Automated ABPI in Peripheral Arterial Disease a Pilot Study (AUTO-PAD)

September 30, 2026 updated by: Hull University Teaching Hospitals NHS Trust

Assessing the Diagnostic Accuracy of AUTOmated Ankle-Brachial Pressure Index Devices Across the Spectrum of Peripheral Arterial Disease (AUTO-PAD)- A Pilot Study

The aim of this pilot study is to investigate the diagnostic accuracy of two automated ABPI devices across the spectrum of PAD (asymptomatic PAD, suspected symptomatic PAD [IC; including mild moderate and severe IC based on the Rutherford classification (21) and CLTI] and post-bypass surveillance). A second aim is to assess their useability and tolerability through semi-structured interviews with patients and clinicians. This means the research will be split into two workstreams.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
400

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Group 1: Asymptomatic PAD:

Patients identified by the GP (PIC sites). Records screened to identify 'at risk' of PAD with >1 cardiovascular disease risk factor

Group 2: Suspected symptomatic PAD:

2a. Patients with suspected IC referred to dedicated nurse-led claudication clinic.

Group 2b. Patients with suspected CLTI referred to dedicated urgent vascular (HOT) clinic.

Group 3: Patients undergoing surveillance seen in dedicated clinics by vascular scientists

Description

Inclusion Criteria:

Group 1: Asymptomatic

  • Adults aged 18 and over
  • At risk of PAD with ≥1 cardiovascular risk factor
  • No previous diagnosis of PAD
  • English speaking and able to understand test protocols

Group 2a: Suspected PAD (intermittent claudication)

  • Adults aged 18 and over
  • Referred and booked into the nurse-led claudication clinic due to signs/symptoms in keeping with suspected intermittent claudication
  • English speaking and able to understand test protocols

Group 2b: Suspected PAD (CLTI)

  • Adults aged 18 and over
  • Referred and booked into the vascular HOT clinic due to signs/symptoms in keeping with suspected CLTI
  • English speaking and able to understand test protocols

Group 3: Post-bypass surveillance

  • Adults aged 18 and over
  • History of lower limb bypass surgery, enrolled in and attending the local surveillance programme
  • English speaking and able to understand test protocols

Exclusion Criteria:

  • Patients who are unable to provide informed consent
  • Recent (≤4 weeks) lower-limb surgery
  • Ulcers, casts or bandages that cannot or should not be compressed
  • Patients who have had a therapeutic intervention (stent or graft) which extends to the ankle
  • Patients with known or suspected acute deep vein thrombosis (DVT) or superficial thrombophlebitis
  • Marked oedema in one or both feet
  • Inability to tolerate a supine position
  • Patients with spasms or tremors of any kind
  • Arm arteriovenous fistula
  • Inability to cooperate due to impaired cognition

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: CROSS_SECTIONAL

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Group 1 Asymptomatic

Participants with one or more CVD risk factors
Device: MESI mTablet

The MESI mTablet uses 3CUFFTM technology to detect pulse waveforms to assess ABPI. This involves placing a blood pressure cuff on all 4 limbs at the same time. The two arm cuffs then inflate and simultaneously measure the blood pressure in both brachial arteries. The cuff with the highest systolic pressure than reinflates with both the ankle cuffs simultaneously. The ABPI is then calculated and displayed on the tablet. A ratio of <0.9 will indicate the presence of PAD.

Device: BlueDop vascular Expert (BlueDopVE)

The BlueDop device is a cuffless device which comprises an egg-shaped handheld probe component and an output monitor device. The device measures mean arterial blood pressure through an algorithm. Simply, it calculates the average blood pressure based on the normal rise and fall of pressure during each heartbeat. The device then automatically generates an ankle-brachial pressure index and a corresponding traffic-light classification for each lower-limb artery, based on waveform. This output is interpreted using table 2 below. Essentially an ABPI of 0.8-1.0 with a biphasic or triphasic waveform indicates no disease whereas an ABPI <0.8 and / or a monophasic/non-specific waveform indicates the presence of PAD.
Group 2a Suspected PAD (intermittent claudication)

Partcipants presenting with Suspected PAD (intermittent claudication)
Device: MESI mTablet

The MESI mTablet uses 3CUFFTM technology to detect pulse waveforms to assess ABPI. This involves placing a blood pressure cuff on all 4 limbs at the same time. The two arm cuffs then inflate and simultaneously measure the blood pressure in both brachial arteries. The cuff with the highest systolic pressure than reinflates with both the ankle cuffs simultaneously. The ABPI is then calculated and displayed on the tablet. A ratio of <0.9 will indicate the presence of PAD.

Device: BlueDop vascular Expert (BlueDopVE)

The BlueDop device is a cuffless device which comprises an egg-shaped handheld probe component and an output monitor device. The device measures mean arterial blood pressure through an algorithm. Simply, it calculates the average blood pressure based on the normal rise and fall of pressure during each heartbeat. The device then automatically generates an ankle-brachial pressure index and a corresponding traffic-light classification for each lower-limb artery, based on waveform. This output is interpreted using table 2 below. Essentially an ABPI of 0.8-1.0 with a biphasic or triphasic waveform indicates no disease whereas an ABPI <0.8 and / or a monophasic/non-specific waveform indicates the presence of PAD.
Group 2b Suspected PAD (CLTI)

Participants presenting with tissue loss or rest pain
Device: MESI mTablet

The MESI mTablet uses 3CUFFTM technology to detect pulse waveforms to assess ABPI. This involves placing a blood pressure cuff on all 4 limbs at the same time. The two arm cuffs then inflate and simultaneously measure the blood pressure in both brachial arteries. The cuff with the highest systolic pressure than reinflates with both the ankle cuffs simultaneously. The ABPI is then calculated and displayed on the tablet. A ratio of <0.9 will indicate the presence of PAD.

Device: BlueDop vascular Expert (BlueDopVE)

The BlueDop device is a cuffless device which comprises an egg-shaped handheld probe component and an output monitor device. The device measures mean arterial blood pressure through an algorithm. Simply, it calculates the average blood pressure based on the normal rise and fall of pressure during each heartbeat. The device then automatically generates an ankle-brachial pressure index and a corresponding traffic-light classification for each lower-limb artery, based on waveform. This output is interpreted using table 2 below. Essentially an ABPI of 0.8-1.0 with a biphasic or triphasic waveform indicates no disease whereas an ABPI <0.8 and / or a monophasic/non-specific waveform indicates the presence of PAD.
Group 3 Post-bypass surveillance

Participants presenting for post-bypass surveillance
Device: MESI mTablet

The MESI mTablet uses 3CUFFTM technology to detect pulse waveforms to assess ABPI. This involves placing a blood pressure cuff on all 4 limbs at the same time. The two arm cuffs then inflate and simultaneously measure the blood pressure in both brachial arteries. The cuff with the highest systolic pressure than reinflates with both the ankle cuffs simultaneously. The ABPI is then calculated and displayed on the tablet. A ratio of <0.9 will indicate the presence of PAD.

Device: BlueDop vascular Expert (BlueDopVE)

The BlueDop device is a cuffless device which comprises an egg-shaped handheld probe component and an output monitor device. The device measures mean arterial blood pressure through an algorithm. Simply, it calculates the average blood pressure based on the normal rise and fall of pressure during each heartbeat. The device then automatically generates an ankle-brachial pressure index and a corresponding traffic-light classification for each lower-limb artery, based on waveform. This output is interpreted using table 2 below. Essentially an ABPI of 0.8-1.0 with a biphasic or triphasic waveform indicates no disease whereas an ABPI <0.8 and / or a monophasic/non-specific waveform indicates the presence of PAD.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Diagnostic Accuracy
Time Frame: From enrolment to the end of treatment (1 day)

Diagnostic accuracy assessed via sensitivity, specificity, positive predictor value (PPV) and negative predictor value (NPV).
From enrolment to the end of treatment (1 day)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Validity assessed via correlation
Time Frame: Data collected at enrolment (1 day)

Diagnostic performance assessed via area under the receiver operating characteristic (AUROC) curve and the assessment time difference, assessed via measurement of the time taken to perform each automated ABPI assessment and the manual ABPI assessment.
Data collected at enrolment (1 day)
Diagnostic performance
Time Frame: Data collected at enrolment (1 day)

Assessed via area under the receiver operating characteristic (AUROC) curve.
Data collected at enrolment (1 day)
Time taken to perform each automated ABPI assessment and the manual ABPI assessment.
Time Frame: Data collected at enrolment (1 day)

Time taken to perform each assessment in seconds
Data collected at enrolment (1 day)
Qualitative Workstream - Assessment of usability and tolerability of automated devices.
Time Frame: Within the 2 year recruitment period

Semi structured interviews analysed using thematic analysis
Within the 2 year recruitment period
Visual Analogue Scale (VAS) score of 0-10
Time Frame: Data collected at point of enrolment (1 day)

VAS used to assess tolerability
Data collected at point of enrolment (1 day)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hull University Teaching Hospitals NHS Trust

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 24, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 14, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 30, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 30, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • R4364

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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