Brazilian researchers develop multifunctional spectrometer

The equipment will serve as a scientific research tool for a variety of fields such as agriculture, petroleum, materials science and medicine.

By Noêmia Lopes

Agência FAPESP – A group of researchers from the São Carlos Institute of Physics (IFSC) at the University of São Paulo (USP) has developed a multifunctional digital magnetic resonance spectrometer that is capable of performing several functions in a manner that is more efficient and user-friendly than a conventional spectrometer.

The new equipment, whose hardware architecture is nestled inside a computer chip, is fully adaptable to the demands of each user. Researchers were able to achieve such versatility through the use of programmable logic technology (i.e., field programmable gate arrays; FPGAs).

“An FPGA chip is like the brain of a baby whose neuron synapses have not yet been trained,” explained Alberto Tannús, coordinator of the IFSC Magnetic Resonance Imaging and In Vivo Spectroscopy Center (CIERMag). “What you do is establish linkages between the logic ports of the chip to give it digital functionality. In our case, we made a generically configured chip into a device capable of serving various functionalities.”

The spectrometer was developed under the scope of a thematic project led by Tannús and associated with the FAPESP program known as the Inter-Institutional Cooperation to Support Brain Research (CInAPCe). The project also included support from the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (CAPES), the National Council for Scientific and Technological Development (CNPq) and the Brazilian Innovation Agency (Finep).

The device can be customized to operate as a relaxometer, which is used in the petroleum industry, for example, to measure multiphase flows of oil, water and gas or rock porosity.

Another feature allows the equipment to operate as a magnetic resonance analytical tool in organic chemistry laboratories. The device is also suitable for in vivo and ex vivo (human and animal) magnetic resonance spectrometry and as an imaging scanner, which makes it possible to perform a variety of analyses, such as determining the degree of oil or kerosene contamination on a plane’s wing or conducting morphological analysis of seed damage and viability in agriculture.

“One of our main objectives was to make the spectrometer a scientific research tool that was not limited to medicine alone. Today’s commercial instruments are being designed for clinical exams; in other words, they’re not ideal for other areas,” Tannús said.

Tannús went on to say that developing new functionalities for conventional hardware that is not multifunctional or upgrading such hardware’s programming is an expensive and time-consuming endeavor that involves layout, fabrication and product testing. Furthermore, such efforts face restrictions imposed by manufacturer licenses. Often, the result is equipment obsolescence.

“Programmable logic allows you to establish a new hardware functionality from one day to the next. You just have to design it, compile the new version of the spectrometer that will execute it and, in about two hours, the system is ready to go. That way, a single system can continue to be functional for many years, undergoing improvements by adding new functions,” explained Tannús.

The researchers sought to create a development environment that represented a stable platform, with no limitations on usability, known as an Integrated Development Environment (IDE).

“The environment we created is very similar to the one used by software application developers. This really facilitates the work of programming and creating magnetic resonance methodology designs that are just like those a programmer uses to create a new piece of software and are just as easy to use,” Tannús said.

Another outcome highlighted by the researcher is the creation of a pulse sequence programming language (language “F”, owned by the CIERMag) and its respective compiler that generates codes for heterogeneous configuration of the multiple digital signal processors that make up the spectrometer.

“To magnetic resonance methodology, a pulse sequence is equivalent to a musical score for a piece performed by an orchestra. One of the processors, as ‘maestro’ (Timing Sequencer), determines the cadence, amplitude and repetition, while the others, the ‘musicians,’ carry out a particular role in the performance – pulse generators, gradients, data acquisition, etc. The role of the compiler is to transcribe the instructions in this language into different versions of ‘scores’ performed by the various processors, all controlled by the Timing Sequencer,” explained Tannús.

The researcher also emphasized the system’s capacity to generate homogeneous data: “Up to now, data generated by conventional systems required interpretation by the user who would do the post-processing – on the images obtained, for example – according to how the data are organized. In the CIERMag system, the compiler utilizes complex semantic analysis algorithms to extract the data structure directly from the pulse sequence and thus provides information directly to the user.”

Applications

The work began in 2008 with the exploration and later acquisition of development kits that allowed for the creation of the first version of the hardware in 2010.

“Right now, we’ve defined and synthesized the hardware for the new spectrometer. All the layers of software are also defined and functional. Now, we’re beginning to develop the suites of methodologies for the various applications,” Tannús stated.

One of these applications, in the field of medical equipment, already has a development design contracted by Finep under the Brazilian Technology System Program (Sibratec) of the Ministry of Science, Technology and Innovation (MCTI) in Innovation Center Networks for Medical, Dental and Hospital Equipment (EMOH Network). Other applications underway involve relaxometry and analytical spectroscopy.

“The latest developmental findings – for both the hardware and the various software systems - are being drafted to be submitted for the filing of five software licenses and three hardware design patents. Publication of these findings is subject to completion of these procedures,” said Tannús.

In addition to the advances in research and innovation, the team also envisions applications in the field of education. “The prospects look good for using benchtop versions of an imaging system for training in laboratories that offer courses in medical physics so that students can have unlimited access to the concepts on all operating levels of the systems. In addition, versions adapted for both imaging as well as analytical spectrometry could be used as tools for advanced physics laboratories, such as those at the IFSC,” Tannús predicted.