[Technology Report]
Electronics Helps Foster Decentralized Healthcare
To stem the tide of escalating healthcare costs, patients are becoming more self-sufficient thanks to the latest medical electronics advances.
There’s no shortage of state-of-the-art imaging endeavors. Magnetic particle imaging (MPI) developed by Philips Research is one new approach for capturing real-time 3D images of arterial blood flow and volumetric heart motion.
According to the company, MPI improves diagnosis and therapy planning for major diseases like altherosclerosis and congenital heart defects. It measures the concentration of iron-oxide nanoparticles injected into a patient’s bloodstream, using sets of static magnetic-field coils for selection, oscillating field coils for the drive signal, and receive coils for measurement.
The selection field provides a single field-free point in space, while it is non-zero in all other spatial positions (Fig. 2). In the close proximity of the field-free floating point, the magnetic orientation of the nanoparticles aligns easily with an applied oscillating drive field. Meanwhile, at all other positions the magnetization is forced to align with the local selection-field direction.
FLARE (fluorescence-assistance resection and exploration) is another new method for medical imaging to illuminate cancer tumors, developed at the Beth Israel Deaconess Center in Boston. Consisting of a near-infrared (NIR) imager, a video monitor, and a computer, FLARE uses various NIR fluorophores that target cancer cells selectively when introduced into patients. Excited by appropriate LEDs, the contrast agents reveal the presence of cancer cells with high precision.
To make the cells visible to surgeons, the imaging system converts the NIR light into bright colors laid over standard images of the surgical field on a video monitor. A foot switch lets physicians control multiple viewing angles and different magnification levels.
Ultrasound imaging is receiving lots of attention. At the National Space Biomedical Research Institute, scientists are developing an ultrasound technology that will allow for the early prediction of bone disorders such as osteoporosis and a guided acceleration of fracture healing.
The objective of their scanning confocal acoustic navigation (SCAN) project is to come up with a mobile scanner that’s small, easy to use, and patient-friendly. SCAN employs noninvasive and non-destructive ultrasound for diagnosis and low-intensity pulsed ultrasound for treatment. It’s more advanced than comparable present diagnostic ultrasound scanners, since it can assess a higher number of parameters and image hard tissue such as bones.
Common, inexpensive electronic components can be used to make advanced ultrasound devices. Cornell University developed a prototype portable device that fits in the palm of the patient’s hand and can be built for about $100. The unit moves ultrasound imaging well past the diagnostic stage and into therapeutics for treatment of kidney stones and prostate tumors as well as relief from arthritic pressures. The battery-powered therapeutic unit can stabilize a gunshot wound or deliver drugs to brain cancer patients. It contains a ceramic probe transducer and creates waves so strong they instantly cause water to bubble, spray, and turn into steam.
Researchers at Duke University proved that 3D ultrasound can be quite helpful (see “3D Ultrasound Penetrates Skull To Identify Strokes And Save Lives”). They developed a helmet that could detect strokes earlier than previously possible by providing real-time images of major blood vessels for emergency medical personnel. The speed of the diagnosis and subsequent treatment can often mean the difference between life or death.
The prototype device positions ultrasound wands or transducers against the temples on either side of the head. The researchers estimate that a helmet scan can be completed in 15 to 30 minutes—far faster than a typical CT scan, which can take an average of four hours to be scheduled and performed.
Ultrasound imaging at the point of care is now possible using a smartphone as shown by researchers at the University of Washington, who developed ultrasound probes for displaying images on a handheld device. The probes couple their output into the USB port of phones that are compatible with Microsoft’s Windows platform, enabling users to view the image (Fig. 3).
Signostics has obtained FDA approval to market what it calls the world’s smallest ultrasound device. The company describes its pocketsized half-pound Signos as a visual stethoscope. Priced about $4000, Signostics hopes it will someday become as omnipresent as the signature doctor’s tool.
To make higher-quality imaging products, ultrasound equipment manufacturers are expanding the number of input channels, which in turn require higher-resolution analog-to-digital converters (ADCs) and higher frame rates for image processing. This has led to new signal-compression techniques like the patented Port Concentration and Prism technologies from Samplify Systems Inc. Incorporated into the company’s CMOS SAM1610/05/00 8/16-channel 65-Msample/s 12-bit low-power compressing/concentrating ADCs, the products are aimed at ultrasound, sonar, and other medical imaging applications.
“The trend in medical imaging is to use thousands of input channels, a phenomenally challenging task. It requires generically integrating on silicon high-speed DSP with highperformance analog functions while dissipating low power, instead of conventionally using fieldprogrammable gate arrays (FPGAs). Our experience in mixed-signal processing has enabled us to meet this challenge,” says Allan Evans, vice president of marketing for Samplify.
Smartphones and PDAs are becoming essential to healthcare. More physicians are turning to them in clinical care. According to Manhattan Research, 54% of U.S. physicians own a smartphone or a PDA, and more than half consider them to be an integral part of their practice. Physicians can use these devices to view and manipulate X-rays and ultrasound images, as well as access pharmaceutical libraries.
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