Innovative technique for rapid tuberculosis detection

May 30 2004

NTU develops innovative technique for rapid tuberculosis detection Tuberculosis (TB) detection in the future will become faster, cheaper and easier using an innovative TB detection technique and device developed by Nanyang Technological University (NTU).

The NTU technique of using light waves to detect the presence of TB agents was developed by a project team led by Associate Professor Lim Chu-Sing, group leader of the Biosensors Section, Biomedical Engineering Laboratory, School of Mechanical and Production Engineering, NTU. Using NTU’s detection technique over conventional methods.

The two conventional techniques used to detect TB are acid-fast smearing and culturing. All detection techniques use sputum samples. Acid-fast smearing has very low sensitivity and specificity, and cannot distinguish between Mycobacterium Tuberculosis (the bacterium that causes TB) and other types of bacilli.

The culture technique, on the other hand, has good specificity and sensitivity but typically takes about three to six weeks to complete. Assoc Prof Lim and his team thus set out to invent a new technique that was both fast and accurate. Because 80 per cent of TB cases occur in third world countries, Assoc Prof Lim decided that affordability and ease of use were also qualities he wanted for his team’s TB detection device.

Bearing all these requirements in mind, the team decided on the innovative use of light waves to identify minute biological indicators of the TB bacterium. Because light waves comprise of photons, they are sensitive enough to “pick out” minute biological and chemical changes accurately. From the behavioral pattern of the spectra obtained from the light waves, the presence of the TB bacterium can be analyzed very rapidly.

The result, they found, was a technique that could detect TB accurately in days compared to conventional methods that take weeks. With the technique finalized, the project team then condensed all the necessary laboratory functions incorporating lasers, filters, optical lenses and detectors into a lightweight, palm-sized device. Being accurate and efficient, the new TB screening system is expected to lower current costs of TB testing by up to 10 times. The impact of this cost reduction will be especially felt in poorer countries, especially those which do not enjoy the extent of laboratory facilities and equipment available in first world countries.

The three-member NTU team (Assoc Prof Lim and two graduate students) took one and a half years to develop their TB detection device. NTU engineering students are taught engineering principles that can be applied to medicine and the life sciences through a module called “Life Sciences for Engineers”. The curriculum for this module includes the topic of developing sensors and devices to detect diseases.

Initial clinical trials for NTU’s TB detection device have just been completed. Commercialization of the device is in the pipeline as several local and overseas biomedical companies have already shown interest. Says Assoc Prof Lim, “Throughout the research and development of this project, we were motivated by the hope of inventing a TB detection device that will become widely-used and hence lower TB incidence rates worldwide. Commercial partnerships will help us meet this goal.”