All the sensors we use are 3rd generation, medical grade sensors that are tested against 'gold standards'.

Large scale clinical trials are run and supervised by our Nightingale university hospitals

These will test Sentinels accuracy against hospital intensive care room equipment.

In some cases, we will exceed ICU accuracy.

Sentinel is probably the most accurate vital signs sensor in the world.

Sentinel is also very usable for Nurses and carers. Simple to use, easy to fit and unobtrusive for the patient.

Configured, integrated, fitted to the patient and working in under 20 seconds.

For Hospitals, there is full PAS and EHR integration through HL7, FHIR and SNOMED-CT



ECG Signal Strength – We use the upper LEFT arm to maximise ECG signal strength. It is closer to the heart.  This improves accuracy. The slight curve helps the dry ECG contacts maintain a better contact. The sensor will still work in the right arm but will take longer to isolate the ECG signal.

Motion – The left upper arm has considerably less motion than the hand or wrist or the right arm. The arm is essentially a pendulum and monitoring blood perfusion at the wrist is prone to flow variation due to gravity and blood viscosity. Less motion in the upper left arm also makes isolating ECG signals easier as there is less ‘noise’. The PPG signal is also more accurate as it has less motion. People often gesticulate with their hands and this will also result in inaccuracies especially in a continuous monitoring scenario.

Out of patient sight \ unobtrusive – The upper left arm is less obtrusive to patients and the sensor will often be covered with the patient’s sleeve. They are therefore more inclined to forget that they are wearing the sensor. It can also be easily concealed from sight.

Patches - Usability – Firstly they are expensive. Throwing advanced electrical devices with Li-Po batteries away is not desirable. Sentinel is far cheaper, much more advanced and accurate. For some males with chest hair, an area on the chest would have to be prepared by shaving and dead skin removal. Nurses felt that this was more work. Additionally, there was concern about chest-based sensors being used on patients with cardiac implants or who had recently had cardiac surgery. The adhesive can also tear skin on elderly patients. The experience of having an adhesive patch removed, especially if it has been attached for several days will not be pleasant for any patients.

Comfort – Sentinel incorporates a slight curve to allow a better fit onto the upper arm and create a better ECG contact area. Even though there is a wide range of upper arm girth, the weight of the sensor is distributed over a wider area than say a watch or wrist situated device. The weight of wrist devices is also amplified by motion. They can feel heavy when the arm is moved. We will produce a range of upper arm sensor sizes for both adults and children. The sensor can also be changed without removing the strap.

Accuracy – Creasing – Chest based adhesive sensors have been reported as inaccurate when patients turn on their sides.  The centre of the patch can bulge or crease. Adhesives can also tear skin or detach if the patient is sweating.

Skin tone \ Fitzpatrick Scale – Sentinel can be moved round the arm to avoid tattoos and other skin blemishes if required.

Body Mass Index – The ideal BMI for our sensor is between 16-35. For patients outside of this range, the sensor may not be optimal. The sensor can optionally be set for use on patients with a higher BMI. This will slightly increase the power of the LED’s to obtain a more accurate result.