Feasibility Study of a New Peripheral Oedema Monitor for Heart Failure
Condition: Heart Failure, Diastolic; Edema Brain; Decompensated Heartfailure
MeSH terms: Heart Failure; Heart Failure, Diastolic; Edema
Study type: Observational

Summary: 
      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.
    

Detailed 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.
    

Intervention name(s): Heartfelt-1; Weighing scales; Medical grading of oedema; Baseline assessements; Water displacement method; Callipers measurements; Measuring tape
Intervention type(s): Device; Device; Other; Other; Device; Device; Device
Intervention description(s): The patients will stand in front of the Heartfelt-1 in order for images to be captured and the volume of their lower legs measured.; The patient will be asked to stand on standard medical weighing scales, to measure their weight.; A member of the research team will assess the severity of the peripheral oedema on a scale of 1-5.; At the point study participants are recruited, their age, sex, diagnosis, aetiology of heart failure, LVEF (Left ventricular ejection fraction), medical and device therapy, time since diagnosis, BNP (B-type Natriuretic Peptide), CRP (C-Reactive Protein), renal function (EGFR), Haemoglobin, albumin and urinalysis will be assessed unless recent (less that 6 months old) results are available. The number of Heart failure hospital admissions in the last 2 years, LACE score, co-morbidities will also be noted.; This will involve filling a gauge with lukewarm water (27-35oC +-2oC) up to the appropriate level. The appropriate level is determined by the water stabilising after some has flown out of the gauge into the waste bucket. Once the water level is stable the patient, who is sitting on a chair will be gently plunging the foot (naked) in the gauge until their foot is flat on the bottom on the gauge. The water flowing out of the gauge into the measuring bucket will be collected until the flow of water stops. Four small marks with non-toxic /non-permanent pen will be made on the lower leg of the patient to indicate where the water level was at. The water which has been collected in the measuring bucket will be weighted with precision scales to determine the volume of water displaced by the insertion of the foot. The patient's foot will then be dried.; This will involve making 4 marks on one of the foot/lower leg (small cross) using non-toxic / non- permanent pen. The measurement will consist of making 6 measurements between those marks using callipers, and reporting the distance on a calibrated tape.; The measurements taken using a medical tape measure will involve the circumference of the ankle to be measured as well as the circumference at the level of the arch of the foot. The medical tape used will be a CE marked disposable medical measuring tape to minimise the risk of infection. The measurements will be done on both feet.
Other intervention name(s): HF-1
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adults able to give consent to take part in the study
      
Keywords: Heart Failure; Edema; Oedema; Decompensated Heartfailure