40 years of Micro Thermistor Tech
Myocardial Temperature Probe
In the early 1980’s, there was a demand for a small, fast response temperature probe for cardiac surgery. At that time, to operate on the human heart, surgeons would chill the organ to slow down the beats per minute to perform the needed surgery. There were disadvantages and risks to this surgical approach. The surgeon had to work quickly because of the side effects of having the heart chilled for too long was detrimental to the patient’s health. The second problem was controlling the temperature of the heart itself; too cold could cause tissue damage and other problems.
At that time, I worked for an NTC thermistor house that came up with one of the solutions. We were able to develop a process where we could produce an NTC thermistor that would fit inside a 22-gage stainless steel needle probe. (North Star Sensors manufactures a similar probe). Not only could we produce a tight-tolerance, interchangeable needle probe that met the desired dielectric requirements (needed in case an electro-scalpel was used) but we produced it at a low enough cost that the myocardial temperature probe could be disposable.
Since then, heart surgery procedures have vastly improved and the need to chill the heart to operate on it is now longer needed. However, the need for micro temperature sensors has expanded into many other commercial fields, from agriculture to telecommunications. Small, precision leadless chip thermistors are vital to the operation of tunable lasers, widely used in hundreds of photonic applications. The micro leaded NTC thermistor is used wherever a small, fast response sensor is needed. Temperature-monitoring of microfluidic applications are many; in-vitro diagnostics, pharmaceutical and life-science testing, proteomics, and genomic assays. Our micro stainless-steel probe is used in agricultural field instruments used by farmers to increase crop production. More than one customer in this industry has told us that, today, their biggest marketplace is the production of marijuana plants to meet the high demand for CBD-related products.
The difference today is that with improved electronic ceramics manufacturing processes, better controlled deposition of electrodes and modern dicing equipment, we are producing a far superior product at lower costs. Also, many NTC thermistor houses are willing to customize temperature sensors to meet the growing needs of their customers.
Author: Daniel McGillicuddy III