PaperlayerView exact revision on arXiv

Source-linked AI summary

Breeze: Sharing Biofeedback Through Wearable Technologies

Jérémy Frey, May Grabli, Ronit Slyper, Jessica Cauchard

arXiv:1802.04995v1cs.HC

TL;DR

The paper addresses how breathing can be digitally encoded and perceived as emotional biofeedback. It presents Breeze, a wearable pendant for real-time breathing feedback, and studies how people interpret breathing patterns across modalities. Participants intentionally mimicked a foreign breathing pattern to understand it.

  • Problem

    The paper investigates how people perceive emotions through breathing patterns and how a wearable device can sense and convey breathing biofeedback.

    Source: INTRODUCTION · pp. 1–2

  • Method

    The authors built Breeze, a wearable breathing-feedback pendant, and conducted a laboratory study of perceived emotions from generated breathing patterns across visual, audio, and haptic modalities.

    Source: FUTURE WORK AND CONCLUSIONS · p. 9

  • Results

    Participants naturally mimicked foreign breathing patterns to understand them, as assessed through breathing measurement and semi-structured interviews.

    Source: FUTURE WORK AND CONCLUSIONS · p. 9

  • Takeaways & Limitations

    The findings may reinforce bonds in remote communication, while making physiological signals more visible could promote empathy and connectedness.

    Source: FUTURE WORK AND CONCLUSIONS · p. 9

    A larger sample is needed to determine whether the three modalities are equally meaningful and effective in conveying biofeedback.

    Source: CHALLENGES AND LIMITATIONS · p. 9

Abstract

from arXiv · show

Digitally presenting physiological signals as biofeedback to users raises awareness of both body and mind. This paper describes the effectiveness of conveying a physiological signal often overlooked for communication: breathing. We present the design and development of digital breathing patterns and their evaluation along three output modalities: visual, audio, and haptic. We also present Breeze, a wearable pendant placed around the neck that measures breathing and sends biofeedback in real-time. We evaluated how the breathing patterns were interpreted in a fixed environment and gathered qualitative data on the wearable device's design. We found that participants intentionally modified their own breathing to match the biofeedback, as a technique for understanding the underlying emotion. Our results describe how the features of the breathing patterns and the feedback modalities influenced participants' perception. We include guidelines and suggested use cases, such as Breeze being used by loved ones to increase connectedness and empathy.

INTRODUCTION

The paper investigates how people perceive emotion through breathing patterns and how a wearable can sense and convey breathing biofeedback. It presents Breeze and examines visual, audio, and haptic feedback.

INTRODUCTION

  • Biofeedback makes physiological signals more noticeable, directing attention to internal processes and raising awareness of body and mind.The paper notes that displayed biofeedback can trigger a self-regulation feedback loop.Source: INTRODUCTION · p. 1
  • Breathing can be modulated easily, and the paper uses physiological signals for human-human communication rather than mainly as HCI input.The authors advocate breathing biofeedback for internal awareness and mediating between people.Source: INTRODUCTION · p. 1
  • The authors envision shared wearable biofeedback connecting close ones at a distance.They describe the work as a first stepping stone toward fundamental knowledge of multi-modal biofeedback.Source: INTRODUCTION · pp. 1–2
  • The study asks how breathing can be digitally encoded, perceived across modalities, and used to communicate another person’s state.It also asks whether people are affected by perceiving someone else’s breathing and which non-invasive sensors can measure it.Source: INTRODUCTION · p. 2
  • Breeze is a wearable pendant that monitors breathing and communicates it to a connected companion’s pendant through multi-modal output.The pendant supports both input and output.Source: INTRODUCTION · p. 2
  • The paper contributes an account of how people interpret breathing biofeedback across visual, audio, and haptic modalities, plus a lexicon relating breathing features to perceived emotions.It also offers guidelines for shared breathing biofeedback.Source: INTRODUCTION · p. 2

RELATED WORK

Prior work has linked breathing patterns to emotion and explored breathing biofeedback in several applications. The paper reviews reported breathing-emotion relationships and notes factors that complicate their interpretation.

RELATED WORK

  • Earlier breathing-biofeedback studies used avatars for breathing synchronization, slowed respiratory feedback for stress reduction, and breathing to shape robots’ emotional expressiveness.Other work has examined breathing’s links with cognitive processes, although much prior research focuses on emotion.Source: RELATED WORK · p. 2, The Language of Breathing · p. 2

The Language of Breathing

  • Prior research associates shorter inhalation with pleasantness, faster breathing with excitement, and different pauses, depths, and irregularities with distinct emotional states.The reviewed patterns also include longer post-inspiration pauses for amusement or disgust, and mid-cycle breath holds as a sign of surprise.Source: The Language of Breathing · p. 2
  • Breathing-emotion relationships are complicated by interacting features, variation by age and gender, and imperfect measurement tools.For example, few techniques account for differences between thoracic and abdominal respiration.Source: The Language of Breathing · p. 2

Measuring Breathing

The paper reviews breathing measurement and biofeedback display approaches, then presents a simple visual mapping for breathing. Its aim is to communicate breathing to others in a form that can be understood emotionally.

Measuring Breathing

  • Breathing measurement methods include airflow sensing, body-mounted sensors, and non-contact approaches, while remote methods are constrained to fixed environments.Breeze uses an IMU for portability and non-invasiveness.Source: Measuring Breathing · p. 2

Digitally Presenting Biofeedback

BREATHING ENCODED ACROSS MULTIPLE MODALITIES

  • The design maps the full breathing range to one degree of freedom, using a normalized IMU signal for visual, audio, and haptic representations.Taste and smell were considered unsuitable for real-time breathing mapping because of latency and inertia.Source: BREATHING ENCODED ACROSS MULTIPLE… · p. 3

Visual

  • For visual feedback, the authors discarded color to avoid biasing emotion perception and selected point-light brightness to represent breathing.They applied gamma correction because perceived brightness does not double with raw light intensity.Source: Visual · p. 3

Audio

Breeze is designed as a wearable breathing sensor and multi-modal biofeedback device. This section describes the audio and haptic mappings, device requirements, and body-position tradeoffs.

Audio

  • Pink noise provides neutral audio feedback, with breathing mapped to perceived loudness and then to speaker gain.Recorded breaths were considered complex to manipulate, while binary “breathe in” and “breathe out” commands could not represent a continuous signal.Source: Audio · p. 3

Haptic

  • Vibration was selected for haptic breathing feedback because other sensations may require bespoke hardware or have latency issues; breath amplitude controls vibration intensity.The selected vibration approach is low-cost and widely available.Source: Haptic · p. 3

BREEZE: A WEARABLE DEVICE FOR BREATHING

  • Breeze monitors breathing in real time and provides multi-modal biofeedback, with its signal compared against a traditional breathing belt for validation.The device streams the breathing pattern live.Source: BREEZE: A WEARABLE DEVICE FOR BREATHING · p. 3

Design

  • The design balances device capabilities and aesthetics while requiring a comfortable, non-invasive, enclosed, and easily worn apparatus.The case designs included neutral teardrop shapes, a compass, and an avatar.Source: Design · p. 3, Figure 2 · p. 3

Body Positioning

  • The chest was chosen over the wrist for breath-sensing accuracy, but sensing is unreliable while walking and the pendant’s light lies outside the active field of view.The authors cite wrist movement as a source of reduced sensing accuracy and note that people may be accustomed to looking down while working or reading.Source: Body Positioning · pp. 3–4

Form Factor

Breeze’s pendant design balances alternative visual forms, privacy choices, and real-time breathing sensing with multimodal feedback.

Form Factor

  • The pendant’s form was treated as consequential for perception and acceptability, so the team explored neutral, symbolic, and avatar-like designs.Options included a teardrop with an “air” symbol, a compass, and an avatar.Source: Form Factor · p. 4

Privacy Concerns

  • Users can remove the pendant at any time, while future versions could add explicit sharing modes and should protect data through secure pairing, encryption, and collection indicators.Source: Privacy Concerns · p. 4

Technical Implementation

  • The pendant contains removable electronics, including a BLE Arduino board, speaker, haptic motor, RGB LEDs, battery, and 9DOF IMU.The vibration motor was moved to the pendant’s outside back wall because it created unintended noise inside the case.Source: Technical Implementation · p. 4

On-board implementation

  • Sensor fusion combines accelerometer, gyroscope, and magnetometer data to estimate orientation and linear acceleration in the terrestrial frame.Individually, the sensors are noisy, drift over time, or provide relative values.Source: On-board implementation · p. 4
  • The pendant’s component breakout is shown in Figure 3.Source: Figure 3 · p. 4

Real-Time processing

  • Pitch-axis rotation is streamed over Bluetooth at 24Hz, and biofeedback returns at 10Hz.Breathing extraction uses 0.5s epochs, a 0.125s sliding window, a third-order 1Hz Butterworth low-pass filter, and the epoch average.Source: Real-Time processing · p. 4

Measurement Validation

The pendant’s breathing signal tracked a traditional belt during pattern mimicry; the study then used fixed feedback setups to examine perceptions of breathing patterns across modalities.

Measurement Validation

  • r = 0.54 (p < 0.001): Breeze and a traditional breathing belt produced correlated signals during breathing-pattern mimicry.The 20-minute validation session included 30 trials of 40 seconds; the signals displayed the same patterns despite sensor-response differences.Source: Measurement Validation · p. 4, Figure 4 · p. 5

Fixed vs. Mobile Implementation

  • Audio and visual feedback were presented in a fixed monitor-and-earbud setup to control the experiment and avoid hardware novelty and technical limitations.Participants used Breeze for breathing monitoring and haptic feedback.Source: Fixed vs. Mobile Implementation · p. 5

USER STUDY

  • The user study examined how people perceive emotions conveyed by breathing patterns.Source: USER STUDY · p. 5

Task

  • Five breathing features were varied into ten traits, including pace, inhale–exhale timing, breath holds, amplitude, and variability.Traits were combined into ten patterns to reduce task monotony.Source: Task · p. 5
  • Participants rated the presumed breather’s valence, arousal, and dominance after each trial using the nine-point SAM scale.The scale used picture choices to help participants express feelings that could be difficult to verbalize.Source: Task · p. 5

Breathing analysis

The study recorded participants’ breathing during trials, extracted signal features, and collected workload ratings and post-study feedback.

Breathing analysis

  • Pendant signals were synchronized to each 40-second trial, then filtered and smoothed before a first-order derivative detected peaks for breathing-feature extraction.Extracted features included pace, inhale–exhale timing, breath-hold duration, and amplitude.Source: Breathing analysis · p. 6

Post-study questionnaires

  • Twelve participants completed NASA-TLX workload ratings, and all fourteen completed interviews and two modality questionnaires on enjoyment and usefulness.NASA-TLX measured mental, physical, and temporal demand, performance, effort, and frustration; the modality questionnaires used five-point Likert scales.Source: Post-study questionnaires · p. 6, Protocol · p. 6

Protocol

  • Fourteen participants experienced 30 randomized trials, covering ten breathing patterns in visual, audio, and haptic modalities, each lasting 40 seconds.Training introduced the pendant, questionnaire, modality mappings, and sample trials; the experiment averaged 45 minutes.Source: Protocol · p. 6

Results

Breathing traits and feedback modality shaped perceived emotion, while participants also changed their own breathing in response to the presented patterns.

Effects of breathing traits and feedback modality on emotion

  • Every SAM emotional dimension was significantly affected by at least one breathing trait.Source: Effects of breathing traits and… · p. 6
  • Longer exhalation increased valence (Hold-out mean +1.43), whereas more variable and deeper breathing lowered it (Variable -1.16; Deep -1.31); faster pace most increased arousal (Fast +3.33).The respective 95% confidence intervals were [0.35, 2.47], [-2.20, -0.09], [-2.39, -0.27], and [2.25, 4.38].Source: Effects of breathing traits and… · p. 6
  • Haptic feedback significantly increased perceived valence (+0.88), whereas audio and visual feedback had no significant overall effect on perceived emotion.Source: Effects of breathing traits and… · p. 6
  • The study could not fully investigate interactions among output modality, breathing trait, and emotional dimension because of its small sample size.The authors identify a larger study as needed to confirm preliminary interaction findings.Source: Effects of breathing traits and… · p. 6

Change in breathing

  • Participants’ breathing rate rose with Fast (+2.04 breaths/minute), fell with Slow (-2.64) and Variable (-1.44), and shifted toward longer exhalation for Minus (+2.05 seconds).All listed changes are reported with 95% confidence intervals in the results.Source: Change in breathing · p. 7
  • Haptic feedback received lower enjoyment and usefulness ratings than audio and visual feedback, despite its positive effect on perceived valence.The differences were significant (p < 0.05).Source: Effects of breathing traits and… · p. 6, Change in breathing · p. 7

Interviews

Participants interpreted breathing pace and pattern as cues to arousal, dominance, context, and emotion, and nearly all tried to mimic the patterns. They generally responded positively to visual and audio feedback, while interviews also surfaced preferences and concerns around sharing and wearing Breeze.

Feedback modalities

  • Visual feedback was often considered easy to imitate, and audio was often described as relaxing and easy to understand, though some found it noisy or difficult.One participant found visual feedback harder to follow than audio; nine participants gave negative feedback about haptics, while two were neutral.Source: Interviews · p. 8

Breathing Pace and Perception

  • Participants used breathing pace to infer arousal and dominance, but associated faster breathing variously with stress or excitement and slower breathing with relaxation.Some interpreted fast pace as higher arousal and lower dominance, and slow pace as higher dominance; pattern changes also shaped judgments about control and intensifying emotion.Source: Interviews · p. 8

Breathing Context

  • Participants associated shallow breathing with exercise or stress and fear, while slow breathing suggested sleep, relaxation, meditation, or tranquility.Four participants reported no particular context during the experiment.Source: Interviews · p. 8

Mimicking

  • All but one participant actively mimicked the breathing pattern, with some saying matching its pace helped them understand its context or the other person's state.Participants reported that they would have difficulty determining what the generated breather was feeling without mimicking.Source: Interviews · p. 8

Usages

  • Participants envisioned sharing Breeze with partners or family to convey emotions, notice mood changes, monitor health, or communicate feelings that are hard to express.Some considered it too intimate for friends; four participants cited privacy concerns, although 12 said they would be comfortable sharing breathing activity or heart rate this way.Source: Interviews · p. 8

Case Design

  • Participants' pendant preferences ranged from simple colored or compass designs to shapes representing loved ones, while many found the pendants too large.The avatar was generally considered cute and more suitable for children, though two participants found it frightening.Source: Interviews · p. 8

Discussion

Participants changed their breathing rate to match displayed patterns without being instructed, and almost all reported consciously mimicking them to understand another person's experience. The authors connect this behavior to breathing as a possible means of communicating at a distance.

Breathing to communicate

  • Participants' breathing rate changed to match displayed patterns without instruction, and almost all consciously mimicked them to understand what another person was experiencing.One participant stopped after interpreting the task as an attempt to control their breathing; the authors were surprised that simple cues elicited empathy.Source: Breathing to communicate · p. 8
  • The authors suggest that making inner-body activity explicit may prompt people to use it to understand others, with reproducing emotion proposed as a strategy for assessing others' states.They relate this possibility to Philippot et al.'s account of similar breathing when acting and feeling an emotion.Source: Breathing to communicate · p. 8

Breathing features

The discussion highlights meaningful information in breathing features and differing responses to feedback modalities, while noting that a larger sample is needed to assess modality effectiveness. The authors describe Breeze and their study as a basis for further work on shared breathing biofeedback and its use beyond the laboratory.

Breathing features

  • Advanced breathing features extracted with Breeze were meaningful during mimicry; for example, exhalation duration matched the source biofeedback.The authors propose their lexicon as a starting point for extracting meaningful information from breathing signals.Source: Breathing features · p. 9

Biofeedback modalities

  • Haptic feedback produced slightly higher perceived valence despite negative connotations for some participants, while wave-like interpretations of pink noise did not significantly affect pattern perception.Some participants reported difficulty interpreting haptic patterns, but this was not reflected in the SAM test.Source: Biofeedback modalities · p. 9

CHALLENGES AND LIMITATIONS

  • A larger sample is needed to determine whether the three modalities are equally meaningful and effective for conveying biofeedback.The authors also identify reducing Breeze's size, porting signal processing to a mobile device, and making peak detection more robust to movement as prerequisites for longitudinal deployment.Source: CHALLENGES AND LIMITATIONS · p. 9
  • The authors suggest revising haptic feedback to seem more neutral, since vibrations can carry notification-related negative connotations despite not lowering perceived emotion ratings.Inflation is offered as a noiseless alternative form of actuation.Source: CHALLENGES AND LIMITATIONS · p. 9, Biofeedback modalities · p. 9

FUTURE WORK AND CONCLUSIONS

  • Breeze is a bidirectional wearable that collects physiological data and provides ambient biofeedback, and the study assessed perceived emotions from generated breathing patterns across visual, audio, and haptic modalities.The authors describe their mixed quantitative and qualitative account of natural mimicry as a methodology for studying breathing and perceived emotion.Source: FUTURE WORK AND CONCLUSIONS · p. 9
  • The authors envision shared biofeedback reinforcing bonds and promoting empathy and connectedness, and plan to study Breeze in a long-term deployment outside the laboratory.They also propose exploring a wider repertoire of breathing patterns and extending the protocol beyond emotions to metaphors or richer adjectives.Source: FUTURE WORK AND CONCLUSIONS · p. 9, CHALLENGES AND LIMITATIONS · p. 9
Loading 1802.04995v1…