Hardware Interaction
Let them Cry : Baby cry cause analysis
using a wearable device and app
Helping parents understand their babies better
Problem
91.5% of caregivers said they felt stressed by their baby’s crying
A baby’s cry is their first and only way to communicate.
However, many caregivers don’t know why the baby cries, making it hard to respond properly.
Solution
Confidence in Care
Hungry!
The device detects cries and explains the reason, giving caregivers clarity.
Practical Support
There's a change!
His crying pattern has changed, but that's okay, he's thriving!
Cry cycle
Cry pattern changes
Typical
Typical
3 Hours
8 Days
Hungry
Discomfort
Sleepy
Bored
찝찝함
Feeding them cold formula works well.
Note-taking keywords
Adjusting the feeding experience
61%
39%
Adjusting the feeding experience
5 minutes on the back
Low temperature formula
Split feeding
21 cases
14 cases
8 cases
2 cases
Last week
The app provides scientific analysis and solutions for daily care.
Pattern Insights
Time to feed soon
90%
Discomfort
10%
Ian may cry from hunger in 30 minutes!
March
15
14
13
16
19
18
17
Daily Record
Daily Stats
Home
Recording
Analysis
Overview
Week 6, Day 4 Log
2:30pm
Hunger
12AM
12PM
9:41
Tracking crying patterns helps caregivers understand their baby and gain confidence.
Problem
Unexplained crying can overwhelm first-time caregivers
91.5%
The baby's crying is stressing me out.
85.6%
I've had a baby cry because I didn't get what I wanted.
*2024.01.01~01.10 Parenting cafe survey for parents under 16 months old
Literature Research
Parents feel most stressed by crying in the first 6 weeks.
“Crying peaks around 6 weeks of age, which overlaps with the period when
parents report the greatest stress in childcare.”
Vermillet, A., Tølbøll, K., Litsis Mizan, S., C. Skewes, J., & Parsons, C. E. (2022). Crying in the first 12 months of life:
A systematic review and meta‐analysis of cross‐country parent‐reported data and modeling of the “cry curve.” Child Development, 93(4), 1201–1222. https://doi.org/10.1111/cdev.13760
Contextual Inquiry
Caregivers seek to understand crying to connect & communicate better.
Competitor Analysis
Existing cry-analysis devices are cumbersome and not intuitive.
Why Cry Plus
Result check
Name
Image
Result display
Doesn’t analyze specific reasons
LED light + small text
LED light + small text
LED light + icon
Not easy to carry around
Not easy to carry around
Why Cry Mini
Biloop Cry Translator
Not intuitive
& slow
Not analyzing specific reasons
Poor
portability
How might we..
.. reduce their stress?
.. help them communicate with baby better?
UX Goal
Aiming to ease parenting anxiety and offer real help.
😱
Ease parental anxiety
Analyze baby crying causes & provide clear feedback
💨
Rapid response
Intuitive and easy interface for fast response
📖
Continuous learning
& adaptation
Personalized solutions that are increasingly accurate to your baby's characteristics
Opporturnity
Integrating services with wearable devices
*Survey Conducted(2024.02), n=22
Q. What are some things you try to keep in mind when parenting a newborn?
Keeping an eye on the baby 89.5%
Importance of real-time monitoring
Respond quickly to small incidents 65.5%
Instant alerts and quick feedback
Being close to baby 75.4%
Easy accessibility
Even while juggling other chores,
using a wearable and an app together helps you respond more quickly and proactively.
Appropriateness Evaluation
The wearable device should be a necklace type.
[ Product Sketch ]
Wearable Device Display
Hands-free care, real-time connection.
Hands-free
Design the display to be in a position where users can see it without the use of both hands
Compact device
Smallest display size that stays compact
and doesn't interfere with readability
*Wearable device displays
Annoyed
Annoyed
For caregivers rather than babies
Even if it's technically safe, there's a fear that it could be harmful to babies. electromagnetic radiation fears that could harm babies.
Worn by baby
Worn by parent
Ideate
Added a mobile app to record cries and track long-term trends.
Recording
Monitoring
Interaction Design
Considered interaction between wearable device and smartphone.
MP3
MP3
INPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
TEXT
TEXT
TEXT
TEXT
Waveform analysis
Pattern analysis
Mobile Device
Product
Wearable Device
Microphone
Sound Analysis
Crying pattern
Sleep pattern
Display
Display
Display
Speaker
Crying cause detection
Crying cause detection
Anti-noise generation
Sleep suggestions
Sound capture
Anti-noise output
Crying cause output
Crying cause output
← 제품과 앱 인터랙션 정리
Mobile Device
Product
Wearable Device
Anti-noise output
MP3
MP3
INPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
TEXT
TEXT
TEXT
TEXT
Waveform analysis
Pattern analysis
Microphone
Sound Analysis
Crying pattern
Sleep pattern
Display
Display
Display
Speaker
Crying cause detection
Crying cause detection
Anti-noise generation
Sleep suggestions
Sound capture
Crying cause output
Crying cause output
MP3
Microphone
Microphone
Caregiver voice recording
Caregiver voice recording
← (Additional idea, not final) What if the product could play the caregiver’s voice through a smartphone or smartwatch?
Service Modeling
Instant response builds trust in care.
Scenario 1: Coping before crying
Scenario 2: Sudden bursts of crying
Crying Cause Reminder: Sleepiness
Analyzing Cry Pattern Waveforms
Analyzing Cry Pattern
Analyze sleep patterns
Identify the cause of crying
Output cry cause
Output cry cause
울기 전 대처
Wearable
Device
Before crying
Cry prediction
Crying
Record and reflect
Real-time analysis of cries,
identify and reflect on causes
Track calendars and
data, and note taking
Real time Pattern
Feedback
Mobile
Device
Capture Cry Signal
(always-on recording)
Cause concurrent notification
Interaction
Delivering solutions
Technology & Applications
Analytics report generation model
Calendar: A system for reflecting tracking history
Crying Pattern Cycle Establishment Model
Pattern learning model
Internal interaction dividers
Seeing that your baby is going to cry in 30 minutes because of 'hunger'
Cry prediction based on crying patterns
Send phone notifications
Home
'Cry Pattern' Cycle
‘배고픔'에 대한
해결책 확인
In-app ‘Let them cry’
In-app ‘Let them cry’
Product Display
Click the notification,
Roughly check
Witnessed crying pattern predictive alerts
울기 전 선제적 해결 : 밥을 줌
Baby Cries Suddenly: Identifying the Cause of 'Sleepy' Crying
Recording Notes &
Update Changes
User behavior
Steps
Teachable
Machine
Text data
p5.js
/Arduino
micro OLED Display
PC
💻
Frequency Waveform Analysis System
Microphone
🎙
Display
🖥️
Cause Analysis & Resolution Model
CNN Convolutional Neural Network Model
Cry pattern data
Manage childcare
solutions
INPUT
Audio
INPUT
Touch
OUTPUT
Text
Playing sounds to fall asleep
수면 패턴 분석
울음에 대처
상황에 맞는
대처법 추천
울음에 대처:
재우기
수면 도움/관련 제안
수면 도움 솔루션
스피커
🔈
백색 소음 출력
OUTPUT
MP3
Cope before crying
Identify a solution to 'hunger'
Preemptive resolution before crying: feeding the baby
Manage childcare
solutions
Cope with crying
Coping with crying:
Putting her to sleep
Speaker
🔈
Analyze sleep patterns
Recommend actions based on your situation
Sleep help/suggestions
Sleep help solutions
White noise output
OUTPUT
Audio
Guideline
A wearable captures and analyzes crying sounds.
Guidance is shown as speech bubbles, as if the baby is talking.
Annoyed
Hyperarousal
Sudden changes
No burp
Pain
Temperature discomfort
Posture discomfort
Hungry
Approaching feeding time
Fasting discomfort
Sleepy
Wake in sleep
Sleep desire
Bored
Attention/Attachment Needs
Lack of visual stimulation
Unsettled
Diaper wetting
Tickling
*Source: The study “Emotional Perception of Infant Crying by Expectant Couples”
Usability Test
Improving cry detection with a wearable necklace device
Each device with a clear role: mobile logs, device records.
Wearable device
Mobile
Switched from phone recording to necklace only recording for busy users
Recording, analyzing, and logging across both mobile and device.
TO-BE
AS-IS
Record crying on mobile
and transcribe the cry on your mobile.
Task 1
User Voice
*2024.02.8 / 5 People
I’m too busy soothing my baby to record anything on phone.
Usability test led to reduced neck and eye discomfort
User Voice
*Head angle of 35 degrees:
The easiest and most comfortable angle
110% larger display with a 5° forward tilt to ease neck and eye discomfort.
Visibility Drop at Flat Display Angle
TO-BE
AS-IS
Though it’s handy, I can’t read the text when looking down.
*2024.02.8 / 5 People
Record
Log
[How the product works]
Microphone
PC
Teachable machine
Text data
Display
p5.js
Arduino
Sound
(Sample)
‘Hungry’
Hungry
🎙
🔈
💻
[Secondary Product Development]
Proceed with physical mockups, test prototypes
1:1 scale prototyping
Feature
Turning cries into meaning, closing the distance between hearts.
Waveform-based cry analysis reveals the baby’s condition and displays the reason on the device screen.
Initial Ideation
Users said the hierarchy is confusing and needs more explanation.
“Even within the 4 categories, the reasons for crying should be more detailed.”
“It’s unclear when exactly the baby will cry tomorrow.”
Inspirations from Other Services
Caregivers can respond to a baby’s cry with positivity.
Crying patterns at a glance
Source : Period app ‘clue’
Compared a baby’s cry to a bird’s song
Types of birds the baby collected
Sulfur-crested Cockatoo
Find out which bird your call sounds like
Adaptability
Cutie
Liveliness
Energy
Lu
Specialness
Source : Crying Bebe
Using Notes for Insights
Baby Cry Reason
Hungry
Sensitive
Memo about ‘What’s happening’
Sleepy
Source : Crying Bebe
Direction
UI updates in real time with changes and explains reasons in detail.
Highlight color coding
Daily crying cycle & detailed baby status tracking.
Draft A
Draft B
Cons
Pros
Contents
Daily Growth
Total Growth
Week 2 of June
He will asleep soon
6/22
6/23
6/24
Daily Growth
Total Growth
Cycle
Calendar
Record
Analysis
Setting
# 30min later
#Accuracy 90%
#Hungry
Next Cry:
Result
(Cry type, accuracy)
See record
Go Home
Feedback
To sleep better, feed until the later milk
After about 15–18 minutes, the breast milk that comes out is richer in fat and thicker. Because it has higher calories, it helps your baby gain weight and grow well. If your baby only drinks the foremilk in the early stage and falls asleep, they won’t get the fat from the hindmilk. As a result, they may wake up more often during sleep and feel hungrier more frequently.
Hungry
Sensitive
Sleepy
There has been a change!
What soothes my baby when they’re hungry versus when they’re sleepy.
What calms my baby when they’re fussy versus when they’re teething.
Cry Cycle
3 Hours
See more
+
Meets most user needs, easy to use
-
Lacks a unique format, but that isn’t something users particularly expect here.
-
Difficult to view detailed records,
which conflicts with the mobile goal.
+
Unique interactions
Final Design
Identifying specific cause, giving solution,
and predicting crying for effective care.
By analyzing the frequency patterns of crying, cycle and daily/monthly reports offer insights into
the baby’s condition—empowering parents with a deeper understanding for better care.
Daily Cry Log: Analysis of specific reasons for baby crying
Logs That Talk Back — Memos and Daily Reports in One View
Hunger-Time to feed soon
It feels like formula suits my baby best.
Discomfort – Uncomfortable position
If he seem uneasy, a side turn might help!”
Discomfort – Wet diaper
My baby’s really sensitive to a wet diaper.
Sleepy – Briefly awakened
Every 2 hours
Baby’s Crying Cycle
User Feedback
Predictive Cry Cycle: From Worry to Readiness
Knowing the pattern ahead of time
makes things so much easier!
*2024.02.10 / 3 people
Time to feed soon
90%
Discomfort
10%
Ian may cry from hunger in 30 minutes!
March
15
14
13
16
19
18
17
Daily Record
Daily Stats
Home
Recording
Analysis
Overview
Week 6, Day 4 Log
2:30pm
Hunger
12AM
12PM
9:41
Feature
Track history through scientific cry records.
Cry pattern insights offer reassurance and help caregivers feel confident about their baby’s growth.
Crying time per day
Crying Pattern
울음 빈도
My baby is easy going
Other babies cry a lot at 9-10am, and my baby is more sensitive at night than during the day, so he cries a lot at 8pm.
My baby
Other Baby(Average)
Comparing with peers
3H 13M
😀
5H 17M
Last week
Feel reassured through statistical comparison.
Growth anxiety meets reassurance through clear comparison.
Knowing that other babies cry often at this age really reassures me.
User Feedback
*2024.02.10 / 3 People
There's a change!
His crying pattern has changed, but that's okay, he's thriving!
Cry cycle
Cry pattern changes
Typical
Typical
3 Hours
8 Days
Real-time tracking, even as patterns change.
Adaptive Monitoring for Evolving Cry Patterns
It’s really convenient how it monitors
every time there’s a change.
User Feedback
*2024.02.10 / 3 People
Hungry
Discomfort
Sleepy
Bored
찝찝함
Feeding them cold formula works well.
Note-taking keywords
Adjusting the feeding experience
61%
39%
Adjusting the feeding experience
5 minutes on the back
Low temperature formula
Split feeding
21 cases
14 cases
8 cases
2 cases
Last week
Effective solutions, tailored to my baby
My baby’s unique traits, all at a glance—no need to check old memos.
I used to struggle to find what I had recorded — now it’s all in one clear view.
User Feedback
*2024.02.10 / 3 People
Accessibility Validation
Grasp at a glance, even while doing housework
Reflections
What I learned
Empathy before data
In sensitive situations like a baby’s cry, users don’t analyze, they feel.
I learned that trust comes not from detailed explanations, but from delivering a sense of emotional safety. The product should start with reassurance, not precision.
What Could Be Improved
Rather than simply labeling emotions, the product leverages AI to deliver clear, actionable guidance that helps in the moment. To enable this, the system is powered up through AI and requires further iteration using real-world data and contextual UX research.
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