Increment 1 (2011)
Preliminary study |
Theoretical design for electronics and programme structure diagram was developed that provides feedback by use of two and, respectively, three LEDs, including two micro-switch sensors. The system only gives feedback about using the dispenser (yes or no) before opening the incubator door; no feedback was provided about the necessary 30 s interval between dispensing alcohol and opening the incubator door. The system was analogue so could neither record nor save any data.
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Increment 2 (2013)
Research into feedback scenarios |
Red light as feedback should be avoided because it can be confused with other red safety alarm lights. A constant orange-coloured to yellow-coloured light was preferred for the stand-by modus (the ‘idle’ state of the feedback system before dispending alcohol). Alternating orange to yellow light was preferred for ‘negative’ feedback, and green light for positive feedback. Sound as feedback was rejected to prevent discomfort for prematurely born infants and confusion with vital signs monitors. NICU healthcare professionals desired a visual timer that shows the 30 s countdown near the incubator doors for example, a strip of 10 LEDs, of which one would dim in each 3 s time frame. The idea rose to have a display above the alcohol dispenser showing a welcome screen, to remind the healthcare professional to disinfect the hands, and a 30 s countdown timer during hand rubbing. The feedback scenario was translated in a programme structure diagram and a proof-of-principle prototype was realised based on an Arduino microprocessor, a LED strip with 3D printed housing, a micro-switch in the alcohol dispenser and a magnetic switch (reed) on the incubator door.
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Increment 3 (2014)
Validation of feedback scenario |
NICU healthcare professionals requested a ‘social control light’ above each incubator visible for all NICU healthcare professionals and parents present. This was to make compliance with hand hygiene ‘visible’ and was added to the feedback scenario. Furthermore, NICU healthcare professionals desired an additional video being played showing (during the 30 s) instructions for correct hand rubbing technique. Electronics and plastic housing parts for the LED strip and the social control light (including connecting wires situated on the incubator) were designed and evaluated with NICU healthcare professionals. A second proof-of-principle prototype was built based on Arduino, a RGB LED strip and RGB LED social control light with 3D printed plastics housing parts.
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Increment 4 (2015)
Further research into the physical ergonomics, addition of Wi-Fi and database |
The prototype was complemented with a 7-inch display showing a sequence of still pictures with hand rubbing instructions, suggesting a moving video. The video also included a ‘ring’ of green rectangles forming in 30 s, as a countdown timer. A Wi-Fi module was added that can wirelessly send recorded compliance data to a computer, registering when alcohol was dispensed and the elapsed time between dispensing and opening the incubator door. The compliance data of multiple incubators were visualised in one view in a dashboard. To demonstrate the complete feedback system to NICU healthcare professionals, a fully working prototype was mounted on a Dräger Caleo incubator (Dräger, Lübeck, Germany, type Caleo).
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Increment 5 (2016)
Final design of electronics, software and housing, including Wi-Fi, data server and dashboard |
The manual alcohol dispenser (lever operated) was replaced by a touchless operated dispenser (Ophardt, Issum, Germany, type Ingo-man plus Touchless) that eliminates touching the handle with a hand, which is regarded more safe hygienically. Ergonomic placement of the main unit and display on the incubator was re-evaluated and the unit was replaced from the left side (where it blocked view on monitors) to the right side of the incubator. The final architecture of software and electronics was developed according to the method of structured analysis of Yourdon.32
The final design and construction of the plastic housing parts was engineered for 3D print production based on the physical dimensions of printed circuit boards, the touchless dispenser, the display and available space around the standard 38 mm tube of the incubator. The LED-strip housing was re-designed and could now be clicked on the incubator door (instead of attaching it with double-sided tape, which was un-desirable due to cleaning requirements). Database server software was developed including a new dashboard. The final design and construction of the plastic housing parts and electronics were evaluated with and approved by infection prevention specialists and medical device safety specialists.
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