Medical Electronics

Medical electronics has an $18 billion slice, approximately, of the medical-device market and that is said to be the largest piece of the pie. With such rewards being dangled before them, its not surprising that electronics manufacturers are willing to run the long gauntlet of approvals needed to bring new medical products to market.

The following products represent a small sample of the recent medical innovations that range from subsystems to discrete devices to new materials.

Power supplies

Responding to increasing demand for medically rated power supplies Lambda Americas (www.lambdapower.com) has extended its NV power supply family of to include a range of configurable dc power supplies the NV-175M seriesdesigned with reinforced 4-kVac input-to-output isolation to meet IEC 60601 international safety standards for patient-connected medical equipment.

Priced from $126 ea/1,000, the supplies include PFC, efficiencies to 90%, and output power ratings to 180 W continuous, 200 W peak. The supplies can have one to three outputs with voltages of 3.3, 5, 12, 15 and 24 Vdc (adjustable to 28 V). No minimum loads are required.

Lamda Americas NV-175M power supply

Measuring only 10.54 x 3.50 x 1.59 in., the Xmite Series modular dc supplies from Excelsys (www.excelsys.com) consists of three powerPac chassis rated at 200, 400, and 600 W that can be populated by users with up to four powerMod output modules offering outputs ranging from 1.5 to 58 Vdc. Safety qualified to UL60601-1/EN60601-1, the units typically find application in medical lasers, monitoring systems, radiological imaging, clinical diagnostics, and chemistry. Standard pricing is as low as $0.40/W in 1,000-piece quantities.

Excelsys Xmite series modular power supplies

Capable of providing up to 150 W, PMP150 Series external desktop power supplies from PowerGate (www.powergatellc.com) have product approvals in process for UL/cUL60601-1 and TUV EN60601-1, are RoHS compliant, and will carry the CE Mark and meet Class B Emission Standards. With operating efficiency in excess of 85% and no-load power consumption of less than 0.5 W, the products provide single output voltages of 12, 15, 19, 24, 27, or 48 Vdc and meet CEC Level IV “green power” requirements.

PowerGate PMP150 external power supplies

ICs and components

Housed in 2 x 2-mm SON package, TPS719xx dual, 200-mA low-dropout linear regulators from Texas Instruments (www.ti.com) suit portable battery-powered medical equipment. The low-noise LDOs provide high PSRR up to 10 MHz, fast 160-µs startup time, and excellent line and load transient response, while consuming just 90-µA ground current with both LDOs enabled.

The devices feature an active shutdown circuit to quickly discharge capacitors at the output voltage. Discharging the capacitors to zero during shutdown helps manage power-up when sequencing applications. Priced from $0.75 ea/1,000, the devices use 1-µF ceramic capacitors for stability and a linear BiCMOS process to yield a 230-mV typ dropout voltage at output loads of 200 mA. A precision voltage reference and feedback loop provides 3% overall accuracy over all load, line, process, and temperature variations.

Texas Instrument TPS719xx dual LDOs

Aimed at portable and battery-operated applications, such as patient monitors and defibrillators, the AD8663 iCMOS low-noise rail-to-rail op amp from Analog Devices (www.analog.com) delivers a combination of high accuracy, power efficiency, and versatility with a wide 5 to 16-V operating range. With prices as low as $0.60 ea/1,000, the devices are available in packages that are 70% smaller than competing devices, suiting them for applications where board space is at a premium.

Analog Devices AD8663 op amp

Displays and material

The 5.7-in. passive-matrix CSTN and 6.5-, 8.4-, and 10.4-in. active-matrix TFT LCDs from Apollo Display Technologies (www.apollodisplays.com) are bright high-reliability displays that offer legibility and image clarity with low surface reflectivity and wide viewing angles over wide temperature ranges for 3 to 5 years.

Apollo medical CSTN and TFT LCDs

High-specific-gravity thermoplastic materials that can be injection molded have been developed by GE Plastics (www.geplastics.com). They can be molded into new forms, replacing lead in gamma- and x-ray-producing medical equipment while protecting both people and sensitive electronic components.

Richard Comerford