Feasibility Study of a New Peripheral Oedema Monitor for Heart Failure

Heartfelt Technologies

Status: Completed

Conditions: Edema Brain; Heart Failure, Diastolic; Decompensated Heartfailure

Treatments: Device: Measuring tape; Other: Baseline assessements; Other: Medical grading of oedema; Device: Weighing scales; Device: Water displacement method; Device: Heartfelt-1; Device: Callipers measurements

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT02993601

RBH01

Details and patient eligibility

About

The study aims at assessing the usefulness of the Heartfelt1 device in patients suffering from heart failure, who have peripheral oedema. The device is non-contact and does not requires patient compliance to work. It gives an output reading of the patient's lower leg volume.

During the study, this measurement will be compared to clinical standard and gold standard measurements as well as clinical grading of peripheral oedema.

Full description

The Heartfelt-1 device is a CE (Conformité Européenne = European Conformity) mark medical device used to measure biometric parameters of the foot and lower leg. The study aims at assessing the usefulness in patients suffering from heart failure, who have peripheral oedema. Models used for the measurements of foot and lower legs have not yet been validated for this group of patients, who are likely to have feet with abnormal surface contours and appearance secondary to oedema. Peripheral oedema can be a leading indicator of heart failure de-compensation which can lead to hospitalisation of patients, and therefore the device could be a useful clinical tool to monitor patients in their home. The Heartfelt-1 device has the ability to recognise the patient's feet (amongst an average size household setting), and trigger automatically the measurements when the feet are naked (for example as the patient goes in and out of bed). This makes the device an obvious choice for patients with compliance issues with current methods of monitoring (e.g. daily use of weighing scales) and treatment (e.g. diuretics) if it could be validated in this patient group.

The study has two general aims:

The first is to collect a time-series of data on inpatients with peripheral oedema caused by heart failure, as they receive intravenous or oral diuretic treatment to remove excess fluid and achieve optimal body weight and fluid balance. This data will be used both to determine the attainable resolution of foot biometric measurements on a patient as their fluid status changes, and also to further develop the algorithms used in the device and make them usable on a wide range of feet/lower legs which have been deformed by oedema. The data required for this study are images taken using the Heartfelt-1 device, as well as validation measurements such as the figure of eight using a medical grade tape measure, callipers, or the water displacement method using a volumetric gauge, at multiple time-points whilst the peripheral oedema reduces.

The second, on a second group of stable ambulatory (Heart Failure) HF patients with variable levels of oedema, is to evaluate the performance of the Heartfelt-1 device in determining foot biometric parameters one a wide range of patients at a single point in time. Patients with stable chronic heart failure will have their foot/lower legs measured by the Heartfelt-1 device, as well as standard medical measurement (figure of eight using a medical grade tape measure, callipers) and gold standard measurement (water displacement method using a gauge), as well as the patient's weight and a clinical grading of oedema. These will be compared and an estimate of the accuracy of the Heartfelt-1 device over this wider patient group can be extrapolated.

Enrollment: 70 patients

Sex: All

Ages: 18 to 99 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Inpatients with admission for de-compensated heart failure requiring increase or initiation of diuretic therapy for fluid congestion.
• Patients attending cardiology outpatients at the Royal Brompton hospital with a diagnosis of heart failure and fluid retention.
• Cardiology patient without fluid retention (cardiology controls) Non-Cardiology patient without fluid retention (controls)

Exclusion criteria

• Patients unable to provide informed consent.
• Unstable arrhythmias in previous 48 hours
• Systolic BP<90mmHg or need for inotropic support
• Ulceration on lower limbs (below shin) - excluded from water displacement but could have image recording and calipers
• Inability to transfer from bed to chair
• Patients with broken skin or cellulitis will not have their foot volume measured using the water displacement equipment to reduce the risk of infection for the patient and other participants.

Trial design

70 participants in 4 patient groups

20 outpatients with peripheral oedema

Description:

20 outpatients with clinically detectable peripheral oedema for 1 set of measurements.

Treatment:

Device: Callipers measurements

Device: Water displacement method

Device: Heartfelt-1

Other: Medical grading of oedema

Device: Measuring tape

Other: Baseline assessements

Device: Weighing scales

20 cardiology controls

Description:

20 outpatients with heart failure without clinically detectable peripheral oedema (control group) for 1 set of measurements.

Treatment:

Device: Callipers measurements

Device: Water displacement method

Device: Heartfelt-1

Other: Medical grading of oedema

Device: Measuring tape

Other: Baseline assessements

Device: Weighing scales

10 in-patients peripheral oedema

Description:

10 in patients hospitalised as a result of heart failure and fluid congestion with peripheral oedema, those patients will have several sets of measurements taken over time to measure the reduction of peripheral oedema which is likely to show common features with the formation of peripheral oedema.

Treatment:

Device: Callipers measurements

Device: Water displacement method

Device: Heartfelt-1

Other: Medical grading of oedema

Device: Measuring tape

Other: Baseline assessements

Device: Weighing scales

30 control without cardiac conditions

Description:

less than 30 normal controls (healthy volunteers and patients without heart failure) in the age group 55 and above who agree to have images taken using the Heartfelt-1 device (not the whole set of measurements).

Treatment:

Device: Heartfelt-1