Dr. Kraus Uses the C100 to Deliver Small Amounts of H2S in Suspended Animation Experiments
For Dr. David Kraus, linearity and precision matters. Imagine being suspended in time—having your metabolism slow, heart rate decrease, and temperature drop.  This is what Dr. Kraus and other scientists are discovering—with small amounts of H2S, we can buy time in suspended animation.

In his earlier experiments, Dr. Kraus, a seasoned Sulfide Biologist from the University of Alabama at Birmingham, partnered with Sierra to demonstrate how garlic derived compounds produce Hydrogen Sulfide (H2S) and can relax the vessels in our bodies.  These experiments proved that garlic is indeed beneficial to our cardiovascular systems, relaxing our smooth muscles to increase blood flow. (Read Story)

In 2005, Dr. Kraus decided to take his experiments with H2S to a new level.  At this time, Mark Roth a scientist from the Fred Hutchinson Cancer Center in Seattle was conducting groundbreaking suspended animation experiments.  Roth also used Sierra’s C100 for this research. Inspired by Roth’s work, Dr. Kraus set out to conduct his own suspended animation experiments.  From his previous experience and Mark Roth’s reference, Kraus thought that the C100 could successfully handle this application.

Dr. Kraus described his application to David Burks, Sierra’s representative from Engineered Products, LLC out of Alabama.  According to Burks, “most controllers are used for common standard-popular gases (air, argon, nitrogen). But Dr. Kraus’ testing and research uses a special blend of: 5% hydrogen sulfide, 95% balance nitrogen”, with a very low flow range of 1-10 sccm, mixed into another stream of combined air and N2 mixture. 

Dr. Kraus did have some “concerns about the ability to accurately measure ‘mixed gases’” with the Smart-Trak.  To get to the bottom of this, Burks quickly e-mailed Sierra’s lead Application Engineer, Fred DeJesus, to confirm that the C100 could indeed remain accurate even with his specialty gas blend application.

Laminar Flow Technology Allows Dr.Kraus to have Accuracy Even With a Custom Blend  
Fred DeJesus confirmed that Sierra’s Laminar Flow technology was perfectly suited for Dr. Kraus’ custom blend application.  Technicians at the factory could use the Smart-Trak’s Dial-a-Gas® capability to program a custom listing for his 5% H2S blend.  Then in the laboratory, Kraus could select this programmed mixture from the Dial-a-Gas® menu or use the same instrument to measure any of the other nine pre-programmed gases.  

Dr. Kraus’ concerns about accuracy are well-founded.  His application requires the C100 to precisely maintain 1% accuracy from 0-10 sccm of H2S, an anesthetic gas.  When delivered appropriately, H2S is beneficial but in excess can be poisonous, even lethal.  With traditional mass flow controllers, gas mixtures are notorious for being inaccurate.  During calibration, most instruments are “curve-fit” to the application because they are not linear.  They are calibrated with a primary gas, but a gas mixture has different properties than the primary gas, so the original curve is not correct for the mixture.  Sierra’s Laminar Flow technology, however, creates a linear relationship that allows the K factors programmed into the C100 to correct for any gas blend over the entire flow range.  The C100 is so linear that it's only calibrated at zero and full scale.

David Burks, Sierra’s Representative Out of Alabama, Responds Quickly to Dr. Kraus
Dr. Kraus contacted David Burks again upon receiving his C100s.  Apparently, an early calculation had been incorrect and the maximum flow for one of his controllers was now too low.  Dr. Kraus could not get enough flow through his controller to do his research. With diligent correspondence with the factory, Burks worked to solve the problem and eventually found a way to have Sierra re-range the controller, so Kraus could begin his research. This is what differentiates Sierra:  Our ability to readily collaborate with customers to solve problems and customize solutions, quickly, innovatively, and in good spirit.

Burkes states that “Dr. Kraus was (and is) very much appreciative of our effort and support.”

Suspended Animation is a Major Medical Breakthrough
After getting these answers, Dr. Kraus installed his C100s to precisely deliver small amounts of H2S to his laboratory mice.   Sierra’s powerful solenoid valve gives the C100 this type of precision control and accuracy even at the very low flow range of 1-10sccm.  No mice died from the toxic H2S gas and all his subjects reached suspended animation-a C100 success. 

Just like Mark Roth, Dr. Kraus observed a suspended animation-like state in his laboratory mice.  Excitedly, he explains that their heart rates decreased from 650 to 50 beats per minute and their breathing rate dropped from 140 to 20 breaths per minute.  Their metabolic rate and core body temperature also decreased, suspending their body in time.  And when the H2S was removed, the mice came "back to life". 

According to Dr. Kraus’ these suspended animation breakthroughs will change the face of the medical field. He believes "this may be one of the most important medical breakthroughs of this century."

Imagine, being able to inject a trauma patient with H2S to completely stop their metabolism, slow their bleeding, “to buy time for critically injured trauma victims. Putting these patients into suspended animation could stave off deterioration of their tissues while doctors repaired their injuries" (Roth and Nystul).  The Army also is very interested in this work with suspended animation.

In 2007, Dr. Roth recently received a MacArthur Genius Award for his work with H2S induced suspended animation.  And he used Sierra.

Dr. Kraus also plans to go commercial with his discoveries and create sulfur baths using the Smart-Trak® C100 Digital Thermal Mass Flow Controller.

When Precision Control Matters.  Linearity by Smart-Trak.






Click Here to Read More Smart-Trak® Stories