Bio Patch

Mike,

Personally, I am not familiar with tetra polar method.

My assumption is that your question is related to the Designing and evaluating an NFC-enabled bio-patch for medical and health & fitness applications paper which we wrote? The heart of the patch is the RF430FRL152H IC. What makes the IC unique is that it incorporates a (MCU which itself incorporates a SPI, I2C and ADC peripheral) instead of using a state machine like most tags. The patch is passive which means it gets all of its energy from the NFC field produced by the phone. More complicated sensors might required incorporating a battery to the system.

One question that I have is will your system be batteryless or will it incorporate a battery? Also, how will your system display its data? Will it be communicating over Bluetooth, NFC, etc ? When you say pulse do you mean pulse-ox?

Have you looked into the ADS1292R IC? It incorporates both ECG, HR and respiration rate. It is also low power. There is a EVM out www.ti.com/.../ads1292recg-fe which has this chip and allows you to evaluate it.

Also, to measure pulse (Ox?) have you looked into the AFE44XX?

Ricky,

Application Report
SBAA202–October 2013
Impedance Measurement with the AFE4300
Application Report
SBAA202–October 2013
Impedance Measurement with the AFE4300
This article gives a brief overview of bio-impedance measurements and discusses the methodology to measure impedance with AFE4300, an analog front end for weight and body composition measurement.
The article also includes the step-by-step procedure to calibrate and measure the impedance using the AFE4300 demonstration kit and the PC application software. The measurement results of two typical bioimpedance networks are analyzed. Just below is a section:
1.1 Tetrapolar Single (SF-BIA) and Multi-frequency (MF-BIA) BIA
First thing you need to get the BI is a sensor 8 electrodes, Tetra uses 4. Once you get the impedance you can analyze it. A system doing this was attached, the current was fed in and the output analyzed for ECG, etc. And that was question-1. Do you have a Tetra polar sensor to get the BI from the user. Check this link.
www.ti.com/.../sbaa202.pdf

The design is given in Fig-2.
Note that the AFE4300 can also measure body composition
How: [Back to the diag sent]
by applying a sinusoidal current into the body. The – 6-Bit, 1-MSPS Sine-Wave Generation sinusoidal current is generated with an internal Digital-to-Analog Converter (DAC) pattern generator and a 6-bit, 1-MSPS DAC. A
– 375-µArms, ±20% Excitation Source voltage-to-current converter applies this sinusoidal
– Dynamic Range : 0 Ω to 2.8 kΩ current into the body, between two terminals. The
voltage created across these two terminals as a
– 0.1-Ω Measurement RMS Noise in 2-Hz BW result of the impedance of the body is measured back
– Body Composition measurement : 970 µA with a differential amplifier, rectified, and its amplitude
• Analog-to_Digital Converter (ADC): is extracted and measured by the 16-bit ADC.
– 16 Bits, 860 SPS The AFE4300 operates from 2 V to 3.6 V, is specified
– Supply current: 110 µA from 0°C to +70°C, and is available in a TQFP-80
package.
We want to keep Body composition and add ECG + HR + Pulse and send the collected data to our cloud server. The tetra Polar sensor is part ot the patch that is attached to the user. maybe I am misunderstanding the technology.