Comparison of Pulse Wave and Blood Pressure Measurements Before, During and After Ergometry in Healthy Women

In a randomized single-blind study design the investigators explore how well blood pressure parameters calculated using a Pulse Transit Time-based method (device: SOMNOtouchTM RESP) match blood pressure parameters measured by a classic upper arm blood pressure cuff (BOSO-TM-2430 ) under standardized load conditions (ergometry).

In 30 healthy female subjects (age 18 - 40 years), cardiovascular parameters before, during and after a standardized load on a bicycle ergometer (half-lying position) are recorded with three different devices (BOSO-TM-2430 versus SOMNOtouchTM RESP versus GeTeMed Vitaguard 3100) and compared.

Primary outcome is the difference of the systolic blood pressure values between the devices BOSO-TM-2430 versus SOMNOtouchTM RESP during the three phases.

The BOSO-TM-2430 blood pressure cuff is applied randomized to the arm with the previously determined higher or lower systolic blood pressure mean difference. The subjects are blinded to the results of the measurements during ergometry.

After a pre-rest period of 12 minutes, the subjects are physically strained on the ergometer for 48 minutes (6 minutes loading phase followed by a 2-minute rest phase; 30 watts increase every 8 minutes up to a maximum load of 180 watts), followed by a 12-minute rest period. Measurements are taken every two minutes with the BOSO-TM-2430; data acquisition with the SOMNOtouchTM RESP and GeTeMed Vitaguard 3100 devices takes place continuously over a total duration of 72 minutes.

Inclusion criteria

• Signed informed consent
• Healthy at the time of the examinations
• Inconspicuous anamnesis regarding cardiovascular diseases and bronchial asthma
• resting heart rate 50 to 100 beats per minute
• Normal blood pressure or appropriately treated and controlled hypertension (systolic blood pressure ≤ 140 mmHg and diastolic blood pressure ≤ 90 mmHg)

Exclusion criteria

• Acute or chronic (especially cardiovascular) diseases, including cardiac arrhythmia and vegetative regulatory disorders (recorded via anamnesis)
• Taking allopathic medication: digitalis, beta blockers, antiarrhythmics
• Bronchial asthma (recorded by anamnesis)
• Alcohol abuse
• Heart diseases NYHA class IV
• Blood pressure side difference ≥ 10mmHg
• Fever (> 37,5°C)