Rapid Development of Medical Electronic Equipment Based on NI LabVIEW

Investment in the medical device industry has been on the rise in recent years. In the past two years, venture capital for medical devices has almost doubled, reaching $4 billion in 2007. From a global perspective or in the Chinese market, small, unlisted medical device manufacturers are gradually becoming the new favorites of investment with products, markets and innovation elements. For these small companies, it is very difficult to gain a foothold and stand out from the fierce market competition. Their core technical personnel may be experts in the biomedical field and have mastered certain patents or research results, but how to quickly transform patents or research results into products and ensure the reliability and stability of products with very limited team members is a big difficulty. Through the graphical development environment LabVIEW and commercial embedded prototyping platform provided by NI, field experts or R&D personnel can seamlessly integrate hardware I/O and algorithms to quickly develop medical devices with a limited team size. The reasons are mainly divided into three aspects:

1. Most domain experts—here referring to doctors and biomedical engineers—are primarily good at improving and innovating diagnosis and treatment methods, rather than complex electronic, mechanical, or embedded solutions. Through the seamlessly integrated hardware and software platform provided by NI, they can focus on the technology of diagnosis and treatment itself, rather than the underlying system implementation details.

2. Rapid functional prototyping can attract the next round of venture capital in the early stages of product development. NI is one of the few companies that provides solutions for rapid prototyping, providing a variety of software and hardware features for rapid system prototyping.

3. The weak signals generated by the human body require sufficiently high analog acquisition accuracy. NI is a pioneer and leader in PC-based test and measurement technology, providing the industry's most advanced data acquisition equipment.

This article will mainly introduce examples of three start-up companies designing medical devices based on the LabVIEW graphical development platform.

1. OptiMedica

OptiMedica has developed a new laser therapy device for diagnosing and treating diabetic retinopathy based on the NI graphical development platform.

Laser therapy mainly aims to fire laser pulses to seal microvascular tumors and abnormal vascular leakage. Due to the complexity and precision of the surgery, this laser aiming and firing has been manually controlled by doctors for nearly 35 years. The innovative laser therapy platform based on LabVIEW FPGA and NI R series devices assists doctors in aiming and firing multiple laser pulses in a certain mode through a high-precision, automated control system, thereby speeding up the surgery and reducing the number of treatment sessions.

OptiMedica's R&D team has some experience in LabVIEW development. In order to shorten the product development and certification cycle, they decided to use LabVIEW FPGA and NI R series intelligent data acquisition devices, eliminating a lot of work such as board-level design and hardware verification. Through the graphical development environment and commercial hardware platform, the development team quickly and effectively developed a prototype system for the therapeutic device and successfully demonstrated the system functions to potential investors. Because the R series device has a built-in FPGA, this hardware solution improves the reliability of the system and makes it easier to obtain FDA certification. Using programmable FPGAs instead of custom ASIC chips reduces development time by 30%.

2. Sanarus Medical

Sanarus is a medical device startup company. They plan to develop an innovative surgical device, the Visica2 Treatment System (V2), which uses liquid nitrogen to freeze and kill tumors in outpatients. V2 is designed to be an instrument that can be placed in a doctor's office or clinic. The treatment process includes painless local anesthesia and real-time ultrasound to locate the lesion. The treatment lasts about 10 to 20 minutes and freezes and kills the target tissue through a small incision. Patients do not need to have stitches after surgery.

In order to catch up with the product launch schedule, the developers plan to develop a working prototype of the V2 system within four months. In addition, according to the requirements of investors, they also need to produce V2 as soon as possible to meet market needs. The cycle of writing firmware for the device and developing a custom circuit board is long. Once there is a problem in the firmware or software layer, it will cause additional delays, which is a disadvantage for ensuring the progress of the entire project. Since V2 is a medical instrument device, it requires that the device must not contain any firmware and software errors that impair system performance. If the device cannot pass the consumption test required for 510(k) certification, the entire project will fail and V2 cannot be put on the market. Based on these requirements, V2 requires a very reliable development solution.

The developers decided to use the commercial embedded prototyping platform CompactRIO to develop the project. The CompactRIO system contains a 400 MHz embedded microprocessor, an Ethernet controller, and a 3 million gate FPGA on the backplane. They run the control algorithms for the liquid nitrogen pump and the pure resistive heating components in the embedded controller, and manage the interfaces of the necessary input/output signals to control these devices in the FPGA. This resource configuration makes the programming mode of prototyping and final system release very similar. In a very short time, the developers used it to design and verify the functions of V2. The benefits of using CompactRIO are obvious-it takes months to use a customized solution, while the NI solution only takes a few weeks.

In addition, with custom firmware, new requirements lead to tedious updates. Using the CompactRIO platform, they can modify the code without much effort. For example, user interaction requires the use of a touch screen instead of a keyboard and LED lights, so the developers developed a touch screen control program using LabVIEW under Windows. With LabVIEW's shared variable technology, data transfer between the touch screen and CompactRIO can be easily managed. Because the development platform is very flexible, the development process was not delayed when new functional requirements were put forward.

Since CompactRIO has passed EMC certification, this also ensures that they do not need to consider special EMC-related designs during prototype verification.

3. Fluidnet

According to a survey, nurses spend 15%-60% of their time on intravenous infusion and other matters. Therefore, Fluidnet and Boston Engineering developed a series of easy-to-use infusion devices based on LabVIEW embedded modules to solve the problem of insufficient nurses in hospitals. This new infusion device is more accurate and safe, provides a wide range of optional flow rates, and is cheaper than existing infusion devices.

Fluidnet used the LabVIEW platform and NI data acquisition equipment to design the first closed-loop control infusion prototype system, which has patented real-time flow and automatic liquid volume sensing capabilities. In the actual productization stage, Fluidnet cooperated with NI system alliance Boston Engineering to develop the final product using the FlexStack micro-board based on the ADI Blackfin processor. Since the LabVIEW embedded module can directly program the Blackfin processor and support C code generation and optimization, this graphical programming method significantly reduces the workload of code development and accelerates the system development process. In addition, due to the openness of LabVIEW, it is very convenient to add new features to the system. For example, Fluidnet added RFID tags to some new infusion equipment to record and identify drug information, and nurses can remotely monitor the operation of the infusion pump via Bluetooth.

IV. Summary

The LabVIEW graphical development platform provides a unified environment from algorithm design, prototype verification to product release, from software debugging, functional testing to production testing, allowing engineers and R&D personnel to design and develop products on the same platform, reducing development cycles and code revisions, thereby speeding up the design process. At the same time, through the NI commercial embedded prototyping platform, researchers can quickly transform patents or research results into products and ensure the reliability and stability of the products, thereby shortening the development time of medical electronic equipment.