Introduction:
My design proposal is to develop a Vital Monitor for babies using the Analog Devices Inc. EVAL-ADPD4100Z-PPG Evaluation Board.
This project work intends to try out the EVAL-ADPD4100Z-PPG Evaluation Board to be used to measure
The evaluation board will be used to design a wearable sensor which can be mounted on the chest of the baby.
An Arduino Nano IOT 33 or ESP 32 will be used to acquire the data and send it to cloud through Wi-Fi.
ADPD4100 Description:
It’s a complete Multimodal Sensor Front End, can be considered to be an all-rounder in biomedical sensor design. The AFE is based on Trans Impedance Amplifier [TIA].
It has capability of driving up to eight light emitting diodes (LEDs) at total 400mA peak current and measuring current inputs through eight separate channels. Twelve separate time slots can be utilized to measure parameters in a single sampling period. It has programmable sampling rate from 0.004 Hz to 9 kHz using internal oscillators.
AFE consists of transimpedance amplifier (TIA), band-pass filter (BPF), integrator (INT) and analog-to-digital converter (ADC) stages. Dual-channel processing provides simultaneous sampling of two different parameters or a single differential signal.
A selectable second- to fourth-order cascaded integrator comb (CIC) filter provides on chip digital filtering.
The evaluation board is populated with ADPD4100 which supports SPI interface and operates @ 1.8v [analog core] and 1.8v / 3.3v [digital I/O].
** EVAL-ADPDUCZ microcontroller board is suggested by Analog Devices Inc. in the EVAL-ADPD4100Z-PPG product page, which can be used with the Wavetool Evaluation Software graphical user interface (GUI) that provides users with low level register access and high level system configurability. If I could get the EVAL-ADPDUCZ microcontroller board, that would reduce the development time period. Unfortunately [or may be actually fortunately!!], now I have to work from scratch – which is time consuming but I am enjoying the learning curve.
Modes of Operation:
The following layouts show the potential modes of operation of ADPD4100 for measuring SPO2, ECG and Impedance –
SPO2:
ECG:
Impedance: can be used for dehydration and respiration rate measurement
I could not complete the project within the time limit. However, working with the ADPD4100 evaluation board from scratch seemed to be very challenging and time consuming. I am still working on setting the configuration registers. Therefore, I am presenting my project scopes as an introductory blog. I’ll keep posting updates on my progress from time to time.
My next blogs will be on the modes of operation where I'll present my previous experience of working on vital signs.
My design proposal is to develop a Vital Monitor for babies using the Analog Devices Inc. EVAL-ADPD4100Z-PPG Evaluation Board.
This project work intends to try out the EVAL-ADPD4100Z-PPG Evaluation Board to be used to measure
- SPO2 using PPG,
- Heart rate with single LEAD ECG and
- Dehydration using skin impedance
The evaluation board will be used to design a wearable sensor which can be mounted on the chest of the baby.
An Arduino Nano IOT 33 or ESP 32 will be used to acquire the data and send it to cloud through Wi-Fi.
ADPD4100 Description:
It’s a complete Multimodal Sensor Front End, can be considered to be an all-rounder in biomedical sensor design. The AFE is based on Trans Impedance Amplifier [TIA].
It has capability of driving up to eight light emitting diodes (LEDs) at total 400mA peak current and measuring current inputs through eight separate channels. Twelve separate time slots can be utilized to measure parameters in a single sampling period. It has programmable sampling rate from 0.004 Hz to 9 kHz using internal oscillators.
AFE consists of transimpedance amplifier (TIA), band-pass filter (BPF), integrator (INT) and analog-to-digital converter (ADC) stages. Dual-channel processing provides simultaneous sampling of two different parameters or a single differential signal.
A selectable second- to fourth-order cascaded integrator comb (CIC) filter provides on chip digital filtering.
The evaluation board is populated with ADPD4100 which supports SPI interface and operates @ 1.8v [analog core] and 1.8v / 3.3v [digital I/O].
** EVAL-ADPDUCZ microcontroller board is suggested by Analog Devices Inc. in the EVAL-ADPD4100Z-PPG product page, which can be used with the Wavetool Evaluation Software graphical user interface (GUI) that provides users with low level register access and high level system configurability. If I could get the EVAL-ADPDUCZ microcontroller board, that would reduce the development time period. Unfortunately [or may be actually fortunately!!], now I have to work from scratch – which is time consuming but I am enjoying the learning curve.
Modes of Operation:
The following layouts show the potential modes of operation of ADPD4100 for measuring SPO2, ECG and Impedance –
SPO2:
Figure: SPO2 configuration - needs couple of this for RED and IR LED to measure SPO2
**image courtesy: Multiparameter Vital Signs Monitoring Is Easier Than Ever Before by Electronics Maker November 21, 2020ECG:
Figure: ECG configuration - single LEAD
**image courtesy: Multiparameter Vital Signs Monitoring Is Easier Than Ever Before by Electronics Maker November 21, 2020Impedance: can be used for dehydration and respiration rate measurement
Figure: Combined ECG and Respiration Rate configuration
**image courtesy: Multiparameter Vital Signs Monitoring Is Easier Than Ever Before by Electronics Maker November 21, 2020I could not complete the project within the time limit. However, working with the ADPD4100 evaluation board from scratch seemed to be very challenging and time consuming. I am still working on setting the configuration registers. Therefore, I am presenting my project scopes as an introductory blog. I’ll keep posting updates on my progress from time to time.
My next blogs will be on the modes of operation where I'll present my previous experience of working on vital signs.
- BLOG 02 - measuring PPG [ for SPO2 ] following traditional method - transimpedance amplifier
- BLOG 03 - measuring ECG single LEAD following traditional method - instrumentation amplifier
- BLOG 04 - measuring skin impedance following traditional method - Tetrapolar Bioimpedance
