SavaPrana

Interactive yoga mat for deep breathing to increase interoceptive awareness

The design of the SavaPrana draws from the concept of controlling breath when a person engages in a certain posture. It is designed to utilize human body posture, breathing, and biodata as materials that trigger responses from the system.

OVERVIEW

TIMELINE
September - December 2020


SOLO PROJECT
Developed the concept
Applied research-through-design method
Built prototypes using physical computing

PROJECT FOCUS
Experience Design, Embodied Interaction, Affective Computing

BACKGROUND
An independent project from Dr. Dina El Zanfaly’s class hyperSENSE: Augmenting human experience in environments in CMU’s School of Design.

RESEARCH QUESTION

How might we increase interoceptive awareness by augmenting the human senses?

A growing number of studies suggest that poor interoceptive awareness can lead to difficulties with emotion regulation.

One way to increase interoceptive awareness is to practice mindfulness through deep breathing.

THE SOLUTION

An interactive yoga mat with haptic guidance for deep breathing

SavaPrana is a combined word of Savasana and Pranayama.

Savasana, literally translated as “corpse pose” in Sanskrit, is the pose done at the end of yoga practice that involves lying on one’s back with arms and legs outstretched and eyes closed.

Pranayama, translated as “breath control,” is the practice in yoga that allows an individual to control the timing, duration, and frequency of every breath.

HOW IT WORKS

A full body interactive experience using vibrotactile stimuli corresponded to the user’s heart rate

FINAL PROTOTYPE

I integrated each component into a single yoga mat.

RESEARCH

INSPIRATION FROM CASE STUDIES

What body part best perceives vibrotactile stimuli?

Recent research has shown the effect of affective wearables in emotion regulation by measuring breathing rate. Besides wearables, programmable physical materials also induce different kinds of sensory stimuli in the human body to generate similar effects.

Apple Watch Breathe

Uses visual and haptic stimuli to guide breathing

Affective Sleeve

Produces rhythmic haptic action with warmth and slight pressure to promote calmness (Papadopoulou et al., 2009)

Soma Mat

Induces heat to guide users to turn their gaze inward to different parts of their body (Ståhl et al., 2016)

THE DESIGN PROCESS

IDEATION

What body part best perceives vibrotactile stimuli?

To identify the optimal parts of the body that perceive vibrotactile stimuli, I first considered employing wearable devices on different parts of the body while sitting on the mat.

To create a full-body experience, however, I chose the lying down position. While lying down, I induced vibrotactile stimuli on the back side of the body to find out which part is the most sensitive. The upper shoulder and hip area were the most ideal parts to induce such stimuli.

What vibration factors influence the user's experience of breathing?

In terms of direction, the vibration motor in the shoulder area will be activated first to guide inhalation and the motor in the hip area will be followed to guide exhalation.

In terms of intensity, the motor that guides inhalation vibrates from low to high intensity to make the user feel like they are breathing in. In contrast, the motor that guides exhalation vibrates from high to low intensity to make the users feel like they are breathing out.‍

Correlating Heart Rate with Vibration by manipulating Intensity and Duration

If the heart rate is in the normal range (below 90 bpm), the vibration motors induce low-intensity vibration. I designed motor 1 (shoulder) to vibrate for 4 seconds to guide inhalation and motor 2 (hip) to vibrate for 6 seconds to guide exhalation.

If the heart rate is out of the normal range(above 90 bpm), presuming the user not being able to feel the low-intensity vibration, I programmed the vibration motors to induce high-intensity vibration. Assuming the user is out of breath, I chose motor 1 to vibrate for 3 seconds (shorter than the normal inhalation duration) and motor 2 to vibrate for 7 seconds (longer than the normal exhalation duration) to promote calmness and relaxation by leading the user to breathe out longer.

How to trigger vibration?

To create an embodied interaction that encourages users to purely use their body parts to control interaction, I created a pressure-sensitive sensor with velostat and copper tape to trigger a vibration.

I identified three parts of the body that have the highest pressure point when lying down. After testing on these three parts, I found placing the pressure sensor under the head area would be most ideal as vibration motors are placed in both the upper and lower back.

ITERATIONS

Initially used a physical switch to control the motors. Yet, a switch wasn’t appropriate to create a natural embodied interaction as it requires voluntary control.

Created a pressure-sensitive sensor with velostat and copper tape and tried three different patterns to make it most conductive.

Tested a pressure-sensitive sensor’s conductivity with LED blinks.

REFLECTION

MY KEY TAKEAWAYS

SavaPrana was my first physical computing project. Since it was a solo project, ideating possible opportunities and executing a code to successfully implement the design was a bit challenging. Yet, applying the research-through-design method and refining the concept in response to the principles of embodied interaction was truly a rewarding experience. ✨

WHAT CAN BE BETTER

Increase strength and frequency of the vibration motors

The vibration motors weren’t strong enough to induce an appropriate sense of vibrotactile stimuli on the upper shoulder and hip area. The frequency can also be further experimented with to investigate its effect on vibrotactile stimulation to guide breathing.

Define a target audience

The effect of SavaPrana on different types of users can be more clearly defined. There’s a possibility that SavaPrana might unintentionally create a reliance on a system instead of providing an opportunity to build self-efficacy when meditating.