Technology meets lung physiology

Complex requirements, efficient solution

Thanks to the combination of our customer's expertise in lung physiology and ventilation and our know-how in electronics and software, a mobile, 2.5 kg lightweight baby lung simulator was created that generates realistic breathing patterns and makes it possible to train various ventilation procedures without risk. The high-precision training device supports the realistic training and further education of doctors - especially in the assessment of lung function and the application of respiratory therapies in infants. The simulator offers a unique solution for the risk-free handling of various ventilation procedures.

Collaboration and project scope

The innovative project required a wide range of experience due to the high functional density of the electronics. Thanks to our expertise in the field of electromechanical lung simulation, we were able to provide the customer with targeted support in the development of electronics and software. The scope of the project included circuit diagram and layout design, EMC-compliant measures and comprehensive quality assurance through tests and inspections. 
A central aspect of the collaboration was the balance between technical excellence and a clear view of the financial framework conditions - particularly important for an innovative, growing start-up. The result was a cost-optimized solution with high technical quality.

The challenges

The technical implementation of the project placed high demands on development and system integration. One of the main challenges was the mechatronic simulation of natural lung movement - a complex interplay of precise sensors and actuators. At the same time, the measured values had to be transmitted wirelessly in real time, supported by a mobile, battery-based power supply. A powerful firmware framework was developed to meet these requirements efficiently. It enables the simple control of sensors and actuators as well as reliable data transmission via Bluetooth. This enabled the customer to implement the application firmware for simulating lung physiology themselves - without having to rely on in-depth embedded software knowledge.

Technical details

The project included the creation of the circuit diagram, the layout and an EMC-compliant design. The development was carried out using tools such as Altium Designer for the PCB layout and Keil uVision and STM32CubeMX for the firmware development. 

The simulator combines various technologies on a specially developed electronic board that integrates all the essential functions for lung simulation and PC communication:

• Real-time operating system (Keil RTX) on a Cortex-M4 microcontroller
• Bluetooth interface for connection to a PC
• MP3 codec (VS1053) and file system for the realistic playback of sounds
• Energy-saving low-power circuit for safe battery operation

A bellows driven by a DC servo motor simulates chest movement and thus lung function. The motor is controlled via the circuit board and is regulated by software. The system is supplemented by:

• A Bluetooth module for wireless communication
• A charging circuit with monitoring for NiMH batteries
• Sensors for recording pressure, air supply, CO₂ development and lung volume
• SPP-based (Serial Port Profile) Bluetooth data communication for transmitting physiological measurements and parameters such as lung mechanics and breathing control

Finally, the entire system was subjected to a thorough inspection and extensive functional tests.