Gyrocardiography- A New Non-invasive Cardiac Measurement Method to Measure Exercise Capacity and Cardiorespiratory Fitness

The goal of this study is to produce a solution to measure the cardiorespiratory fitness (CRF), which can be used by commercially available smartphones without extra equipment, add-ons and special know-how.

This observational study with follow-up is to test the feasibility of a new non-invasive cardiac measurement method (gyrocardiography, GCG) in detecting hemodynamic parameters to measure exercise capacity and cardiorespiratory fitness in healthy subjects.

The objective is to produce a solution which can be used to measure the exercise capacity and cardiorespiratory fitness (CRF) of the exercisers, keep-fit athletes and professional athletes using hemodynamic parameters such as:

• Heart rate and Heart rate variability
• Cardiac Strength profile
• Systolic and diastolic phase
• Breathing frequency
• VO2max

Participants are either athletes or non-athletic persons. The athletes will perform spiroergometry and non-athletic persons ergometry to measure the CRF expressed as VO2max.

Following parameters will be measured during the (spiro)ergometry:

• Maximum workload (W)
• VO2max (ml/kg/min)
• HRmax
• Blood lactate
• Respiratory exchange ratio RER (VO2/VCO2)

The GCG measurements for acquiring the hemodynamic parameters are performed before and after the (spiro)ergometry using smartphone. During a 1- minute GCG measurement, the smart phone is placed on the chest in the middle of the sternum.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Diagnostic test: Ergospirometry; Diagnostic test: Ergometry

• Study Type: Observational
• Enrollment (Actual): 102

Contacts and Locations

Study Locations

• Finland
  • Turku, Finland, 20540
    • Paavo Nurmi Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Healthy subjects from the area of Turku. Half of the subjects (n=100) are allocated to athletic group (moderate to high Physical activity, PA, levels according to International Physical Activity Questionnaire, IPAQ) and other half (n=100) to non-athletic group (low levels of PA according to IPAQ).

Description

Inclusion Criteria:

• Age: 18-65 years
• No diagnosed cardiovascular diseases (mild hypertension or hypercholesterolemia are still allowed)
• No medication affecting heart rate (i.e. Beta blocker)
• Signed informed consent

Follow-up visit:

• Belong to non-athletic group
• Intention to change physical activity habits
• Willing to participate to the follow-up visit

Exclusion Criteria:

• Not meeting inclusion criteria
• Declined to participate
• Resting RR before the ergometry > 180/110mmHg

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
athletic group; Moderate to high PA levels according to IPAQ.	Diagnostic test: Ergospirometry; VO2max is measured using a stationary bicycle ergometer (Ergoline 800 s; VIASYS Healthcare, Germany. For males, the test starts with 100 W which is increased by 25 W every 1 min until volitional exhaustion. For females, the test starts with 50 W which is increased by 25 W every 1 min until volitional exhaustion. Ventilation and gas exchange (Vyntus CPX, Vyaire Medical Gmbh, Leibnizstrasse, Hoechberg, Germany) are measured during the test. Subject's blood lactate concentration is measured from capillary samples immediately and 1 min after exhaustion (Biosen C-Line Glucose and Lactate analyzer, EKF-diagnostic GmbH, Germany). The heart rate of the participants is followed continuously (CardioSoft GE, CardioSoft V6.51; GE Medical Systems Information Technologies, USA). (Heiskanen et al. 2021.)
non-athletic group; Low levels of PA according to IPAQ.	Diagnostic test: Ergometry; Maximal exercise test is performed on a cycle ergometer (Ergoline 800 s; VIASYS Healthcare, Germany). The test begins at a workload of 50 W, which is increased by 25 W (males) every 1 min or the test begins with 25 W which is increased by 25 W (females) every 1 min until exhaustion. The mean workload during the last 4 min of work is calculated and the VO2max is estimated according to the American College of Sports Medicine (American College of Sports Medicine. ACSM's guidelines for exercise testing and prescription. Sixth edition. Baltimore: Williams & Wilkins 2000:304). Blood lactate concentration is measured immediately and 1 min after exhaustion from capillary samples (Biosen C-Line Glucose and Lactate analyzer, EKFdiagnostic GmbH, Germany). (Pahkala et al. 2013.)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The maximum (max) rate (V) of oxygen (O₂) your body is able to use during exercise.		4 minutes
Gyrocardiography measurement	Lasts 1 minute and is performed at least once at rest before the (spiro)ergometry.	1 minute
Gyrocardiography measurement	Lasts 1 minute and is performed 3 minutes after the (spiro)ergometry.	3 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate per minute and Heart rate variability	Lasts 1 minute and is performed at least once at rest before the (spiro)ergometry.	1 minute
Heart rate per minute and Heart rate variability	Lasts 1 minute and is performed 3 minutes after the (spiro)ergometry.	3 minutes
Systolic and diastolic phase (blood pressure RR)	Will be performed at least once at rest before the (spiro)ergometry.	1 minute
Respiration rate per minute	Lasts 1 minute and is performed at least once at rest before the (spiro)ergometry.	1 minute
Respiration rate per minute	Lasts 1 minute and is performed 3 minutes after the (spiro)ergometry.	3 minutes
Cardiac Strength profile	Lasts 1 minute and is performed at least once at rest before the (spiro)ergometry.	1 minute
Cardiac Strength profile	Lasts 1 minute and is performed 3 minutes after the (spiro)ergometry.	3 minutes

Collaborators and Investigators

• Sponsor: Precordior Ltd
• Collaborators: Paavo Nurmi Centre
• Investigators: Principal Investigator: Olli Heinonen, PhD, Paavo Nurmi Center

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2023
• Primary Completion (Actual): December 31, 2024
• Study Completion (Actual): December 31, 2024

Study Registration Dates

• First Submitted: June 16, 2023
• First Submitted That Met QC Criteria: June 29, 2023
• First Posted (Actual): July 10, 2023

Study Record Updates

• Last Update Posted (Actual): July 14, 2025
• Last Update Submitted That Met QC Criteria: July 9, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: Sport Study

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No