FIELD OF THE INVENTION

The present invention relates to a photoplethysinogram (PPG) based blood pressure and heart rate measurement integrated mobile phone. More particularly, the present invention relates to an integration of heart-rate and blood pressure sensor with printed circuit board of mobile phone to give accurate results of the heart rate and diastolic, systolic blood pressure.
BACKGROUND OF THE INVENTION
Among the physiological signs of a human body, blood pressure and heart rate are considered as vital signs which represents the physiological and physical status of a human body. According to medical definitions the force that moves blood through circulatory system for the body is known as blood pressure. There is normal range of blood pressure which is necessary to maintain delivery of white blood cells along with antibodies for immunity and balancing level of hormones. The speed of the heartbeat evaluated by the number of contractions of the heart per minute is termed as heart rate. The heart rate can fluctuate according to the body's physical needs, together with the need to absorb oxygen and evacuate carbon dioxide.
The measurement of blood pressure is made of two values i.e. systolic blood pressure and diastolic blood pressure. When the heart beats and the heart muscles contract for pumping oxygen rich blood into the blood vessels, the pressure is termed as systolic blood pressure whereas, the pressure when the heart muscles relax is known as diastolic blood pressure. Several kinds of devices and techniques are available in the public domain for measuring blood pressure. One such device is sphygmomanometer for monitoring the blood pressure that is made up of an inflatable cuff for collapsing and releasing the artery under the cuff in a meticulous manner along with an aneroid manometer for pressuring the pressure. In current times both manual and digital sphygmomanometer are used according to conditions. One such

method is auscultatory method that uses mercury sphygmomanometer which is viewed as the 'gold standard' for office blood pressure measurement. But extensive use of mercury sphygmomanometers is banned as this method is less accurate and often needs frequent calibration.
Another such method is oscillometric method in which oscillations initiated around a systolic pressure and endured below diastolic, so that systolic and diastolic pressure can only be valued indirectly to some empirically derived protocols. The oscillometric method is beneficial as there is no necessity of a transducer over the brachial artery which make it less susceptible to external noise. However, the foremost disadvantage is that such method does not work well during any kind of physical activity when there may be substantial movement artifacts. Another method for measuring blood pressure is ultrasound method, the devices for measuring blood pressure based on ultrasound method make a use of an ultrasound transmitter and receiver that is placed over the brachial artery under a sphygmomanometer cuff. The disadvantage of this technique is that during any movement of the human body, the ultrasonic path changes which leads to inaccurate results.
The current available blood pressuring and heart rate monitoring device, methods provide less accurate results, associated with heavy cost and need of special skills for proper use. Moreover, for measuring blood pressure and heart rate, people have to purchase separate devices which is expensive in nature, and every individual could not afford multiple devices for measuring some vital physiological signs, also the available devices are complex to use and can only be operated by medical practitioners which make the daily monitoring of health difficult and expensive.
JP2012157435A teaches about a sphygmomanometer worn on an arm or the like, and more particularly to a sphygmomanometer that can record information about the body of a subject before blood pressure measurement that comprises of a microwave generator and a microwave receiver, and at

least one of a pulse and a breath of a measurement subject is detected from a Doppler-shifted reflected wave detected by the microwave receiver, and the detection is performed. The drawback of this sphygmomanometer is the generation of microwave pulses which may transiently increase the arterial blood pressure and decrease the heart rate. Also, any movement in the arm from where the sphygmomanometer is attached to the wrist of the left arm of the person may alter the measurements.
JP2014068824A describes about an electronic blood pressure monitor and a control method that comprise of an electronic sphygmomanometer to detect a volume of an artery in a blood pressure measurement site with a first arterial volume detection unit in a state where the blood pressure measurement site of the measurement subject is compressed with a cuff, and detects the blood pressure measurement site. The disadvantages of this electronic blood pressure monitor and a control method are high sensitivity, high cost, and operation only by a medical practitioner and incorrect readings once in a while which leads to requirement of regular counter check.
US20170245769A1 teaches about devices and methods for estimating blood pressure using intelligent oscillometric blood pressure measurement techniques, where some implementations of the devices include multiple biometric sensors that can obtain sensor data from a connected device. In some implementations, the devices automatically determine an identity of a user. In some implementations, the devices automatically provide instructions to users to take blood pressure measurements. The disadvantages of this device and method include difficulty in accurately reading the oscillometric curves, high sensitivity towards movements due to the bandwidth of the signals, so the arm must be immobile and the accuracy of the systolic and diastolic pressure totally depends on the protocol used.
Therefore, there is a need of a cost effective and affordable technology that enables accurate and regular measurement and monitoring of blood pressure

along with heart rate to the people deficient of basic amenities around them which is convenient in use eliminating need of a medical practitioner to read and interpret their health condition and can be carried along comfortably. Further, there is a need of a device with integrated blood pressure and heart rate measurement unit that consequently eliminates the need of maintaining multiple devices for measuring heart rate along with blood pressure.
OBJECT OF THE INVENTION
The main object of the present invention is to provide a photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone.
Another object of the present invention is to provide a photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone in order to eliminate the need of maintaining multiple devices for measuring heart rate and blood pressure.
Yet another object of the present invention is to provide a mobile phone with a customized printed circuit board assembly for integrating a high accuracy heart rate sensor to identify pulsatile blood flow accurately.
Yet another object of the present invention is to provide a compact and customized integrated chip along with an ambient light sensor inside a mobile phone for measuring heart rate and blood pressure accurately.
Still another object of the present invention is to provide a
photoplethysmogram (PPG) based blood pressure and heart rate
measurement integrated mobile phone that works on average of multiple
results in order to produce accurate readings.
SUMMARY OF THE INVENTION

The present invention relates to a mobile phone integrated with a high accuracy heart rate and blood pressure sensor that works on photoplethysmogram (PPG) and eliminates the need of maintaining multiple devices for measuring heart rate and blood pressure and has an ambient light source for reflecting light rays into human skin for measuring blood pressure and heart rate in a simpler way.
In an embodiment, the present invention provides a mobile phone with integrated photoplethysmogram (PPG) based heart rate and blood pressure sensor. The invention comprises a low power consuming customized printed circuit board assembly of mobile phone along with an integrated chip with at least one ambient light sensor, a green light emitting diode (LED), an analog to digital converter and a heart rate sensor to give accurate results of the heart rate and diastolic and systolic blood pressure. The green LED emits light rays onto a user's skin and the ambient light sensor measures the amount of rays reflected back from the skin and being absorbed by the photo-diode. The green LED is driven by an integrated current driver inside the mobile phone. The ambient light source cancellation is improved for accurate results. The integrated current driver provides a regulated current sink on terminal of a resistor that eliminated the need for an external current limiting resistor. The register setting sets the sink current from 12.5 mA to 40 mA. The heart rate sensor uses a specific technique to suppress background noise effectively. Further, the customized printed circuit board assembly functions on an algorithm calibrated to measure pulsatile blood flow and use at least five readings to average out and reduce the error.
In another embodiment, the ambient light sensor is customized to work on low currents for providing accurate results. The result in register and control are accomplished through an I2C serial compatible interface to a set of registers that provide access to control functions and output data.

The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
An understanding of the device of the present invention may be obtained by reference to the following drawings:
Figure 1 is a circuit diagram of customized printed circuit board assembly of a mobile phone with integrated photoplethysmogram (PPG) based heart rate and blood pressure sensor.
Figure 2 shows a perspective of the mobile phone with integrated photoplethysmogram (PPG) in accordance with the present invention.
Figure 3 shows standard writing and reading protocol supported by the heart rate sensor in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Many aspects of the invention can be better understood with references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The embodiments of the invention are capable of being practiced and carried out in various ways. In addition, the phraseology and terminology

employed herein are for the purpose of description and should not be regarded as limiting.
The present invention relates to a mobile phone integrated with high accuracy heart rate and blood pressure sensor based photoplethysmogram (PPG) for eradicating the urge of maintaining multiple devices for measuring heart rate along with blood pressure and have a customized printed circuit board assembly of mobile phone along with integrated chip with an ambient light source for reflecting light rays into human skin for measuring blood pressure and heart rate in a simpler way.
In an embodiment, the present invention provides a mobile phone with integrated photoplethysmogram (PPG) based heart rate and blood pressure sensor. The invention comprises a low power consuming customized printed circuit board assembly of mobile phone along with integrated chip with at least one ambient light sensor, a light emitting diode (LED), an analog to digital converter and a heart rate sensor to give accurate results of the heart rate and diastolic and systolic blood pressure. The ambient light source emits light rays onto a user's skin and the sensors measure the amount of rays reflected back from the skin and being absorbed by the photo-diode. The green light emitting diode has a wavelength of 525 nm. The LED is driven by an integrated current driver inside the mobile phone. The ambient light source cancellation is improved for accurate results. The current driver provides a regulated current sink on terminal of a resistor that eliminated the need for an external current limiting resistor. The register setting sets the sink current from 12.5 mA to 40 mA. The heart rate sensor uses a specific technique to suppress background noise effectively. To reduce noise, a digital filter based on equi-ripple finite impulse filter is used. The filter helps to suppress the noise with minimum order. Further, the customized printed circuit board assembly functions on an algorithm calibrated to measure pulsatile blood flow and uses at least five readings to average out and reduce the error. The customized printed circuit board is such that it supports and the analog to digital converter

works on low current. Low dropout regulator (LDO) has been optimized for use with the customized printed circuit board. The customization of printed circuit board includes customization to accommodate the heart rate sensor, customization of algorithm, calibration to give accurate results and modification for compactness to work inside mobile phone.
In another embodiment, the ambient light source is customized to work on low currents for providing accurate results. The result in register and control are accomplished through an I2C serial compatible interface to a set of registers that provide access to control functions and output data.
Figure 1, shows a circuit diagram of customized printed circuit board assembly of mobile phone with integrated photoplethysmogram (PPG) based heart rate and blood pressure sensor. The customized printed circuit board assembly 1 with ambient light sensor is associated with the analog to digital converter along with the heart rate sensor 2. The user of mobile phone touches the phone by a finger and the green light emitting diode emits multiple light rays on to the finger upon emission some light rays are absorbed, and some are reflected back to ambient light sensor. The reflected rays are evaluated by the sensors for producing the accurate results, wherein the heart rate sensor 2 uses a specific technique for suppressing background noise and the heart rate sensor supports the standard writing and reading protocol. The result in register and control are accomplished through an I2C serial compatible interface 3 to a set of registers that provide access to control functions and output data. The register index will automatically increase by 1 after the addressed register has been accessed (read or write). Since the light is reflected by which pulsatile blood flow is measured, it takes multiple results average outs the results. If the finger is not placed properly the results could vary.
The green light emitting diode 6 is driven by an integrated current driver 4 that provides a regulated current sink on the LDR terminal 5. The green light

emitting diode 6 is provided below the camera unit of the mobile phone at the rear side of phone as shown in Figure 2. The register setting i.e. PDRTVE register setting (PDRTVE[1] register 0x01, bit 3, PDRIVE[0] register OxOC, bit 6) sets the sink current from 12.5 mA to 40 mA. The analog to digital converter of heart rate sensor converts a value and stores the result in (CHODATAx) register and controls are accomplished through an I2C serial compatible interface to a set of registers that provide access to device control functions and output data. The heart rate sensor is preferably HRS3306 chip with address of 0x44 supporting the 7-bit I2C addressing protocol. The heart rate sensor supports the standard writing and reading protocol as shown in Figure 3 with following interpretation
a. A Acknowledge (0)
b. P Stop Condition
c. R Read (1)
d. S Start Condition
e. W Write (0)
Sr Repeated Start Condition ■ Master-to- Slave □ Slave-to-Master
EXAMPLE 1 EXPERIMENTAL ANALYSIS
For a set of 50 people, the systolic and diastolic blood pressure and heart rate are measured over a time with multiple data sets using photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile

phone provided by the present invention and a manual sphygmomanometer for comparative analysis out which some 75 result sets are shown in Table 1.
Table 1 Comparative Analysis

SN Manual Sphygmomanometer Photop
(PPG)
pressure
measur
mo lethysmogram based blood and heart rate
ing integrated
rile phone

High BP Low BP HR High BP Low BP HR
1# 116 72 72 101 66 71

122 77 71 93 52 72

116 72 71 104 66 73
2# 111 69 60 118 85 64

108 67 58 107 76 63

104 74 63 108 73 60
3# 120 80 82 111 74 89

126 74 88 112 78 88

122 81 83 116 71 83
4# 114 71 70 100 78 76

113 70 69 104 79 70

128 70 77 101 81 72
5# 110 70 67 123 77 70

114 62 71 125 68 76

114 69 74 128 70 77
6# 117 71 77 120 80 80

108 67 85 131 77 90

108 59 83 125 73 87
7# 99 52 66 108 77 66

96 56 66 107 76 65

96 52 64 105 75 64
8# 100 60 68 122 76 72

101 58 75 108 70 78

100 53 77 122 76 75

9# 105 73 84 125 68 80

112 71 81 125 73 86

108 74 82 119 79 81
10# 128 76 75 128 78 79

131 78 72 122 81 78

133 77 80 131 72 80
11# 117 76 98 131 77 90

118 74 96 137 81 94

113 73 98 129 76 92
12# 115 75 80 134 79 82

99 71 91 137 81 94

103 71 83 111 69 79
13# 110 79 81 125 75 82

119 76 81 129 75 81

120 72 88 112 78 89
14# 123 74 68 119 74 70

105 81 77 113 70 73

102 81 70 110 69 72
15# 132 85 72 120 75 74

123 89 70 123 77 74

116 85 73 128 70 78
16# 130 90 87 126 74 87

128 80 84 120 80 83

104 72 79 120 80 74
17# 105 78 71 111 69 68

115 79 83 126 69 77

117 78 77 119 74 73
18# 100 59 75 108 67 76

102 58 82 108 67 78

101 59 76 105 65 74
19# 96 64 74 106 66 79

97 61 76 103 64 80

98 60 73 104 68 78
20# 110 68 81 105 68 88

118 69 80 125 69 82

121 69 80 119 70 83
21# 115 75 69 119 88 68

108 81 71 110 86 75

119 86 66 120 79 66
22# 99 69 72 119 79 73

105 68 77 116 75 77

105 69 70 120 72 69
23# 120 80 71 110 72 72

119 79 73 109 68 76

110 72 71 108 71 72
24# 99 61 85 105 76 82

97 68 81 110 70 80

93 71 80 106 72 79
25# 104 69 86 115 75 90

104 64 84 112 75 85

97 68 91 102 78 92
Average -4% -3% -1%
Further, a variance study is performed to study total variation in which reading of systolic blood pressure (SBP) and diastolic blood pressure (DBP) along with heart rate (HR) is taken as shown in Table 2.
Table 2
Total variation in Systolic Blood Pressure (SBP) and Diastolic Blood
Pressure (DBP) along with Heart Rate (HR)

Total Var.
SBP DBP HR
9% 11% 4%
Tables 3, 4 and 5 depicts an analysis carried over the variance of systolic blood pressure (SBP), diastolic blood pressure (DBP) and the heart rate (HR).

This analysis proves that the accuracy of present invention is higher than the conventional blood pressure and heart rate measuring devices.
Table 3 Variance analysis of Systolic Blood Pressure (SBP)

10%-20%
Less than 5%

5% 10%

SBP Yariance Analysis
Less than (5%)
Above 20%
(5%) (10%)

(10%) (20%)

Above (20%)

9 8 5 2 8 23 19 1
12% 11% 7% 3% 11% 31% 25% 1%
Table 4 Variance analysis of Diastolic Blood Pressure (DBP)

10%-20%
Less
than
5%

5% 10%

DBP Yariance Analysis
Less than (5%)
Above 20%
(5%) (10%)

(10%) (20%)

Above (20%)

8 8 9 3 12 12 18 5
11% 11% 12% 4% 16% 16% 24% 7%
Table 5 Variance analysis of Heart Rate (HR)

Less than 5%

5% 10%

10%-20%

HR Yariance Analysis
Less than (5%)
Above 20%
(5%) (10%)

(10%) (20%)

Above (20%)

22 11 0 0 25 17 0 0
29% 15% 0% 0% 33% 23% 0% 0%

Hence, the present invention has a primary application of a mobile handset not having internet connectivity but enabled with calling and message sending functionality. Secondarily, the present invention is capable of measuring and maintaining the blood pressure and heart rate records of user through this mobile phone. The mobile phone provides alert if the blood pressure or if heart beat is high or low than a threshold value. The mobile phone is even helpful to doctors as the user interface (UI) is easy to comprehend.
The present invention is a cost effective and affordable solution eliminating need of maintaining multiple devices for measuring heart rate and blood pressure. Additionally, the present invention achieves higher accuracy than the conventional devices.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

CLAIMS
We claim:
1. A photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone comprising:
a low power consuming customized circuit board assembly (1) of said mobile phone;
an integrated chip with at least one ambient light sensor;
a light emitting diode (6);
an analog to digital converter; and
a heart rate sensor (2) to measure heart rate, and diastolic and systolic blood pressure;
wherein,
said light emitting diode (6) and the ambient light sensor together act as
the photoplethysmogram;
said light emitting diode (6) emits light rays onto a user's skin and the ambient light sensor measures the amount of rays reflected back from the skin; and
the customized circuit board assembly (1) integrated with ambient light sensor and heart rate sensor function to measure pulsatile blood flow and use at least five readings to average out and reduce error for determining heart rate, diastolic and systolic blood pressure.

2. The photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone as claimed in claim 1, wherein the light emitting diode (6) is a green LED having a wavelength of 525 nm.
3. The photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone as claimed in claim 1, wherein the light emitting diode (6) is driven by an integrated current driver (4) that provides a regulated current sink on a terminal (5) of a resistor.
4. The photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone as claimed in claim 1, wherein the regulated current sink is set from 12.5 mA to 40 mA.
5. The photoplethysmogram (PPG) based blood pressure and heart rate measurement integrated mobile phone as claimed in claim 1, wherein the heart rate sensor (2) uses a digital filter based on Equi-ripple finite impulse filter for suppressing background noise.