Heartbeat™’s main competitive advantage is the MUST™ patented UNIFICATION of existing medical devices sensors and using mobile devices like Smartphones or tablets to present the UNIFIED continuous information.
The first HeartBeat Product which is based on MUST is a wrist watch wireless pulse oximeter CMS50FW.
The wireless watch transmits through Bluetooth to a Smartphone or tablet mobile device the continuous PPG (PhotoPlethismoGraph) signal. The Smartphone App software analizes the PPG signal in real time, combines it with intermitent BP measurements, and produces new parameters and signals.
All Cardiovascular information is extracted from the micro-circulation blood flow, as red and infra-red light is shined into the tiny blood vessels. While current pulse oximeters calculate only the SpO2 and ignore the continuous PPG (PhotoPlethismoGram) signal, MUST™ Smartphone App performs full analysis of the blood flow signal. It can differentiate between your Cardiac Output changes and blood vessels resistance (Systemic Vascular Resistance), leading to much better assessment of patient progress.
Users can then access the data at any given moment on their Smartphone App, in the website, or as regular reports sent securely to their e-mail.
MUST - Mobile Unified Sensors Technology is a signal processing technology that extract more information from existing sensing devices. By integrating or unifying the signals, it arrives at new parameters (single values or time sequences signals) that have significant clinical value (for Medical applications) and Fitness and Welness value (for the Lifestyle app)..
The underlying assumption is that measured signals have additional information than the part used today, and by extracting the unused part and combining it with other measurement, one can achieve much higher efficiency and cost effectiveness, as well as featured that cannot be obtained otherwise in a mobile environment.
The "Buttons" approach (New GUI)
As can be seen from the picture above, the upper part of the screen includes "Buttons". Each "Button" can be perceived as a Medical device implemented in Software. According to MUST patented approach, we can add as many devices as we want where each "Button device"implements a specific function when clicked.
Each "button" is a S/W object that displays itself as "button" on the button grid, with Title (E.g. CO, BP, ..), Numeric value and color. The color is taken from the rainbow continuoum from Low to High ( deep blue - green - yellow -orange - red).
The reference can be either the user or the users population group. Green signifies desired range, while blue is lower and red higher.
A complete "buttons" arrangement can be chosen as a template or "Skin" according to the application:
Medical - CHF, Medical - COPD,.. or Fitness/Wellness.
Pressing a button will give more info on the parameter and displaying its graph below.
E.g. pressing PPG (or PI) will display the real time graph below.
The Architecture of MUST
The programm is divided to 3 parts:
1. Data acquisition through Bluetooth - PPG, BP, ..
2. GUI - The design based on "Buttons" as described above where each parameter is a "button" (A S/W object in Object Oriented terminology). Such an Object is clickable and represents functionality in the corresponding module in the signal processing part.
3. Signal processing - This is the computational part which is the heart of App.
It is divided to 2 parts:
a. General service procedures that do Peak-Detection, SQI (Signal Quality Index) filter to filter out noisy segments, feature extraction like decomposition of the waves, Machine learning algorithm, plotting routines, etc..
b. Signal processing modules associated with specific "Buttons" modules that include specific functionality.
E.g. The BP "Button" gets as in input PPG signal after SQL filtering and marking of Sys peak and Dia peak. It gets also BP measurements from an external BP device (or manually). It computes BP estimations every 5-10 sec and output it. The Output is sent to the GUI to display both as number and graphic.
The graphic is both the 'Button" color (Blue - green - yellow - orange - red) and display of the corresponding time line in the Graphic Pane (Lower part of the display)
Below is a different "template" or "Skin" designed for Fitness application.
MUST for computing CO/CI
The continuous monitoring of CO is based on good quality and continuous Blood Pressure (BP) signal, preferably from an optical sensor that is less affected by motion artefacts and does not apply pressure on the skin and the blood vessels.
The first step as depicted in the figure below is to move from a BP measurement expressed as a pair of numbers corresponding to Systolic/Diastolic BP, to a continuous measurement that provides the complete BP waveforms.
Several sensors are capable of capturing good quality BP signal like this. We are using the PPG signal from Pulse Oximeter.
The second step is to validate each BP pulse a legitimate representative of the heart beat. The shape of the heart beat BP signal is shaped by the ejection of blood during the Systole with typical parameters representing an individual heart. In the diastolic stage.
Once there is a good quality signal with high sampling rate and good ADC resolution. The higher is the quality of the signal, the better are the estimation, so consideration of cost/effectiveness determine the best configuration for a specific case.
we are ready for the next stage of peak detection and identifying high quality pulses and segments. The detection is done on several peaks for each BP pulse.
The peaks as well as their relative timing (that is proportional to BP) are estimated using multi-channel signal processing proprietary algorithms.
The next step is to analyze the representative wave forms by subjecting them to Wavelets analysis.
As can be seen in the figure above, there are 4 components that can be identified by decomposing the BP waveforms to its basic ingredients.
These four components, designated as A, B, C and D have each a physiological meaning and are very instructive in estimating the Cardiac Output, as well as the Systemic Vascular Resistance.
Component A is the forward moving wave, generated by the left ventricle ejection and the area under this component is proportional to the Cardiac – Output measured in Litres/minute. The other 3 components – B, C and D are reflections of the forward moving wave mainly from the iliac and real arteries as well as from the end of the conduit arteries.
PPG recorded from different sites of the body and even from bi-lateral recording yields somewhat different signals as can be seen from the figure below.
A motion artefact is not necessarily from exercise and can be generated even from taking a deep breath, moving in bed, etc..
If not treated properly, it can introduce a major measurement error and an unreasonable CO value, that might render the device unreliable.
The 3 components are proportional to the Systemic or total vascular resistance. These reflected waves component depends on the resistance and diminish when the blood vessels dilate as a response to higher flow. This mechanism is mediated by the endothelial cells layer that line up the inside of all blood cells and also generate NO that acts on the Vascular Smooth Muscles and dilates and results in vascular dilatation.
The breakdown of the BP to its 2 basic components: Flow and Resistance is essential to the correct interpretation and decision on the most appropriate treatment
This wavelet analysis is an important part in the computation of the CO as it helps to differentiate between the Systolic forward going component that is used for the computation of the CO and the reflected component (with its 3 sub-components) that is proportional to the resistance. This wavelet analysis is also important in “denoising’ – removing noise components that distort the original wave form.
The figure below shows estimation of CO from the PPG signal compared to Thermodilution gold standard.
As can be seen, the estimation falls within the allowed error range. This is the initial estimation that improves in personalization based on adapting or learning personalized wave shapes.
Mobile and Continuous
Simple to use and wearable
This is the only device of its kind currently in the market that provides continuous stress level and Cardiovascular info that does not interfere with daily life. Other devices in the market lack this info or require skilled placement of electrodes or placing finger in a device.
CE&FDA approved Watch Pulse Oximeter
It is a watch: just strap it on and activate the Smartphone App. It is light, does not require extra cost for disposable and is inexpensive. It can be easily used by every one at any age.
The graphic presentation
is intuitive and immediately indicates relevant Stress Management patterns. This info is then used to adjust training and provide advice on lifestyle measures such as Stress Management, diet and sleep.