Development story of the ferromagnetic material detector for MRI “MAGGUARD”

Development story of the ferromagnetic material detector for MRI “MAGGUARD”

Along with advancements and sophistication in medicine, the number of MRI (Magnetic Resonance Imaging) machines has increased, and there are now approximately 6,500 MRI scanners in Japan (as of 2014). The more high-field scanners are installed, the number of MR system related accidents, caused by the presence of ferromagnetic materials, has increased. This, as well as the growing number of scans globally, means there is a higher risk. Precautions must be taken to protect patients, hospital staff and MR scanners. According to estimates by the Japan Medical Imaging and Radiological Systems Industries Association (JIRA), there were approximately 200 ferromagnetic accidents in 2011 handled by manufacturers alone. To prevent this type of accident, it is important to screen patients and hospital staff for ferromagnetic materials before they enter the examination room.

Fujidenolo developed “MAGGUARD”, the MRI ferromagnetic material detector and began selling it in the global market . This device is equipped with the MI (high-sensitivity magneto-impedance) sensor that was developed over the course of many years of research, and can detect small changes in magnetic fields.


The healthcare challenge began with production of the bolus,  the necessary tool for the particle beam cancer therapy

Fujidenolo, which has been involved everything from general processing of press forming, adhesives, and welding to machine processing such as lathing and machining, entered into healthcare in 2008. The production of the bolus used in particle beam therapy for cancer treatment was the start of our participation in the healthcare field. Bolus is made of polyethylene, and because it is used to adjust the depth of the irradiation, it is produced individually by NC machine based on data sent by medical institutions.

Production of bolus was laying the groundwork for subsequent Fujidenolo business in the healthcare sector. Hiroyuki Koizumi of the Healthcare Division says “By working with physicians, radiological technologists and medical physicists, we were able to hear about issues and demands in the medical field directly. We also learned about ferromagnetic accidents with MRI and voiced our opinion on how we believed that the Fujidenolo ferromagnetic material detection sensor could help with this.” As the manager for MAGGUARD sales, Koizumi works with medical facilities across the country to raise awareness about prevention of MRI ferromagnetic accidents, and is opening up the way for new distributors.

As a result, development of the ferromagnetic material detector that would become a new original product proceeded along with the assistance of the Technology Development Division that developed the MI sensor.


Harnessing the infinite possibilities of the MI Sensor for the healthcare field

Working together with universities, the Fujidenolo Technology Development Division had proceeded in research and development of biomagnetic measurement. Rather than a measurement taken using an electrode contacting the body surface, the MI sensor was developed to detect minor electrical fields produced by the action current that occurs from the body’s functional electrical activity. This is an ultra high-sensitivity magnetic sensor that makes use of amorphous wire magneto-impedance (MI) theory, and is also used in the electronic compasses of mobile phones and smartphones.


Development of the shieldless ultra high-sensitivity sensor had helped contribute to the popularization of biomagnetic diagnosis just as Yoshitaka Taguchi of the Technology Development Division says “Originally, development of a pT (picotesla) level MI sensor went forward in order to evaluate cell physiology at universities.” It was hoped that the traditional superconducting quantum interference device (SQUID) that requires a large-scale facility could be made more compact and low cost, however, improvements in measurement precision, reliability, and stability were required in order to use it for actual magnetoencephalography (MEG) and magnetocardiography. Then, when searching for other uses for the MI sensor, stories about MRI ferromagnetic accidents suddenly appeared and development of the MRI ferromagnetic material detector began in 2012.

Taguchi says “Device development is a new field for Fujidenolo. However, our advantage over other medical equipment manufacturers is that we possess a high level of processing technology nurtured over the years through resin processing, and an environment that ranges from prototypes to testing.” Instead of being at a disadvantage for being new to the field, Fujidenolo is not caught up in past practices, but is of a mind where we are free to imagine and take on new challenges, accelerating development.

A strong desire to prevent from ferromagnetic accidents provided the driving force to develop a product

Worries about MRI ferromagnetic accidents were present when MR scanners began being introduced to medical facilities. However, this was not considered a serious problem even among medical institutions, as they practiced prevention in medical interviews and simple metal detection. In recent years, however, high-performance MRI units produce more powerful magnetic fields, and when ferromagnetic metals are brought into the MRI examination room, those pieces of metal fly toward the scanner with a great deal of speed, causing serious injuries to patients and medical staff alike if they are hit. Even when the device is not being used for exam it can produce powerful magnetic fields, meaning that danger always lurks in the MRI examination room or magnet room.

At that point in time, we had very little experience in the medical field and did not grasp the marketability of an auxiliary device to prevent ferromagnetic accidents. Because of this, members of the development team continued advocating the importance and significance of preventing ferromagnetic accidents even within the company.


Also, because this was to be a new product in a new market, we were working in the dark when it came to determining functions, specifications, and price for a ferromagnetic material detector, as well as finding sales channels, making it a long and difficult road to finally realizing a product. However, the strong desire to prevent MRI ferromagnetic accidents proved to be the driving force for development staff, and after two years of development, a product was brought to the market.

“I’m ecstatic that the MI sensor has borne fruit in the form of the ferromagnetic material detector, and has gone out into the market to help society,” says Koizumi. Taguchi says “Regarding devices other than the MI sensor, there were many other technical challenges, especially electric and electronic parts, processing circuits, and software. It was deeply moving to see a finished prototype that resulted from teamwork with the development team.” As evidenced by these words, when MAGGUARD became a product after overcoming so many obstacles, this was Fujidenolo’s first step into a new global effort.

Desire to permeate the global market with the name of Fujidenolo as a manufacturer of healthcare products

It is estimated that by 2020, sensor devices market will account 4.5 trillion yen* across the world, and among that number, biological sensors are expected to grow significantly. Using MAGGUARD equipped with the MI sensor as a foothold, Fujidenolo is making a step forward into the global market. We are not interested in simply selling products, but want to lend a sincere ear to our customers in each country and region, and thereby make appropriate improvements. Taguchi says “I believe that upgrades and customization are essential in this field where products are linked to human lives.” We have also begun development on sensors that can detect even much smaller changes in magnetic fields than MI sensor, and are working day and night to research and develop with a view toward second and third products.


By 2020, it is likely that the world’s population will reach eight billion people. It is Fujidenolo’s mission as a manufacturer of healthcare products to continue to provide products that maintain the health of those eight billion people. Therefore, the Healthcare Division and the whole of Fujidenolo will continue to meet the challenges to come.

* Source: “2012 Sensor Device/Solution Business Market Survey” by Fuji Chimera Research Institute, Inc.

< Interview cooperation >
koizumi prof

Healthcare Division

Hiroyuki Koizumi

taguchi prof

Acting Manager, Technology Development Division

Yoshitaka Taguchi

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