The Hemodynamic Cardiac Profiler (HCP) uses a dedicated thorax electrode configuration of 16 electrodes (quite similar to ECG electrodes) which are connected to a small wearable patient unit (PU) via cables. Data from the patient unit are transmitted to a medical PC and display using wireless telemetry.
Figure 1: General arrangement of the Hemodynamic Cardiac Profiler
A harmless weak electrical current is injected into the patient's skin by two electrodes at the neck base and two at the lower abdomen. The movement of the heart structures and the blood emptying/filling fraction by the heart chambers and large associated vessels, as well as breathing action and upper body muscle use, causes local changes to voltage potentials measured by the strategically placed electrode array on the patient's chest.
Figure 2: Application of a weak harmless current injection.
After measuring and storing the voltage potential shift data on eight separate channels, and using a unique patented algorithm called "Field Recognition", the HCP patient unit is able to filter the data by an algorithm into an atrial and ventricular 'fingerprint'. These signals are then plotted as a stoke volume curve that represents and quantifies the left atrial and left ventricular filling during the cycle of a heartbeat. Data refreshes every 20 seconds.
Figure 3: The atrial and ventricular fingerprint in the voltage shift pattern during a hemodynamic cycle.
Figure 4: Example of a ventricular filling curve with associated ECG timing and filling phases.
The patient unit transmits the data wirelessly to a remote viewing station. The profile of the presented curve holds valuable data about the emptying and filling action and volume of the heart and possible abnormalities that may be asymptomatic.
Such data is otherwise only available to a clinician if ordered through more complicated and extensive diagnostic tests such as Echocardiography (Echo Doppler), or magnetic resonance imaging (MRI) to be scheduled, usually during a second, third and fourth visit which takes time to organize and places burden on both the patient and hospital resources, and are more costly.
Figure 5: Typical cardiac abnormalities that can be derived from the curve profile
Curve profiles differ for the young patient versus the old, the healthy versus the ill, and also the influence of exercise can be seen. The results of the Hemodynamic Cardiac Profiler are easy to interpret by a trained physician. Thereby, for the first time hemodynamics can be assessed very early on in the dagnostic process.
It is a tool that provides objective hemodynamic insight without operator bias, and allows comparison of hemodynamic performance of a longer period of time.