Juan Manuel Gonzalez-Carmona, Iker Rodrigo Chávez-Urbiola, Pablo Alfonso Tirado Cantu, Jesus Alcantar, Gilberto León Muñoz, Noé Amir Rodriguez, Francisco Rodriguez Oronia, Daniela Diaz Alonso, Centro de Ingeniería y Desarrollo Industrial, CIDESI-Querétaro, Querétaro, México.
This work presents the design process and its implications for the mass production of a flow sensor according to mechanical ventilation needs and its normative regulation. The principle employed for the micro anemometer was a calorimetric flow or hot wire. The calorimetric flow sensor is done by two main components, a micro heater, and a resistive temperature detector: analytical methods and finite element simulations designed both components as the first stage. The anemometer design is a micro heater surrounded by resistive temperature detectors. The mechanical ventilator needs a fast response of at least 500 microseconds and a monitoring range between 120 to -120 lpm (litters per minute). The principal asset of mass production is the allowed error, which is 10%. First of all, the permitted error of the final product is 10%, but it has to be taken into account that this implies the sensor design error and the produced variation in mass production. This mass production variation changes some factors, especially physical properties, which should be considered during the validation. In order to check these requirements, a rigorous process should carried out to ensure the ISO 5356 and ISO 10993. The physical transducer variance by fabrication should define which part of the system can be absorbed; this kind of sensor is made of three parts: the transducer, the case, and the electronic. This sensor has an absorber in each part. In the transducer, wide pads were implemented; in the sensor case, a venturi configuration was implemented, and the electronics absorbed some part of it as well. The presented design covers the requirements for a mechanical ventilator for a human adult. We presented our implemented system for variation detection and error mitigation that allows a lab sensor technology to scale to a mass production.