More than 50% of colleagues worldwide are not flushing follicles during egg collection.  The primary reason for this are studies, published in the early nineties, comparing egg retrievals using two needles with the same outer diameter (Single Lumen Needles and Double Lumen Needles). All of the authors concluded that that they harvested the same number of oocytes with either needle, but the duration of egg collection procedure took 2 to 3 times longer using the double lumen needles.

Consider Poiseuille`s law about flow of fluid through pipes, which concludes that a decrease of a lumen of 19% would halve the flow rate in a pipe.

Since the flushing tubing inside a Double Lumen Needle decreases the inner

lumen more than 19%, the turbulences and the flushing effect using a Double Lumen Needle compared to a single lumen needle is minimized. It is likely this explains why the results of the above comparative studies showed no differences.

My invention of the STEINER-TAN Needlecombines the effect of a free inner lumen as in a Single Lumen Needle, but with the benefit of flushing. There is a communication approximately 7 to 8cm proximal of needle tip of a 17 gauge or a 21a gauge needle with a plastic flushing tubing that is surrounding the needle that makes this possible.

Please click for more information (physical background, Computer Animation):

-          Textbook Of Minimal Stimulation IVF(PDF)

-          STEINER-TAN Needle in IVM and normal IVF in egg collection(video)

-          Egg collection in IVF flushing follicels with a single lumen needle(video)

-          STEINER-TAN Needle 21 gauge vs. 17 gauge Double Lumen Flushing Effect(video)

In these times where going back to nature is so popular (Mild IVF and Natural Cycle IVF), the STEINER-TAN Needle21 gauge is the only needle in the world designed for flushing follicles as small as 3mm in diameter.

The combination with STEINER Flush/ Valve,flushing pump with syringe warmer, will open a new era of Egg Collection and hopefully change the paradigm from non-flushing towards flushing follicles in IVF.