Culturally Situated Design Tools (CSDTs):
Performing Arts and Sports Science
Project Research Blog
The goal of the Culturally Situated Design Tools (CSDT) team is to “improve education, justice, and equality through new STEM+C educational methods.” The Performing Arts and Sports Sciences group focuses on creating CSDTs for use in performing arts and sports. The Summer Group members, Devin Malanaphy and Ciaran Young, are tackling the use of heart rate monitors and music in dance specifically, with the current goal being to design a program that can play music for a dancer at the beat of their own heart rate. Below are blog entries, updated at minimum weekly, detailing the progress of the group from Devin. See also Ciarans blog here: Link, and the CSTD homepage here: Link.
Last week we worked with Capital District educators and showcased our hardware and software and prototype lesson plans. It was interesting and fun to see the teachers chatting and getting excited about implementing our work into their lesson plans. After the first showcase day, we worked specifically with two teachers and went in depth on the hardware and software and the cultural connections they offered.
This week we tested our lesson plans with the high school interns. During the two opportunities we had to run through the lesson plan we learned a lot about what worked and what didn’t in terms of engaging the students and accomplishing the learning goals. Specifically, the feedback we got largely indicated that the readings needed to be kept short and to the point, and that we should minimize lecturing overall. In addition to minimizing lecturing, in the following days we will be working on flushing out the teacher information sheets so that the teachers have the knowledge base necessary to guide the discussion/lessons. Below is a short video from this past week. The student in the video is wearing a wireless chest strap heart rate sensor and is dancing to the beat of his heart, which is also being displayed on the EL-Wire bar graph on the table.
Late last week we recieved the polar chest strap heart rate sensor and had some time to do preliminary testing with it. The receiver board outputs a brief square wave pulse on every heart beat is senses, which luckily works well with the pulsesensor Arduino library. Below is the simple three wire configuration for the receiver board (5V, Ground, and signal). The polar sensor is already a big improvement over the optical pulse sensors, but it is not without it’s faults. The first issue is that occasionally, for around 10-20 seconds, the sensor will count every other heartbeat, causing the BPM reading to be half the actual BPM of the user. This week I’m going to be working on a software solution to this problem that will be able to detect when the BPM drops by half and can temporarily double it to keep the readings accurate. The other issue is that actually implementing the sensor in a classroom requires the user to wear the device on their chest, which can be uncomfortable for some participants. It is for this reason that we are making the use of the polar sensor explicitly elective, and will offer alternatives for students to demonstrate the ECG technology.
Last week I worked on furthering the development of the software interface and it’s functionality, adding a text box to input the audio file name, and investigating the use of minim to detect the original BPM of the song that is begin played so that the BPM can be changed.
The software is working! I have successfully modulated the speed of the audio based on the input heart rate data, but for now the speed modulation is very primitive, and does not result in beat for beat matching with the heart rate of the user. Another issue that we have been running into constantly is the need for the user to have the heart rate sensor on their finger and for them to be almost completely still to get an accurate heart rate reading. We’re hoping to resolve this with an upgraded heart rate sensor, this one using a chest strap design shown below. Additionally a processing program to provide a graphical user interface for the use of the heart rate sensor is being developed.
Below are some diagrams drawn to represent in a visual fashion the concepts behind our project thus far. Also included below is a preliminary hypothesis, and the processing code that takes serial data from the arduino and modulates the speed of the song selected.
Dancing at one’s own heart rate allows the dancer to have agency in directing the music he/she dances to, in a bottom-up organizational structure.
The DIY heart sensor has been tested alongside the off the shelf heart sensor and the functionality of both has been proven. The next goal is going to be working on incorporating the heart rate sensor along with accompanying software to change the tempo of music based on a person’s heart rate. Below are some photos of us testing the off the shelf pulse sensor in a glove to limit its movement in relation to the users skin for better accuracy. We also tested a different placement on the chest. Nither of these solutions worked particularly well.
The DIY Heart Rate sensor is almost complete. The circuit design as well as breadboard implementation can be seen below. The basic design uses two red LEDs to pass light at a wavelength of around 620nm through the finger, where the hemoglobin in the user’s blood interrupts the path of the photons. This interruption can be measured with a simple photoresistor, and the results plotted on an oscilloscope.
In the coming days I’ll be working on improving the analog and digital signal processing using an arduino and multiple op-amp stages to remove the high frequency noise (seen as the dark yellow shading below) and the 60Hz interference from the power grid. I’ll also be developing a 3D enclosure for the electronics and LED/light sensor combination.