Tag Archives: health

iEAT – A Powerful Keychain Detector To Detect Food Allergens

For kids and adults with food allergies, having meals from restaurants or hotels can sometimes be very risky. Even when ultimate care is taken, freshly prepared meals can accidentally become cross-contaminated with an offending food and trigger an allergic reaction. Every year many people end up in the emergency room due to food allergies. Researchers of the Harvard Medical School developed an affordable device called iEAT for detecting allergens, which can reduce the anxiety of the people prone to allergies.

iEAT - A Portable allergen-detection system
iEAT – A Portable allergen-detection system

Conventional methods to detect the hidden allergens require massive laboratory equipment. They are slow and also do not work on a low concentration of allergens. Ralph Weissleder, Hakho Lee, and their colleagues at the Harvard Medical School wanted to make a more practical, consumer-friendly alternative. They reported in the journal ACS Nano the development of a new portable allergen-detection system that features a keychain analyzer for detecting allergens in food anywhere, anytime.

The portable allergen-detection system called integrated exogenous antigen testing or iEAT is small enough to fit in your pocket and it costs $40 only. The iEAT consists of a handheld device to extract allergens from food and an electronic keychain reader for sensing allergens. Then, the result is wirelessly sent to a smartphone. The prototype is able to detect five allergens within 10 minutes, one each from wheat, peanuts, hazelnuts, milk, and egg whites, even if they are in very low concentration.

The main device uses a disposable sample collector which is inserted into the small-sized main unit. The device is so sensitive that the scientists were able to detect gluten in foods advertised as being “gluten-free”. For example, the device detected gluten in salad and an egg protein in beer. Although the prototype was primarily designed to sense five allergens only, the researchers say the device could be expanded to test for many additional compounds, including other allergens and non-food contaminants such as pesticides.

A $20 Heart Rate Module For Health-Tech Projects

Heart rate monitoring is a common procedure for most of health related projects. Therefore, producing sensors modules and circuit boards for such tasks will facilitate and push forward the development of new health-tech projects.

Maxim Integrated, an analog and mixed-signal integrated circuits manufacturer, has developed a new module for measuring heart rate and pulse oximetry. It’s called “MAXREFDES117#”, derived from Maxim Reference Design, and it is a small board which is compatible with Arduino and Mbed boards, enabling a wide range of possibilities for developers.


MAXREFDES117# can be powered by 2 to 5.5 volts. It is a photoplethysmography (PPG)-based system that uses optical method for detecting heart rate and SpO2. It consists of three main parts:

1. MAX30102, a high sensitivity heart rate and pulse oximetry sensor. It is used with integrated red and IR LEDs for heart rate and pulse oximetry monitoring.

2. MAX1921, a low-power step-down digital-to-digital converter. It generates 1.8 V from input to supply the sensor.

3. MAX14595, a high speed logic-level translator. It works as an interface between the sensor and the connected developing board.

MAXREFDES117 Block Diagram
MAXREFDES117 Block Diagram

The board size is only 0.5” x 0.5” (12.7mm x 12.7mm) and has low power consumption that make it suitable for wearable applications. Thus, it can be placed on a finger, an earlobe, or other fleshy extremity.

MAXREFDES117# uses open-source heart-rate and SpO2 algorithm in its firmware. It also can be used with any controller having I2C interface. But the available firmware had been tested only on 6 different development boards, three of them are Arduinos (Adafruit Flora, Lilypad USB, and Arduino UNO), and the others are mbed boards (Maxim Integrated MAX32600MBED#, Freescale FRDM-K64F, and Freescale FRDM-KL25Z).

The MAXREFDES117# Firmware Flowchart
The MAXREFDES117# Firmware Flowchart

Accuracy of data collected by MAXREFDES117# depends on the used platform. According to the results with tested boards, Arduino boards give less accuracy than mbed ones because of theirs smaller SRAM size.

MAXREFDES117# is available for $20, it can be ordered online through the website.
More detailed information and quick start guide are presented here. In addition, all of the source files including schematic, PCB, BOM, and firmware are open and can be reached at the official product page.

Sensor Technology for Health and Fitness Applications


By Jon Gabay @ digikey.com:

Determining the state of our health has always been a matter of finding a way to monitor and measure the body’s most basic functions. Before instrumentation, visual indicators were used that allowed us to know, for example, what our body temperature should be, what a healthy pulse is, and what an acceptable respiration rate is.

Today, with an aging population more people now need some sort of portable health monitoring, which could take the form of devices that, among other things, dispense medication at regular intervals, stimulate the heart, or measure blood sugar levels and inject insulin. This article looks at medical- and fitness-sensor technology—contacted and contact-less, placed on the skin, subcutaneous, or internal—that now or soon will be available to design engineers. All parts, tools, and data referenced here can be found on the Digi-Key website.

Sensor Technology for Health and Fitness Applications – [Link]