Chronic PainNCT04896827
DNIC Using Deep Learning and Artificial Intelligence
An observational study of Chronic Pain, run by Université de Sherbrooke at 1 site in Canada.
Trial summary
Chronic pain (CP) is disabling for people triggering important costs for society. A deficit of diffuse noxious inhibitory controls (DNIC) is one of the CP mechanisms. DNICs are evaluated in research setting using a CPM protocol (conditioned pain modulation). Read more about this study
- Who is it for?
- Ages 18 to 79 yearsHealthy volunteers can take part
- Conditions the study is for
- Chronic Pain
- What is being tested?
- Conditioned pain modulation test
- How many people
- 244 participants
- Where
- 1 siteCanada
- Study dates
- 5 Apr 2022to Dec 2028
- Phase
- Observational
- Are there results?
- None posted in the registry
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 18 to 79 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Male and female volunteers, with and without chronic pain.
Who may be able to join
- 18-79 years old
- No chronic pain
- Able to provide consent
- 18-79 years old
- Chronic pain (chronic pain is defined by any regular pain for more than 6 months)
- Able to provide consent
Who cannot join
- Cardiovascular disease (arrhythmia, cerebrovascular accident, infarction...)
- Raynaud syndrome
- Severe psychiatric disease (dementia, schizophrenia, psychosis, major depression)
- Injuries or loss sensitivity to their forearms or hands
- Pregnant women or in post-partum period (<1 year)
- Participants with chronic pain
Show all 12Show fewer
- Cardiovascular disease (arrhythmia, cerebrovascular accident, infarction...)
- Raynaud syndrome
- Severe psychiatric disease (dementia, schizophrenia, psychosis, major depression)
- Injuries or loss sensitivity to their forearms or hands
- Pregnant women or in post-partum period (<1 year)
- Chronic pain caused by cancer or migraine
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Reference Values and Clinical Screening Test of Diffuse Noxious Inhibitory Controls (DNIC) Using Deep Learning and Artificial Intelligence
Chronic pain (CP) is disabling for people triggering important costs for society. A deficit of diffuse noxious inhibitory controls (DNIC) is one of the CP mechanisms. DNICs are evaluated in research setting using a CPM protocol (conditioned pain modulation). There is a lack of reference values on the effectiveness of DNICs. Wider research on DNIC will help to understand CP and to develop a clinical screening test evaluating DNICs. This study aims more specifically to determine whether it is possible to develop a facial recognition system to automate pain measurement and the effectiveness of pain control mechanisms.
Read the detailed description
This study aims:
- To develop and validate a predictive tool (using deep learning and artificial intelligence) to estimate the efficacy of pain control mechanisms.
- To estimate references values for facial expressions of pain control mechanisms in healthy and in chronic pain participants.
The target population will be healthy volunteers and volunteers with chronic pain, male and female, stratified by age.
The reference values (healthy volunteers) will be established via a non-parametric method for a standard conditioned pain modulation (CPM) protocol in which two "stimuli tests" of the same intensity and nature (heat) will be applied before and after the application of another "conditioning stimulus" (cold water bath). The perceived pain difference between the 1st and 2nd stimuli tests will reflect the intensity of the DNICs. Participants' facial expressions will be captured simultaneously by three cameras during the CPM testing.
These results will be compared to those from volunteers suffering with chronic pain. The clinical decision rule will result from clinical and paraclinical elements correlating with the amplitude of the efficacy of CPM (serum noradrenaline, intensity of pain, heart rate and blood pressure measurements, psychometric questionnaires assessing anxiety, depressive feelings and pain catastrophizing). Logistic regression analysis will determine the best predictors of a CPM deficit.
- Conditions
- Chronic Pain
- Being tested
- Conditioned pain modulation test
- Keywords
- Conditioned pain modulation (CPM), Diffuse Noxious Inhibitory Controls (DNIC), Pressure pain threshold (PPT), Reference values, Clinical decision rule, Deep learning, Artificial intelligence
- Medical subject headings
- Chronic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Conditioned pain modulation testOther
Conditioned pain modulation (CPM) protocol consist of evaluating pain during a heat test, before and after one conditioning stimulus (cold water bath); 3 cameras will be capturing participants' facial expressions during the tests.
| Study group | Role | What they receive |
|---|---|---|
| Chronic pain | Patients with chronic pain (n=100) Receives: Other: Conditioned pain modulation test | |
| Healthy participants | Healthy participants (n=144) Receives: Other: Conditioned pain modulation test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Conditioned pain modulation (CPM) profiles
Sensitivity and specificity of the classification algorithm according to different profiles (normal vs altered) of conditioned pain modulation, as defined by the change of pain perception before and after the cold water bath measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] in healthy and in chronic pain volunteers together.
Measured: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)
Temporal summation profiles
Sensitivity and specificity of the classification algorithm according to different profiles (normal vs altered) of temporal summation, as defined by the change of pain perception during the first stimuli test measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] in healthy and in chronic pain volunteers together.
Measured: Once, at baseline, at recruitment (during the first stimuli test)
Secondary outcomes (8)
Conditioned pain modulation (CPM) profiles of healthy volunteers
Conditioned pain modulation, as defined by the change of pain perception before and after the cold water bath measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] only in healthy volunteers.
Measured: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli
Temporal summation profiles of healthy volunteers
Temporal summation, as defined by the change of pain perception during the first stimuli test measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] only in healthy volunteers.
Measured: Once, at baseline, at recruitment (during the first stimuli test)
Conditioned pain modulation (CPM) profiles of volunteers with chronic pain
Conditioned pain modulation, as defined by the change of pain perception before and after the cold water bath measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] only in volunteers with chronic pain.
Measured: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)
Temporal summation profiles of volunteers with chronic pain
Temporal summation, as defined by the change of pain perception during the first stimuli test measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] only in volunteers with chronic pain.
Measured: Once, at baseline, at recruitment (during the first stimuli test)
Demographic factors
Association of demographic factors (age, gender) with different response profiles of CPM and temporal summation established by the algorithm.
Measured: Once, at baseline, at recruitment
Psychologic factors
Association of psychologic factors (anxiety measured with HADS questionnaire) with different response profiles of CPM and temporal summation established by the algorithm.
Measured: Once, at baseline, at recruitment
Physiologic factors
Association of physiologic factors (continuous blood pressure, heart rate, electrodermal activity) with different response profiles of CPM and temporal summation established by the algorithm.
Measured: Once, at baseline, at recruitment
Facial expressions and postures
Association of facial expressions and postures with different response profiles of CPM and temporal summation established by the algorithm.
Measured: Once, at baseline, at recruitment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 May 2021
- Study start5 Apr 2022
- Primary completionDec 2028 (estimated)
- Study completionDec 2028 (estimated)
Why it stopped: The funding of the study is challenged. We might resume enrollment if new funds are found or will terminate the study.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic PainStudies 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
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 244 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Université de Sherbrooke
- Sponsor type
- University, hospital or other
- Collaborators
- Lucine, Centre for Research of CHUS (CRCHUS)
- Responsible party
- Sponsor
- Investigators
- Guillaume Léonard, PhD, Principal investigator, Université de Sherbrooke
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04896827
- Sponsor's protocol ID
- 2021-4227
- Status last verified
- May 2026
- First submitted
- 5 May 2021
- Last updated
- 28 May 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Reference Values and Clinical Screening Test of Diffuse Noxious Inhibitory Controls (DNIC) Using Deep Learning and Artificial Intelligence
- ClinicalTrials.gov ID
- NCT04896827
- Acronym / sponsor ID
- 2021-4227
- Conditions
- Chronic Pain
- Keywords
- Conditioned pain modulation (CPM), Diffuse Noxious Inhibitory Controls (DNIC), Pressure pain threshold (PPT), Reference values, Clinical decision rule, Deep learning, Artificial intelligence
- Study type
- Observational
- Recruitment status
- SuspendedReason stopped: The funding of the study is challenged. We might resume enrollment if new funds are found or will terminate the study.
- Enrolment
- 244 participants (estimated)
- Lead sponsor
- Université de SherbrookeUniversity, hospital or other
- Collaborators
- Lucine, Centre for Research of CHUS (CRCHUS)
- Study start
- 5 Apr 2022 (actual)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 21 May 2021 (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.
Chronic pain (CP) is disabling for people triggering important costs for society. A deficit of diffuse noxious inhibitory controls (DNIC) is one of the CP mechanisms. DNICs are evaluated in research setting using a CPM protocol (conditioned pain modulation). There is a lack of reference values on the effectiveness of DNICs. Wider research on DNIC will help to understand CP and to develop a clinical screening test evaluating DNICs. This study aims more specifically to determine whether it is possible to develop a facial recognition system to automate pain measurement and the effectiveness of pain control mechanisms.
Detailed description
This study aims:
- To develop and validate a predictive tool (using deep learning and artificial intelligence) to estimate the efficacy of pain control mechanisms.
- To estimate references values for facial expressions of pain control mechanisms in healthy and in chronic pain participants.
The target population will be healthy volunteers and volunteers with chronic pain, male and female, stratified by age.
The reference values (healthy volunteers) will be established via a non-parametric method for a standard conditioned pain modulation (CPM) protocol in which two "stimuli tests" of the same intensity and nature (heat) will be applied before and after the application of another "conditioning stimulus" (cold water bath). The perceived pain difference between the 1st and 2nd stimuli tests will reflect the intensity of the DNICs. Participants' facial expressions will be captured simultaneously by three cameras during the CPM testing.
These results will be compared to those from volunteers suffering with chronic pain. The clinical decision rule will result from clinical and paraclinical elements correlating with the amplitude of the efficacy of CPM (serum noradrenaline, intensity of pain, heart rate and blood pressure measurements, psychometric questionnaires assessing anxiety, depressive feelings and pain catastrophizing). Logistic regression analysis will determine the best predictors of a CPM deficit.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Chronic pain | – | Other: Conditioned pain modulation testPatients with chronic pain (n=100) |
| Healthy participants | – | Other: Conditioned pain modulation testHealthy participants (n=144) |
Who may qualify
- Ages
- 18 to 79 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Male and female volunteers, with and without chronic pain.
Key inclusion criteria (6 listed)
- 18-79 years old
- No chronic pain
- Able to provide consent
- 18-79 years old
- Chronic pain (chronic pain is defined by any regular pain for more than 6 months)
Key exclusion criteria (12 listed)
- Cardiovascular disease (arrhythmia, cerebrovascular accident, infarction...)
- Raynaud syndrome
- Severe psychiatric disease (dementia, schizophrenia, psychosis, major depression)
- Injuries or loss sensitivity to their forearms or hands
- Pregnant women or in post-partum period (<1 year)
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 |
|---|---|---|
| Conditioned pain modulation testConditioned pain modulation (CPM) protocol consist of evaluating pain during a heat test, before and after one conditioning stimulus (cold water bath); 3 cameras will be capturing participants' facial expressions during the tests. | Other | Chronic pain, Healthy participants |
Primary outcome
Conditioned pain modulation (CPM) profiles
Time frame: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)
Sensitivity and specificity of the classification algorithm according to different profiles (normal vs altered) of conditioned pain modulation, as defined by the change of pain perception before and after the cold water bath measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] in healthy and in chronic pain volunteers together.
Temporal summation profiles
Time frame: Once, at baseline, at recruitment (during the first stimuli test)
Sensitivity and specificity of the classification algorithm according to different profiles (normal vs altered) of temporal summation, as defined by the change of pain perception during the first stimuli test measured by computerized visual analog scale (CoVAS) ranging from 0 [no pain] to 100 [most intense pain that could be tolerated] in healthy and in chronic pain volunteers together.
8 secondary outcomes
Conditioned pain modulation (CPM) profiles of healthy volunteers
Time frame: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli
Temporal summation profiles of healthy volunteers
Time frame: Once, at baseline, at recruitment (during the first stimuli test)
Conditioned pain modulation (CPM) profiles of volunteers with chronic pain
Time frame: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)
Temporal summation profiles of volunteers with chronic pain
Time frame: Once, at baseline, at recruitment (during the first stimuli test)
Demographic factors
Time frame: Once, at baseline, at recruitment
Psychologic factors
Time frame: Once, at baseline, at recruitment
Physiologic factors
Time frame: Once, at baseline, at recruitment
Facial expressions and postures
Time frame: Once, at baseline, at recruitment
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2026.
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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.
Guillaume Léonard, PhD principal investigator
Université de Sherbrooke
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Chronic Pain, run by Université de Sherbrooke at 1 site in Canada.
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 6 inclusion and 12 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: paused, as of the sponsor's last update on 28 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. 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?
Results are not available in the source record.
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?
Conditioned pain modulation (CPM) profiles (time frame: Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)). 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?
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 28 May 2026.