Pain, PostoperativeNCT04011189
Pain Detection Through Automated Video Analysis
A study testing Videotaping, Questionnaires and Empatica E4 wristband in people with Pain, Postoperative, run by KK Women's and Children's Hospital at 2 sites in Singapore.
Trial summary
The study team has developed an algorithm for pain assessment based on automated video facial and body pose analysis. The investigators aim to assess the sensitivity of this algorithm in detecting pain in post-surgical patients and refine the algorithm to increase the sensitivity of pain detection in patients. Read more about this study
- Who is it for?
- Ages 6 to 70 years
- Conditions the study is for
- Pain, Postoperative
- What is being tested?
- Videotaping, Questionnaires and Empatica E4 wristband
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 370 participants
- Where
- 2 sitesSingapore
- Study dates
- 1 Aug 2019to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 70 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Phases 1, 2:
- Patients undergoing surgical and pain procedures, inpatient and outpatient consultations
- American Society of Anaesthesiologists (ASA) physical status 1, 2 or 3 (ASA 1, 2 or 3) patients
- Phase 3: Male children undergoing laser circumcision in day surgery
Who cannot join
- Phases 1, 2:
- Pregnant patients;
- Medical problems/ medications:
- Psychiatric disorders (e.g. anxiety, depression)
- Neurological disorders (e.g. Cerebrovascular accident, Parkinson's Disease)
- Musculoskeletal limitations that result in gait abnormalities/limitations
Show all 13Show fewer
- Phase 3:
- Developmental delay/ cognitive impairment
- Autism Spectrum disorder
- Attention-deficit/hyperactivity disorder
- Excessive anxiety or requires sedative premed
- Chronic pain conditions and/or medication
- Previous traumatic pain experience
Trial locations and contacts
2 sites in 1 country.
Singapore2 sites
KK Women's and Children's Hospital
Singapore, 229899
Singapore General Hospital
Singapore
About this study
The study team has developed an algorithm for pain assessment based on automated video facial and body pose analysis. The investigators aim to assess the sensitivity of this algorithm in detecting pain in post-surgical patients and refine the algorithm to increase the sensitivity of pain detection in patients.
Read the detailed description
Post-surgical pain, if inadequately controlled, has deleterious short and long term consequences for the patient. Although most patients are able to report their pain scores, a minority are unable to do so and assessing their pain can prove to be a challenge for healthcare professionals. In recent years, facial recognition tools have been developed based on the premise that subtle facial variations signifies pain. However, changes in body, and head posture can also represent pain. As such, these tools are with their limitations and are only validated on certain groups of patients, thus may not be sensitive enough to detect pain in post-surgical patients.
The first stage of the study will be conducted on 40 patients presenting for major gynaecological surgery, with the obtained data used to fine tune the algorithm. The patients will be video-taped pre-surgically in the pre-evaluation anaesthetic clinic and post-surgically in the ward. They will be asked to rate their pain scores on the numerical rating scale and fill in questionnaires on their psychological and quality of health status. The pain scores will be correlated with the results obtained from the pain assessment algorithm.
The second phase will improve and enhance the model by (1) analysing body pose to improve the model performance; (2) validating the improved model by recruiting 200 patients undergoing surgical and pain procedures, inpatient and outpatient consultations to collect their videos before and after surgery and inpatient and outpatient pain consultations; (3) integrate the model into a standalone electronic application to improve its usability in both inpatient and outpatient settings.
The third phase will recruit 130 male paediatric patients presenting for circumcision surgery to improve algorithm by i) Adding body posture analysis and other physiological measurement to further improve the performance of our model; ii) Developing our model for use in the pediatric population; and iii) Improving its usability in both clinical and non-clinical settings. Deidentified keypoints will be extracted from the videos to further validate the model.
- Conditions
- Pain, Postoperative
- Being tested
- Videotaping, Questionnaires, Empatica E4 wristband
- Keywords
- Postoperative pain, Automated video analysis, Pain score, Face recognition
- Medical subject headings
- Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VideotapingProcedure or surgery
Also called Videotaping via mobile phone
Before the videotaping, patients will be asked on their baseline pain scores. Their face and body pose from a frontal view will be videotaped via a mobile phone with no internet access. The collected videos will be further processed to extract key points, which will be the primary input for modelling algorithms and will further ensure anonymity of the patients in the video sequences.
QuestionnairesOther
Also called Questionnaires (HADS, EQ-5D-3L or CPASS)
Patients will be asked to fill in 1-2 questionnaires before surgery/procedure/consultation (Hospital Anxiety and Depression Scale (HADS) and/or EQ-5D-3L). After surgery/procedure/consultation, patients will be again asked to fill in HADS questionnaire (optional).
For pediatrics patient, only Child Pain Anxiety Symptoms Scale (CPASS) will be administered before the surgery.
Empatica E4 wristbandDevice
A medical grade wearable device, Empatica E4 wristband, will be used in phase 3 for pediatrics patients to monitor real-time physiological data on heart rate and body temperature.
| Study group | Role | What they receive |
|---|---|---|
| Videotaping | Experimental | First phase: Patients will complete questionnaire, pain score in pre-anaesthetic clinic. Their face and body pose are videotaped. Patients are reviewed on pain scores with videotaping at 12-36 hrs, 36 hrs till before discharge post-operatively.
Second phase: Patients will complete questionnaires, pain score, videotaping in pre-operative/-procedural/inpatient/outpatient consultation waiting areas. After surgery/procedure/consultation, i) Surgery: Patients rate pain scores with videotaping at 12-36 hrs, 36 hrs till before discharge.
ii) Procedure: Patients are asked on questionnaire, pain score, videotaping. iii) Consultation: Patients are asked on questionnaire, pain score, videotaping on next consultation.
Third phase: Patients will complete questionnaire and pain score in preoperative areas. They are videotaped while wearing a physiological wristband to monitor heart rate and body temperature. After surgery, pain score is rated while being videotaped with wristband. Receives: Procedure: Videotaping; Other: Questionnaires; Device: Empatica E4 wristband |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Pain score
Difference of Pain score before and after surgery/procedure/consultation. Pain scores (Numeric Rating Scale 0-10) will be asked, with zero being no pain, and 10 being the worst pain possible.
Measured: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
Extracted key points from video
The collected videos will be further processed to extract key points, which will be the primary input for modelling algorithms and will further ensure anonymity of the patients in the video sequences. This will then be used for pain score prediction by correlated to outcome 1 (patients' reported pain score).
Measured: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
Secondary outcomes (3)
Change in Hospital Anxiety and Depression Scale (HADS) score
HADS Anxiety and Depression score before and after surgery/procedure/consultation. HADS is commonly used by doctors to determine the levels of anxiety and depression that a patient is experiencing. Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 and 21 for either anxiety or depression. The HADS uses a scale and therefore the data returned from the HADS is ordinal. For each subscore (anxiety/depression), 0-7 = Normal; 8-10 = Borderline abnormal (borderline case); and 11-21 = Abnormal (case).
Measured: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
EQ-5D-3L score
EQ-5D-3L score before surgery/procedure/consultation. EQ-5D-3L is a standardized instrument for measuring generic health status. It is made up for two components; health state description and evaluation. The health status is measured in terms of five dimensions (5D); mobility, self-care, usual activities, pain/discomfort, and anxiety/depression; each dimension ranging from 1-3. From these five dimensions, EQ-5D index is calculated, having a value between 0-1. The evaluation part involves an analogue scale, asking to mark health status on the day of the interview on a 20 cm vertical scale with end points of 0 and 100. Zero corresponds to " the worst health you can imagine", and hundred corresponds to "the best health you can imagine".
Measured: Before surgery/procedure/consultation (1 day)
Child Pain Anxiety Symptoms Scale (CPASS) score
CPASS score before surgery. The CPASS is a 20-item scale to evaluate pain anxiety in children. For each item, children are asked to rate the extent to which they think, act, or feel that way on a scale from 0 ("never think, act or feel that way") to 5 ("always think, act, or feel that way"). Total scores range from 0 to 100, with higher scores indicating higher levels of pain anxiety.
Measured: Before surgery/procedure/consultation (1 day)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2019
- Study start1 Aug 2019
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Pain, PostoperativeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 370 participants (estimated)
Sponsor and investigators
- Lead sponsor
- KK Women's and Children's Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Sng Ban Leong, KK Women's and Children's Hospital
- Investigators
- Ban Leong Sng, FANZCA, Principal investigator, KK Women's and Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04011189
- Sponsor's protocol ID
- 2019/2293
- Status last verified
- Aug 2026
- First submitted
- 4 Jul 2019
- Last updated
- 7 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Lee M, Kennedy L, Girgensohn A, Wilcox L, Lee JS, Tan CW, Sng BL. Pain Intensity Estimation from Mobile Video Using 2D and 3D Facial Keypoints. arXiv preprint arXiv:2006.12246. 2020 Jun 17.
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pain Detection Through Automated Video Analysis
- ClinicalTrials.gov ID
- NCT04011189
- Acronym / sponsor ID
- 2019/2293
- Conditions
- Pain, Postoperative
- Keywords
- Postoperative pain, Automated video analysis, Pain score, Face recognition
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 370 participants (estimated)
- Lead sponsor
- KK Women's and Children's HospitalOther government
- Study start
- 1 Aug 2019 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 8 Jul 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study team has developed an algorithm for pain assessment based on automated video facial and body pose analysis. The investigators aim to assess the sensitivity of this algorithm in detecting pain in post-surgical patients and refine the algorithm to increase the sensitivity of pain detection in patients.
Detailed description
Post-surgical pain, if inadequately controlled, has deleterious short and long term consequences for the patient. Although most patients are able to report their pain scores, a minority are unable to do so and assessing their pain can prove to be a challenge for healthcare professionals. In recent years, facial recognition tools have been developed based on the premise that subtle facial variations signifies pain. However, changes in body, and head posture can also represent pain. As such, these tools are with their limitations and are only validated on certain groups of patients, thus may not be sensitive enough to detect pain in post-surgical patients.
The first stage of the study will be conducted on 40 patients presenting for major gynaecological surgery, with the obtained data used to fine tune the algorithm. The patients will be video-taped pre-surgically in the pre-evaluation anaesthetic clinic and post-surgically in the ward. They will be asked to rate their pain scores on the numerical rating scale and fill in questionnaires on their psychological and quality of health status. The pain scores will be correlated with the results obtained from the pain assessment algorithm.
The second phase will improve and enhance the model by (1) analysing body pose to improve the model performance; (2) validating the improved model by recruiting 200 patients undergoing surgical and pain procedures, inpatient and outpatient consultations to collect their videos before and after surgery and inpatient and outpatient pain consultations; (3) integrate the model into a standalone electronic application to improve its usability in both inpatient and outpatient settings.
The third phase will recruit 130 male paediatric patients presenting for circumcision surgery to improve algorithm by i) Adding body posture analysis and other physiological measurement to further improve the performance of our model; ii) Developing our model for use in the pediatric population; and iii) Improving its usability in both clinical and non-clinical settings. Deidentified keypoints will be extracted from the videos to further validate the model.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Videotaping | Experimental | Procedure: Videotaping, Other: Questionnaires, Device: Empatica E4 wristbandFirst phase: Patients will complete questionnaire, pain score in pre-anaesthetic clinic. Their face and body pose are videotaped. Patients are reviewed on pain scores with videotaping at 12-36 hrs, 36 hrs till before discharge post-operatively. Second phase: Patients will complete questionnaires, pain score, videotaping in pre-operative/-procedural/inpatient/outpatient consultation waiting areas. After surgery/procedure/consultation, i) Surgery: Patients rate pain scores with videotaping at 12-36 hrs, 36 hrs till before discharge. ii) Procedure: Patients are asked on questionnaire, pain score, videotaping. iii) Consultation: Patients are asked on questionnaire, pain score, videotaping on next consultation. Third phase: Patients will complete questionnaire and pain score in preoperative areas. They are videotaped while wearing a physiological wristband to monitor heart rate and body temperature. After surgery, pain score is rated while being videotaped with wristband. |
Who may qualify
- Ages
- 6 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (4 listed)
- Patients undergoing surgical and pain procedures, inpatient and outpatient consultations
- American Society of Anaesthesiologists (ASA) physical status 1, 2 or 3 (ASA 1, 2 or 3) patients
- Phase 3: Male children undergoing laser circumcision in day surgery
Key exclusion criteria (13 listed)
- Pregnant patients;
- Medical problems/ medications:
- Developmental delay/ cognitive impairment
- Autism Spectrum disorder
- Attention-deficit/hyperactivity disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| VideotapingAlso: Videotaping via mobile phoneBefore the videotaping, patients will be asked on their baseline pain scores. Their face and body pose from a frontal view will be videotaped via a mobile phone with no internet access. The collected videos will be further processed to extract key points, which will be the primary input for modelling algorithms and will further ensure anonymity of the patients in the video sequences. | Procedure or surgery | Videotaping |
| QuestionnairesAlso: Questionnaires (HADS, EQ-5D-3L or CPASS)Patients will be asked to fill in 1-2 questionnaires before surgery/procedure/consultation (Hospital Anxiety and Depression Scale (HADS) and/or EQ-5D-3L). After surgery/procedure/consultation, patients will be again asked to fill in HADS questionnaire (optional). For pediatrics patient, only Child Pain Anxiety Symptoms Scale (CPASS) will be administered before the surgery. | Other | Videotaping |
| Empatica E4 wristbandA medical grade wearable device, Empatica E4 wristband, will be used in phase 3 for pediatrics patients to monitor real-time physiological data on heart rate and body temperature. | Device | Videotaping |
Primary outcome
Change in Pain score
Time frame: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
Difference of Pain score before and after surgery/procedure/consultation. Pain scores (Numeric Rating Scale 0-10) will be asked, with zero being no pain, and 10 being the worst pain possible.
Extracted key points from video
Time frame: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
The collected videos will be further processed to extract key points, which will be the primary input for modelling algorithms and will further ensure anonymity of the patients in the video sequences. This will then be used for pain score prediction by correlated to outcome 1 (patients' reported pain score).
3 secondary outcomes
Change in Hospital Anxiety and Depression Scale (HADS) score
Time frame: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)
EQ-5D-3L score
Time frame: Before surgery/procedure/consultation (1 day)
Child Pain Anxiety Symptoms Scale (CPASS) score
Time frame: Before surgery/procedure/consultation (1 day)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2026.
- Results publicationLee M, Kennedy L, Girgensohn A, Wilcox L, Lee JS, Tan CW, Sng BL. Pain Intensity Estimation from Mobile Video Using 2D and 3D Facial Keypoints. arXiv preprint arXiv:2006.12246. 2020 Jun 17.
- Pain Intensity Estimation from Mobile Video Using 2D and 3D Facial KeypointsLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ban Leong Sng, FANZCA principal investigator
KK Women's and Children's Hospital
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Videotaping, Questionnaires and Empatica E4 wristband in people with Pain, Postoperative, run by KK Women's and Children's Hospital at 2 sites in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 7 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Pain score (time frame: Before surgery/procedure/consultation (1 day) and after surgery/procedure/consultation(1-3 days)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04011189, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Aug 2026.