Hardware Requirements Outline

Summary of hardware design requirements for Project Tetra.

Section formatting

Name of requirement domain

*Goal* = Aim that the below items seek to address/provide

Requirement or Criteria

  • specification or test

  • *leading asterisk denotes specification or test needed

  • trailing question mark denotes that definitive requirement for specification or test is unknown?

Overall device requirements/criteria:

Functional
*Goal* = Provide adequate splitting of a single ventilator for up to four (4) simultaneous patients.
Criteria/requirements
All airflow entirely self contained, no leaks
  • test splitter system across the full spectrum of possible loads and verify that no component or joint experiences leakage
  • *test sustained load(s) for X hours?
Device does not permit cross-contamination between patient airways
  • *specify test, requirement, and acceptable tolerances
Device will operate consistently on 1, 2, 3, and/or 4 patients connected
  • *specify tolerable variance
  • *specify repeatability metrics for each component and/or inspiratory/expiratory arm
  • *specify a duration of consistency?
Device allows for or provides means to maintain and adjust PEEP (10-25cm H2O)
  • CONFIRMED using test ventilator
  • test other ventilator models?
  • verify with external valve [optional]
Device is capable of configuring and maintaining the full range of PIP
  • flow control valve permits adjustments of tidal volumes within therapeutic range, from 200-500 mL
Device will have means to measure and report pressure and/or flow for each individual patient across the entire range of values/loads
Shutoff valves allow to safely attach and detach patients
  • no air leakage when valves are shut during patient attaching/detaching
  • *verify that when when patients are attached or detached, conditions in the other patients remain stable [specification required]
Device must be powered from standard wall outlets with failsafes
  • power cable minimum length = 10 feet [3.3 meters]
  • power cable needs to have locking safeguard from accidental unplugging?
  • power connection should be controllable via rocker switch
  • power switch should have safeguard to prevent accidental shutoff?
  • battery power failover safeguard required for 20 minutes (minimum) of use in case of power loss
Useability
*Goal* = Device is easy and comfortable to use by as many medical professionals as possible.
Criteria/requirements
Adequate clearance for grabbing and turning knobs for adjustment
  • specify clearances?
Labels or marker on the housing are visible from more than one viewpoints/angles
  • specify number of viewpoints?
Monitor is readable from a wide range of viewing angles and is not easily obstructed by anything that might be placed on top of the housing (even tho nothing should be placed here)
  • specify viewing angle ranges?
Knobs are easy to turn
  • comfortable to grasp
  • specify force to begin rotating knob?
Repetitive use of device (viewing display, knobs gripping, etc) does not cause strain for users [ergonomics]
  • specify operating time limits?
Adequate clearance for filters (vertically from surface the device is placed); verify that tubing cannot get lodged or pinched underneath filters
  • specify clearance range?
Device operation is simple and easy to understand (requires sample of medical workers to test)
  • specify % of successful operators with 20 minutes (or whatever time) of training?
Device surfaces are easily cleanable and soiling is easily visible
Label and markers are have easily readable font (Helvetica), size, and color; with obvious placement and visibility
  • specify distance/angle markers can be easily read by someone with 20/20 vision?
Device makes it simple to differentiate between each patient quickly
- *specify test and requirement
Determine force required to move, rotate, or slide the device on a surface??
- *specify test and requirement (if any)
Appearance
*Goal* = Device has an appropriate form and look for a medical setting
Criteria/requirements
Shape and color of device is soft and non-threatening
Device appearance is clean and simple
Housing should likely be white in color (or something similar)
Discrete placement of Tetra Bio-Distributed logo
Internal balance
*Goal* = Device weight distribution is mostly even, so it does not tip/fall over when carried.
Criteria/requirements
Weight distribution is no more than 60-40 side-to-side
  • suspend device and measure tension required for either side?
Weight distribution is no more than 60-40 front-to-back (with preference for higher amount in the front)
  • suspend device and measure tension required for either side?
> Device is not top heavy
  • determine tipping angle
Handle placement
*Goal* = device is easy to pick up and carry for anyone
Criteria/requirements
Device handles are comfortable to grasp
  • subjective assessment?
Handles are not too far apart
  • subjective assessment?
Handles are located such that the device weight can be properly supported
  • handles must be structural components
Based on weight and size, determine if possible to carry with one person or if two will be needed
  • Regulatory weight/size requirement?
Serviceability
*Goal* = Device is easily serviceable by medical staff.
Criteria/requirements
Interior of device is easy to access
  • *specify number of steps required to access internals
  • *specify tools required to access internals
Ease to clean surfaces and/or parts
  • *specify number of steps required to clean each component (including removal and reinstallation if needed)
  • determine device materials compatibility with various cleaning methods/solvents?
Device has readily available replacement parts/components
The internal clearances for components are reasonable for device servicing
  • ability to remove any one part and install a new one without removing other components)?
  • *specify clearances between components
Provide functional/dynamic [analog] feedback that components are correctly assembled/replaced?
Durability and robustness
*Goal* = Ensure the device will maintain functionality under normal conditions for a reasonable amount of time before service/maintenance is required.
Criteria/requirements
Device display is secure and will not dislodge under normal stationary use (including periodic touch presses)
  • specify number of hours of use?
The tubing connections and component complexes are secure such that they do not move significantly, nor decouple when device experiences standard use (without moving)
  • specify the number of connect/disconnects before maintenance is required?
Device can withstand a drop from some height and remain functional
  • *specify drop height and/or angle
  • *specify drop with or without electronic components
Device can withstand cleaning and/or light splashes
  • IPx rating?
  • Materials solvent compatibility?
Device does not have ingress for airborne particulates to enter the housing.
  • IPx rating?
When device is used, carried, or leaned on, the panels do not flex in such a way that impeades any of the devices functionality, damages components, or causes any detrimental outcomes.
  • *determine specifications and appropriate testing
No internal build up of heat
  • determine max internal temperature of fully loaded device [provide heat control as required]


Last modified September 11, 2020: replace underscores w/ hyphens in page names (#80) (5e4726b)