Evaluation of Objective Pain Measurement Device

This study will attempt to objectively measure pain with an experimental device. The investigators will apply the device to measure patients "pain" due to uterine contractions during routine clinical care to correlate patients verbal pain ratings and analgesia requirements to that measured by the device. A brain oxygenation device, Edwards Foresight, will be used to concurrently to monitor brain oxygenation and hemodynamics, so the relationship between the CereVu ROPA device objective measure of pain and brain oxygenation/hemodynamic changes and patient-reported pain can be determined.

Study Overview

• Status: Completed
• Conditions: Pain; Analgesia; Labor Pain
• Intervention / Treatment: Device: Pain Measurement Device

Detailed Description

Despite all the progress in our understanding of the basic mechanisms of pain, the gold standard for measuring pain is still a subjective verbal numeric rating scale rating (0-10) obtained from the individual reporting pain. This method is not objective and cannot be used in all patient populations. This study will attempt to objectively measure pain in laboring mothers with a pain measurement device. The investigators aim to 1) see if the pain measurement device (CereVu ROPA) is capable of reflecting different levels of pain ratings in patients in labor having uterine contractions and then changes in pain after receiving different neuraxial techniques for labor pain and to 2) additionally determine the relationship between the CereVu ROPA device, brain oxygenation/hemodynamic changes and patient-reported pain scores.

• Study Type: Interventional
• Enrollment (Actual): 130
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18-50
• ASA 1 or 3 +/-E
• Patient requesting epidural labor analgesia
• Good toco tracing (clearly showing contractions at least every 5 minutes)
• Pain score greater than or equal to 3 out of 10 with contractions

Exclusion Criteria:

• History of chronic pain
• History of chronic opioid use
• BMI > 45
• Allergy to sensor adhesive material, local anesthetic or opioids
• Contraindication to neuraxial block
• Patient on magnesium infusion
• Inability to give informed consent or understand English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Device Calibration and Validation; Patients requesting epidural labor analgesia will have pain levels monitored during labor.	Device: Pain Measurement Device; When participants request labor analgesia, the sensors of the pain measurement device (ROPA System [CereVu Medical, Inc. San Francisco, CA] and Edwards Foresight device) will be applied to the forehead and connected to the device. Data recording is then started.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Self-report Pain Score	Average patient self-reported pain score on 0 to 10 scale (higher scores correspond to more pain)	During labor up to 2 hours after epidural
Correlation of Average Device Pain Score to Average Self-report Pain Score	Pearson correlation	During labor up to 2 hours after epidural
Correlation Between Pain Score and Brain Oxygenation	Pearson correlation between patient self-reported pain score on 0 to 10 scale (higher scores correspond to more pain) and brain oxygenation (0-100%). This outcome will be assessed in part 2 only.	During labor up to 2 hours after epidural
Correlation Between Pain Score and Noninvasive Blood Pressure	Pearson correlation between patient self-reported pain score on 0 to 10 scale (higher scores correspond to more pain) and hemodynamic parameter noninvasive blood pressure. This outcome will be assessed in part 2 only.	During labor up to 2 hours after epidural
Correlation Between Pain Score and Heart Rate	Pearson correlation between patient self-reported pain score on 0 to 10 scale (higher scores correspond to more pain) and hemodynamic parameter heart rate. This outcome will be assessed in part 2 only.	During labor up to 2 hours after epidural
Correlation Between Pain Score and Pulse Oximetry	Correlation between patient self-reported pain score on 0 to 10 scale (higher scores correspond to more pain) and hemodynamic parameter pulse oximetry (Sp02). This outcome will be assessed in part 2 only.	During labor up to 2 hours after epidural

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Reach Pain Score 2 or Less Out of 10	Pain score on 0 to 10 scale (higher scores correspond to more pain)	within 45 minutes after the block placement
Time Taken for Pain Device Score to be Below Validated Value	Validated value is from the validated reading recorded by the sensor in the pilot study	within 45 minutes after the block placement
Patient Reported Pain Scores After Block	Pain score on 0 to 10 scale (higher scores correspond to more pain). Pain scores were obtained at random intervals and the scores were summed and averaged to create the reported score. Patients stopped rating pain once the level dropped to zero.	Up to approximately 45 minutes after the block placement
Device Recorded Pain Scores After Block	Device pain score validated measure (range: 0 to 10, higher scores correspond to more pain). Pain scores were obtained at random intervals and the scores were summed and averaged to create the reported score. Device recording was discontinued when pain level dropped to zero.	Up to approximately 45 minutes after the block placement
Dermatomal Level at 45 Minutes After Block Placement as a Measure of Sensory Blockade Level		45 minutes
Count of Participants With Block Failures		within 45 minutes after the block placement
Count of Participants With Maternal Side Effects	Monitored maternal side effects will include nausea, pruritis, hypotension	within 45 minutes after the block placement
Count of Participants With Fetal Side Effects	Monitored fetal side effects include fetal decelerations early/variable/late	within 45 minutes after the block placement
Count of Participants Needing Physician Intervention		within 45 minutes after the block placement
Time From Epidural to Delivery		from epidural to delivery (average approximately 9 hours)
Count of Participants With Normal Vaginal Delivery		from epidural to delivery (expected average: 24 hours)
Count of Participants With Assisted Vaginal Delivery		from epidural to delivery (expected average: 24 hours)
Count of Participants With Cesarean Delivery		from epidural to delivery (expected average: 24 hours)

Collaborators and Investigators

• Sponsor: Stanford University
• Investigators: Principal Investigator: Brendan Carvalho, MBBCh, FRCA, Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2019
• Primary Completion (Actual): October 31, 2023
• Study Completion (Actual): October 31, 2023

Study Registration Dates

• First Submitted: June 1, 2019
• First Submitted That Met QC Criteria: June 3, 2019
• First Posted (Actual): June 5, 2019

Study Record Updates

• Last Update Posted (Actual): June 8, 2025
• Last Update Submitted That Met QC Criteria: June 6, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Labor Pain
• Other Study ID Numbers: 51101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No