Stackable shield design

[olemis]

Overview
Add new functionality to a respirator unit by plugging shields for specific purposes.

Describe the solution you'd like
Allow for stacking one shield on top of another in the form of a tower (or alike). Standardize common features and well defined interfaces. A generic layout .

Mechanical specifications
Since this issue is not for adding specific features to the respiration set, the only real mechanical requirement are the following:

• Define location for shield-specific area i.e. the available space to place components implementing specific shield features
• Determine clamps or alike for shields to be attached to / detached from respirator set.
• It should be "easy" to attach/detach a whole shield from assembled operational respirator
  • Use case: swapping non-configurable pneumatic oscillator blocks
  • Use case: Calibration
• Strong connection of individual shields while attached on to an assembled respirator unit
• If design consists in an external chasis then provide a parametric 3D file for instantiating a model given the number of shield bays needed in it.

For the moment mechanical aspects of shields other than aforementioned items shall be considered too specific to be standardized and designed for a particular purpose .

Pneumatic and flow requirements
Some shields will involve the presence of gases flowing from the drive on to the patient.

• Define standard pipe positions and provide specs for pipe holders
• Define flow management (direction, valves, ...)
  • Needs to consider shield insertion and removal procedures while respirator unit still operational

Electronics requirements
Some shields will include electronic components to fully or partially implement some feature . Multiple such shields may be combined , hence electrical signals shall be combined in a common bus interface connector for shields to have access to vars in context.

• Define stackable electrical connectors to use in shared electrical bus
• Define what signals needed and reading resolution (in bits)
• Choose a real-time data exchange bus . It shall provide accurate high-resolution readings in a timely manner for real time tracking of respirator variables. Since access to this bus is more demanding , it'd be nice if it was a separate slot
• Provide pins for generic low-speed communication channels (e.g. SPI , I2C, ...)
• VCC (3V , 5V, 12V) and GND pins
• GPIO pins

Software requirements
No software involved.

Describe alternatives you've considered
Ideas borrowed from following products

• Beaglebone Black capes are a good reference to understand stackable electronic towers.
• Jun-Electron for Raspberry Pi 4/3 B+ Stackable Rack Case 4 Layer Grey Acrylic with Fan, Heatsink may be another one.
• Industrial stackable containers may be of help in finding a definitive mechanical arrangement.
• Tactix assortment case includes side lock for secure stacking

• Similar principle for Navaris Plastic Storage Box - Stackable Organizer Case

Patent claims
No research performed yet.

Articles and references
Modular respirators are not a new concept. For instance, VORTRAN Go2Vent may be connected to other modules such as VORTRAN manometer, VAR-Monitor , and airway pressure monitor.

Additional context
Ideas to explore (consider as suggestion only)

• Electromechanical shields in horizontal position and vertical flow control shields
• All shields in same direction , and including passthrough placeholders for non implemented features
• All shields in same direction and including (electronic, flow, mechanical) connection artifacts only when needed.

[olemis]

• Beaglebone Black capes are a good reference to understand stackable electronic towers.

Other similar stackable electronic solutions exist for e.g. Raspberry Pi , Arduino , etc ... however BBB variant is quite interesting and there is a considerable number of capes with male and female headers to actually support many stack levels (as opposite to Arduino one level shields).