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

Study Overview
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Brief Summary
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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.

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

Conditions
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Healthy

Intervention / Treatment
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* Diagnostic Test: Ergometry
* Diagnostic Test: Ergospirometry


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| athletic group<br>Moderate to high PA levels according to IPAQ. | Diagnostic Test: Ergospirometry<br>* 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.)<br>|
| non-athletic group<br>Low levels of PA according to IPAQ. | Diagnostic Test: Ergometry<br>* 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.)<br>|

What is the study measuring?
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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 |