⌚ Calmpilot

Real-time biometric pipeline for adaptive haptic feedback in VR
User study: 3 haptic patterns × 10 participants, HR time-series analysis

📊 Calmpilot is a user study investigating how haptic feedback patterns affect physiological arousal in VR. The system uses real-time heart rate data from wearables to automatically trigger calming haptics when arousal exceeds thresholds. We compared three patterns—slow vibration, breathing guidance, and butterfly hug—in a controlled VR public speaking experiment (N=10). Breathing-guided haptics achieved the most sustained heart rate reduction (avg. -4 BPM).

📊 Calmpilot은 VR 프로그램을 활용한 노출 치료에서 햅틱 피드백 패턴이 불안 감소에 미치는 영향을 연구한 프로젝트입니다. 웨어러블 디바이스의 실시간 심박수 데이터를 활용해 임계값을 초과하면 자동으로 이완 햅틱 패턴을 트리거합니다. 임상적으로 검증된 세 가지 햅틱 패턴—느린 진동, 심호흡 유도, 나비포옹법—을 설계하고 VR 발표 환경에서 통제된 실험을 통해 효과를 검증했습니다. 분석 결과 심호흡 유도 햅틱이 가장 유의미하고 지속적인 심박수 감소(평균 4 BPM 감소)를 보였습니다.

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📋 Table of Contents

1. 🎯 Overview
2. 📚 Research Background
3. ⚙️ System Architecture
4. 🔬 Experiment Design
5. 📊 Data Analysis
6. 🏆 Publications & Awards

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🎯 Overview

📖 Introduce

Project: Calmpilot
Type: Academic Research Duration: 2023.09 ~ 2024.02
Advisor: Seokhee Jeon (KHU Haptics and Virtual Reality Lab)

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👥 Team

Position	Role	Name	Affiliation
💻 Research	First Author Research Design & Client Development	Jaehyun Byun	Kyung Hee Univ. Computer Science
💻 Research	Co-Author Data Analysis	Jihye Ryu	Kyung Hee Univ. Software Convergence
💻 Research	Co-Author Backend Development	Hyeon Roh	Kyung Hee Univ. Industrial & Management Engineering
🎓 Advisor	Academic Advisor	Seokhee Jeon	Kyung Hee Univ. Haptics and Virtual Reality Lab

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📚 Research Background

📖 Problem Statement

Social anxiety disorder causes excessive fear in social interactions—4 out of 10 university students experience these symptoms. While exposure therapy with cognitive feedback shows superior outcomes, two barriers exist: (1) CBT specialists require 1+ years of training, and (2) real-time third-party intervention is nearly impossible during social interactions.

사회 공포증은 사회적 상호작용에서 과도한 불안을 유발하며, 대학생 10명 중 4명이 이를 경험합니다. 노출 요법에 인지적 피드백을 병합하면 효과가 우수하지만 두 가지 장벽이 존재합니다: (1) 인지행동치료 전문가 양성에 최소 1년 이상 소요, (2) 사회적 상호작용 중에는 제3자의 실시간 개입이 어려움.

🔍 Prior Work & Insight

This research designed a biometric-driven automatic haptic feedback pipeline (Galaxy Watch → WebSocket → Unity → bhaptics) for VR exposure therapy, and compared which haptic pattern most effectively reduces tension through a controlled user study.

본 연구는 VR 노출 치료 중 생체 신호 기반 자동화된 햅틱 피드백 파이프라인(Galaxy Watch → WebSocket → Unity → bhaptics) 을 설계하고, 통제된 사용자 연구를 통해 어떤 햅틱 패턴이 긴장 완화에 가장 효과적인지 비교했습니다.

Study	Key Finding	Our Pattern
Azevedo et al. (2017)	Vibration 20% slower than resting HR reduced anxiety	Slow vibration
Haynes et al. (2022)	Breathing-guided haptic most effective for tension relief	Breathing guidance
Butterfly Hug (EMDR)	Alternating shoulder taps used in trauma therapy	Butterfly hug

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⚙️ System Architecture

🔧 Cross-Platform Data Pipeline

이종 플랫폼 데이터 파이프라인

┌──────────────────┐    ┌──────────────────┐    ┌──────────────────┐    ┌──────────────────┐
│  Wearable Layer  │    │  Streaming Layer │    │   Client Layer   │    │   Output Layer   │
│  Galaxy Watch 6  │    │     HypeRate     │    │   Unity Engine   │    │  bhaptics Suit   │
├──────────────────┤    ├──────────────────┤    ├──────────────────┤    ├──────────────────┤
│ • HR Sensor      │    │ • WebSocket API  │    │ • Data Reception │    │ • 40 Vibration   │
│ • 1Hz Sampling   │───→│ • Real-time      │───→│ • Threshold      │───→│   Motors         │
│ • BPM Output     │    │   Relay          │    │   Detection      │    │ • Pattern Play   │
│                  │    │ • Multi-device   │    │ • CSV Logging    │    │ • Haptic Design  │
└──────────────────┘    │   Support        │    │ • Trigger Logic  │    └──────────────────┘
                        └──────────────────┘    └──────────────────┘

📡 Real-time Heart Rate Streaming

실시간 심박수 스트리밍

Component	Implementation
Sensor	Galaxy Watch 6 optical HR sensor, 1-second interval sampling 갤럭시 워치 6 광학 심박 센서, 1초 간격 샘플링
Middleware	HypeRate WebSocket relay—unified API for diverse wearables HypeRate WebSocket 중계—다양한 웨어러블 통합 API
Reception	Unity HypeRate SDK, real-time BPM variable access Unity HypeRate SDK, 실시간 BPM 변수 접근
Threshold	HR ≥ 115 BPM triggers haptic feedback (pilot test max: 130, normal: 60-100) 심박수 115 이상 시 햅틱 피드백 트리거 (파일럿 테스트 최대: 130, 정상: 60-100)

📝 Timestamp-Synchronized Logging System

타임스탬프 동기화 로깅 시스템

// CSV Logging with StreamWriter
public class BiometricLogger : MonoBehaviour
{
    private StreamWriter writer;
    private string filepath;
    
    void Start()
    {
        filepath = $"Data/HR_{participantID}_{DateTime.Now:yyyyMMdd_HHmmss}.csv";
        writer = new StreamWriter(filepath);
        writer.WriteLine("Timestamp,HeartRate,FeedbackType,ScenePhase");
    }
    
    void OnHeartRateReceived(int bpm)
    {
        string timestamp = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff");
        string feedbackType = currentFeedback.ToString();
        string phase = currentScene.ToString();
        
        writer.WriteLine($"{timestamp},{bpm},{feedbackType},{phase}");
        writer.Flush();
    }
}

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🎨 Haptic Feedback Design

🎛️ Three Clinically-Grounded Patterns

임상적으로 검증된 세 가지 패턴

Patterns were designed using bhaptics Designer—a web-based haptic authoring tool for TactSuit's 40 vibration motors.

패턴은 bhaptics Designer를 사용해 설계했습니다—TactSuit의 40개 진동 모터를 위한 웹 기반 햅틱 저작 도구입니다.

Pattern	Clinical Basis	Implementation
🫀 Slow Vibration	Azevedo (2017): Sub-heartbeat rhythm induces physiological entrainment 심박 이하 리듬이 생리적 동조 유도	10-second continuous vibration at 20% below resting HR frequency 안정 시 심박수보다 20% 느린 주파수로 10초간 지속 진동
🌬️ Breathing Guide	Haynes (2022): Most effective for tension relief 긴장 완화에 가장 효과적	Abdominal-centered expanding/contracting circular vibration pattern 복부 중앙 기준 확장/수축하는 원형 진동 패턴
🦋 Butterfly Hug	EMDR-based trauma therapy technique EMDR 기반 외상 치료 기법	Alternating single taps on left/right shoulders 양쪽 어깨를 번갈아 단발적으로 두드림

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🔬 Experiment Design

🎭 VRET Environment Design

The VR public speaking simulation was built in Unity Engine with psychological pressure elements:

VR 발표 시뮬레이션은 Unity Engine으로 심리적 압박 요소를 포함하여 구현했습니다:

Element	Implementation	Purpose
Audience NPCs	Animator Controller with Idle/Clapping/Questioning states Idle/Clapping/Questioning 상태를 가진 Animator Controller	Social pressure simulation 사회적 압박 시뮬레이션
Event Sequences	Timeline + Playable Director for host, warnings, disruptions 사회자, 경고, 돌발 상황을 위한 Timeline + Playable Director	Controlled stressor delivery 통제된 스트레스 요인 전달
Interactions	Ray Interactor for PPT control, script checking PPT 제어, 대본 확인을 위한 Ray Interactor	Realistic task engagement 현실적인 과제 몰입
UI Elements	World Space Canvas for recording indicator, timer 녹화 표시, 타이머를 위한 World Space Canvas	Performance pressure 수행 압박
Scene Transitions	Async Scene Loading with fade effects 페이드 효과가 적용된 비동기 씬 로딩	Immersion maintenance 몰입 유지

📋 Experiment Protocol

Variable	Definition
Control	Presentation content & interactions (constant)
Independent	Haptic type: None / Slow / Breathing / Butterfly
Dependent	Heart rate change (BPM Δ)

Participants: N=10 (5M/5F), ages 20-25, university students

Procedure: Pre-survey → Equipment fitting (VR + Watch + bhaptics) → Waiting room → Presentation → Post-SUS

• 4 trials per participant (within-subjects, counterbalanced)

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📊 Data Analysis

🔄 Data Preprocessing

Raw CSV data (HR + timestamp + feedback type) was cleaned by handling missing values with median imputation, encoding categorical feedback types to integers, and validating 1-second interval uniformity for synchronized analysis.

원시 CSV 데이터(심박수 + 타임스탬프 + 피드백 유형)를 전처리: 결측치는 중앙값 대체, 범주형 피드백 유형은 정수 인코딩, 1초 간격 균일성 검증 후 동기화 분석에 활용.

📈 Statistical Results

Condition	Mean HR (BPM)	Δ from Baseline
No Feedback	111	—
With Feedback	107	-4 BPM

Pattern	Immediacy	Duration	Effectiveness
🌬️ Breathing Guide	Immediate	Longest	Most Effective
🫀 Slow Vibration	Immediate	Moderate	Effective
🦋 Butterfly Hug	Delayed (2-3 reps)	Short	Least Effective

📉 Time-Series Observations

• Feedback-triggered group: HR spiked to 120-130 BPM upon waiting room entry
• Breathing guide & slow vibration: immediate HR reduction post-trigger
• Butterfly hug: required 2-3 repetitions before measurable effect

📝 Usability Evaluation

Metric	Score
SUS Score	78.95 / 100 (Good)
Perceived Effectiveness	4.0 / 5.0

🏆 Publications & Awards

📄 Publication

Designing Haptic Feedback for Social Phobia Improvement and VRET Environment for Data Analysis

Korea Computer Congress (KCC) 2024
Jaehyun Byun, Jihye Ryu, Seokhee Jeon

🥇 Awards

Award	Event	Year
🏆 학부생 우수논문상	Korea Computer Congress (KCC) 2024	2024
🌏 Honored Partner Startup Exhibition	Vietnam Mobile Summit 2024	2024

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📚 References

1. 권석만. 현대 이상심리학. 서울 학지사. 2012
2. Azevedo, R.T., et al. The calming effect of a new wearable device during the anticipation of public speech. Sci Rep 7, 2285. 2017
3. Haynes AC, et al. A calming hug: Design and validation of a tactile aid to ease anxiety. PLoS One. 2022
4. Deusdado & Antunes. VR rehabilitation with bHaptics TactSuit. 2023
5. Heimberg, R.G. Cognitive-behavioral therapy for social anxiety disorder. Biological Psychiatry, 51, 101-108. 2002

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📬 Contact

For questions about this research, please contact:
Jaehyun Byun — bjh1750@khu.ac.kr