PhysioFlow. Hemodynamics Redefined.
The new reference in Cardiac Output monitoring
- PhysioFlow is a range of non invasive hemodynamic monitors. They provide continuous, accurate, reproducible and sensitive measurements of cardiac output and other parameters. Their innovative and patented technology is based on the proprietary principles of signal morphology impedance cardiography (SM-ICGTM).
- Only PhysioFlow is proven to work in demanding measurement conditions (highly instrumented ICU, maximal exercise, etc.) and difficult patients (obese, pulmonary oedema, emphysema etc.).
- PhysioFlow is the only non invasive cardiac output monitor approved by US FDA based on proven non inferiority to the predicate device Thermodilution Swan-Ganz catheter AND superiority to standard ICG.
- PhysioFlow is Health Canada Licenced and is in use in hospitals in Canada.
- PhysioFlow is non-invasive, easy to use, reliable, cost effective and has unique features.
Why Measure Cardiac Output?
Cardiac Output is the amount of blood pumped by the heart in liters per min. It is the true “raison d’être” of the heart.
Cardiac Output is a hemodynamic parameter that plays a key role in several physiological equilibriums. For instance: it is the dynamic force that generates arterial blood pressure by combination with the systemic vascular resistance. Another example is the close interaction between Cardiac Output, oxygen consumption (VO2) and peripheral oxygen extraction described by the “Fick” equation.
As a result and for instance, systemic hypertension should not be managed without the knowledge of cardiac output because Cardiac Output is a key contributor to the calculation of Systemic Vascular Resistance which is essential in understanding and managing this pathology. Similarly, relying on VO2 only to evaluate the physiology of exercise is way too restrictive considering the importance of cardiac and peripheral parameters as potential limiting factors for human performance.
Cardiac Output, Stroke Volume and their components (preload, contractility, afterload) need to be evaluated in dynamic manner. For instance, the rate of increase of Stroke Volume and contractility during exercise differs considerably from a heart failure patient to an athlete. Abnormal trend patterns in Stroke Volume during exercise are proven signs of cardiac function impairment (e.g. coronary artery disease). Another example: In critical care, fluid management is of paramount importance. Evolution and variation of Stroke Volume are markers of fluid status and need, for instance during Passive Leg Raise test.
Very unfortunately Cardiac Output has so far been underused because of the invasive, cumbersome and inaccurate nature of the available measurement techniques. Their cost has also been a limiting factor.
What makes a good Cardiac Output measurement system?
Ideally, a Cardiac Output measuring system should be non invasive, easy to use, cost effective and of course accurate. Invasive techniques, although being generally considered accurate, clearly lack in the first three departments.
Non invasive techniques are generally considered to be less reliable. This vision belongs to the past and needs to be revised. A more comprehensive understanding of a Cardiac Output device performance should encompass criteria such as reproducibility, sensibility and should take into full consideration the clinically significant margin of error of the so called “gold standards”.
In reality, with a margin of error of 15 to 20%, reference techniques are clearly flawed. Indeed, a change in Cardiac Output is considered being clinically significant starting with 15% (Pinsky. Why measure cardiac output? Critical Care, April 2003, 7:114-116 *). If one accepts a similar margin of error for the new technique (15%), even a difference in reading between the two techniques of as high as 30% (twice the clinical margin!) does not allow the operator to decide which device is right and which device is wrong (Critchley et al. A meta-analysis of studies using bias and precision statistics to compare cardiac output measurement techniques. J Clin Monit, 1999, 15: 85-91 *).
If a real and near perfect “gold standard” Cardiac Output measurement tool existed for validation purposes, it is not obvious that widely used Cardiac Output methods such as Thermodilution would be accepted as valid today by the medical community, the more so as they are often operator dependent and variable.
Furthermore, the invasive nature of these techniques and the inherent risk associated with their use (often under estimated by the operators) result in questionable outcomes in terms of mortality and morbidity, as shown in some well known studies (Connors et al. The effectiveness of right heart catheterization in the initial care of critically ill patients. JAMA 276, 1996).
The reasonable doubt about the accuracy and safety of these invasive techniques and the direct and hidden costs associated with their use should pave the way for alternative noninvasive approaches. This process is unfortunately very slow precisely because of the widespread confusion between clinical standard and gold standard. One may even consider doubting the validity of the entire scientific literature describing studies comparing new methods to these questionable gold standards, to say the least.
In summary a new gold standard in Cardiac Output measurement should feature:
- Reasonably correlated Cardiac Output readings as compared with invasive references considering their intrinsic margin of error.
- Superior reproducibility and sensitivity has compared to invasive reference techniques.
- PhysioFlow has it all !
PhysioFlow Enduro PF07
EnduroTM is a portable, battery powered, noninvasive cardiac output device that was designed primarily to be used while a subject or patient is exercising. EnduroTM is unique in that it is the only device that can reliably and repeatedly provide cardiac output during exercise.
A fundamental characteristic of patients with chronic heart failure is an impaired ability to increase cardiac output appropriately with exercise. Many patients are able to improve cardiac output after interventions; cardiac resynchronization therapy and exercise training are directly correlated with this. Quantifying cardiac output can therefore provide important information about these and other interventions. Recent studies have also demonstrated that this information is valuable in predicting outcomes in patients with cardiovascular disease.
PhysioFlow Enduro Features
- Small Size: 115 x 85 x 18 mm
- Light Weight: Less than 200g (with batteries)
- 6 thoracic surface electrodes
- Advanced adaptative filter for noise cancellation (HD-Z™)
- High performance AA batteries or rechargeable AA batteries, 6 hours autonomy
- 24 hours MMC memory, USB or BlueTooth wireless download
- Real time wireless monitoring using BlueTooth (type I). Range is 40 meters
- Works with PhysioFlow® PF107 MS WindowsTM-based software for display, data analysis, and storage
- Main Hemodymic parameters determined: Stroke Volume, Cardiac Output, Systemic Vascular Resistance, Ejection Fraction, End Diastolic Volume, Left Ventricular Ejection Time.
- Minimum computer configuration:
- Windows XP SP2 or later
- Windows 7 (avoid Windows Vista) or later 1.7 ghz X86 processor
- Ram : 1Gb
- Hard Drive 500 Mb Free
- 14 inch screen XVGA
- Preferably no Bluetooth module
- Recommended computer configuration:
- Windows XP SP2 or later
- Windows 7 (avoid Windows Vista) or later 2.3 ghz X86 processor
- Ram : 2Gb
- Hard Drive 500 mo Free
- 15 inch screen XVGA
- Preferably no Bluetooth module