Streamlining the design of portable medical electronics

Quality healthcare aimed at prevention is a trend that is rapidly gaining momentum. Medical devices that capture vital parameters and possess multiple connectivity features enable a seamless flow of information between caregivers and patients. Patient vitals can be located in a centralized repository, which can be accessed and processed by authorized personnel. Home healthcare is booming because of an increase in the aging population, rising healthcare costs, and demand of quality healthcare from remote locations.

Technological innovations in the field of medical electronics and communication can drive the cost of healthcare. Applications for health at home include chronic disease management, post operative care, fitness, general wellness etc.

An example of a device is a Patient Vital Signs monitor which measures the basic parameters from the patient, including electro-cardiogram (ECG/EKG), pulse oximeter, blood pressure, glucose monitor, respiratory measurement, and temperature measurements. Medical devices designed for home use have different requirements in terms of performance, connectivity features, cost, and ease of use compared to equipment for professionals. With the use of highly integrated system-on-chip (SoC) architectures, the cost and size of medical devices is going down.

Some of the functional blocks of medical devices are common to many medical devices. These include bio-sensors, signal conditioning circuitry, analog-to-digital converters (ADC), and power management circuitry, among others. Today’s SoC devices offer configurable blocks which, along with the capability to integrate analog and digital components, allow the same circuitry to be reused among different functional blocks to significantly the reduce cost of a system compared to architectures designed using discrete components.

Figure 1 gives an overview of a patient monitor designed for home use. The device will also have a stable operating system to handle various peripherals such as USB, capacitive touch sensing solutions, image sensors for high speed video, memory to store data, and integrated analog front-end design with in-built micro-controllers for robust and effective design.

Ease of use plays a critical role in medical devices at home. Features like an intuitive user interface, graphical interface, ease of connecting probes to measure parameters, touch interface, gesture based recognition are very important. The device can also have interfaces which will enable video and audio interaction with caregivers.

Figure 1: Main block diagram

The most important and critical factor for a medical device at home is connectivity. Once the vital parameters are captured in the device, it can be connected to a computer through USB to upload medical information to data centers. Complete medical data related to patients can be stored in a centralized repository. The database of the patient along with the all the essential medical parameters (i.e., the time data was captured, patient’s previous medical history, etc.) can be logged onto the server.