Apparatus and Method for Optical Spectroscopy and Bioimpedance Spectroscopy using a Mobile Device Case to Gather Physiological Information

A mobile touchable system for user fitness and health monitoring is presented. The system is designed in one form as a mobile phone case and in another form as integrated in a mobile phone. It encompasses a series of measurement devices, including, but not limited to, arrays of electrodes for bio-impedance analysis, impedance tomography, and electrocardiographs, near-infrared spectroscopy for glucose level measurement, and heart rate monitoring. The touchable system performs incidental measurement in the background each time the user holds the mobile phone and hence enables long term health monitoring without user intervention. The touchable monitoring system further performs targeted spot measurements by following defined procedures. Spot measurement is enhanced through an extension measurement cable. Furthermore, an extension strap along with the mobile touchable system provides detailed activity tracking. The touchable system performs long term health monitoring, and provides early alerts for abnormal condition such as diabetes, dehydration, hypertension, cardiovascular anomalies, breast cancer and prostate cancer.

TECHNICAL FIELD

The present application relates to mobile touchable system for physiological fitness and health monitoring.

BACKGROUND

Health monitoring involves expensive, cumbersome and even painful test procedures. As a result, the majority of the population has sparse and scarce data points about their own body and personal health. For instance, even with breast cancer risk on the rise, a mammogram may be performed only once every 24 months. On the other hand, early detection vastly improves a patient's prognosis. In most cases, people on the verge of diabetes or hypertension (i.e. people with prediabetes or prehypertension) go to a clinic or a medical facility once a year and thus the clinical information is episodic. Daily information on glucose or blood pressure can stop or delay the onset of diagnostic diabetes or hypertension respectively. Most diabetic patients rely on taking blood samples by finger pricking using lancets for glucose level measurements, which again are limited samples and the repetitive procedure itself can be painful.

A number of wearable activity monitoring devices are available on the market, most prominently Apple Watch and a series of FitBit devices. They provide the benefit of continuous measurement. However, these devices mostly record a spot measurement of basic parameters such as heart rate, motion etc. and provide very little insight into the general health of a user. Furthermore, these wearable devices suffer from fading consumer interest because they require skin contact with the wrist and become uncomfortable. On the other hand, the mobile phone has increasingly become an indispensable part of every person's life. A study shows that an average user holds 150 mobile phone sessions each day. The mobile phone is already the most touched device.

There are a wide range of non-intrusive procedures popular in both clinical settings and, more recently, the fitness industry. Bioimpedance analysis is one such procedure. Bioelectrical spectroscopy (BIS) uses mathematical modeling and mixture equations to determine body fat, fat-free mass (FFM), total body water (TBW) consisting of extra-cellular water (ECW) and intra-cellular water (ICW). Body hydration management is a key objective in the sports and fitness world, and has a positive impact on mental functioning and general physiological health maintenance. The ratio of ECW/ICW is a key indicator of tissue health including general inflammation levels. On the other hand, the percentage body fat has a direct impact on the health condition and is in most times a key indicator for several pathophysiological conditions, including breast cancer and prostate cancer.

Other popular non-intrusive procedures include electrocardiogram (EKG), generally performed to treat a clinical condition, that is critical for monitoring information about the structure and function of the heart. Near infrared spectroscopy is another important example of a measurement procedure for blood glucose level monitoring.

Health measurement and monitoring of a clinical condition often involves expensive tests, and there are sparse and scarce data points. On the other hand, current activity tracking systems, most notably wearable products, suffer from over simplistic measurement and improper sensor contact location, mostly involving only heart rate and motion sensing.

SUMMARY

An apparatus and method for optical spectroscopy and bioimpedance spectroscopy using a mobile device case to gather physiological information is disclosed. According to one embodiment, a system comprises a case suitable for use with a mobile device; and a first recess in the case. The first recess has first optoelectronic sensors and first electrodes that facilitate one or more scans. The scans include bioimpedance measurements and optical scans.

DETAILED DESCRIPTION

The touchable phone case design provides sampled measurement of multiple vital body parameters. This enables a big data approach for the user health condition. A single user is analyzed over time for individualized trend analysis. Regular (whether periodic or random) monitoring and feedback allows users to make micro adjustments in behavior on daily basis and macro adjustments of habits over longer periods. These include behaviors and habits in diet, hydration, exercise, and supplements among others. For healthcare patients, body parameters before, during and after the administration of medicine allows for detailed and individualized evaluation of medication effects. Furthermore, statistical analysis can be applied to groups of users with similar backgrounds. Such backgrounds may include similar age, gender, ethnic group and family history. Cross-comparison of the data can lead to insight into individual health risk, and serves as an early alert for abnormal health condition.

For all types of measurements, along with accuracy, reliability is equally important. The large volume of data that the touchable phone case collects helps improve both consistency and precision. Furthermore, not every user touch or measurement may lead to a successful measurement, and accordingly, machine learning is applied to filter out bad measurements as noise. Given the daily data collection, statistical analysis will be applied to detect short- and long-term trend changes in various health care biometrics measures.

FIG. 1depicts a touchable health and activity monitoring system with a mobile phone case, according to one embodiment. Health and activity monitoring system100includes a mobile phone case110and a mobile phone or device101that may be used for collecting and analyzing health and activity data from a user. With minimal or no user interaction, the mobile phone case110collects health and activity data when the user makes contact with the sensors on the case, such as when the user picks up the case. The two main sensor locations are on a side of the case, allowing for the user's finger to rest on a groove-like, finger notch sensor130. The finger notch sensor130houses optical spectroscopy sensors131along with electrodes111. An additional sensor140, such as a bioimpedance sensor, also houses electrodes112, and is located on the diagonally opposite side of the case from finger notch sensor130, where a groove allows for a user's palm to contact the mobile phone case110. These positions may be reversed for users who hold the mobile phone case110in their right hand. In another embodiment, the finger notch that houses the optical spectroscopy sensors may be moved to the center of the case to make a common design for both right- and left-handed users.

Sensors130and140may include a photodiode array150, an LED array151, and a laser diode array152. The photodiode array150may be placed substantially orthogonal to the LED array151or laser diode array152, according to one embodiment.

In certain embodiments, the mobile phone case110contains additional types of sensors such as pressure sensors153attached to electrodes111and112, moisture sensors154, temperature sensors155, and humidity sensors156, built in to the phone case to aid, for example, in the monitoring of measurement quality.

In addition to the sensors and accessories described above, the following additional sensors may be used with the present system:

GSR sensor157measures galvanic skin resistance to calculate skin moisture and conductivity. This data may also be used to measure stress.

Infrared thermopile sensor158is used for contactless temperature measurement.

Sweat analyzer159is a sensor that analyzes sweat to detect dehydration as well as various types of diseases.

In one embodiment, the LED array151may be deployed as a light source and the laser diode array152may be deployed as a detector. Multiple LEDs of various center wavelengths can be produced to generate a light source to perform a scan over a large range of frequencies. According to one embodiment, the touchable mobile phone case110may contain an array of four (4) LEDs as sources. The number of LEDs in the array could be larger, in one embodiment, with eight (8) or even twelve (12) LEDs that cover a wide spectrum of wavelengths (ranging from visible to mid-infrared regions).

The LED array151and the laser diode array152may be deployed in multiple arrangements applying transmission/reflection/refraction spectroscopy. According to one embodiment, they may be arranged across from each other for measurement of light transmitted through the user's tissue. In an orthogonal arrangement, the laser diode array152measures light generated by the LED array151that is scattered or diffracted through the tissue. In a side by side arrangement the laser diode array152measures light generated by LED array151reflected from the user's tissue.

In another embodiment, the LED array151could be deployed in a tightly packed package right at the source placement. According to another embodiment, the LEDs could be placed at the convenient location where spacing is less of a limitation to expand the number of LEDs with light carried to the source placement using optic fibers or light pipes. In another embodiment, the mobile phone case110can include arrays of electrodes for bioimpedance spectroscopy, LEDs for near infrared spectroscopy, and LEDs for heart rate monitoring.

In another embodiment, the mobile phone case110implements optical scanning via optical spectroscopy in the visible and near infrared regions using the integrated LED array151and the laser diode array152. According to another embodiment, the laser diode array152performs scattering spectroscopy (Raman Scattering) using light in visible to infrared regions.

In an alternate embodiment, sensors contained in mobile phone case110, can be integrated directly into the mobile phone101and function in the same manner. The foregoing description uses the example of mobile phone case110for simplicity of explanation of the present system.

FIG. 2depicts optical spectroscopy performed with the mobile phone case, according to one embodiment Mobile phone case210performs optical spectroscopy using the integrated LED array251as an IR source, and the laser diode array252as the photodetector. To capture a Photoplethysmography (PPG) signal222from the user's fingertip221, light generated by integrated LED array251passes from one side of the finger221and is captured on the other side by the laser diode array252. The output of the analysis is a waveform that corresponds to the pulse wave amplitude (“PPGA”)222and heartbeat interval (“HBI”)223. Various characteristics of the PPGA signal HBI signal are analyzed using a process, such as Beer-Lambert law to gather additional information about the user's health.

The measurements described above can be performed without any human intervention, and they provide continuous measurement data for the human body, called incidental measurements.

FIG. 3depicts various components of a mobile phone that trigger automatic measurements, according to one embodiment. First, there are built in sensors302in most modern mobile phones301to detect rotation change and wake up the screen303, triggering the mobile app304to launch and take a measurement attempt at the same time. Second, built-in pressure sensors305can trigger the mobile app to make another measurement attempt. In another embodiment, measurement can be triggered by capacitive sensing enabled through the metal electrodes306on the mobile phone301. Capacitive sensors307can also be placed under the surface of the phone covering in close proximity, to detect user contact, and trigger incidental measurements. For example, a single touch by a user on the screen303having capacitive sensors307can initiate a scan by activating the bioimpedance sensors or any of the sensors described above. According to one embodiment, the material of the phone case acts as a dielectric medium. According to one embodiment, a user would use her finger to tap over the screen303having capacitive touch sensors307. In another embodiment capacitive touch sensors are within the finger notch, such that a user can tap her finger in the finger notch to activate the system intentionally. Depending on the number of taps, different aspects of the measurement system could be activated, according to one embodiment.

The type of incidental measurement depicted inFIG. 3is built upon existing user habit with a mobile phone, and it does not alter user behavior in any aspect. As such, it enables regular measurements throughout the day, and thereafter statistical analysis using deep data mining techniques. This represents a complete paradigm shift from current state-of-the-art health monitoring, where measurement data is sparse and scarce.

In an alternate embodiment, bioimpedance analysis (“BIA”) for biometric identification is performed by mobile phone case310. The system utilizes user-specific unique impedance response patterns to electrical stimulation to determine user signatures allowing for identification of a user. The present system can use Bluetooth and/or WiFi communication mechanisms to interact with external systems to employ BIA-based biometric identification. External systems may be a mobile device within the case, or other computing devices within range of the case310. The system, according to one embodiment, performs BIA measurements for many types of BIA applications.

FIG. 4depicts a system for collecting health and activity data from the present mobile phone case, according to one embodiment.FIG. 4depicts a system400where the health and activity data collected by mobile phone case410can be transmitted to a centralized server420for various processing and analytics, according to one embodiment. The centralized server420may transfer data with an analytics server430, such as a cloud server, or an enterprise server. Each mobile phone device401or mobile phone case410that is deployed can connect to the centralized server420via a WiFi connection421or via cellular network system422.

In another embodiment, health and activity data collected from the mobile device case410is transmitted to the centralized server420, and then transferred to and stored on analytics server430for the purpose of performing data analytics. As data is collected from a sufficiently large sample set of users, deep data mining (e.g., impedance body fat, ICW, ECW, reactance, phase, tomographic images, etc.) may be performed to establish an individualized baseline for a user. According to one embodiment, BIA measurements are performed using sinusoidal signals in the 10 kHz-1 MHz range. Furthermore, the same electrodes that are used for BIA can be repurposed into a listening mode to function as ECG electrodes. The analytics server430may monitor statistics to detect shifts from the user's baseline and interpret anomalies to infer health conditions. A communications server440allows for comparison of individual user data to a larger population provides for deeper analysis and allows for better diagnosis of health conditions.

In another embodiment, the communications server440provides anonymous user social networking to enable communications between users with similar physiologies and pathologies. According to another embodiment, the system provides a portal450for healthcare infrastructure for primary care physicians to monitor users offline. Individual users may choose to release data for research studies on an anonymous basis.

In another embodiment, the mobile phone case410may be used for various applications, such as glucose monitoring, blood pressure monitoring, heart rate monitoring, alcohol level monitoring and testing, and testing for other specific substances in blood stream including molecules released into blood stream from medications. Data collected from these applications can be provided to centralized server420for processing, and analytics server430for data analytics, according to one embodiment.

FIG. 5depicts a system that measures vital body parameter trends over time, using analytics within a mobile device or in the cloud, according to one embodiment. As depicted inFIG. 5, a system560allows for measuring vital body parameter trends over time using analytics within a mobile device501or in the cloud561. This analysis and instant feedback allows the user502to adjust activity behavior at granular level. Body hydration change562, for instance, can be used to trigger a reminder for fluid intake563. A blood glucose level change564will trigger user feedback for dietary control565, including changing both type of food consumption and timing of food intake. Such behavior changes provide benefits to maintain and improve the body's health, and can also aid in treating certain users with health ailments, such as diabetes. Spot measurement data can be used in an analytics platform to establish a normal baseline for user502, and further for trend analysis to monitor for aberrations and anomalies.

FIG. 6depicts a touchable mobile phone with a circular array of electrodes, according to one embodiment.FIG. 6depicts the mobile phone case600with a circular array of electrodes610on the back of the case. The circular array610is used for bioimpedance measurement with active electrodes620and passive electrodes630similar to a 4 electrode tetra polar electrode arrangement (i.e. 2 voltage and 2 current electrodes) being made by electrical multiplexing. BIA in this setup may be performed with the tetra polar set up (with electrodes on the side of the case) in a frequency range of 10 KHz-1 MHz and the frequency range may be expanded beyond 1 MHz to explore tissue/bone properties in finer detail.

FIG. 7depicts the mobile phone case with a matrix array of electrodes, according to one embodiment.FIG. 7depicts the mobile phone case700with a matrix array of electrodes710on the back of the case. The matrix array710is used for bioimpedance measurement with active electrodes720and passive electrodes730similar to standard tetra polar electrode arrangement being made by electrical multiplexing. A similar BIA frequency range (e.g., 10 KHz-1 MHz or beyond) may be applied to this situation of matrix array of electrodes.

FIG. 8depicts the mobile phone case with an electrode extension cable, according to one embodiment.FIG. 8depicts the mobile phone case800with an electrode extension cable810, connecting to bioimpedance extension module820. The extension cable810contains a set of electrodes830used to make bioimpedance measurements across the body, for example the front and back of the user's trunk. A similar BIA frequency range (e.g., 10 KHz-1 MHz or beyond) may be applied to this embodiment.

FIG. 9depicts a user making a bioimpedance measurement using an electrode extension cable attached to the mobile phone case, according to one embodiment.FIG. 9depicts a user920making a bioimpedance measurement using an electrode extension cable910attached to mobile phone case900. In one embodiment, the electrode extension cable910accessory allows for a focused spot measurement to be recorded. The electrode extension cable910can be plugged into the mobile phone case900through the data port901. The extension cable910can be equipped with additional electrodes611at one end. Upon detecting the extension cable910, a mobile app prompts the user for a targeted measurement, for instance, bioimpedance by touching the mobile phone case900or extension cable910to the user's breast issue. In another example, a user may perform BIS through the liver by holding the mobile phone case900or extension cable911against the abdomen and extending the electrodes911to his lower back.

FIG. 10depicts a touchable mobile phone case strap design wrapped around a user's arm, according to one embodiment.FIG. 10depicts a touchable mobile phone case strap design1010wrapped around a user's arm1020. The mobile phone case strap design1010contains the touchable mobile phone case1000, and may be wrapped around the user's arm1020. When a user wears the touchable mobile phone case1000on the arm1020during exercise, the phone case is in touch with skin, and can measure continuous user data such as heart rate, glucose level, blood oxygen level, and hydration level. Monitoring such continuous data, and allowing for immediate feedback, allows users to achieve the maximum benefit of a workout, for example. A similar BIA frequency range (e.g., 10 KHz-1 MHz or beyond) may be applied to this embodiment.

FIG. 11depicts an expanded view of a mobile phone case having a finger notch sensor for improved haptic feedback to the user, according to one embodiment. The present case may include a softer material around the finger notch1110laid on to the finger notch sensor1120for improved haptic feedback to the user. The softer material can also be applied to the sensor1130, where the user's palm contacts the case. In certain embodiments, the mobile phone case1100has tactile sensors1140that measure forces exerted by the user on the interface, such as at finger notch sensor1120and palm sensor1130. The softer material allows for increased sensitivity to user touch and improved haptic feedback upon contact with the user's finger or palm. Tactile sensors1140also guide the user to properly position her finger in contact with the finger notch1110. For example, the user may feel a buzz when her finger is properly placed within the finger notch1110.

FIG. 12depicts an optical scan apparatus in the mobile phone case being used to study the optical response characteristics of fruits, vegetables and other food substances to determine freshness or levels of decay, according to one embodiment.FIG. 12depicts an optical scan apparatus1200in the mobile phone case1210being used to study the optical response characteristics of fruits, vegetables and other food substances1201to determine freshness or levels of decay. Optical sensors1220located on an outer side of the phone case, include an array of photodetectors1230, and the user can place the phone case near a food substance1201for evaluation. The photodetectors1230can determine the freshness of a given food substance based on comparing measured data with known data characteristics of that substance, such as coloring or transparency, which can indicate whether the food substance, for example, is fresh. The system1200uses absorbance principles to look for the presence of certain materials that indicate decay. This comparison and evaluation process can be driven by a mobile app installed on the mobile phone1211.

FIG. 13is a block diagram of an exemplary spectrometry circuit, according to one embodiment. The spectrometry circuit1300includes a Bluetooth microcontroller1310, such as a CC2650 chip from Texas Instruments. The spectrometry circuit also includes a pulse oximeter controller1320, such as the AFE4490 chip from Texas Instruments. The two chips communicate with each other using the SPI protocol. The spectrometry circuit also includes an LED array where there are at least four (4) LEDs1330. According to one embodiment, the LEDs may be one or more of a 640 nm Red LED (MTPS9067MC), 940 nm IR LED (MTE9460MC), 1200 nm IR LED (MTSM0012-843-IR), or 1550 nm IR LED (MTSM0012-843-IR). These LEDs may be obtained from Marktech Optoelectronics with the model information provided above, or from any other suitable LED manufacturer. The photo diode array1340may be one or more of the MTPD1346D-100 from Marktech Optoelectronics or TEMD7100X01 from Vishay Semiconductor, according to one embodiment. According to one embodiment, the power of the LED array may be controlled to improve the signal quality for each user of the case.

FIG. 14depicts the mechanical integration of electronics platform and the phone case1400, according to one embodiment. Sensors, such as a flex to palm electrodes1410, are attached to flex cables1420that are built into the main PCB1430. In certain embodiments, a power source such as a battery1440is connected to main PCB1430. The battery1440and main PCB1430fit into cutouts in the phone case body1450, allowing for the flex finger notch sensor1460to protrude through to the other side of the case to the finger notch position1470.

FIG. 15illustrates a process for data collection by incidental touch, according to one embodiment. Additional measurements can be performed with the mobile phone case1500. As depicted inFIG. 15, one type of measurement is achieved through incidental touch, for example, when a user touches the mobile phone case at1510. Users typically make such touches with mobile phones more than 150 times each day. At each touch, the mobile phone case can perform incidental bioimpedance measurements using electrodes located at both sides of the phone case or incidental optical PPG measurements using LEDs and Photodiode sensors in the finger notch at1520. The data collected allows for determining body fat composition, hydration levels, blood glucose, blood pressure, blood oxygen saturation and heart rate at1530.

FIG. 16illustrates a process for spot measurement, according to one embodiment. As depicted inFIG. 16, the mobile phone case can be used to take spot measurements, occurring when the user intentionally takes measurements by holding the mobile phone case1600in a recommended manner at1610. The user then starts a scan at1620by either triggering it from the mobile app or by depressing a switch on the phone case. According to one embodiment, the user obtains spot measurements at1640by holding the phone against a targeted body position, making contact with the functional array of electrodes on the backside of the phone case at1630, which provides the user with tomographic images or detailed spectroscopic information of the scanned tissue (e.g., tissue/organ specific spectroscopic information, local cell health, etc.) on the mobile app at1650. The mobile app can accomplish this through electrical impedance tomography (“EIT”). The array of electrodes serve as a closed domain under this test. Electrical current is sent through a pair of driving electrodes and the voltage information is collected from a pair of sensing electrodes. The process is repeated until each electrode pair has served as a driving electrode while the other electrode pair automatically takes the role of a sensing electrode. EIT modality, conductivity, permittivity, and impedance information is collected at1660from the surface electrodes on the backside of the phone case. In another embodiment, an additional accessory, having the same or greater number of electrodes than the number of electrodes on the phone case can provide for a higher resolution tomographic images. The images obtained by spot measurements can provide important electrical property data electrical properties vary from organ to organ, as well as from normal tissue versus abnormal tissue. Studies have shown that abnormal electrical property data can give an early indication of breast cancer, liver disease and prostate cancer, for example.

FIG. 17illustrates a process for segment measurement, according to one embodiment. As depicted inFIG. 17, the mobile phone case performs segment analysis1700. To take segment measurements, the user is guided by a mobile app to touch the mobile phone case against the user's body at two or more designated points at1710. For instance, the phone case can perform a scan employing bioimpedance spectroscopy when the case is touched from right hand to the left hand, from hand to foot, and from hand to trunk at1720. The scan can be triggered by rotating the mobile phone case in the instructed manner, by a pressure sensor signal triggering at, or upon a capacitive sense of touch by the user at1730. Bioimpedance data is collected between electrodes on one side of the phone case body and electrodes in the back of the phone case, by holding the case in a recommended manner at1740. The resulting segment measurements enable full body composition analysis at1750. Segment measurements can be performed at a much larger interval, for example, on a weekly basis, for tracking long term health and fitness goals at1760. These measurements are taken as often as a user feels convenient. This data is information-rich for health analysis.

FIG. 18illustrates a process for deep data analysis using the present mobile phone case, according to one embodiment.FIG. 18depicts a data flow diagram for an embodiment of the system. The mobile phone case with sensors makes contact with the user at1810and the case reads data from those sensors at1820. The health application running on the mobile phone processes and analyzes the data at1830. The health application displays real-time processed data and provides alerts and haptic feedback to the user at1840. In another embodiment, the health application sends the data to a central server at1850. The central server processed the data and returns historical data to the health application at1860. The health application displays the historical data at1870. The health application sends the data to a server at1880. The server processes the data and returns historical data to the health application at1890.

FIG. 19illustrates a process for collecting data for haptic feedback, according to one embodiment. User data is collected by a mobile phone case upon user touch at1910. The mobile phone processes the data and then returns a haptic response that alerts the user to the data at1920. If desired, the user responds to the alert at1930.

Although the various embodiments described herein, describe functionality performed by the present phone case, a person of skill in the art would understand that the functions described herein may be performed by a combination of mobile device, the present phone case, and servers. A person of skill in the art would also understand that the functions described herein may be performed by a mobile phone without the present phone case if the mobile phone includes one or more of the components described as part of the present phone case. Processing performed on the mobile device may also be performed on a server. A person of skill in the art would understand that the phone case may communicate with a mobile device through a standard communications port (e.g., USB, Lightning, etc.) or wirelessly (e.g., Bluetooth, WiFi, EHF, UHF, etc.).