Mobile phone measures the ease of breathing

A new innovation developed at the University of Oulu makes it easier to measure asthmatics’ breathing, among other things. The smartphone-based application is an easy and cost-effective alternative to expensive hospital examinations.

Allergies and different types of asthma are becoming more common worldwide, and air pollution and indoor air problems put a strain on the respiratory organs of increasing numbers of people. From the 1990s onwards, Professor of Biomedical Technology and Head of the Physiological Signal Analysis Group Tapio Seppänen has focused on the research of respiratory wave signals with his research team.

Their long-term work has resulted in a mobile respiratory measurement tool called the Respiratory effort test.

“We wanted to create a quick, easy and affordable way to measure the ease or difficulty of breathing”, says Professor Seppänen. “We explored the possibilities of using a mobile phone to measure respiration. Today's mobile phones contain many sensors and advanced measurement technology, making them a versatile measuring tool.”

The mobile phone travels with everyone, without the need for separate measuring devices. Now the Respiratory effort test is in the phase of clinical testing, and a global patent application has been submitted.

Chest movements reveal heavy breathing

Traditionally, respiratory events in the upper and lower airways are measured with a whole body plethysmograph, BodyBox, only available in the largest hospitals. The measurement is conducted in an airtight box, by inhaling into a tube. Measurements performed with BodyBox require trained personnel and a visit to a hospital. Lasting one whole hour, the examination can be strenuous for the patient.

The Respiratory effort test provides the same information within a few minutes by using the patient’s own mobile phone. “In this respect, we have replaced the BodyBox with a mobile phone,” Tapio Seppänen laughs.

"We use a mobile phone to measure the breathing, and mathematical models to calculate details related to the respiratory wave. The resulting information can be used to interpret abnormal respiratory events.”

As breathing becomes constricted, the airways contract and air resistance grows. This also increases the amount of breathing work. “Chest movement reflects the breathing work performed by the diaphragm and intercostal muscles between the ribs. They create a vacuum to draw in air, and when relaxing, they let the air flow out,” Seppänen says.

“If there is a stenosis in the airways, you will have to press with your muscles and do more work to move the airflow. As a result, the chest movement changes. We can calculate such a blockage on the basis of the signal shape.”

“The Respiratory effort test uses artificial intelligence in a medical application. The application recognises patterns in the respiratory event, that is, the machine is taught how to find a pattern reliably. The application also instructs the user on how to take the measurement correctly. In other words, a person has dialogue with a machine.”

Measurements within a few minutes

In addition to Tapio Seppänen, the Respiratory effort test is developed by Professor Olli-Pekka-Alho from the Ear, Nose and Throat Clinic, MSc Tiina Seppänen, who is working on her doctoral dissertation in the field of medical technology, and Project Researcher Niina Palmu.

Niina Palmu is an expert in the commercialisation of health technology, and she is also involved in the commercialisation of the Respiratory effort test. She also examines how patients can best be guided through the measurement process.

“During the measurement, a mobile phone is placed in the correct position on the chest. Inhalation takes place according to precise instructions: at first, you breathe through your nose, mouth closed, in and out, taking big breaths but in a normal manner,” says Palmu. This provides material on respiratory events taking place in the upper airways.

“Then you breathe through your mouth, holding your nose in order to obtain a result of the respiratory event taking place in the lower airway. Finally, the Respiratory effort test provides results on the ease of breathing separately for the upper and lower airways, and the overall result,” Niina Palmu says.

A measurement can be taken at home, at the workplace or at a doctor's office.

“In order to make the measurements taken at home reliable, we need to instruct the user on how to conduct the measurements correctly. This is one of our research questions: how to instruct people?” Niina Palmu says contemplatively.

“The device must also be instructive; it must indicate whether the measurement has been taken correctly,” adds Seppänen.

The Respiratory effort test has many target groups

In interviews with doctors, measurements based on a smartphone received a surprised and enthusiastic reception. “It is handy to measure with a device that is already in your pocket,” says Niina Palmu.

“The Respiratory effort test is a convenient method for assessing the effectiveness of treatment and for home monitoring. Asthmatics’ drug response can be assessed by using the test. Moreover, measurements can be taken several times a day, at different times of the day and in different situations. You can also do this at the workplace if there are problems with indoor air, or outdoors in surrounded pollution or street dust”, describes Tapio Seppänen.

The Respiratory effort test also supports parents in assessing the situation of an asthmatic child or young person. A measurement makes it is easier to decide whether to administer more medication or take the child to see a doctor.

“If you have a pulmonary disease, asthma or COPD, you will adapt to it. The situation starts to feel normal, even if it is objectively poor. A measurement gives you the right picture of the situation”, says Tapio Seppänen.

Before the Respiratory effort test can enter the market, there is a long and thorough test phase ahead. 'Clinical testing lasts for years, as this is a medical device. We are now looking for funding for the validation phase,” Seppänen and Palmu say.

MobiResp project, in which the Respiration effort test was developed, received Proof of Concept funding from the University of Oulu in 2017. The New business from business ideas (TUTLI) funding granted by Business Finland made it possible to identify the innovation’s business opportunities. Research funding is still needed before the Respiration effort test can be placed on the market.

Text: Satu Räsänen

Physiological Signal Analysis Group

Center for Machine Vision and Signal Analysis

Last updated: 13.6.2019