Mixed signal FPGA for clinical application development

Due to medical care costs rising, chronic disease epidemic, the ageing of the population, as well as China, India and Brazil, and other major emerging markets rise on low cost and reliable medical equipment needs very large, with a view to improving the millions patient treatment and care, and expand the range of disease treatment.

On the one hand, medical equipment designers are also working on from different fields of new technologies, is committed to promoting the next generation of equipment for diagnosis, monitoring, and treatment.

To enable medical devices cheaper, easier for patients to use, there are two trends appear – small and portable.

Today, medical device manufacturers to integrate the entire system integration in a Palm-size even smaller portable devices. For example, the EKG (electrocardiogram), blood dialysis equipment and patient monitors, and other clinical medical equipment is essential in hospitals/clinics, their volume will continue to shrink. Used must be fixed to the wall of large equipment, now can be equipped with mobile clinics, ambulances and even doctor's "visits" packs.

Compact and portable development trend of the meaning of these complex equipment must be reliable enough to be able to apply to a wider range of work environments.

In the past, these instruments as long as we can in clean operating room, clinic or the laboratory work is sufficient. But today, the modern medical equipment must also be able to on the mobile clinic or ambulance, provide the same precision and reliability.

Many clinical medical devices are based on microprocessor and mechanical installations, using the same set of building blocks: power control and temperature management; including keyboard user interface; LCD monitor and audio control; Flash memory for data logging, or EEPROM; as well as for connecting other devices in the device interface.

Despite many similarities, but each medical application equipment specificity are still very strong and often very complex.

Therefore, in addition to the construction of the "core" module components, clinical medical device also contains the corresponding to their tasks unique diagnostic or functional "module".

For example, ultrasonic detector probe, with a sensor with sensor-pulse control functions; and hemodialysis instrument is adopted a dialyzer. These ever-changing and complex functionality integrated in small size, low power, high precision and reliable performance of the chip that makes clinical medical devices become available heavy programming non-volatile semiconductor technology of a great market. Flash-based FPGA mixed signal not only with highly integrated, intelligent power and system management features and small footprint area and highly reliable, and other advantages, particularly suitable for these applications.

Application example: hemodialysis machine

Blood dialysis apparatus used to filter the blood and continuous control and monitoring of venous and arterial pressure/during treatment management of anticoagulant medication.

In dialysis, blood is extracted from the human body to a hemodialysis machine. Instruments in the dialyzer (filter) the human body's metabolic waste removal, allowing blood to restore normal electrolyte balance, and removes the excess liquid. And then, then clean the blood back to the human body. In order to achieve its main function, blood dialysis instrument usually several micro-controller, used to monitor and control the blood and other body fluids flow, alerts, and turn off equipment when necessary (as shown).

A typical hemodialysis device contains a number of specialized design of building blocks.

For example, power control module temperature sensing for fan drives, also perform watchdog and battery backup feature. The user module by keyboard or touch screen enter patient information, achieving treatment parameters of personal customization. It also can help medical service providers to better monitor the patient's body during dialysis status and therapeutic effect.

Data logging/communication interface you manage Flash/EEPROM, and communications ports.

Audio/alarm output function provided by several modules and the controller will be able to achieve a timely issue status alerts.

Signal conditioning/sensor control module and dialyzer and catheter systems tightly integrated mechanical parts, common control various anticoagulant dosage; the use of comparators, universal high precision operational amplifier as well as the ADC to control and sensing temperature; control of dialysis fluid mixing and flow, and other clinical features.

Pump/motor control and drive circuit management devices in a large number of pumps, valves, motors and heater, and the arteries and veins control function monitoring level and pressure sensors.

It is worth noting that, although the pump/motor control and artery/vein control monitor for hemodialysis instrument unique, numerous controller is the most common clinical medical equipment.

Multi-function integrated

Today's single-chip Flash memory mixed signal FPGA with integrated simulation capabilities, Flash, FPGA architecture, often there are the embedded industry standard microprocessor.

Therefore, they are equivalent to a system capable of implementing power management and control of thermal management, clinical medical equipment of various functions – from the system on/off function and record data to temperature and voltage sensing. This reduces system cost and board space requirements, while improving the security of medical equipment and system reliability.

In addition, these highly integrated devices allow designers to put the original from several discrete component provides fully integrated in a single highly reliable mixed signal FPGA.

For example, generally contains a watchdog components, fan drive and temperature sensor power control module can consist of a single mixed-signal FPGA devices. Mixed signal FPGA also offers original by motor/pump drive module referenceFor full functionality, including the microprocessor and the ADC.

Dialysis equipment in the user interface usually consists of a keyboard, touch screen or LCD screen, and speakers.

A well-designed interface allows health service providers to better monitor patient status, the effective implementation of treatment programmes. These features can all be integrated in a mixed-signal FPGA chip. The device's embedded microprocessor and Flash memory can record task data, and other IP solutions help manage data input, alerts, and other tasks.

In dialysis apparatus, power and thermal management unit to perform key tasks, such as blood temperature sensor and system power down/power features.

A separate module accurately measure temperature and control system power may increase our costs, but also improve the reliability of the device, thus extending the product's lifespan and the patient's life. Today's mixed-signal simulation circuit in the FPGA allows these critical functions can be easily integrated and implemented.

Removal of discrete devices, as well as the processing, analog input and output, real-time clock and Flash and many other functions integrated in a single mixed-signal FPGA, you can increase reliability, reduce costs and power consumption, and as much as possible to reduce board space.

Figure: a typical hemodialysis adopts several micro-controller, used to monitor and control the blood and other body fluids flow, alerts, and turn off equipment when necessary.