for establishing variable set point.

• Gear reductor mechanism needed so as to control distance
• Standardize to using M4 screws
• Pneumatic oscillator block must have placeholders for nuts so as to reduce friction between screw and (plastic) case surface
• Clamps to preserve screw position relative to block surface even under vibration or other mechanical perturbation
  • particularly important for PEEP adjustment screw

Pneumatic and flow requirements
Not related to flow .

Electronics requirements

• MCU can be one of
  • Arduino Nano
  • Arduino UNO
  • MicroArduino
• Knobs (potentiometers) for setting oscillator parameters
  • PIP => 0 - 100 hPa (resolution 1hPa)
  • PEEP => 0 - 20 hPa (step 1 hPa)
  • I:E => ?
• Servomotors for rotating screws
• In this first version electrical signals in high-speed variables bus shall be used to connect sensors to measure target physical variable(s) servomotors act upon.

The exact location of a given servomotor will depend on target screw position, dimensions of the gear reductor mechanism and relative position with respect to other screws. Up to this point the number of servomotors as well as their position will be fixed and bound to the geometry of the target ARMEE v1 oscillator .

Software requirements

• In operational mode an internal table should establish the correlation between potentiometer position <---- linear ----> variable set point <----non-linear ----> screw position for desired variable value.
• Main menu with sub-menus
• Detect / probe sensor input
• Calibration mode for independent variables
• Variable set point resolution adjustment (logarithmic scale)

Clinical references
For configurable oscillators the goal of this shield is to provide the means for clinicians to configure the main parameters of the pneumatic oscillator according to patient's health condition.

Taking Evita 4 as a reference this shield is the equivalent to rotary knobs for setting parameters after selecting a ventilation mode .

No valuable use case is foreseen for static blocks , since they do not have screws.

Describe alternatives you've considered
Implemented from scratch.

Patent claims
No known patent claims, but no exhaustive research performed.

Articles and references
Dräger Medical AG & Co. KGaA, "Evita 4. Intensive Care Ventilator. Instructions for Use. Software 4.n", 4th Ed., 2003 Spanish PDF text

Additional context
Forthcoming shield versions might consider development of a movable mechanisms for placing servos on top of screws located at arbitrary positions , which will allow for reusing same calibration shield for multiple oscillator designs.