Master Thesis - Ultrasonic Transducer Modeling for Oxygen Measurement in Ventilators

Master Thesis project in VCT Sense & Control at Getinge, Solna, Sweden 

Background 

At Getinge, our passion is to ensure that every person and community has access to the best possible care, offering hospitals and life science institutions products and solutions that aim to improve clinical results and optimize workflows. Every day we collaborate to make a true difference for our customers – and to save more lives. All our employees make a real difference every day. 

Are you looking for an inspiring environment for your thesis project? You just found it.  

Our Solna site is in an exciting and intensive phase of change, and we are now looking for you who would like to execute your thesis project in our Value Creation Team Sense & Control. The group consists of 10 employees in the R&D organization. 

The assignment 

A ventilator is a medical device that assists patients in breathing by delivering oxygen and removing carbon dioxide, especially when they cannot breathe adequately on their own. One of its key components is the oxygen sensor, which measures the concentration of oxygen in the gas mixture supplied to the patient. Among various sensing technologies, some ventilators use ultrasound-based sensors that employ piezoelectric ultrasonic transducers to convert mechanical vibrations into electrical signals. 

The sensing principle relies on the fact that the speed of sound in air varies with oxygen concentration. By transmitting a known ultrasonic wave from one transducer and measuring the time it takes to reach another transducer positioned at a fixed distance, one can design an algorithm that accurately calculates the speed of sound in the gas. This value is then compared to the speed of sound in pure air to determine the oxygen concentration.

However, such algorithms must be highly robust because they are sensitive to environmental factors such as mechanical design, temperature, and other variations.  

In this project you will kick start the development of an advanced modeling of the ultrasonic transducer and develop a simulator emulating the oxygen sensing technology adopted in the Servo ventilators. The main purpose is to investigate the impact of external changes on the transducer parameters and on the algorithm's performance.   

Some of the suggested tasks in the project: 

• Understand the O2 sensor working principle. 

• Apply advanced modeling with Comsol and MatLab. 

• Study the effects of external changes on a transducer in the sensor. 

• Potential numerical analysis of the Piezo transducer studying effects on the physical properties of the transducers given external changes.  

• Ideally, validation of the developed model against experimental data or analytical models 

• Documentation for a master thesis. 

Your qualifications: 

• Current enrollment in a Master's program going for a degree in Math, Physics or Engineering fields such electronics, medical technology, computer science, or any similar field. 

• Experience using MatLab. 

• Experience using Comsol is a plus. 

• Genuine interest in medical technology, sensors and embedded applications. 

• Social and able to express yourself well in speech and writing in English. 

Number of students: 1 
Preferred start date: 2026-01-11 or any date suitable for all.  
Number of credits: 30 hp: 

Result of the thesis work should be documented in a report in English. A presentation should be given both in school and at Getinge. 

Why should you apply? 

Getinge is a leading MedTech company on an exciting transformation journey constantly looking for new ways to innovate together with our customers to meet the healthcare challenges of the future.  

This is an exciting opportunity for you who aspire to work in MedTech in the future and in an environment that is characterized by great care for the end customer, high pace, continuous learning and improvement. 

Welcome with your application no later than 2025-12-07 

For questions, please contact Lars-Erik Hoffsten : +46 (0)70 782 7626, lars-erik.hoffsten@getinge.com.