TOP 5 Reasons why researchers choose the Finapres® NOVA:
1. Well-validated non-invasive continuous blood pressure monitoring
2. Re-usable finger cuffs
3. More than 50 cardiovascular parameters available
4. Analog I / O module to import and export analog signals
5. Various data export options, beat-to-beat, and raw data exports.
And since Finapres devices are being used by so many research institutes worldwide, it is much easier to compare your data and efficiently collaborate with other universities and research institutes, for example in multi-center clinical trials.
The volume-clamp method for non-invasive beat-to-beat blood pressure measurements was first introduced in 1973 by the Czech physiologist Prof. Dr. J Peňáz. He demonstrated that it is possible to perform continuous measurements of finger arterial pressure by using a finger cuff! All Finapres® devices include a calibration algorithm called Physiocal. This algorithm prevents drifts in the measured finger pressure due to arterial contractions and relaxations, related to smooth muscle activity in the finger arteries.
The development and validation of the Physiocal algorithm has been widely described in the peer-reviewed literature (Wesseling 1995, Imholz et al. 1998, Langewouters et al. 1998). Additionaly, Guelen et al. (2008) showed that generalized waveform filtering and level correction enables a reliable conversion from finger artery pressure waveform to the brachial arterial pressure in 37 cardiac patients. The blood pressure signal of the Finapres® NOVA with NANO CORE® technology meets accuracy requirements of ISO 81060-2: 2013 standards, with the radial artery as used reference site.
1. Peňáz, J. “Photoelectric measurement of blood pressure, volume and flow in the finger” In: Digest of the 10th International Conference on Medical and Biological Engineering. Dresden (1973) ( Available upon request)
2. Wesseling, KH. “Physiocal, calibrating finger vascular physiology for Finapres.” Homeostasis (1995) ( Available upon request)
3. Imholz et al. 1988 “15 years experience with finger arterial pressure monitoring”
4. Langewouters et al. 1998 “Why use Finapres or Portapres rather than intra-arterial or intermittent non-invasive techniques of blood pressure measurement?”
5. Guelen et al. 2008 “Validation of brachial artery pressure reconstruction from finger arterial pressure”
The Finapres® NOVA is an innovative hemodynamic monitoring system, which provides accurate non-invasive continuous blood pressure measurements using just a finger cuff. This facilitates several applications, such as autonomic failure diagnosis, hemodynamic evaluation, physiology education, sleep disorder research, and exercise testing!
In 1988, Imholz et al. already demonstrated that the Finapres® device is able to reliably monitor the beat-to-beat blood pressure response during the Valsalva maneuver in 15 subjects. This makes the Finapres® device a reliable alternative to intra-arterial blood pressure monitoring. Many other papers describe the value of continuous blood pressure monitoring with Finapres® during tilt table testing, the active stand test, sleep monitoring, etc.
- Valsalva maneuver: Imholz et al. 1988 “Continuous non-invasive blood pressure monitoring: reliability of Finapres device during the Valsalva maneuver”
- Active stand testing: Finucane et al. 2019 “A practical guide to active stand testing and analysis using continuous beat-to-beat non-invasive blood pressure monitoring”
- Tilt table testing: Cheshire & Goldstein 2019 “Autonomic uprising: the tilt table test in autonomic medicine”
- Physiology education: Hodgson et al. 2012 “Continuous and noninvasive recording of cardiovascular parameters with the Finapres finger cuff enhances undergraduate student understanding of physiology”
- Sleep monitoring: Leroy et al. 1996 “Short-term variability of blood pressure during sleep in snorers with or without apnea”
In autonomic testing, standardized procedures are essential for reliable test results. Finapres Medical Systems developed a Guided Autonomic Testing (GAT) Application as part of the Finapres® NOVA, which guides the operator and the patient through a series of autonomic test maneuvers. The GAT application facilitates the Valsalva test, Tilt Table test, Deep Breathing test, Stand test, Cold Pressor test, Carotid Sinus Massage test, and Drugs Administration test.
- ESC guidelines: Brignole et al. 2018 “ESC Guidelines for the diagnosis and management of syncope”
- Quantitative testing: Novak 2011 “Quantitative Autonomic Testing”
- Autonomic testing: Lahrmann et al. 2011 “Diagnosing Autonomic Nervous System Disorders – Existing Guidelines and Future Perspectives”
- Valsalva maneuver: Goldstein & Cheshire 2017 “Beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver”
- Tilt table testing: Cheshire & Goldstein 2019 “Autonomic uprising: the tilt table test in autonomic medicine”
- Active stand testing: Finucane et al. 2019 “A practical guide to active stand testing and analysis using continuous beat-to-beat non-invasive blood pressure monitoring”
The Advanced Hemodynamics (HD) software application enables relevant hemodynamic parameters on the Finapres® NOVA. This HD application gives more insight into various cardiovascular parameters, supporting health care professionals and researchers in studying and diagnosing their patients. It uses a statistical model of the human circulation to calculate the hemodynamic parameters from the finger arterial pressure waveform.
This algorithm computes the aortic flow waveform by simulating a non-linear three-element model of aortic input impedance, as described by Wesseling et al. in 1993. The aortic impedance is modeled based on the age, length, weight and gender of the patient, while the systemic vascular resistance is predicted from the mean pressure and model mean flow. This so-called Modelflow® algorithm is widely validated, for instance by Harms et al. (1999), Jansen et al. (2001), Leonetti et al. (2004) and Bogert et al. (2005).
- Wesseling et al. 1993 “Computation of aortic flow from pressure in humans using a nonlinear, three-element model”
- Harms et al. 1999 “Continuous stroke volume monitoring by modeling flow from non-invasive measurement of arterial pressure in humans under orthostatic stress”
- Jansen et al. 2001 “A comparison of cardiac output derived from the arterial pressure wave against thermodilution in cardiac surgery patients”
- Leonetti et al. 2004 “Stroke volume monitored by modeling flow from finger arterial pressure waves mirrors blood volume withdrawn by phlebotomy”
- Bogert et al. 2005 “Non-invasive pulsatile arterial pressure and stroke volume changes from the human finger”
The Autonomic Testing (AT) software application enables various Heart Rate Variability (HRV) parameters on the Finapres® NOVA with ECG module. These parameters can aid the physician to obtain detailed insights into the dynamics of sympathetic and parasympathetic innervation of the human cardiovascular system.
Heart rate variability (HRV) is the fluctuation in time intervals between adjacent heartbeats. Our HRV parameters are derived from the ECG signal, obtained in time- and frequency domain, and based on a 5-minute interval. Subsequently, the HRV signals are updated every heartbeat. A filter is applied to detect and remove abnormal beats. The method to calculate the HRV parameters is based on the HRV Guidelines (Camm et al. 1996), published by the European Heart Journal.
Both the HD application and the AT application provide the Baroreceptor sensitivity (BRS) parameter. This parameter describes the amount of response in heartbeat interval to a change in blood pressure, expressed in ms / mmHg. The BRS is obtained from the systolic blood pressure signal and derived using a well-validated cross-correlation method, published by Westerhof et al. (2004). This so-called xBRS method calculates the correlation between beat-to-beat blood pressure and delayed pulse intervals. The measurement of the baroreflex is a source of valuable information in the clinical management of cardiac disease patients, particularly in risk stratification (La Rovere et al., 2008).
Calculation and validation of Finapres® xBRS parameter
- Westerhof et al. 2004 “Time-domain cross-correlation baroreflex sensitivity: performance on the EUROBAVAR data set”
- Westerhof et al. 2006 “Time course analysis of baroreflex sensitivity during postural stress”
- La Rovere et al. 2008 “Baroreflex sensitivity: measurement and clinical implications”
