Proportional Technologies, Inc. (PTI) was founded in 1991 by Jeffrey L. Lacy, Ph.D., whose previous experience includes fifteen years working in high energy astrophysics at the NASA Johnson Space Center and eight years immersed in the clinical cardiology setting at Baylor College of Medicine. His combined background in nuclear physics, instrumentation, and clinical nuclear medicine underlie the company’s focus on radiation-based technologies for medical applications.

PTI's initial efforts centered on the development of a mobile gamma camera system for use in cardiac imaging and the ⁶²Zn/⁶²Cu radiopharmaceutical generator for use in positron emission tomography (PET) imaging. Although the greatest efforts have been focused on the improvement of the ⁶²Zn/⁶²Cu microgenerator, the company's activities have diversified substantially over the past decade and now include development of radiolabeling kits (⁶⁴Cu & ⁶²Cu), gamma ray detectors for PET, high pressure xenon gamma ray spectrometers, straw detectors for neutron imaging, and neutron-gamma straw detectors for homeland security. 

PTI’s research and development efforts are supported by multiple avenues of funding, including federal grants through the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) Programs, government contracts and product sales. The SBIR and STTR programs were formulated to encourage small businesses to engage in highly innovative research with significant commercial potential. Although it can be of great scientific and economic value, research and development is often avoided by small businesses because of the high risk and costs involved. More recently, government contracts have become a major support component of our research efforts. DOD contracts have been awarded to PTI for the development and delivery of two novel detector systems. A highly portable neutron detector and a large-area directional neutron/gamma detector, both of which are used in active interrogation for homeland security applications. PTI has had substantial success with contract awards and the SBIR/STTR programs. 

PTI is located in the Genesis Biotechnology Park complex, immediately adjacent to the BioHouston Resource Center at the core of biomedical developments in Houston just south of the Texas Medical Center.