MEASUREMENT OF CHOLESTEROL AND HEMOGLOBIN LEVEL USING PPG SIGNALS

Abstract

ABSTRACT Title: MEASUREMENT OF CHOLESTEROL AND HEMOGLOBIN LEVEL USING PPG SIGNALS The titled invention “a measurement of cholesterol and hemoglobin level using ppg signals” offers a non-invasive alternative to traditional blood tests. This invention typically includes a light source (1), a photodetector (2) , a signal amplification or transimpedance amplifier (3) ,a signal conditioning (4), an analog-to-digital converter(5), a microcontroller (6), a power supply (7), an user interface (8), a finger probe (9), and an enclosure (10). This invention can be used to monitor cholesterol and hemoglobin levels in individuals at home, potentially enabling early detection of health issues and proactive management. Figure.2: illustrate the block diagram of proposed system.

Specification

FORM 2
THE PATENTS ACT, 1970
COMPLETE SPECIFICATION
Section 10

MEASUREMENT OF CHOLESTEROL AND HEMOGLOBIN LEVEL USING PPG SIGNALS

SRI MANAKULA VINAYAGAR ENGINEERING COLLEGE
Madagadipet, Mannadipet Commune, Puducherry-605 107, India.

The following specification particularly describes the nature of invention and the manner in which it is to be performed.

FIELD OF INVENTION
The present invention is related to biomedical engineering and healthcare technology domain. Particularly, the present invention is relates to develop a user-friendly and accurate system that allows people to monitor their cholesterol and hemoglobin levels without intrusive blood testing. More particularly, the present invention is relates to a measurement of cholesterol and hemoglobin level using ppg signals. This invention offers a non-invasive, convenient, and potentially cost-effective method for health monitoring. This invention has applications in health monitoring, early disease detection, and personalized healthcare.

Prior Art:

This invention relates to a measurement of cholesterol and hemoglobin level using ppg signals. Traditional methods of monitoring cholesterol and hemoglobin levels frequently include intrusive blood tests, which can be painful, time-consuming, and may discourage regular monitoring. These disadvantages underscore the need for a non-invasive monitoring solution that provides a more user-friendly and accessible method of tracking important physiological indicators. Traditional blood testing methods have a number of problems, including discomfort, pain, limited monitoring frequency, and the inconvenience of repeated intrusive procedures. These characteristics highlight the need for a non-invasive system that can offer precise and reliable readings of cholesterol and hemoglobin levels without the disadvantages of invasive methods.

One of prior art US20210137464A1, titled "System and method for obtaining health data using photoplethysmography". A photoplethysmography (PPG) circuit or non-contact camera captures PPG signals at various wavelengths. A signal processing module extracts spectral responses around a first and second wavelength. These spectral responses are used to create PPG input data containing parameters. A neural network processes this data to generate an output vector with health information, such as oxygen saturation, heart rate, or sepsis indication.

Another prior art US20190029532A1, titled "Diabetes and Hypertension Screening by
Assessment of Arterial Stiffness and Autonomic Function". The present invention offers methods and devices to gauge vascular stiffness in a subject and to diagnose diabetes or hypertension based on this assessment. Specific embodiments involve measuring the arrival time of a blood pressure wave at a peripheral site in relation to
the subject's cardiac cycle under various measurement conditions. At least two of these conditions should differ in central or peripheral transmural pressure. The gathered data is then used to evaluate vascular stiffness.

Another prior art RU2640006C2, titled "Method and system of identifying artifacts of displacing and improving reliability of measurements and alarms in photoplethysmographic measurements". A system for identifying movement artifacts in physiological measurements comprises a probe to measure a patient's physiological parameter and generate signals, an accelerometer, a first unit to process these signals, and a second unit to process accelerometer signals and determine movement characteristics. The second unit processes signals independently from the first, and a unit labels physiological measurements based on movement characteristics. The method involves receiving physiological and acceleration signals, processing them to determine measurements and movement characteristics, and marking physiological measurements. This system expands the available tools for. photoplethysmographic
measurements.

Another prior art US20210145334A1, titled "Systems and methods for biological metrics measurement". A wearable device can include multiple energy transmitters arranged on its surface to project energy into the user's tissue. It may also have
multiple energy receivers that generate signals based on reflected energy. These transmitters and receivers can be arranged multi-dimensionally to capture energy reflected from different locations in the user's tissue. A processor can then use these signals to calculate biological metrics.

Another prior art US10952682B2, "System and method of a biosensor for detection of health parameters". A photoplethysmography (PPG) circuit captures PPG signals at various wavelengths of light reflected from a user's tissue. A processing device calculates parameters from these signals to determine the glucose level in the user's
blood flow. These parameters include one or more ratio values derived from the multiple PPG signals, the phase delay between these signals, the correlation of phase shape among them, or the periodicity of one or more of the PPG signals.

While measuring cholesterol and hemoglobin levels using PPG signals offers a noninvasive alternative to traditional methods, it faces several drawbacks. The accuracy of these measurements can be influenced by factors such as skin pigmentation, ambient light conditions, and individual physiological variations. Additionally, the relationship between PPG signals and cholesterol or hemoglobin levels is complex
and may not be universally applicable. Further research is needed to refine the algorithms and techniques used for these measurements, ensuring their reliability and clinical viability.

Therefore, the present invention overcomes the drawbacks of the prior art by providing a measurement of cholesterol and hemoglobin level using ppg signals.

1. The principal object of this invention is to design and development of a measurement of cholesterol and hemoglobin level using ppg signals.

2. Another object of this invention is to develop a non-invasive method for estimating blood cholesterol and hemoglobin levels using photo
plethysmography (PPG) signals.

3. Yet another object of this invention is to develop a system capable of measuring blood parameters by transmitting specific wavelengths of light through a fingertip and analysing the resulting photodiode signal, which is influenced by the absorption and scattering of light by blood components and reflects variations in blood flow.

4. Another object of this invention is to develop a signal processing algorithm for the Arduino Uno that effectively filters noise from PPG signals, accurately identifies systolic and diastolic peaks, and extracts relevant features (e.g., peak
ratios) for estimation of blood parameters.

5. Another object of this invention is to develop a mapping algorithm that accurately correlates processed PPG signal features with corresponding
cholesterol and hemoglobin levels, utilizing pre-defined mathematical relationships or calibration tables stored in the Arduino's memory for individual parameter estimation..

6. Another object of this invention is to provide a clear and user-friendly visual representation of estimated cholesterol and hemoglobin levels on an LCD screen.

7. Another object of this invention is Implement code for signal processing,
potential estimation of blood parameters, and LCD display.

8. Another object of this invention is to calibrate the system using reference measurements from blood tests for both hemoglobin and cholesterol.

9. Another object of this invention is to validate the system's accuracy through testing with various subjects and lighting conditions.

BRIEF SUMMARY OF THE INVENTION
The invention presents a system for non-invasive cholesterol and hemoglobin level assessment using photo plethysmography (PPG). LEDs emit specific wavelengths of light that interact with hemoglobin and cholesterol in blood. The Trans Impedance
Amplifier (TIA) amplifies the photodiode signal, while a Bandpass Filter (BPF) removes noise. The Analog to Digital Converter (ADC) converts the signal for microcontroller processing. Users place their fingers on a finger probe containing photodiodes. The system processes the ADC signal and displays results on an LCD. The Beer-Lambert
law models the relationship between PPG signal intensity and the concentration of hemoglobin and cholesterol in the blood. Linear interpolation is used to calculate the concentration of these substances from the processed PPG signal. The device aims to provide a user-friendly, cost-effective, and portable solution for continuous health monitoring, empowering individuals to improve their health outcomes.

BRIEF DESCRIPTION OF THE RELATED ART

The embodiment of the present invention is illustrated with the help of accompanying drawings.

Figure.1: show the circuit diagram of proposed system.
Figure.2: illustrate the block diagram of proposed system.
Figure.3: show the hardware module of proposed system.
Figure 4: illustrate the result of the system
Figure.4: illustrate the circuit configuration of the proposed system.

The proposed invention offers a novel approach to non-invasively monitoring cholesterol and hemoglobin levels. It utilizes multi-wavelength PPG signals and Arduino technology, LEDs, and photodiodes to measure these crucial physiological is indicators. By analysing PPG signals, the system accurately assesses hemoglobin and cholesterol levels, providing valuable health information to users. This advancement paves the way for earlier disease detection and proactive health management. The development process involves researching PPG principles, understanding its limitations for direct cholesterol and hemoglobin measurement, selecting appropriate components, designing and building the circuit, coding the Arduino for signal processing and estimation, calibrating the system with reference measurements, and finally testing and validating the invention under various conditions.

The main components of a measurement of cholesterol and hemoglobin level using 25 ppg signals, typically include:

1. Light Source
2. Photodetector
3. Signal Amplification
4. Signal Conditioning
5. Analog-to-Digital Converter
6. Microcontroller
7. Power Supply
8. User Interface
9. Finger Probe
10. Enclosure

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWING
1. Light Source:
LEDs (Light-Emitting Diodes) emitting multiple wavelengths (e.g., 600-950nm) to interact with hemoglobin and cholesterol.

2. Photodetector:
Photodiodes to convert the reflected light into an electrical signal.

3. Signal Amplification or Transimpedance Amplifier:
Transimpedance Amplifier (TIA) to amplify the weak photodiode signal.

4. Signal Conditioning:
Bandpass Filter (BPF) to remove unwanted noise and isolate the signal of interest.

5. Analog-to-Digital Converter:
To convert the analog signal from the photodiode into a digital format for processing.

6. Microcontroller:
Arduino Uno or similar microcontroller to handle signal processing, data analysis, and output.

7. Power Supply:
A battery or external power source to provide power to the system.

8. User Interface:
LCD display to display the measured cholesterol and hemoglobin levels.

9. Finger Probe:
A device to hold the user's finger and ensure proper contact with the LEDs and photodiodes.

10. Enclosure:
A case or enclosure to protect the components and provide a user-friendly interface.

Generally, this invention employs LEDs emitting multiple wavelengths of light to interact with blood components and a photodiode to detect the reflected light. The resulting signal is amplified, filtered, and converted to a digital format for processing by a microcontroller. By analysing the PPG signal, the system estimates cholesterol and hemoglobin levels based on their absorption characteristics. This approach offers
a convenient and potentially cost-effective alternative to traditional blood tests.

DETAILED DESCRIPTION OF THE INVENTION:
The light source (1), typically an LED or similar emitter, is positioned on one side of the finger probe, opposite the photodetector. It emits light at specific wavelengths (e.g.,600-950 nm) that can penetrate the skin and interact with hemoglobin and cholesterol molecules in the blood. When the light passes through the tissue, some of it is
absorbed by these molecules, while the remaining light is scattered. The amount of absorption and scattering depends on the concentration of hemoglobin and cholesterol in the blood.

A photodiode (2) is positioned on the opposite side of the fingertip from the light source, facing the user's skin. As the light passes through the finger, some of it is absorbed by hemoglobin and cholesterol, while the remaining light is scattered and reflected back. The photodiode detects the reflected light, converting the light energy into an electrical current. The intensity of this current is proportional to the amount of light that reaches the photodiode, which provides information about the absorption and
scattering properties of the blood within the finger.

The transimpedance amplifier (3) is typically placed between the photodiode and the microcontroller. It acts as a current-to-voltage converter, converting the small current generated by the photodiode into a larger voltage signal. This amplified voltage signal is then easier for the microcontroller to process and analyse. A bandpass filter (4) removes unwanted noise and isolates the frequency range of interest in the PPG signal. The amplified and filtered signal is converted into a digital format using analog to digital converter (5) that the microcontroller can understand.

The microcontroller (6) processes the digital PPG signal, performs calculations to estimate cholesterol and hemoglobin levels, and controls other components of the system. A battery (7) or external power source provides power to the entire system. An LCD screen or other display device (8) shows the measured cholesterol and hemoglobin levels to the user. The finger probe (9) holds the user's finger in place and ensures proper contact with the light source and photodiode. The enclosure (10) houses all the components and provides a protective casing for the device.

METHOD OF PERFORMING THE INVENTION
The light source (1) emits light that penetrates the skin and interacts with hemoglobin and cholesterol in the blood. The specific wavelengths of light are chosen to optimize the interaction with these substances. Hemoglobin and cholesterol absorb and scatter the light, with the amount of absorption and scattering depending on their concentration in the blood.

The photodetector (2), typically a photodiode, converts the reflected light into an electrical current. This current is then amplified into a voltage signal by the transimpedance amplifier (3), making it suitable for processing by the microcontroller. The bandpass filter (4) removes unwanted noise from the PPG signal, improving measurement accuracy. The analog signal is then converted into a digital format for easier processing by the microcontroller. Algorithms are applied to extract relevant features such as peak amplitudes, pulse intervals, and other characteristics related to blood flow and oxygenation.

The system may be calibrated using reference data from blood tests to compare PPG- derived measurements with known cholesterol and hemoglobin levels. Additionally, the rriicrocontroller (6) can employ mathematical models or algorithms to correlate extracted PPG signal features with the concentrations of these substances. These
models can be grounded in empirical data or theoretical principles.

The system provides a clear and understandable display of estimated cholesterol and hemoglobin levels, allowing users to visualize their health data. Additionally, the user interface may offer features such as viewing historical data, setting alerts for abnormal levels, and exporting data for further analysis.

ADVANTAGES:
> It eliminates the need for blood draws, making it less painful and more convenient for users.
> PPG can provide real-time or near-real-time measurements, enabling
continuous tracking of health parameters.
> Regular monitoring can help identify changes in cholesterol or hemoglobin levels early, potentially leading to timely interventions.
> PPG devices can be small and portable, allowing for easy use in various settings.
> Compared to traditional blood tests, PPG measurements can be more costeffective in the long term.

Claim(s)
l/We claim:

1. A system for a measurement of cholesterol and hemoglobin level using ppg signals, comprising:
a light source (1) to interact with hemoglobin and cholesterol;
a photodetector (2) to convert the reflected light into an electrical signal;
a signal amplification or transimpedance amplifier'(3) to amplify the weak photodiode signal;
a signal conditioning (4) to remove unwanted noise and isolate the signal of interest;
an analog-to-digital converter (5) to convert the analog signal from the photodiode into a digital format for processing;
a microcontroller (6) to handle signal processing, data analysis, and output;
a power supply (7) to provide power to the system;
an user interface (8) to display the measured cholesterol and hemoglobin levels;
a finger probe (9) to hold the user's finger and ensure proper contact with the light source and photodiode; an enclosure (10) to protect the components and provide a user-friendly 25 interface.

2. The method of claim 1, wherein the light source (1) is configured to emit light at multiple wavelengths selected to maximize the absorption of light by hemoglobin and cholesterol.

3. The method of claim 1, wherein the photodetector (2) is configured to have a high sensitivity to the wavelengths of light emitted by the light source.

4. The method of claim 1, wherein the signal amplification (3) or transimpedance amplifier is configured to have a bandwidth that is sufficient to capture the highfrequency components of the ppg signal.

5. The method of claim 1, wherein the signal conditioning (4) has a cutoff frequency that is selected to pass the frequency components of the ppg signal that are most informative for measuring cholesterol and hemoglobin levels.

6. The method of claim 1, wherein the analog-to-digital converter (5) has a high resolution and a low sampling rate that is sufficient to capture the relevant features of the ppg signal.

7. The method of claim 1, wherein the microcontroller (6) is configured to run a
signal processing algorithm that is specifically designed for extracting cholesterol and hemoglobin levels from ppg signals.

8. The method of claim 1, wherein the finger probe (9) is configured to minimize the amount of ambient light that can interfere with the ppg measurement.

9. A method for measurement of cholesterol and hemoglobin level using ppg signals, comprising the steps of:
a. illuminating tissue of a user with light at multiple wavelengths;
b. detecting reflected light from the tissue using said photodetector (2);
c. amplifying the detected light signal using said transimpedance amplifier (3);
d. filtering the amplified signal using a bandpass filter;
e. converting the filtered signal to a digital format using said analog-todigital converter (5);
f. processing the digital signal using said microcontroller (6) to extract parameters indicative of cholesterol and hemoglobin levels; and
g. displaying the extracted parameters.


Dated this: 15th day of November 2024
(Signature of the Applicant)

(SRI MANAKULA VINAYAGAR ENGINEERING COLLEGE)
(Dr.V.S.K. VENKATAC HAL APATHY, Director cum Principal)

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