Fujitsu Electronics

Progress in Health Services with FRAM RFID

Articles | By Fujitsu Electronics | 28 November 2013
RFID technology allows to read multiple tags at the same time even through optical obstacles. RFID technology allows to read multiple tags at the same time even through optical obstacles. Photo: Fujitsu Semiconductor

RFID in healthcare

In combination with RFID a fast and radiation tolerant memory creates advantages for healthcare

Nowadays the lack of hygiene in the field of medicine is a major issue and a recurring problem – multi-resistant germs can only hardly be treated by the application of drugs. According to estimates of the European Center for Disease Control and Prevention 4.3 million people in Europe become infected in hospitals every year. The German Society for Hospital Hygiene refers to a number of 40,000 deaths as a result of infection every year in Germany alone. In times of overworked clinical staff higher hygiene standards improving this situation can be best achieved by modern technology providing gapless traceability of devices and equipment. In this case RFID labels (so called „tags“) based on ferroelectric random access memory (FRAM) are the ideal solution as they do not lose any data when exposed to gamma particles in contrast to EEPROM tags. FRAM is the non-volatile memory of the future, combining S-/DRAM and EEPROM/Flash advantages. Through combination with RFID wireless technology a great deal can be achieved particularly in healthcare.

By Jozsef Miho, Product Marketing Engineer at Fujitsu Semiconductor Europe

Irradiation is the most effective sterilization

Methods of medical device sterilization are versatile and go hand in hand with different advantages and disadvantages. During autoklave sterilization for instance usually 121°C affect on the sterilization items with a pressure of two bar for 20 minutes. For many materials this is too much stress. Chemical sterilization (gas sterilization) bears the risk of residues, thus making laborious cleaning necessary. Meanwhile gamma radiation is used more and more frequently for sterilization. The gamma rays' high permeability provides enormous advantages. Particularly in the manufacturing process many items can thus be sterilized on pallets shortly before dispatch. The process is carried out at room temperature and material-friendly, making an expensive aseptic production process obsolete. In healthcare, radiation doses of 25kGy up to 45kGy are common, depending on the requirements. These high radiation doses are a problem for standard EEPROM based tags. They often lose their data even when they are exposed to 2kGy only. FRAM products passed all tests with this radiation dose without a single malfunction.

Fast and radiation tolerant memory

FRAM is a non-volatile memory technology – like EEPROM and Flash – which means that stored values will be saved without voltage. It combines the advantages of non-volatile EEPROMs and fast SRAMs. FRAM is based on the polarization of a ferroelectric layer. Gamma radiation won't result in dielectric material discharging as it does not lose its polarization. EEPROM or Flash technologies lose their stored data as they are based on charge (so called „Floating Gates“).

The ferroelectric layer consisting of lead-zirconate-titanate (Pb(ZrTi) O3) is polarized by two electrodes like a capacitor and keeps this polarization direction even after the electrical field was removed. Reversing the field allows to reverse the direction. In this way the logical values 0 and 1 are saved.

FRAM technology is based on the PZT material's polarization.FRAM technology is based on the PZT material's polarization. Picture: Fujitsu Semiconductor

Like a DRAM cell an FRAM cell consists of a resistor and a (FRAM) capacitor. Accordingly the access time is comparable to a DRAM. This memory is faster than other non-volatile memory types by a factor of about 33,000. FRAM does not work with long winded block access for write and delete procedures, thus simplifying and accelerating user handling.

Energy efficient endurance runner

Another major advantage of FRAM compared with competing technologies is energy efficiency. Due to the fact that only low charge quantities have to be moved for writing, only little programming voltage is required. This enables longer service life in battery operated applications as well as wider read and write ranges. Another special feature of FRAM technology is that read and write procedures require the same amount of energy. Due to EEPROM tags' higher energy requirements, write access is only possible over short distances. Regarding FRAM, read and write distance are the same and allow a higher distance to the antenna.

Frequent write and delete access, common at logging applications for instance, are a challenge for every memory type. The usual number of guaranteed write accesses ranges from 100,000 to 1 million. FRAM provides 10 billion (1010) up to 1 trillion (1012) guaranteed accesses – hardly any application reaches this limit. High reusability allows cost and maintenance reduction.

FRAM RFID by Fujitsu

Fujitsu provides FRAM RFID ICs in HF (13,56MHz, ISO15693) and UHF (860MHz - 960MHz, ISO18000, EPC Class 1, Gen 2) frequency bands with different memory sizes (up to 8 Kbyte user memory). By using fast FRAM the theoretical maximum which can be achieved with HF technology can be achieved in practice with these ICs. In both frequency bands pure RFID products as well as dual interface products are available. Dual interface products are available as pure Die or in package.

The complete article was published in the November issue 2013 of the magazine "RFID im Blick".

Translated by "RFID im Blick"

Last modified on Wednesday, 04 December 2013 12:21