The purpose of a cardiovascular monitor is to provide an early warning
of an impending cardiovascular disaster. Though cardiovascular monitors have
undergone tremendous technological improvements over the last 50 years (from a "bouncing
ball" display in the '50s to current multicolor display), these technological
improvements have not been paralleled by improvements in outcomes of patients
monitored by these monitors.
Current patient monitors routinely display the digital values of five parameters (Heart Rate, Systolic, Diastolic and Mean Arterial Pressures and the SpO - percentage saturation of oxygen in arterial blood) and several analog signals. The parameters, which the monitors display, have not been chosen as a result of their clinical significance (i.e., related to Oxygen Delivery - an outcome-related parameter) but as a result of their historical availability. With the exception of displayed analog signals (ECG and SpO), which are graphical plots in time, current monitors do not utilize other graphic means to enhance the information provided by the monitor, so it could become more clinician-friendly.
If the monitor has an additional capability to calculate the value of vascular
resistance from measured blood pressure and blood flow, it displays it either
(a) SVRI - Systemic Vascular Resistance Index - [when MAP and CI are used for its calculation], which is hemodynamically incorrect and may mislead the clinician about the actual status of afterload, or as
(b) SVR - Systemic Vascular Resistance - [when MAP and CO are used for its calculation], which value, unrelated to body habitus, does not exhibit a normal range and, therefore, is totally wrong for assessing the level of afterload.
On some patient monitors the operator can set alarms on parameters he/she considers vital and the alarm sounds when the monitored parameter's value exceeds the preset range. Unfortunately, the patient's hemodynamics has to enter the danger zone before the alarm sounds.
Current patient monitors do not provide information about the relationship of the measured parameter to its normal range (if the monitored parameter's value is within a normal range, or if it is high, or low). This situation is further exacerbated by the fact that the normal range for each monitored parameter is different in respect to a patient's gender, age and clinical state. This fact has not become an important design consideration of current patient monitors. It is up to the clinician, his education and past experience, to decide if the parameter is within a normal range for the monitored patient, or if it is infra- or supranormal.
Lastly, monitors do not provide the therapeutic information, i.e., what therapy to administer to a patient, to reach a desired hemodynamic state.
As a result of the points listed above, current monitors support the reactive approach to medicine - the clinician either responds to a cardiovascular disaster already taking place or starts treating the patient if or when the abnormality demonstrates itself or is discovered. It is estimated that in about 40% of population with a latent cardiovascular disease, the first ever indication of a cardiovascular problem in this subgroup is patient's death.
In contrast to the conceptual problems of patient and TEB monitors listed above, BoMed's and HEMO SAPIENS' TEB Products have been designed as proactive systems. They monitor complete hemodynamics (including the Cardiac Index - the only dynamic modulator of Oxygen Delivery), provide information, which of the monitored parameters are within their normal ranges (a function of gender, age and clinical state) and which are not, and provide hemodynamic management information (what therapy to administer to reach the desired hemodynamic and perfusion state - i.e. the therapeutic goal), thus enabling the clinician to maintain a patient in a normohemodynamic and normoperfusion state. In addition, they allow hemodynamic modeling of the hemodynamic effects of cardio- and vasoactive pharmaceutical agents.