Customer SolutionsFlexible Applied Spectroscopic Systems Using PXI and LabVIEW
Author(s):Rosie Abriam, New Focus, Inc.
Industry:Life Science
Product:Data Acquisition, LabVIEW, PXI/CompactPCI
The Challenge:Developing a spectroscopic subsystem for integration into a biomedical chemometric application in less than eight months.
The Solution:Using a system consisting of a New Focus high-speed laser and linear detectors in a National Instruments PXI chassis with controllers and DAQ cards.
New Focus, a photonics company based in A startup biomedical company approached New Focus to develop a spectroscopic subsystem for use with their proprietary hardware and chemometric application. The requirements were:
The technology uses the effects of various physical properties (e.g. reflection, temperature, and pressure) usually on fiber bragg gratings (FBGs). This phenomenon is characterized by changes in data peaks and may be an indicator of 1) vulnerable plaque in coronary arteries, 2) temperature fluctuations in oil-wells, or 3) strain in architectural structures. Previous attempts with another company yielded a system the size of a pool table after two years. We were contracted to deliver a portable solution in one-third the time with improved specifications. Initially, the customer was uncertain which operating system they wanted to use - Windows or Linux. Our choice of PXI and LabVIEW removed this concern. As we tested the system, we uncovered new challenges. We needed to modify our heat sink to control the temperature on our higher-speed laser. This increased our module size and we upgraded from an eight-slot chassis to the 18-slot chassis. We continued to use the smaller chassis for development and testing of individual modules after moving the ‘final system’ to the larger chassis. The solution remained portable and compact. The impact on our development and costs was minimal. The original design included an optical trigger. However, it did not meet the changing system requirements. This challenge fueled the innovation of our Electronic Wavelength Markers (patent pending). These markers were independent of optical performance anomalies and relied on the PXI trigger backplane to provide repeatable system measurements. The complexity of the solution was not limited by the PXI platform. We used the modular PXI products to develop:
The 16-bit resolution and 333 kS/s single-channel sampling rate was crucial for our triggering solution. The need for simultaneous triggering on two separate modules was handled by the NI PXI-4200. Its open architecture enabled development of our integrated high dynamic range power meter, a log scale detector. From this, we converted the log design to a linear detector for use in this project. Having both detectors integrated with 4200 DAQ modules allowed us to adjust critical parameters in-situ. With PXI synchronization and filtering via LabVIEW algorithms, we lowered the noise floor and viewed the data real-time from the DUT. The role of LabVIEW in product development and system integration cannot be overstated. LabVIEW drivers previously developed for generic fiber sensing applications were reused during the feasibility and prototype stages. We also used peak detection algorithms originally used in applications developed on PCI platforms. The use of in-house LabVIEW tests to characterize laser performance and detector specifications decreased costs. Also, because the graphical user interfaces (GUIs) were used in production, New Focus technicians did not require training nor did they experience a barrier to the new platform. For the biomedical application, the confidence in existing tests decreased the time allotted for software development. It facilitated the building of a prototype that our customer presented to venture capitalists to establish the feasibility and viability of their application. To date, our biomedical customer has successfully completed two of their clinical trials required by the Federal Drug and Administration. Additionally, we decreased development costs by more than $400,000. For applications in the civil engineering, aerospace, and oil and gas sectors, alternative peak detection algorithms were easily integrated into the system to model different use cases and field scenarios. Oil and gas companies, as well as government labs, currently use our PXI-based systems for R&D and field tests. PXI and LabVIEW allowed New Focus to:
The development of an easily configured LabVIEW application provided New Focus with the tools to fulfill specifications and requirements of spectroscopic applications across multiple sectors. The PXI platform and LabVIEW allowed New Focus, a photonics company, to concentrate on photonics challenges and not on system challenges unrelated to our core competencies. For more information, contact: Rosemary Abriam New Focus, Inc. a subsidiary of Bookham Tel: (408) 919-1536 E-mail: Rosie.Abriam@bookham.com |
