WO2023283312A1

WO2023283312A1 - Non-invasive arterial tonometry system and method using cellular polypropylene film sensors

Info

Publication number: WO2023283312A1
Application number: PCT/US2022/036321
Authority: WO
Inventors: Yukiko FUKUDA; Yasuyuki Kataoka; Hitonobu Tomoike; Hidekazu Kodama; Yoshinobu Yasuno
Original assignee: Ntt Research, Inc.; Kobayasi Institute Of Physical Research
Priority date: 2021-07-09
Filing date: 2022-07-07
Publication date: 2023-01-12

Abstract

A non-invasive tonometric measurement of instantaneous arterial pressure may be performed using a cellular polypropylene (CPP) film sensor, with a first side and a second side, the CPP sensor in communication with an integrated circuit, wherein the circuit is in communication with a first electrode on the first side of the CPP film and wherein the circuit is in communication with a second electrode on the second side of the CPP film; wherein the system is configured to measure arterial pulses. A technique is disclosed for the measurement of simultaneous arterial pulses. A technique is also disclosed for continuous blood pressure monitoring.

Description

NON-INVASIVE ARTERIAL TONOMETRY SYSTEM AND METHOD USING CELLULAR POLYPROPYLENE FILM SENSORS

CROSS REFERENCE

[0001] This application claims priority from US Provisional application 63/220,274, filed 09 July 2021 , the entirety of which is hereby incorporated by reference.

FIELD

[0002] The disclosure relates to measuring arterial pulses or continuous blood pressure using tonometry and in particular to measuring arterial pulses or continuous blood pressure using a cellular polypropylene (CPP) film sensor.

BACKGROUND

[0003] Hypertension is the most common modifiable risk factor for cardiovascular diseases. Epidemiological and clinical studies have shown a strong association between hypertension and adverse cardiovascular events. Ameliorating high blood pressure is crucial to prevent clinical events related to cardiovascular diseases. The measurement of blood pressure (BP) is nowadays one of the popular maneuvers in healthcare.

[0004] The gold standard of BP measurement has been a sphygmomanometer with an inflatable cuff on the upper arm, listening to the Korotkoff sound with a stethoscope or applying an electrical oscillometric technique. The non-invasive sphygmomanometer provides both systolic BP (SBP) and diastolic BP (DBP) intermittently, while an invasive BP measurement method is commonly used in operating rooms or ICU using a catheter to measure the BP continuously.

[0005] The non-invasive arterial tonometry was invented in 1963. The instantaneous measurements of arterial blood pressure using this method have been developed to quantify arterial wall characteristics, including pulse wave velocity (PWV), central arterial pressure, and augmentation index. However, many arterial tonometers available for clinical examinations are limited to a hand-held device and a rather large wrist-type device using an array of piezoresistive pressure transducers.

[0006] Recently, several applications using cellular polypropylene films have been reported with a high constant piezoelectric d33-coefficient over 100 pC/N, and a significant linear frequency response from 10 Hz to 5 kHz, indicating a high sensitivity to strain toward the thickness direction. [0007] Thus, it is desirable to provide a tonometry system and method that uses a cellular polypropylene (CPP) film, and it is to this end that the disclosure is directed.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIGS 1A and IB illustrate an example of tonometry;

[0009] FIGS 2A and 2B are a block diagram of an embodiment of a CPP sensor and a side view of the CPP sensor in an arterial pulse measurement system/device;

[0010] FIG. 3 illustrates an embodiment of a tonometry system using a CPP sensor for measuring arterial pulses;

[0011] FIG. 4 illustrates an embodiment of a tonometry system using CPP sensors for measurement of simultaneous arterial pulses;

[0012] FIG. 5 illustrates results from the simultaneous measurement of arterial pulses using the system in FIG. 4;

[0013] FIG. 6 illustrates an embodiment of a tonometry system using a CPP sensor for continuous monitoring of blood pressure;

[0014] FIGS 7A and 7B illustrate a smartwatch embodiment of the CPP sensor; and

[0015] FIG. 7C illustrates an example of a user interface of the smartwatch embodiment of the CPP sensor.

DETAILED DESCRIPTION OF ONE OR MORE EMBODIMENTS

[0016] The disclosure is particularly applicable to an arterial pulse measurement system that uses a cellular polypropylene film (CPP) sensor, and it is in this context that the disclosure will be described. It will be appreciated, however, that the system and method may also be used for simultaneous arterial pulse measurement and continuous blood pressure monitoring as described below and may further be used in any other situation in which it is desirable to measure arterial pulses. Furthermore, while the contemplated uses below are medical, the device and method may be used for non-medical uses such as being able to measure arterial pulses for other reasons. Before describing the embodiments, the principle of tonometry is discussed.

Principles of Tonometry

[0017] Figures 1A and IB illustrate an example of tonometry in which FIG. 1A shows the characteristics of a cylindrical tube and FIG. IB illustrates a sensor being used to perform tonometry to an artery. Using tonometry on an artery (to measure arterial pulse(s)) requires a flattening of a measurement site of the artery as shown in FIG. IB. As shown in FIG. 1 A, a cylinder, such as an artery, has a circumferential wall tension T that is derived from the external pressure (P₀), the curvature radius of the external vascular wall (r₀), the intravascular pressure (Pi), and the curvature radius of the internal vascular wall (n), based on the law of Laplace, and thus:

T — PiTi-P_oTo (1)

Pi = rJriP_o + T/n (2)

[0018] When the artery is flattened as shown FIG. IB by a sensor, the r becomes infinity by external pressure P₀ (P_c in FIG. 1), and equation (2) can be calculated as

T/ = 0, n/r, = 1 (3)

[0019] Based on equations (2) and (3), the following equation can be expressed.

Pi = Po (4)

[0020] In other words, if the blood vessel is pressed against a hard tissue, such as bone, the upper wall of the blood vessel can be pushed down by an appropriate force from the upper part with the pressure applied to the CPP sensor flattens exactly that part of the blood vessel, and the pressure sensed by the CPP sensor equals those of the intravascular pressure. Such a representative state may be referred to as tonometric condition, referring to how a tonometry system operates to be able to measure an arterial pulse.

[0021] Figures 2A and 2B are a block diagram of a CPP sensor 204 and a side view of the CPP sensor in an arterial pulse measurement system/device. As shown in FIG. 2A, the CPP sensor 204 may have an integrated circuit 204A that is connected to an electrode 204B on each side of a piece of cellular polypropylene (CPP) film 204C. The CPP sensor 204 may have electric shielding materials that protect the integrated circuit electrodes and film and a flexible coating material 204D that attaches to against a skin surface. Each electrode 204B may be made of aluminum, gold, silver or a conductive ink. The flexible coating material 204D may be made of room- temperature-vulcanizing silicone (RTV) silicone (FC-112) , urethane, or rubber. The flexible coating material 204D may be spray coated. The sensor 204 may be an overall thickness of approximately 1mm, a diameter of 10mm, and a weight of lg.

[0022] The CPP sensor film 204C may be or include a piezoelectric material that is sensitive to dynamic forces to their surface with a high piezoelectric dss coefficient. The dss coefficient quantifies the amount of electricity change in the sensor when a vertical force is applied to the device. For the definition of the

coefficient, the output charge of sensor Q_out can be written as,

Q_out— dssF (5) where Qout is generated charge and F is applied force to the device. When the capacitance C is given, the output voltage AY_out of the Cellular PP sensor 204 can be calculated as

D V ou_t - (1/C) Qout - (1/C) d AF (6)

[0023] The Cellular PP film 204C may have a thickness between 50 and 100 pm and may preferably be a commercially available 60 pm having electrodes on front and back surfaces. As discussed above, the CPP film 204C may be sandwiched between two electrodes 204B that each have a thickness, such as 13 pm. In some examples, each electrode 204B may be formed by evaporation or sputtering of metals such as gold, silver, and aluminum. It can also be replaced with conductive ink printing. Although the material of conductive ink could be made of any number of things, silver paste and carbon ink are examples, and the shape of electrodes can be formed using a screen mesh. 204 D and 204 B are physically the same, and when vibration is given to 204 D, force is applied to 204 B.

[0024] FIG. 2B shows the CPP sensor 204 placed against part of a living body 206 (such as a limb, foot, toe, etc. of a human being). The CPP sensor 204 may be placed adjacent to an artery 208 wherein the artery is pressed against a bone 210 in the human body to measure the arterial pulses by tonometry using the CPP sensor 204.

[0025] FIG. 3 illustrates an embodiment of a tonometry system 300 using a CPP sensor for measuring arterial pulses in a living organism 206. In the example in FIG. 3, the living organism is a human being, but could also be an animal, for example. The system 300 may include a cellular polypropylene film (CPP) sensor 204 that is placed close to the artery, such as on a limb of a human as shown in FIG. 3, and the arterial pulse/pressure is measured. In one embodiment, the CPP sensor 204 may be adhered to a strap that is placed around the limb or other part of the body. The system may also have a wire or set of wires 302 that connect the CPP sensor 204 to a device 304 that includes an arterial pulse/pressure measurement system 306. The wire or set of wires 302 may communicate commands and measurement data between the sensor 204 and the device and may also provide power to the CPP sensor 204 as needed. The device 304 may have a processor and memory and a plurality of lines of instructions executed by the processor that perform the arterial pulse measurement system 306 processes and a display to display the results of the measurement. In another embodiment, device 304 and arterial pulse measurement system 306 are a single device. The arterial pulse measurement system 306 receives the measurement signals from the CPP sensor 204, processes those signals and generates a visual display of the measurement data and/or generates measurement data that may be displayed/viewed on a different device. The system 306 may also control the operation of the CPP sensor 204 and provide power if needed to the CPP sensor 204.

[0026] FIG. 4 illustrates an embodiment of a tonometry system 400 using CPP sensors for the measurement of simultaneous arterial pulses. In this embodiment, two or more CPP sensors 204 are attached/secured to different part of a living organism 202, such as human, as shown, although the living organism could also be an animal, for example. The two or more cellular polypropylene film (CPP) sensors 204 may each be placed close to the artery, such as one on each limb of a human as shown in FIG. 3, and the arterial pulse/pressure of each artery is simultaneously measured. In one embodiment, each CPP sensor 204 may be adhered to a strap that is placed around the limb or other part of the body. The system may also have a wire or set of wires 206 that connect each CPP sensor 204 to a device 208 that includes a simultaneous arterial pulse/pressure measurement system 402. The wire or set of wires 206 may communicate commands and measurement data between the sensor 204 and the device and may also provide power to the CPP sensor 204 as needed. The device 208 may have a processor and memory and a plurality of lines of instructions executed by the processor that perform the arterial pulse measurement system 402 processes and a display to display the results of the measurement. In another embodiment, device 208 and arterial pulse measurement system 402 are a single device. The arterial pulse measurement system 302 receives the measurement signals from the CPP sensors 204A-C, processes those signals and generates a visual display of the measurement data and/or generates measurement data that may be displayed/viewed on a different device. The system 402 may also control the operation of the CPP sensor 204 and provide power if needed to the CPP sensor 204. The measurement of simultaneous pressure waveforms at multiple arteries may be used to then measure/monitor pulse wave velocity that can be used to diagnose issues with hypertension or blood pressure of a patient.

[0027] FIG. 5 illustrates results from the simultaneous measurement of arterial pulses using the system in FIG. 4 in which a CPP sensor may be connected to a patient, for example, adjacent the brachial artery, the radial artery and the dorsalis artery as shown in FIG. 5. The simultaneous measurement of the arterial pulses is possible since the CPP sensor is very small and lightweight in contrast to the large unwieldy conventional systems. As shown in FIG. 5, the system may be used to measure the elapsed time (the As shown in FIG. 5) from the QRS peak of ECG to the start of the arterial pulse was 0.113+0.008 sec; 0.135+0.005 sec; and 0.217+0.004 sec for the brachial, radial, and dorsalis pedis arteries, respectively from the stable ten waveform while the heart rate was 71bpm. All waveforms included three prominent characteristics of each arterial pulse, such as the percussion wave, tidal wave, and dicrotic wave. The elapsed times measured above may be used to determine the pulse wave velocity (PWV). The PWV measurement indicates a stiffness of the artery that is one of the major CV risk factors. Thus, the CPP system can be used to monitor/measure arterial waves and thus used for various medical diagnostic or monitoring applications including measuring/monitoring blood pressure. For example, monitoring the change of the shape of the arterial pulse might enable to evaluate the effect of antihypertensive drugs because the arterial waveform contains very important information such as the arterial stiffness. Furthermore, these measures relate to the stiffness and compliance of the arterial system which represents the level of atherosclerosis or aging and might provide an option for antihypertensive agents.

[0028] FIG. 6 illustrates an embodiment of a tonometry system 600 using a CPP sensor for continuous monitoring of blood pressure. In this embodiment, the system 600 may have one or more CPP sensors 204 are attached/secured to different part of a living organism 206, such as a human as shown, although the living organism could also be an animal, for example. The example in FIG. 6 shows a single CPP sensor 204, but the system may use multiple CPP sensors 204 as was described above with reference to FIG. 4. In this embodiment, the one or more CPP sensors 204 may each be placed adjacent to an artery, such as one on each limb of a human as shown in FIG. 4, and the arterial pulse/pressure of each artery is simultaneously measured. The data about each arterial pulse/pressure in each artery may be used to determine a continuous blood pressure of the user. Note that since each CPP sensor 204 is fairly small and lightweight, the system 600 in FIG. 6 may be a wearable system that is able to continuously monitor/measure the blood pressure of a patient.

[0029] In one embodiment, each CPP sensor 204 may be adhered to a strap that is placed around the limb or other part of the body like the foot of the patient as shown in FIG. 4. The system may also have a wire or set of wires 306 that connects each CPP sensor 204 to a device 208 that includes a continuous blood pressure monitoring/measuring system 602. The wire or set of wires 306 may communicate commands and measurement data between the sensor 204 and the device and may also provide power to the CPP sensor 204 as needed. The device 208 may have a processor and memory and a plurality of lines of instructions executed by the processor that perform the continuous blood pressure measurement/monitoring system 602 processes and a display to display the results of the measurement. In another embodiment, device 208 and blood pressure monitoring/measurement system 602 are a single device. The blood pressure system 502 receives the measurement signals from the one or more CPP sensors 204, processes those signals and generates a visual display of the blood pressure measurement data and/or generates blood pressure measurement data that may be displayed/viewed on a different device. The system 602 may also control the operation of the CPP sensor 204 and provide power if needed to the CPP sensor 204.

[0030] In each of the embodiments above, the CPP sensor device 204 may be implemented in any computing system with processors and memory capable of carrying out software instructions. One such non-limiting example is a smartwatch format that is shown in Figures 7A and 7B with an example user interface for the smartwatch embodiment 700 shown in FIG. 7C. The smartwatch embodiment 700 may include a smartwatch module 702 that includes a display 704 wherein the smartwatch module 702 is connected to a watch strap 706 that may be attached to a user’s extremity. The smartwatch embodiment 700 may also have a CPP sensor assembly 708 that is connected to/embedded within/attached to the strap 706 at a location, such as opposite the module 702 as shown in FIG. 7A. The location of the CPP sensor 708 relative to the module 702 may be varied.

[0031] FIG. 7B illustrates more details of the smartwatch embodiment 700 with a cutaway side view of the smartwatch module 702 and strap 706 around an extremity, such as an arm or leg, etc., of a user wherein the extremity has an artery and bones against which the artery may be pressed to measure using the CPP sensor 708 as described above. In the example in FIG. 7B, the extremity is an arm of the user that has a radial artery, a radius bone and an ulna bone that run along a length of the arm. The CPP sensor 708 may have the same electronics, etc. inside of a sensor housing as discussed above with the electrodes 710 wherein the CPP sensor 708 in this embodiment further has a wireless circuit 712 and an energy source 714, such as a button battery that provides power to the elements of the CPP sensor 708. The wireless circuit 712 captures the signals the sensor 710 and communicate with a blood pressure monitoring system or other system as discussed above.

[0032] FIG. 7C shows more details of an example of the user interface 7041 of the smartwatch embodiment 700 that may be displayed on the display 704 of the smartwatch 702. The user interface may have a blood pressure monitoring user interface 7041 A that may graphically and textually display the blood pressure over time (both diastolic and systolic) as measured by the CPP sensor embedded/attached to the smartwatch or the smartwatch strap as shown in FIG. 7B. The user interface may also have an arterial stiffness portion 704 IB that displays the current arterial stiffness for the user as calculated based on the signals from the CPP sensor. It is understood that a smartwatch embodiment of the CPP sensor may have other user interfaces or different user interfaces that are all within the scope of this disclosure.

CONCLUSION

[0033] The foregoing description, for purpose of explanation, has been with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated.

[0034] The system and method disclosed herein may be implemented via one or more components, systems, servers, appliances, other subcomponents, or distributed between such elements. When implemented as a system, such systems may include and/or involve, inter alia, components such as software modules, general-purpose CPU, RAM, etc. found in general-purpose computers. In implementations where the innovations reside on a server, such a server may include or involve components such as CPU, RAM, etc., such as those found in general-purpose computers.

[0035] Additionally, the system and method herein may be achieved via implementations with disparate or entirely different software, hardware and/or firmware components, beyond that set forth above. With regard to such other components (e.g., software, processing components, etc.) and/or computer-readable media associated with or embodying the present inventions, for example, aspects of the innovations herein may be implemented consistent with numerous general purposes or special purpose computing systems or configurations. Various exemplary computing systems, environments, and/or configurations that may be suitable for use with the innovations herein may include, but are not limited to: software or other components within or embodied on personal computers, servers or server computing devices such as routing/connectivity components, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, consumer electronic devices, network PCs, other existing computer platforms, distributed computing environments that include one or more of the above systems or devices, etc. [0036] In some instances, aspects of the system and method may be achieved via or performed by logic and/or logic instructions including program modules, executed in association with such components or circuitry, for example. In general, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular instructions herein. The inventions may also be practiced in the context of distributed software, computer, or circuit settings where circuitry is connected via communication buses, circuitry or links. In distributed settings, control/instructions may occur from both local and remote computer storage media including memory storage devices.

[0037] The software, circuitry and components herein may also include and/or utilize one or more type of computer readable media. Computer readable media can be any available media that is resident on, associable with, or can be accessed by such circuits and/or computing components.

By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and can accessed by computing component. Communication media may comprise computer readable instructions, data structures, program modules and/or other components. Further, communication media may include wired media such as a wired network or direct-wired connection, however no media of any such type herein includes transitory media. Combinations of the any of the above are also included within the scope of computer readable media.

[0038] In the present description, the terms component, module, device, etc. may refer to any type of logical or functional software elements, circuits, blocks and/or processes that may be implemented in a variety of ways. For example, the functions of various circuits and/or blocks can be combined with one another into any other number of modules. Each module may even be implemented as a software program stored on a tangible memory (e.g., random access memory, read only memory, CD-ROM memory, hard disk drive, etc.) to be read by a central processing unit to implement the functions of the innovations herein. Or the modules can comprise programming instructions transmitted to a general-purpose computer or to processing/graphics hardware via a transmission carrier wave. Also, the modules can be implemented as hardware logic circuitry implementing the functions encompassed by the innovations herein. Finally, the modules can be implemented using special purpose instructions (SIMD instructions), field programmable logic arrays or any mix thereof which provides the desired level performance and cost.

[0039] As disclosed herein, features consistent with the disclosure may be implemented via computer-hardware, software, and/or firmware. For example, the systems and methods disclosed herein may be embodied in various forms including, for example, a data processor, such as a computer that also includes a database, digital electronic circuitry, firmware, software, or in combinations of them. Further, while some of the disclosed implementations describe specific hardware components, systems and methods consistent with the innovations herein may be implemented with any combination of hardware, software and/or firmware. Moreover, the above- noted features and other aspects and principles of the innovations herein may be implemented in various environments. Such environments and related applications may be specially constructed for performing the various routines, processes and/or operations according to the invention or they may include a general-purpose computer or computing platform selectively activated or reconfigured by code to provide the necessary functionality. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and may be implemented by a suitable combination of hardware, software, and/or firmware. For example, various general-purpose machines may be used with programs written in accordance with teachings of the invention, or it may be more convenient to construct a specialized apparatus or system to perform the required methods and techniques.

[0040] Aspects of the method and system described herein, such as the logic, may also be implemented as functionality programmed into any of a variety of circuitry, including programmable logic devices ("PLDs"), such as field programmable gate arrays ("FPGAs"), programmable array logic ("PAL") devices, electrically programmable logic and memory devices and standard cell-based devices, as well as application specific integrated circuits. Some other possibilities for implementing aspects include memory devices, microcontrollers with memory (such as EEPROM), embedded microprocessors, firmware, software, etc. Furthermore, aspects may be embodied in microprocessors having software -based circuit emulation, discrete logic (sequential and combinatorial), custom devices, fuzzy (neural) logic, quantum devices, and hybrids of any of the above device types. The underlying device technologies may be provided in a variety of component types, e.g., metal-oxide semiconductor field-effect transistor ("MOSFET") technologies like complementary metal-oxide semiconductor ("CMOS"), bipolar technologies like emitter-coupled logic ("ECL"), polymer technologies (e.g., silicon-conjugated polymer and metal- conjugated polymer-metal structures), mixed analog and digital, and so on.

[0041] It should also be noted that the various logic and/or functions disclosed herein may be enabled using any number of combinations of hardware, firmware, and/or as data and/or instructions embodied in various machine-readable or computer-readable media, in terms of their behavioral, register transfer, logic component, and/or other characteristics. Computer-readable media in which such formatted data and/or instructions may be embodied include, but are not limited to, non-volatile storage media in various forms (e.g., optical, magnetic or semiconductor storage media) though again does not include transitory media. Unless the context clearly requires otherwise, throughout the description, the words "comprise," "comprising," and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of "including, but not limited to." Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words "herein," "hereunder,"

"above," "below," and words of similar import refer to this application as a whole and not to any particular portions of this application. When the word "or" is used in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list.

[0042] Although certain presently preferred implementations of the invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various implementations shown and described herein may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the applicable rules of law.

[0043] While the foregoing has been with reference to a particular embodiment of the disclosure, it will be appreciated by those skilled in the art that changes in this embodiment may be made without departing from the principles and spirit of the disclosure, the scope of which is defined by the appended claims.

Claims

CLAIMS What is claimed is:

1. A system, comprising: a cellular polypropylene film (CPP) sensor, with a first side and a second side, the CPP sensor in communication with an integrated circuit, wherein the circuit is in communication with a first electrode on the first side of the CPP film and wherein the circuit is in communication with a second electrode on the second side of the CPP film; wherein the system is configured to measure arterial pulses.

2. The system of claim 1 wherein the CPP sensor includes electric shielding materials configured to protect the integrated circuit and electrodes.

3. The system of claim 2 wherein the CPP sensors include a flexible coating material configured to attach to a skin surface.

4. The system of claim 1 wherein the first electrode and the second electrode are made of at least one of aluminum, gold, and silver.

5. The system of claim 1 wherein the first electrode and the second electrode are made of conductive ink.

6. The system of claim 3 wherein the flexible coating is made of at least one RTV silicone, urethane, and rubber.

7. The system of claim 3 wherein the flexible coating is spray coated.

8. The system of claim 1 wherein the CPP sensor has an overall thickness of approximately 1 mm.

9. The system of claim 1 wherein the CPP film has an overall thickness between 50 and 100 pm.

10. The system of claim 1 wherein the CPP film has an overall thickness of approximately 60 pm.

11. The system of claim 1 wherein each of the first electrode and second electrode has an overall thickness of approximately 13 pm.

12. The system of claim 1 wherein each of the first electrode and second electrode are formed by evaporation or sputtering of metals.

13. The system of claim 12 wherein each of the first electrode and second electrode are made of at least one of gold, silver, and aluminum.

14. The system of claim 12 wherein each of the first electrode and second electrode are made of conductive ink.

15. The system of claim 14 wherein each of the first electrode and second electrode conductive ink are made of at least one of silver paste and carbon ink.

16. The system of claim 1 wherein each of the first electrode and second electrode are formed by using a screen mesh.

17. The system of claim 1 wherein the CPP sensor is adhered to a strap configured to be placed around a body part.

18. The system of claim 1 wherein the sensor is configured to determine elapsed time from sensed QRS peak of an electrocardiogram, the elapsed time used to determine a pulse wave velocity (PWV) to determine arterial stiffness.

19. The system of claim 1 wherein the sensor is configured to monitor a change of shape of an arterial pulse waveform to determine arterial stiffness.

20. A method, comprising: receiving data at a computer regarding arterial pulse/pressure in two arteries of a user from a cellular polypropylene film (CPP) sensor, with a first side and a second side, the CPP sensor in communication with an integrated circuit, wherein the circuit is in communication with a first electrode on the first side of the CPP film placed on a first of the two arteries of the user and wherein the circuit is in communication with a second electrode on the second side of the CPP film placed on a second of the two arteries of the user; and determining a continuous blood pressure of the user using the received arterial pulse/pressure data.

21. The method of claim 20 wherein the CPP sensor is adhered to a strap that is configured to be placed around a limb or other part of the body of the user.

22. The method of claim 21 wherein the strap is a watch strap and the computer is a smartwatch computer.