IFD:PhysicalComp2011/Julia Putscher

From Medien Wiki

EHP - Emotion Heartbeat Project

The "Emotion Heartbeat Project" is a project that will collect my heartrate as a datatype. This data will be displayed in a visual way with diagrams and create an emotional diary out of that. With an increased heartrate the heartrate monitor will ask for the cause of it to differentiate between positive and negative stress or sports activities.

First Ideas And Thoughts

One of my first ideas was to connect the heartrate monitor with headphones that would calm down my increased heartrate with music and vibrating sensors at my neck; showing picture 3 and 5. The decision diagram displays how this should work. But within this semester I will just build up the heartrate monitor itself.

Picture 6 and 7 are showing the result of 1 week of collecting heartrate data. I counted my heartbeat within 1 minute manually 4 times a day for 1 week. Pic 6 shows a diagram displaying the whole week at a glance; Pic 7 shows the diagrams of each day in particular. (Unfortunately I couldn't get it work with a consistent scale for the heartrate.)

Related Links To That Topic

How To Build It?

HEARTRATE SENSOR, SIMPLE CIRCUIT

Inspired by diverse links and Youtube videos the very first try to build it was to use IR Emitter and Detector. It didn't work that well: the sensors are pretty sensitive for moving action and the signal at processing was very faint. So I decided to try it again with an amplifier to get a stronger signal of my heartbeat.
To amplify the signal I used a low voltage op-amp LM358N. The images of the third gallery show the circuit, schematic and processing screen result.
The Data Logger Shield for the Arduino board is directly plugged on the top of it and will save the collected data to a SD card.


HEARTRATE SENSOR WITH AMPLIFIER

Codes for Arduino and Processing

Related Links


THE EKG SENSOR


The selfmade sensor with the IR Emitter and Detector is very sensitive for any motion and movements of the finger being measured. So I tried out a EKG Sensor which displayed a higher resolution of the heartbeat on processing. There are 3 electrodes patches placed on the skin: One on the right wrist for the reference, one on right elbow for the negative alligator clip and one on the left elbow for the positive clip. The EKG Sensor is connected with the Arduino to Ground, 5V and Analog Input A0. The heartbeat is displayed with Processing.

Codes for Arduino and Processing - EKG Sensor


This was a pretty good thing to test but unfortunately it wasn't convenient for a design to wear it every day and take everywhere I go. In cause of that and diverse failed trys to make a sensor by my own, I decided to buy a device.


Realization

This device is a Data-Logger which goes with a chest strap: the chest strap measures the heartrate and the Data-Logger saves it every 2nd or each second. The saved values are collected in CSV-files which can be displayed with the program of the Data-Logger, shown with the images below.

The program of the Data-Logger to visualize the collected data is a pretty good way to have a quick view to the results of the measurements. But the CSV-files need to be cleaned of extreme and zero values which were saved in cause of disturbances between the connection of the chest strap and the Data-Logger. The following images below show possible interface designs to display the collected heart rate and to analyse the results.

Ways For Visualization

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Codes for Processing


Alternatives For Visualization

The project and the two devices were a pretty good way for getting started with the idea of heartbeat, collecting emotional data. But there are still some Things which need to be improved: As I mentioned the disturbances between the two devices I had to check the Connection between the two devices permanently because in some cases the signal wasn't strong enough and got interrupted through electro magnetic fields. Furthermore ist was very unconvinient and not very comfortable to wear the chest strap the whole time. I wore it every day for two weeks and was pretty stressed out. It may be ok to wear it while doing sports for that short period of time but not in everyday life. Possible could be to make an earclip or to integrate it into a device or a thing you need every day.