Using Solid State Flash Disks as Cure-All for Medical Storage Systems

In collaboration with Wilson Wei Sheng Wangdetect and evaluate cancer, such as of the lung or
The medical equipment industry has always remainedbreast. It also can be used to evaluate the heart's
at the cutting edge of technology to enhance ormetabolism and blood flow and examine brain
complement the skills of medical personnel in savingfunction.
lives. Millions of dollars, and sometimes billions, haveUltrasound (Sonography)
been spent by hospitals, medical units and clinics inThis diagnostic imaging technique uses high-frequency
acquiring the latest equipment. The question is, whysound waves and a computer to create images of
does the medical sector invest so much in theseblood vessels, tissues, and organs. Ultrasounds are
equipment? The answer is clear: the medical industryused to view internal organs as they function, and to
is all about saving lives. Medical equipment are missionassess blood flow through various vessels.
critical devices that must not fail under anyElectronic Records Management
circumstance despite being deployed in pretty harshThe recent boom in the global healthcare industry has
conditions such as ambulances and mobileramped up demand not only for healthcare
transportation units. In addition, advances in imagingprofessionals but also for related IT equipment.
and data processing have automated diagnosticGovernment regulations such as the Health Insurance
evaluation, reflecting the need for a storage devicePortability and Accountability Act (HIPAA) are
that can ensure the high-performance and reliability ofgradually forcing healthcare providers to upgrade
such systems.legacy information systems with the latest in
Critical Issues in Medical Equipmentlaboratory information management, picture archiving
Size and Weight - Size can be critical in systemsand communication, as well as medical records
destined for use in healthcare environments such assystems.
laboratories, emergency rooms, doctors' offices, andLaboratory information management system (LIMS)
ambulances. Therefore, an embedded computer mayAccording to market research firm Frost & Sullivan,
take up space no greater than the ones used byregulatory compliance as well as the standardization
single-chip microcontrollers. Weight is also anof business practices and have catapulted the LIMS
important factor if the equipment is portable ormarket into the growth stage, with market revenues
intended for mobile use.likely to increase from US$209 million in 2003 to
Power Consumption - System reliability is reduced byUS$328 million in 2009. The development of LIMS has
high heat buildup. Therefore, it is important tobeen influenced by the trend toward the
minimize power consumption when replacingmaintenance of electronic records in lieu of
microcontrollers with embedded PCs. Powerpaper-based documents. LIMS assists lab workers in
consumption and heat generation are importanthandling structured data records such as samples,
criteria in the design of portable and mobile systems.tests performed, and their results.
Shock and Vibration Resistance - Whether intendedPicture archiving and communication system (PACS)
for fixed or mobile use, every medical product mustPACS is an electronics system that uses an image
be transported from where it is made to where it willserver to exchange X-rays, CT scans and other
be used. Desktop PC motherboards and plug-in cardsmedical images over a network. Due to its legal
are notorious for needing adjustment by a trainedmandate under the provisions of the HIPAA, market
technician after delivery, prior to use.research firm Frost & Sullivan projects that 65.2
Such sensitivity to shock and vibration is notpercent of all hospitals and 12.3 percent of U.S
acceptable in embedded applications. In portable orimaging centers will install PACS by 2007. This is not
mobile systems, system electronics undergo a widesurprising considering that PACS offers several
range of movement during storage, handling, andbenefits. The film-less system speeds up the
operation. Vibration and sudden jerking may subjectturnaround time required for delivering images/x-rays
components and solder joints to continual mechanicalto the attending physicians, since they will no longer
stress until chips, modules, and boards becomeneed to wait for film images to be processed and
partially or fully dislodged or disconnected. In addition,delivered before they are analyzed. As a result,
connector pin conductivity can be degraded bydoctors will be able to make quick decisions in
corrosion resulting from electrochemical effects thatemergency or life-threatening medical cases.
are exacerbated by vibration.LIMS and PACS both require a high level of
Operating Temperature Range - Most medicalperformance, availability and reliability, as immediate
systems are used in relatively benign indooraccess to patient information is critical in emergency
environments. Embedded electronics intended forscenarios.
such use are typically rated for operation atThe Solid State Disk Advantage
temperatures up to 55°C. However, some medicalSo what do solid state flash disks offer for these
equipment enclosures need to be fully sealed-toapplications?
protect against spilled liquids such as blood orMedical imaging systems are performance-hungry
chemicals, therefore air vents and cooling fans mayapplications that require real-time performance and
not be permissible. In these cases, internalhigher resolutions while medical information systems
temperature can become elevated, which mayneed reliable components to minimize downtime. All of
require embedded electronics to be rated forthese requirements can be easily met by utilizing
operation up to 70°C. In mobile or portableflash-based solid state disk for storage or as a cache
equipment, an extended operating temperature rangesolution. High transfer rates allow immediate delivery
of -20° to 80°C may be called for.of real time information, while the ruggedized
Environmental Factorspackaging of certain solid state disk models, such as
Electrostatic discharge (ESD) and electromagneticBiTMICRO's E-Disk SSD, immunizes the storage
interference (EMI), both generated and received, aredevice from hazardous ESD and EMI. Moreover, the
key concerns in medical applications. High frequencyVME and cPCI architectures are most commonly
microprocessor clocks, which for PCs commonly fall inused in medical imaging systems, and E-Disk solid
the range of 33-166 MHz, can easily interfere withstate disks are tailor fit for any VME, cPCI, PMC
low-level signal detection or stimulus generation.storage module.
Additionally, medical systems often must operate inSolid state flash disks are capable of much higher
the presence of strong electromagnetic emissionstransfer rates and IOPS relative to other storage
from other devices situated nearby. As a result,mediums such as magnetic disk drives. Flash-based
components embedded in these systems must besolid state disks inherently consume less power and
designed with high noise immunity and low noisegenerate a smaller amount of heat due to the
generation. Consideration also must be given toabsence of spindle motors. ESD and EMI, both
conductive radiation and susceptibility on powergenerated and received, will be minimized with flash
supply and I/O connections. Undesired system resetsdrive implementation. On top of that, the non-volatile
and data loss must, of course, be prevented, but thenature of flash memory makes it resistant to shock
potential danger to human lives from high levels ofand vibration, a useful feature in rugged mobile
electric, electrostatic, or electromagnetic emissions isenvironments.
a far greater concern in medical applications, requiringBiTMICRO's E-Disk solid state flash disk has a unique
designers to incorporate preventive measures.feature that sets it apart from its DRAM-SSD and
Quality and ReliabilityHDD counterparts. E-Disk's patented PowerGuard(R)
Naturally, the required level of system quality andprovides temporary power in the event of a power
reliability depends on the particular application. Forloss, allowing the disk to flush all the content in the
example, equipment used in the entry or retrieval ofcache into the flash memory, ensuring data reliability
non-critical information can include fewer fail-safeand availability in mobile medical systems.
mechanisms than systems performing life-criticalIt is also noteworthy to mention BiTMICRO's
patient monitoring or blood chemistry control.extended warranty support programs in support for
However, it is categorically safe to say that medicalnon-obsolescence and quality control of computerized
users are never as forgiving of system malfunctionsmedical equipment. Extended warranty ensures timely
or crashes as are the users of desktop PCs.and original or functionally equivalent replacements for
Practically every PC user experience messages suchBiTMICRO products that need repair or attention, up
as "Fatal error #XYZ" from time to time, but suchto a period covering 10 years after original purchase.
incidents are totally unacceptable in medicalPrice Trend
equipment, where consequences can range from lossNow that we've established the technical viability of
of critical data to loss of life.solid state flash disks in medical systems, let's
Product Life Spanexamine the practicality of flash disk deployment in
Regarding product longevity, desktop PCenterprise storage. Though there still is a price
manufacturers and users have a different set ofpremium for solid state disks over rotational drives,
priorities compared with the medical systemsthe gap between HDD and solid state flash disk
industry. Desktop PC vendors strive to bring out newquotes is seen to narrow significantly-with a
technologies constantly, and the typical half-life (todifference of only about $0.05 per MByte in
obsolescence) of PC chipsets is around 1.5 years.2007-despite the huge performance advantages of
Clearly, while it may benefit PC manufacturers tosolid state disks (at 100x-150x over magnetic drives
market a new motherboard, video card, diskin terms of sustained transfers and IOPS).
controller, or network controller every year or so,Web-Feet Research also projects a major decline in
this situation is unacceptable for medical equipmentthe solid state flash disk/HDD cost ratio by
manufacturers. Medical products typically require twoapproximately four times, from 433:1 ($0.078 vs.
or more years of development, followed by several$0.0018 per MByte) in 2003 to 107:1 ($0.096 vs.
more years to gain FDA approval. Therefore, medical$0.0009 per MByte) in 2006. Solid state flash disks will
systems design cannot be based on componentsalso maintain its cost-per-MByte advantage over
with a lifespan of as short as 18 to 24 months.DRAM-based SSDs.
Medical Diagnosis in the Digital AgeOne thing the solid state disk industry has benefited
The advent of digital technologies gave birth to afrom is the continued decline in flash memory prices.
variety of electronic medical equipment requiring highHigh demand for portable electronic devices such as
performance and reliability. The following are someMMS-capable phones, digital cameras, and MP3 players
examples:has driven semiconductor manufacturers to boost
Magnetic resonance imaging (MRI)flash memory density and output. Market research
MRI is an imaging technique used primarily forfirm Web-Feet Research predicts that the price per
diagnostic purposes to produce high quality images ofMByte of solid state flash disk will fall by an average
the human body, both internal and external. MRI isof 80.86 percent annually within a 5-year period
based on the principle of nuclear magnetic resonance,starting 2004.
a spectroscopic technique used by scientists to
obtain microscopic chemical and physical informationFigure 1: Disk drive comparison, $ / MB
about molecules.Conclusion
Computed axial tomography (CAT scan or CT scan)The digitization of diagnostics and records
CAT scan is a computerized x-ray procedure thatmanagement procedures in the medical industry has
produces cross-sectional images of the human body.facilitated the evaluation, sharing, and archiving of
The images are far more detailed than x-ray films,patient images and information. However, these data
and can reveal disease or abnormalities in tissue andintensive applications require storage components
bone. The procedure is usually noninvasive and brief.that can operate in an environment where IT system
Positron emission tomography (PET scan)downtime can be fatal. Solid state flash disk is the
PET scan is a test that combines computedideal solution for medical systems, providing fast
tomography (CT) and nuclear scanning. Compared tothroughput and scalability at a price that belies its
CT scans and MRI, PET produces less-detailedwide performance lead over magnetic disk drives.
pictures of an organ. A PET scan is often used to