An inexpensive, fast and reliable estimate of cardiorespiratory fitness

Less than 3 minutes from start to finish

Seismofit® System

Cardiorespiratory fitness (CRF), measured as VO2-max may be determined by the Seismofit® System. Seismofit® measures the vibrations that arise from the beating heart and transmit to the chest wall. The method of measuring these vibrations is referred to as seismocardiography.

Each heart has its own signature relating to the opening and closing of valves and the contraction and relaxation of the heart chambers. The Seismofit® System measures these vibrations using the Seismofit® device. The signal is transferred to a  smartphone app and a cloud-based algorithm analyses the signal. The estimated VO2-max is returned to the smartphone app.


Importance of Cardiorespiratory Fitness

In recent years, the importance of measuring, estimating, and monitoring cardiorespiratory fitness (CRF) has been increasing. CRF is a good indicator of overall health and, according to a statement paper from the American Heart Association, it is potentially a stronger predictor of mortality, compared to commonly used risk factors. 

From the Statement Paper from the American Heart Association

“At a minimum, all adults should have CRF estimated each year using a non-exercise algorithm during their annual healthcare examination. Clinicians may consider the use of submaximal exercise tests or field tests as alternatives because these involve individual-specific exercise responses.“


What is Cardiorespiratory Fitness?

Cardiorespiratory Fitness reflects metabolism and, as the name indicates, the lungs and heart interact by supplying oxygen to tissues and organs and by eliminating carbon dioxide. The maximal oxygen capacity of a person means the maximal oxygen consumption determined until exhaustion and is called VO2-max.

Cardiorespiratory fitness measured as VO2-max correlates not only to fitness but to general health.


Determining VO2-max:
Current methods are too complicated

Ergometer cycling or treadmill running are gold standards for determining VO2 max. Various protocols are used, e.g. increasing the load at given time intervals with measurement of oxygen consumption during the test until exhaustion. Submaximal testing protocols that do not reach maximal pulse and exhaustion may be used if the test subject may be at any health risk with maximal exercise. The test will, when including dressing and preparation, take up to 30 minutes.

Golden Standard VO2-max
Traditional ergometry 8-12 min plus time for preparation


Sports Medicine:
Use of Cardiorespiratory Fitness in Sports

VO2-max is a predictor of performance, although its correlation with athletic success in endurance sports is only 30–40%, with other factors such as sustainable lactate threshold, motivation, training, etc., also playing a role. In general, however, the higher the VO2-max the more potential for a successful performance in an aerobic endurance event.

World-class men will have fitness scores ranging from 60 to 90, and women from 50 to 72.


Our Mission

Making Cardiorespiratory Fitness measurement a part of everyone’s health check

VentriJect was established as a spin-out from a leading research centre in cardiology at Aalborg University in 2018 and is located in Hellerup near Copenhagen, Denmark.

Read about the latest news here.

Ryvangs Allé 81
2900 Hellerup
Copenhagen, Denmark



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