Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12625000866404p
Ethics application status
Not yet submitted
Date submitted
23/07/2025
Date registered
11/08/2025
Date last updated
11/08/2025
Date data sharing statement initially provided
11/08/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
Testing of a Non-Invasive Light Sensor to Estimate Venous Blood Oxygen Levels in Patients in the Intensive Care Unit (ICU)
Scientific title
Calibration and Validation of a Non-Invasive Optical Sensor for Estimating Venous Oxygen Saturation in Intensive Care Unit (ICU) Patients Compared with Blood Gas Analysis
Secondary ID [1] 314446 0
None
Universal Trial Number (UTN)
Trial acronym
CANVOS
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Venous Blood Oxygen Saturation 337480 0
Hypoxemia 337481 0
Sepsis 337482 0
Shock 337484 0
Condition category
Condition code
Public Health 333856 333856 0 0
Health service research
Blood 334691 334691 0 0
Other blood disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Arm 1: Internal Jugular Vein (JVP) Monitoring
WHY: Continuous monitoring of venous oxygen saturation (SvO2) and oxygen extraction ratio (O2ER) using a flexible, non-invasive optical sensor placed over the internal jugular vein (IJV).

MATERIALS:
• Custom-developed reflectance pulse oximetry sensor with red and infrared LEDs, photodetectors, and integrated temperature protection
• Medical-grade adhesive (Tegaderm)
• Commercial finger pulse oximeter for SaO2 reference
• Blood assays

PROCEDURES:
• Optional ultrasound imaging to locate the IJV and optimise placement
• Sensor placed on the side of the neck, preferably contralateral to the central line
• Finger pulse oximeter placed on the same side as the arterial line
• Sensor remains in place for up to 24 hours
• Blood gas samples (arterial and central venous) are taken per routine care and aligned with sensor data
• Sensor is cleaned with alcohol and reused per protocol

WHO PROVIDED:
Research staff with ICU experience will apply the sensor and monitor performance.

HOW:
• Face-to-face, bedside monitoring.
• Individual use.
• Sensor applied and left in place for up to 24 hours.
• At least five blood draws made during 24-hour period (T=0, 2, 6, 12, 24 hours)

LOCATION:
Christchurch Hospital ICU, New Zealand

TAILORING:
• Sensor placement adjusted for neck anatomy or existing lines.
• Signal quality confirmed visually at placement.

Arm 2: Femoral Vein Monitoring
Identical protocol to Arm 1, but the optical sensor is placed over the femoral vein rather than the jugular vein. Sensor placed over the femoral vein if central access exists and jugular placement is not feasible
ADAPTATION:
Only used if the internal jugular site is not available or contraindicated. Placement adjusted based


Allocation to arms:
Participants will initially be allocated to Arm 1 (Internal Jugular Vein monitoring). If an appropriate signal cannot be obtained or maintained from the IJV site, or no jugular catheter is present participants may be switched to Arm 2 (Femoral Vein monitoring) as an alternative site.


Number and duration of sensor assessments:
Each participant will have a single continuous sensor assessment lasting up to 24 hours. Re-application of the sensor for additional or extended monitoring sessions is not planned within this study.

Adherence monitoring strategies:
Sensor placement and signal quality will be checked every 2 hours by research staff to ensure proper positioning and data quality. Any issues with sensor adherence or signal loss will be documented.
Intervention code [1] 331637 0
Treatment: Devices
Intervention code [2] 331638 0
Diagnosis / Prognosis
Comparator / control treatment
Participants will undergo routine venous and arterial blood gas analysis (BGA) as the clinical gold standard comparator to the novel optical sensor device.

Procedure: Blood samples are collected via existing central venous and arterial lines using standard aseptic technique.

Equipment: Blood gases are analyzed using hospital-standard blood gas analyzers in the ICU.

Frequency: Blood gas samples will be collected at five fixed timepoints during the 24-hour monitoring period: immediately at sensor placement (T=0), and at 2, 6, 12, and 24 hours thereafter.

Personnel: Blood samples will be drawn by trained ICU nursing staff as part of routine patient care.

Adherence monitoring: Daily checking of central line placement and blood gas analysis measurements will be performed by research staff to ensure protocol adherence.

All participants will simultaneously undergo continuous sensor monitoring and scheduled blood gas sampling, allowing direct within-subject comparison between the two measurement methods.
Control group
Active

Outcomes
Primary outcome [1] 341907 0
Accuracy of a non-invasive venous oxygen sensor determined by comparing continuous SvO2 estimates with discrete venous blood gas measurements (clinical gold standard)
Timepoint [1] 341907 0
The sensor will be worn continuously for up to 24 hours from the time it is placed on the patient (T=0). Blood samples will be collected at five fixed timepoints after sensor placement: immediately at sensor application (T=0), and at 2, 6, 12, and 24 hours thereafter, with the final blood sample taken just prior to sensor removal. Sensor readings will be recorded continuously throughout the 24-hour period, and measurements taken around each blood sampling timepoint will be compared to the corresponding blood test results.
Secondary outcome [1] 448932 0
Difference in venous oxygen saturation (SvO2) between jugular and femoral sites
Timepoint [1] 448932 0
The sensor will be worn continuously for up to 24 hours from the time it is placed on the patient (T=0). Blood samples will be collected at five fixed timepoints after sensor placement: immediately at sensor application (T=0), and at 2, 6, 12, and 24 hours thereafter, with the final blood sample taken just prior to sensor removal. Sensor readings will be recorded continuously throughout the 24-hour period, and measurements taken around each blood sampling timepoint will be compared to the corresponding blood test results.
Secondary outcome [2] 448933 0
Agreement between non-invasive and invasive oxygen extraction ratio (O2ER)
Timepoint [2] 448933 0
The sensor will be worn continuously for up to 24 hours from the time it is placed on the patient (T=0). Blood samples will be collected at five fixed timepoints after sensor placement: immediately at sensor application (T=0), and at 2, 6, 12, and 24 hours thereafter, with the final blood sample taken just prior to sensor removal. Sensor readings will be recorded continuously throughout the 24-hour period, and measurements taken around each blood sampling timepoint will be compared to the corresponding blood test results.
Secondary outcome [3] 448934 0
Change in SvO2 before and after red blood cell transfusion
Timepoint [3] 448934 0
Readings from the sensor along with extra blood samples 30 minutes before and 30 minutes after the transfusion event, as applicable during the 24-hour monitoring period.
Secondary outcome [4] 448935 0
Sensor usability in the ICU (practical use of the sensor in the ICU environment)
Timepoint [4] 448935 0
Usability feedback will be obtained at three key timepoints relative to sensor placement: immediately at sensor application (T=0), during scheduled blood sampling times (T=2, 6, and 12 hours), and at sensor removal (T=24 hours).
Secondary outcome [5] 450467 0
Sensor signal quality over time.
Timepoint [5] 450467 0
Signals measured continuously during the 24-hour monitoring period and will be assessed once removed from the patient

Eligibility
Key inclusion criteria
• ICU participants with a current or anticipated central line or femoral vein catheter
• 18 years of age or older
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
• Participants who are not expected to survive for 48 hours are excluded from the study
• Participants on any medication or therapy that, in the judgment of clinicians, may affect the accuracy and precision of non-invasive oximetry results
• Patients unsuited for additional blood sampling, for example, difficulty with blood access or an increased risk for needing blood transfusion (for blood sampling participation)

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
All participants will initially be assigned to Arm 1 (Internal Jugular Vein monitoring). If the participant does not have a suitable central venous catheter or if IJV placement is contraindicated or technically not feasible, the sensor will be placed over the femoral vein as an alternative.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/12/2025
Actual
Date of last participant enrolment
Anticipated
1/02/2027
Actual
Date of last data collection
Anticipated
1/03/2027
Actual
Sample size
Target
50
Accrual to date
Final
Recruitment outside Australia
Country [1] 27134 0
New Zealand
State/province [1] 27134 0
Canterbury

Funding & Sponsors
Funding source category [1] 318984 0
University
Name [1] 318984 0
University of Canterbury
Country [1] 318984 0
New Zealand
Primary sponsor type
Individual
Name
Geoff Shaw, Department of ICU, Christchurch Hosptial
Address
Country
New Zealand
Secondary sponsor category [1] 321449 0
University
Name [1] 321449 0
Department of Mechanical Engineering, University of Canterbury
Address [1] 321449 0
Country [1] 321449 0
New Zealand

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 317587 0
Southern Health and Disability Ethics Committee
Ethics committee address [1] 317587 0
Ethics committee country [1] 317587 0
New Zealand
Date submitted for ethics approval [1] 317587 0
01/09/2025
Approval date [1] 317587 0
Ethics approval number [1] 317587 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 141506 0
Prof Geoff Shaw
Address 141506 0
Department of Intensive Care, Christchurch Hospital, 2 Riccarton Avenue, Christchurch Central City, Christchurch 8011
Country 141506 0
New Zealand
Phone 141506 0
+6421619686
Fax 141506 0
Email 141506 0
[email protected]
Contact person for public queries
Name 141507 0
Geoff Shaw
Address 141507 0
Department of Intensive Care, Christchurch Hospital, 2 Riccarton Avenue, Christchurch Central City, Christchurch 8011
Country 141507 0
New Zealand
Phone 141507 0
+64 21 619 686
Fax 141507 0
Email 141507 0
[email protected]
Contact person for scientific queries
Name 141508 0
Jordan Hill
Address 141508 0
Department of Mechanical Engineering, University of Canterbury, 20 Kirkwood Ave, Ilam, Christchurch, 8041
Country 141508 0
New Zealand
Phone 141508 0
+64 278694181
Fax 141508 0
Email 141508 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
Yes
Will there be any conditions when requesting access to individual participant data?
Persons/groups eligible to request access:
• Researchers
Conditions for requesting access:
• Yes, conditions apply:
• Requires review on a case-by-case basis by the trial custodian, sponsor or data sharing committee
• Requires a scientifically sound proposal or protocol
• Requires a data sharing agreement between data requester and trial custodian or sponsor
What individual participant data might be shared?
• All de-identified individual participant data
What types of analyses could be done with individual participant data?
• Any type of analysis (i.e. no restrictions on data re-use)
• Systematic reviews and meta-analyses
• Studies exploring new research questions
When can requests for individual participant data be made (start and end dates)?
From:
After publication of main results
To:
Not yet decided
Where can requests to access individual participant data be made, or data be obtained directly?
• Email of trial custodian, sponsor or committee: [email protected]

Are there extra considerations when requesting access to individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.