Thermodilution injectate system with filter

DETAILED DESCRIPTION The present invention provides an improved thermodilution system that includes a filter that acts as a barrier to prevent bacteria and particulates from passing along with the injectate into the patient.
In particular, a microporous filter is utilized in the system downstream of the pump, syringe and most all of the possible sources of bacteria or other contamination.
The filter is placed as close to the actual catheter that is positioned within the patient so that it traps the bacteria from entering the patient.
The filter itself is of the type currently available for use with syringes that administer one time injections, such as for epideral anesthesia, cardiac block, spinal anesthesia and the like and comprises a microporous membrane having a 0.
2 um pore size, yet it can allow relatively high flows, i.
e.
150 cc/min without difficulties.
Since such typical filter membranes are also hydrophilic, there is an additional advantage that entrapped air in the injectate is also prevented by the filter from entering the patient where such air could cause harm.
One major advantage of the filter barrier is that it acts as a final screen of the injectate liquid and thus will filter out bacteria introduced via any upstream source, thus not only is the syringe eliminated as a possible source of such bacteria, but the connections, tubing, liquid reservoir and all other components can be downplayed as sources where the bacteria may inadvertently enter the injectate.
As a further advantage, the filter itself may be readily available commercially and one such filter is marked as the Super DIL Syringe Filter by Gelman Sources of Ann Arbor, Mich.
That filter is generally sold for affixing on the end of a syringe for one shot or single use applications and is inexpensive.
Accordingly, by the use of such filter downstream of the areas where entering of bacteria is likely, the actual injectate that enters the patient can be filtered and bacteria removed to enhance the safety of the liquid injectate administered to the patient