Patent Publication Number: US-2018042496-A1

Title: System and method for measuring vital signs

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from U.S. Patent Application No. 62/054672 filed on Sep. 24, 2014, which is incorporated by reference herein in its entirety. This application continuation in part of U.S. patent application Ser. No. 14/858,157 filed on Sep. 18, 2015, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF DISCLOSURE 
     The present disclosure relates to the field of healthcare data measurement. More particularly, the present disclosure relates to a wearable device for measuring vital signs of a patient. 
     BACKGROUND 
     High blood pressure or hypertension is one of several factors that can increase the risk of myocardial infarction (heart attack) and cerebrovascular accidents or stroke. Post-operative and post-myocardial infarction patients are required to closely monitor their blood pressure in order to prevent another cardiovascular failure which can lead to paralysis, mortality, or very high cost medical bills. Therefore, it is desirable and important to continuously monitor blood pressure in cardiovascular disease, diabetic, and obese patients. 
     Invasive systems and methods exist for measuring the blood pressure of a patient. For example, invasive blood pressure monitors typically utilize catheters with a pressure transducer or sensor on the tip. These devices are also known as intravascular pressure sensors. However, catheter blood pressure monitors require surgical implantation which can lead to infection requiring the patient to undergo another surgical procedure, which can extend the patient&#39;s stay in the medical clinic. In addition, the catheter method is also large in size and requires bulky and high cost external equipment, which may not be suitable for at-home continuous measurements. Implantable elastic cuffs with micro-electromechanical device (“MEMS”) pressure sensors are another form of an invasive device to measure blood pressure. The cuffs are surgically implanted around the blood vessel to measure the pressure change through the expansion of the walls. However, this system and method exposes the patient to a number of risks such as infection and collapsing of the cuff which can increase the chance of experiencing a heart attack or other cardiovascular-related complications. Furthermore, the implanted cuffs may also require several surgeries for performing maintenance of the system. 
     Noninvasive systems and methods also exist for measuring the blood pressure of a patient. In one example, cuffs or sphygmomanometers are placed either around the wrist or upper arm of the patient. Other methods include a blood pressure monitoring watch. However, these systems and methods do not provide the capability for continuous measurements to be transported to the primary physician. In addition, these systems and methods can also create great inconvenience and momentary discomfort for the patient. Also, the sphygmomanometer is error prone. In particular, the size of a sphygmomanometer must be correctly adjusted to give an accurate blood pressure reading. An adjustment where the cuff is too tight can produce a higher reading while a loose adjustment can produce a lower reading. 
     SUMMARY 
     In one example, a portable wearable computing device configured to continuously obtain data indicative of a patient&#39;s vital signs is disclosed. The portable wearable computing device is formed in the shape of an ear bud and includes a temperature sensor configured to obtain data indicative of body temperature of the patient. The temperature sensor is positioned in the ear so that it can rotate to allow for accurate measurement of the temperature at the tympanic membrane. The portable wearable computing device further includes a Blood Oxygen Saturation (BOS) sensor configured to obtain data indicative of the amount of oxygen present in the patient&#39;s body. The portable wearable computing device further includes an arterial waveform sensor configured to obtain data indicative of an arterial waveform produced by the patient&#39;s artery. The portable wearable computing device further includes a processor coupled to the temperature sensor, the blood oxygen sensor, and the blood pressure sensor, and configured to receive the obtained data indicative of the patient&#39;s vital signs from the patient&#39;s body and more specifically from the region of the ear. 
     In one example, a method for continuously obtaining vital sign data is disclosed. The method includes the step of disposing a wearable measurement device on a patient&#39;s body and more specifically from the region of the ear. 
     The method further includes the step of continuously acquiring data representative of the patient&#39;s vital signs from the wearable measurement device. The method further includes the step of converting the acquired data in real time. The method further includes the step of communicating the converted data. 
     In one example, a non-invasive system for continuously monitoring blood pressure of a patient is disclosed. The system includes a sensor disposed on the patient and in communication with the superficial temporal artery. The Temporoparietal Fascia contains the superficial temporal artery. The sensor is configured to acquire data indicative of an arterial waveform from the patient and to wirelessly communicate the acquired data indicative of the arterial waveform to a patient computer. The patient computer is configured to receive the communicated data indicative of the arterial waveform and to derive systolic and diastolic blood pressure data based on the received data representative of the arterial waveform. 
     In one exemplary example, due to the nature of the anatomy of the face a means of accurately determining the blood pressure and pulse oximetry is needed that cancels the effects of temperature on the skin and vascular plexus that the temporal artery is part of. 
     In one exemplary example, due to differing facial structures there is a need to insure that the blood pressure sensor is aligned with the temporal artery both axial compliance and radial adjustment. The radially adjustment is with respect to the ear and the sensor must be capable of applying adequate pressure to the temporal artery so an accurate reading can be determined. Additionally, due to variability of the skin and capillaries under the skin the ambient temperature needs to be accounted to allow for an accurate blood pressure measurement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration. 
         FIG. 1  illustrates an example system for measuring vital signs. 
         FIG. 2  is an example arterial waveform. 
         FIG. 3  is an example wearable measurement device. 
         FIG. 4  is an example wearable measurement device. 
         FIG. 5  is an example wearable measurement device. 
         FIG. 6  is an example wearable measurement device. 
         FIG. 7  is an example wearable measurement device. 
         FIG. 8  is an example wearable measurement device. 
         FIG. 9  is an example wearable measurement device. 
         FIG. 10  is an example wearable measurement device. 
         FIG. 11  is a schematic illustrating an example positioning of an example wearable measurement device. 
         FIG. 12  illustrates an example system for measuring vital signs. 
         FIG. 13A  illustrates an example blood pressure monitoring patch. 
         FIG. 13B  illustrates an example blood pressure monitoring patch. 
         FIG. 13C  illustrates an example blood pressure monitoring patch. 
         FIG. 13D  illustrates an example blood pressure monitoring patch. 
         FIG. 14  illustrates an example absorption mode BOS patch. 
         FIG. 15  is an example reflectance mode BOS patch. 
         FIG. 16A  is an example wearable measurement device in unfolded position. 
         FIG. 16B  is an example wearable measurement device in folded position. 
         FIG. 16C  is an example wearable measurement device in unfolded position. 
         FIG. 16D  is an example wearable measurement device in folded position. 
         FIG. 16E  is an example wearable measurement device in unfolded position. 
         FIG. 16F  is an example wearable measurement device in unfolded extended position. 
         FIG. 17A  and  FIG. 17B  is an example wearable measurement device. 
         FIG. 18  illustrates an example method for measuring vital signs. 
         FIG. 19  is a block diagram of an example computer for implementing an example third-party computing device of  FIG. 1 . 
         FIG. 20A  and  FIG. 20B  is the design of the blood pressure sensor arm showing both axial compliance and radial adjustment. 
         FIG. 21  shows the superficial temporal artery relatively surface of the skin. 
         FIG. 22A  shows the uncorrected curve for an ambient temperature of 26 degrees C. versus the corrected curve when the correction factor is applied. 
         FIG. 22B  shows the curve taken with a conventional blood pressure cuff. 
     
    
    
     DETAILED DESCRIPTION 
     An ear bud is defined as a device of the invention used to continuously monitoring vital signs of a patient such as blood pressure, Blood Oxygen Saturation (BOS), heart rate, body temperature, respiratory rate, and body position of the patient from the region of the patient&#39;s ear. 
     Referring to  FIG. 1  and  FIG. 20A ,  FIG. 1  illustrates an example system  100  for measuring vital signs. It should be appreciated that the system  100  may be utilized in a hospital setting or in everyday living. For example, system  100  may be utilized by a health care professional to measure vital signs of a patient  104 , either during a clinical visit or at a bedside while admitted at a hospital. In another example, the patient  104  may use system  100  to measure own vital signs while at home or at any other convenient location. System  100  includes a wearable measurement device  102  that has processor  103  for continuously monitoring vital signs such as blood pressure, Blood Oxygen Saturation (BOS), heart rate, body temperature, respiratory rate, and body position of the patient  104  and these sensors are in communication with processor  103  which is part of wearable measurement device  102 . Processor  103  can be configured to interpret the data such as vital signs such as blood pressure, blood oxygen saturation, heart rate, body temperature, respiratory rate, and body position. It should be appreciated that wearable measurement device  102  may include any suitable wearable device, such as a ear bud, watch, a bracelet, a ring, an earring, and so on, that may incorporate suitable computer hardware and software components for collecting vital signs. 
     The wearable measurement device  102  is non-invasive that is configured to come in direct contact with the patient&#39;s  104  skin, without requiring a surgical procedure. It should be understood that although the example system  100  depicts the wearable measurement device  102  positioned on the patient&#39;s  104  ear the wearable measurement device  102  may be positioned on any portion of the patient&#39;s  104  body suitable for continuously monitoring vital signs. For example, the wearable measurement device  102  may be positioned near the superficial temporal artery  514  of the head  114 . In other examples, the wearable measurement device  102  may be positioned near the carotid artery in the neck  116 , the brachial artery in the arm  118 , or the femoral artery in the leg  120 . 
     The wearable measurement device  102  includes a processor  103  and a plurality of sensors (not shown) working to obtain vital sign information. In one example, each sensor may gather more than one type of information. The sensors can be semiconductor sensors or optical sensors, for example. In addition, the wearable measurement device  102  includes a low power circuitry, an integrated power supply, application-specific integrated circuits, and a housing that attaches to the surface of the skin of the patient  104  without requiring a surgical procedure. The wearable measurement device  102  further includes a wireless transmission antenna  90  in communication with processor  103  such as Wi/Fi, Bluetooth or Near Field Communications antenna for wirelessly communicating the obtained vital sign information. 
     The system  100  further includes a patient computing device  106  having a wireless antenna  91  for receiving the vital sign information from the wearable measurement device processor  103  and a user interface  108  for displaying the received information in a concise, organized fashion. The patient computing device  106  may be any suitable device such as a smart phone, a tablet, a personal computer, or a smart watch. The patient computing device  106  includes computer readable tangible storage device and a software application for processing received information and converting the information into common parameters such as systolic blood pressure or diastolic blood pressure before displaying the information on the user interface  108 . The computer readable tangible storage device can be selected from different memory options such as solid-state drive (SSD), Random Access Memory, disk drive or tape drive device. Alternatively, processor  103  can be configured to interpret the data such as vital signs from the sensors such as blood pressure, blood oxygen saturation, heart rate, body temperature, respiratory rate, and body position. 
     In one example, the software application of the patient computing device  106  also communicates information to the wearable measurement device  102  using processor  103 . For example, the computing device  106  may be configured to receive information about operational settings or parameters and to communicate the information to the wearable measurement device  102 . In one example, the wearable measurement device  102  may send using processor  103  other suitable data to the patient computing device, other than vital sign data. For example, the wearable measurement device  102  may communicate information using processor  103  such as battery fife, improper measurement alerts, indications of misaligned sensors, connectivity problems, and so on. 
     In one example, the obtained vital sign information is also communicated to a third-party computing device  110  such as a device associated with, a physician, a family member, or a third-party data-monitoring service. The third-party computing device  110  may be any suitable device such as a smart phone, a tablet, a personal computer, a computer server, or a smart watch, for example. In one example, the third-party computing device  110  includes a computer readable tangible storage device and an electronic health records (“EHR”) system that stores patient health records and is configured to store the received vital sign information in association with the patient&#39;s  104  health records. The computer readable tangible storage device can be selected from different memory options such as solid-state drive (SSD), Random Access Memory, disk drive or tape drive device. In one example, the patient computing device  106  is configured to automatically communicate all received vital sign information to the third-party computing device  110 . In another example, the patient computing device  106  is configured to communicate the received vital sign information to the third-party computing device  110  or an alert only when the vital signs are outside of a normal measurement range. Accordingly, a patient&#39;s  104  physician or family member may be automatically notified when the patient&#39;s blood pressure is high, for example. In one example, the wearable measurement device  102  may be configured to communicate directly with the third-party computing device  110 . Alternatively, processor  103  can be configured to interpret the data such as vital signs such as blood pressure, blood oxygen saturation, heart rate, body temperature, respiratory rate, and body position. 
     In one example, before the wearable measurement device  102  using processor  103  can begin to stream vital sign information to the third-party computing device  110 , the wearable measurement device  102  using processor  103  performs a digital handshake with the third-party computing device  110 . For example, the wearable measurement device  102  using processor  103  may communicate a unique identification number or other suitable identifying information for the third-party computing device  110  to confirm the identity of the wearable measurement device  102  and the associated patient  104 . In particular, after a wearable measurement device  102 , including a unique serial number is assigned to a patient  104 , the unique serial number is provided to the third-party computing device  110  by the wearable measurement device  102  using processor  103 . The third-party computing device  110  may then be configured to associate with a specific patient record of patient  104  all vital sign information received from the wearable measurement device  102  using processor  103  having the unique serial number. 
     In order to non-invasively monitor blood pressure with minimal interference from artifacts such as movements from walking, coughing or sneezing, system  100  monitors&#39; vibrations exhibited from arterial palpation. Arterial palpation is a result of constant contraction and expansion of the arterial walls to pump or carry blood to extremities within the human body. Several major arteries exhibit throbbing or palpation, that can be felt through the skin. By monitoring the palpation of an artery, system  100  is able to acquire an arterial waveform, from which systolic and diastolic blood pressure readings can be derived.  FIG. 2  illustrates an example arterial waveform  200  acquired from monitoring an arterial palpation, including systolic  202  and diastolic  204  blood pressure readings and a dicrotic notch  206 . 
     Palpations from arterial wall expansion and contraction can be found at any of the carotid artery, superficial temporal artery, femoral artery, or radial artery, for example. Since the cardiovascular system is a closed-looped system, the pulse at different locations on the body will remain the same. 
       FIG. 3  illustrates an example wearable measurement device  300  designed to be positioned at a patient&#39;s ear, near the superficial temporal artery. The example wearable measurement device  300  may be configured to be secured to the ear such that the device remains in proximate position to the superficial temporal artery even when the patient performs moderate movements. In one example, the wearable measurement device  300  may be secured to the patient&#39;s ear in such a way as to prevent the device from slipping off or out of place even when the patient performs exercise movements such as jogging. 
     Referring to  FIG. 4  and  FIG. 20A ,  FIG. 4  illustrates an example wearable measurement device  300 . The wearable measurement device  300  includes features that facilitate vital sign data collection as well as that facilitate positioning on the ear of a patient. For example, the wearable measurement device  300  includes, using processor  103 , an ear clip  402  that holds on to the top of the ear at the helix. In one example, the wearable measurement device  300  further includes a tragus clip  410  to clip onto the tragus of the ear and to further facilitate a secure positioning of the device on the ear. 
     To facilitate vital sign data collection, the wearable measurement device  300  includes a sensor  406  in communication with processor  103  configured to measure blood oxygen saturation. The wearable measurement device  300  further includes a sensor  408  in communication with processor  103  configured to measure or acquire an arterial wave form which can then be translated into heart rate and blood pressure. The wearable measurement device  300  further includes a sensor  410  in communication with processor  103  configured to measure body temperature. The wearable measurement device  300  further includes a housing  412  for storing additional suitable electronics, such as a processor  103  for executing suitable program instructions associated with the described functionality of the wearable measurement device, or sensors, such as an accelerometer and a gyroscope for measuring a patient&#39;s body position. In one example, the housing  412  is adjustable to allow for movement and proper alignment of sensor  408  with a patient&#39;s superficial temporal artery. For example, the housing may be configured to extend and retract in order to properly fit a patient&#39;s ear. It should be appreciated that other suitable portions of the wearable measurement device  300  may be adjustable to allow for proper fit on a patient&#39;s ear. For example, the body  414  of the wearable measurement device  300  may be adjustable to properly fit around the back of the ear. In addition the wearable measurement device  300  includes an ambient temperature sensor  2100  which is used to take the ambient temperature. 
     In one example, the sensor  410  is configured to be placed inside an ear canal of a patient&#39;s ear to measure the body temperature. Rotatable hub  460  allows the sensor  410  to align in the ear canal so that the sensor is positioned to read the temperature at the tympanic membrane inside the ear and the rotatable hub  460  also provides a spring load force that pushes the sensor  410  into the ear canal. It should be appreciated that the sensor  410  is configured to fit inside an ear canal of various sizes. In one example, the sensor  410  is an optical sensor, such as a thermopile or IR sensor, configured to measure temperature. 
     It should be appreciated that wearable measurement device  300  illustrated is one example of a possible configuration and that processor  103 , blood oxygen saturation sensor  406 , the arterial wave form sensor  408 , and the body temperature sensor  410  may be positioned on the device in any suitable configuration. In addition, the wearable measurement device  300  may be configured to be secured to any suitable portion of a patient&#39;s body. Examples of a blood oxygen saturation sensor  406 , an arterial wave form sensor  408 , and a body temperature sensor  410  will now be described in more detail. 
       FIG. 5  illustrates an example wearable measurement device  500  including a sensor configured to acquire an arterial waveform  200 . In particular, in order to acquire the arterial waveform  200  and derive the systolic and diastolic blood pressure accurately, a wearable measurement device  500  includes a high sensitivity pressure sensor  502  that is placed over the location of a palpation and anchored to the skin. High sensitivity pressure sensors are low in cost, simple to integrate with other electronics, and can measure small changes in pressure, making it suitable for this application. Sensor  502  can be selected from the following sensors Honeywell TBP Board Mount Pressure Sensors TBPMANN150PGUCV, Amphenol NPC Nova Sensors NPC-100, and STMicroelectronics MEMS Pressure Sensor LPS33HW or similar commercially available devices. Translation of the pressure changes within the arterial walls to the pressure sensor  502  with accuracy is facilitated by a flexible protective layer  504  in the shape of a mound structure that allows the artery to be lightly compressed against the bone. This technique is commonly used when checking a pulse. The palpation from the arterial pulse can be felt with trained fingertips by compressing the artery against the bone and can only be felt in areas where the arteries are able to be compressed against a reference bone. The sensor  502  is placed inside of the flexible protective layer  504  and anchored to a rigid substrate  506 . In one example, the mound formed by the flexible protective layer  504  is filled with a low viscosity material  508  and anchored to the substrate  506 . In one example, as illustrated in  FIG. 6 , a flexible protective layer  604  forms a bubble instead of a mound  504 . 
       FIG. 7  illustrates another example wearable measurement device  700 . In an alternative to using a semiconductor sensor, the wearable measurement device  700  incudes a piezoelectric thin film sensor  702  which exhibits high sensitivity to vibration and mechanical forces such as bending. Piezoelectric films are typically 10 to 150 microns in thickness. They offer several advantages such as low cost, simple signal conditioning, low noise, low power consumption, and high sensitivity. Sensor  702  can be selected from the following commercially available devices such as TE Connectivity, Piezo Film Sheets, CAT-PFS0003, and Alpha, Force Sensors, MF02-N-221-A01 or similar commercially available devices. The piezoelectric film  702  is placed over a cavity  704  filled with low viscosity material  706  and capped with a flexible protective layer  708  in the shape of a bubble structure and anchored to a substrate  710 . Placing the piezoelectric thin film  702  over the cavity  704  will enable the piezoelectric thin film  702  to vibrate, and bend when an outside force pushes against the protective layer  708 . In one example, as illustrated in  FIG. 8 , a flexible protective layer  808  forms a mound instead of a bubble. 
     Referring back to  FIG. 1 , the wearable measurement device  102  may be configured to measure blood oxygen saturation. Blood oxygen saturation (SOS) is a relative measure of the amount of oxygen in the blood. A typical measurement will normally occur on the index finger, the ear, and other parts of the body where the flesh is thin. In one example, the wearable measurement device  102  utilizes an optical method to measure BOS on the earlobe or pinna (top portion of the ear) of the patient  104 . This location is used to negate the device  102  from movement and physical abrasion. It will also work in conjunction with the blood pressure monitoring portion of the device  102  to gather multiple vital signs. 
       FIG. 9  illustrates another example wearable measurement device  900  configured to use an absorption mode to measure blood oxygen saturation. The wearable measurement device  900  includes an infrared LED light source  902  with wavelength of  940  rim, a red LED light source  904  with operating wavelength of  660  rim, and a photo-detector  906  to measure the blood-oxygen saturation of the user. In particular, the LED light sources  902  and  904  are placed on one side of the ear lobe  908 , and the photo-detector  906  is placed on the opposing side and aligned to the LED light sources  902  and  904 . The red LED  904  and the infrared LED  902  blink multiple times independently while the photo-detector  906  measures the absorbed light passing through the ear. Photodiodes in the photo-detector  906  measure the changing absorbance at each of the wavelengths, allowing for determination of absorbance due to the pulsing arterial blood alone, excluding venous blood, skin, bone, muscle, fat, and so on. 
       FIG. 10  illustrates another example wearable measurement device  1000  configured to use a reflectance mode to measure blood oxygen saturation. Wearable measurement device  1000  includes both the LEDs  1002  and a photo-detector  1004  on a single side of the ear lobe  1006 . In both examples illustrated in  FIGS. 9 and 10 , amplification of the signal is achieved through operational amplifiers and linear circuits such as high pass and low pass circuits. Operation of the example wearable measurement devices  900  and  1000  requires the LEDs  902 ,  904 , and  1002  to flash, one at a time, respectively, while the photo-detectors  906  and  1004  measure the absorbed or reflected light respectively by measuring, oxygenated and deoxygenated hemoglobin present in the blood of the patient  102 . Hemoglobin is a protein found within red blood cells that transports or carries oxygen.  FIG. 11  is a schematic illustrating an example positioning of a wearable measurement device  900  or  1000  at either the ear lobe  1102  or the pinna  1104 . 
     It should be appreciated that, although the example system  100  of  FIG. 1  illustrates a single wearable measurement device  102 , another example system  1200  may include a plurality of wearable measurement devices  12021 ,  12022 ,  12023 ,  12024  and  12025 , as illustrated in  FIG. 12 . The network of wearable measurement devices  12021 ,  12022 ,  12023 ,  12024  and  12025 , or flexible patches, gather multiple vital signs simultaneously and transmit the acquired information to a single patient computing device  106 . Each flexible patch  12021 ,  12022 ,  12023 ,  12024  and  12025  locations on the patient  104  can be referred to as a node where each node may contain low power electronic circuits, a powering source and a module/antenna to transmit information wirelessly. 
     Blood pressure monitoring (“BPM”) nodes are placed over the artery where palpation can be found as discussed above while blood oxygen saturation (“BOS”) nodes are placed at the lobe or pinna of the ear. The BPM patch will incorporate the characteristics described in  FIGS. 5-8  such as a pressure sensor or piezoelectric thin film housed within a bubble/mound-like structure and filled with low viscosity material while BOS patches contain the characteristics described in  FIGS. 9-10 . 
       FIG. 13A  illustrates an example BPM patch  1300 . The BPM patch  1300  may include a rigid backing  1302  as a mechanical support structure disposed on a flexible substrate  1304  that will allow the compression of the artery by the mound/bubble protective layer  1306  disposed over the sensor  1308 . BPM nodes  1300  are equipped with an adhesive ring  1310  along the edge. The flexible substrate may further incorporate additional suitable electronic components  1312 . As illustrated in the aerial view of  FIG. 13B , BPM patches  1300  can also incorporate flaps  1314  with adhesive material  1316  to further ensure movement of the patch  1300  is reduced to a minimum. 
       FIGS. 13C-13D  illustrate side views of the example BPM patch  1300 , including a bubble protective layer  1306  and a mound protective layer, respectively. 
       FIG. 14  illustrates an example absorption mode BOS patch  1400 . The patch  1400  is configured to fold over an ear, or other suitable part of the body, where a first side  1402  is secured to either the front or the back of an ear and the second side  1404  is secured to the opposite side of the ear. Absorption mode BOS patches  1400  contain alignment markers  1406  to assist in aligning the first side  1402  with the second side  1404  when folding over and securing to an ear since misalignment of the first side  1402  and the second side  1404  can cause a misreading. The alignment markers  1406  can be in the form of a small dot or stud to assist in alignment. The absorption mode BOS patch  1400  further includes LEDs  1408  placed on one side of the ear and a photodiode  1410  on the other. The LED light  1408  passes through the ear and reaches the photodiode  1410 , assisted by the alignment markers  1406 , in order to capture an accurate measurement. Additionally, other suitable electronics  1412  may be embedded in the patch  1400 . The absorption mode BOS patch  1400  further includes an adhesive  1414  for securing to an ear and to prevent movement. It should be appreciated that the patch  1400  may be fabricated from suitable flexible material. 
       FIG. 15  illustrates an example reflectance mode BOS patch  1500 . The patch  1500  is configured to be secured to a flat, or relatively flat, portion of a body, rather than being folded over a portion of the body as the absorption mode BOS patch  1400  of  FIG. 14  is configured to do. Similar to the absorption mode BOS patch  1400 , the reflectance mode BOS patch  1500  also includes LEDs  1502 , a photodiode  1504 , an adhesive  1506 , and other suitable electronics  1508  mounted to a flexible substrate  1510 . However, the LEDs  1502  and the photodiode  1504  are disposed adjacent to one another, rather than on opposite sides. 
     Using  FIG. 4 ,  FIG. 16A ,  FIG. 16B ,  FIG. 16C ,  FIG. 16D ,  FIG. 16E ,  FIG. 16F ,  FIG. 17 , and  FIG. 21 , a wearable measurement device  300  includes independent components, a BPM  1600 , a BOS  1700 , an ambient temperature  2100  sensor and a body temperature sensor  1602  that can be used in combination or independently of one another. The BPM  1600 , the BCS  1700 , an ambient temperature  2100  sensor and a body temperature sensor  1602  each may include several sensors and their own electronics or power source. The ambient temperature  2100  sensor and a body temperature sensor  1602  gather information independently but transfer the information to the same patient computing device. The placement of the BPM sensor  1600  relative to the superficial temporal artery  514  allows the sensor to receive motion data which is directly related to the pulse within the superficial temporal artery. The anatomy of the face is such that the Temporoparietal Fascia contains the superficial temporal artery  514 . The relatively small distance represented by Delta Y  9000  approximately 5-8 mm makes surface characteristics of the skin  10000  critical to the accuracy of the measurement. The change in ambient temperature has been shown to result in the superficial temporal artery diameter  8000  to vary as well as the Delta Y  9000  dimension. During, testing we found that as ambient temperature went up above 34 degrees C./93 degrees F. the intensity of the pulse went up and the wavelength was increased. This was mirrored as the ambient temperature went down below 28 degrees C./82 degrees F. the intensity of the pulse goes down and the wavelength was decreased, due to the well-known fact that capillaries contract when they are subjected to cold and increase with warmer conditions. As discussed in Moor Instruments Ltd “Microvascular Responses to Skin Heating: an Introduction Issue 1”. When the skin is heated, skin blood vessels dilate, more blood flows and we can detect this increase with laser Doppler. The increase in blood vessel diameter is not the only way in which blood flow increases; under normal, moderate room temperatures (20-24□C.), not all of the smallest vessels (capillaries) have blood flowing through them. Blood flow also increases by more of the capillaries allowing blood to flow through them (capillary recruitment). 
     The variation in BPM readings caused by ambient temperature meant that we had to provide an algorithm that compensated for these small changes so that the accuracy of our readings would be consistent with the accuracy of the more significant reading taken from the bicep area of the body. During testing, we found that the readings varied by as much as 0.1% percent lower when the ambient temperature was above  34  degrees C./ 93  degrees F. The variation depended on the age of the person and varied between −0.02% to −0.1%. The readings varied by as much as 0.1% percent higher when the ambient temperature was below 28 degrees C./82 degrees F. The variation depended on the age of the person and varied between +0.03% to +0.1%. This compensation based on the data required that the data be modified to give accurate results based on the ambient temperature. As shown in  FIG. 22A  curve  2210  is the uncorrected curve for an ambient temperature of 26 degrees C. and curve  2220  is the resulting corrected curve when the correction factor is applied. As shown in  FIG. 22B  shows the curve  2230  taken with a conventional blood pressure cuff.  FIG. 16A  illustrates an example BPM component of a wearable measurement device  1600  containing processor  103  configured to be placed at a temporal artery of an ear. In one example, the BPM component  1600  may incorporate an ear bud  1602  that is inserted into the ear canal. In another example, as illustrated in  FIG. 16C - FIG. 16D , the BPM component  1600  may incorporate a clip  1604  that attaches to the tragus of the ear to prevent movement of the device while the user is in movement. The ear bud  1602  or ear clip  1604  is supported by a rigid backing  1614 . The rigid backing also houses suitable electronics  1616 . The ear clips  1604  adjust in size, as illustrated by arrows  1606 , in order to fit securely on ears of various sizes. The BPM component  1600  incorporates a pressure sensor  1608  with a protective layer  1610  for acquiring an arterial waveform. In one example, the BPM component  1600  further incorporates a temperature sensor (not shown) inside the ear bud  1602  or ear clips  1604  for acquiring the temperature of a patient&#39;s body and an ambient temperature sensor  2100 . 
     In one example, a wearable measurement device includes four independent components, a BPM  1600 , temperature sensor for ambient temperature  2100  and a temperature sensor for measuring the patient&#39;s body temperature  1602  and a Blood oxygen saturation (BOS))  1700  that can be used in combination or independently of one another. The BPM  1600 , a BOS  1700 , an ambient temperature  2100  sensor and a body temperature sensor  1602  each may include one or more sensors and their own electronics or power source. The BPM  1600 , a BOS  1700 , an ambient temperature  2100  sensor and a body temperature sensor  1602  gather information independently but transfer the information to the same patient computing device. 
     Using  FIG. 16  E and  FIG. 16F  the BPM component  1600  further includes a rigid arm  1612  for providing structure and support between the rigid backing  1614  of the ear bud  1602  or ear clips  1604  and the pressure sensor  1608  with protective layer  1610 . The rigid arm  1612  is composed of two pieces first piece  2205  for receiving extension piece  2200 . The extension piece  2200  is slideably adjustable with respect to the first piece  2205  so as to permit the patient to align the BPM component  1600  with the temporal artery  514 . The rigid arm  1612  further provides structure support for the pressure sensor  1608  with protective layer  1610  while the rigid backing  1614  provides structure support for the ear clips  1604  and the ear bud  1602  which incorporates the optical sensor (not shown). The arm is designed with a hinge or adjustable property to allow for flexibility  1614  and proper positioning of the BPM component  1602  to the temporal artery  514 . 
       FIG. 17A  and  FIG. 17B  illustrates an example BOS component  1700  of a wearable measurement device configured to be placed at the lobe or pinna of the ear. The BOS component includes LEDS  1702  and a photodiode  1704  for measuring absorbed light. In one example, the BOS component  1700  is designed in the form of a clip that allows the photodiode  1704  to be placed on one side of the ear and the LEDs  1702  to be placed on the opposing side. The clip will clamp down &lt;along hinge  1706  on the lobe or pinna of the ear to ensure movement of the device is reduced to a minimum. In one example, a portion of the BOS component  1700  will have the ability to move to allow safe and quick removal of the clip. The BOS component  1700  includes a clip housing  1710  for providing support and structure for the LEDS  1702  and the photodiode  1704 . Suitable electronics  1708  are disposed inside the clip housing  1710 . 
     In one example, the BPM  1600 , ambient temperature sensor  2100  and BOS  1700  components each include a power source (not shown). In another example, the BPM  1600 , ambient temperature sensor  2100  and the BOS  1700  components share a power source  1690 . For example, the BPM component  1600  and ambient temperature sensor  2100  may contain a power source while the BOS  1700  component may couple to the BPM component  1600  in order for power to transfer to the BOS component  1700 . The power source  1690  can be selected from the group consisting of a battery a power supply or a solar collector. 
     In one example, both the BPM component  1600 , ambient temperature sensor  2100  and the BOS component  1700  can be worn simultaneously at the ear. In another example, only one of the BPM component  1600 , ambient temperature sensor  2100  and the BOS component  1700  may be worn as the patient desires. 
     As shown in  FIG. 20A , and  FIG. 20B  the wearable measurement device  102  may be selectively positioned on any portion of the patient&#39;s body  104  suitable for continuously monitoring blood pressure from the superficial temporal artery  514  by rotating the arm  112  about pivot  512  such that it aligns with temporal artery  514  of the head  114 . The spring  520  provides an upward force on arm  112  such that wearable measurement device  102  is pressed to insure that the wearable measurement device  102  is in communication with temporal artery  514  of the head  114 . This force provided by spring  520  allows the wearable measurement device  102  to automatically adjust for differing facial structures of head  114 . The ability to rotate the arm  112  about pivot  512  allows the patient or healthcare provider to align with temporal artery  514  of the head  114  and adjust for differing facial structures of head  114 . 
     The example wearable measurement devices described herein incorporate advances in battery technology, RF-powering, and energy storage techniques. In order to power the sensors and discrete components while consuming a low amount of power, the wearable measurement devices includes a custom integrated circuit component that will greatly reduce the size, complexity, and the power consumption. The circuit can be designed in a suitable way to accommodate signal processing and control of the wearable measurement devices. 
     In one example, a battery is utilized to power the wearable measurement device&#39;s components. The battery will provide power for wireless signal transmission to a patient computing device and for the discrete components. In one example, the battery is replaceable or rechargeable. Rechargeable power sources can be charged through a wired connection such as a direct plug-in through a wall outlet or through micro-USB charging where the ear cuff contains the female end of the micro-USB plug. In one example, the wearable measurement device includes energy harvesters to acquire and store energy. Energy harvesters such as those that harvest energy from heat, sunlight, or vibration may be used. This may ensure a longer time of use for the patient. In one example, the wearable measurement device can be charged wirelessly. To ensure proper operation of the wearable measurement device, common power regulating circuits will be used to maximize efficiency and longevity of use. In another example, the wearable measurement device can be wirelessly charged through inductively coupled circuits. No battery is needed in this particular example, but proper regulation of the acquired energy is provided by power electronic circuitry. 
     It should be appreciated that data transmission between a wearable measurement device and a patient computing device will be done wirelessly through suitable technologies and protocols such as Bluetooth, Zigbee or Near Field Comunication (NFC) and other short range data transmission techniques. In one example, proper conversion of the signals contained must be performed to allow efficient transfer of the information. As an example, the sensors may output an analog signal which will need to be converted to a digital signal before being wirelessly transferred to the patient computing device. In one example, Bluetooth technology may be used which is low in cost, easy to interface, small in size, and requires low power operation. In one example, near field communications (“NFC”) can be used for transmitting data to the patient computing device. NFC technology utilizes small circuit components and is low power. With NFC technology, the patient can swipe or move the patient computing device into proximity of the site of the BPM or BOV to initiate transmission of the information. In one example, radio-frequency identification (RFID) can be used for transmitting data to the patient computing device. The signals acquired by the patient computing device are translated and displayed onto a user interface. 
     It should be further appreciated that, although wireless communication is described herein, the wearable measurement device may further be configured to communicate data to the patient computing device via wired connection. For example, the wearable measurement device may include a data port, such as a USB port, to facilitate communication with a patient computing device. In one example, either the same port or an additional port may be used to facilitate charging the battery of the wearable measurement device. 
     In one example, a wearable measurement device includes the ability to track the amount of steps and the posture of the patient. By incorporating micro-electric-mechanical systems (“MEMS”), including accelerometers and gyroscopes, into a wearable measurement device, data indicative of the position of the patient, the number of steps taken, whether the patient is exercising, and for how long the patient is exercising can be captured. 
     In one example, the wearable measurement device has the ability to track the period of use and when the patient uses it. For example, when a blood pressure waveform is acquired and detected, a timer is initiated that will count the number of seconds of use. In another example, the wearable measurement device can use the MEMS devices to know when the device is worn through vibration characteristics. This information can be displayed on the interface of the patient computing device. In one example, the wearable measurement device sends reminders in the form of audio or visual alerts through the user interface of the patient computing device when the device has been inactive or unused for a certain time. Tracking of such information may be useful for ensuring compliance, for example. 
       FIG. 18  illustrates an example method  1800  for measuring patient vital signs. At step  1802 , a wearable measurement device is disposed on a patient body using a suitable mechanism such as a clip, a strap, adhesive, and so on. In one example, the wearable device is disposed on a patient&#39;s ear. In one example, a plurality of wearable measurement devices are disposed on the patient&#39;s body. 
     At step  1804 , the wearable measurement device continuously obtains data representative of the patient&#39;s vital signs. For example, the wearable measurement device continuously obtains data such as blood pressure, blood oxygen saturation, heart rate, body temperature, respiratory rate, and body position. In one example, the wearable measurement device stores the obtained data, while in another example, the wearable measurement device communicates the obtained data to a third-party computing device. 
     At step  1806 , the obtained data is converted and formatted. For example, the obtained data may be converted into a format that is more easily interpreted by a user and more meaningful for the user. In one example, the obtained data is converted by the wearable measurement device. In another example, the data is converted by a third-party computing device. 
     At step  1808 , the converted data is presented to a user. In one example, the data is presented to the user at the wearable communication device. In one example, the data is presented to a user, such as a patient, a doctor, a family member, or another suitable party, via a third-party computing device. In one example, the converted data is first communicated to the wearable measurement device by the third-party computing device before the wearable computing device presents the data. Data presented to the user may include, for example, systolic blood pressure measured in mmHg, diastolic blood pressure measured in mmHg, blood oxygen saturation measured in percentage, heart rate measured in beats per minute, respiratory rate measured in breaths per minute, body temperature measured in degrees Fahrenheit or degrees Celsius. Displayed information can further include signals such as an arterial waveform, polyplethysmography, and respiratory rate. 
     In one example, the third-party computing device stores the received and converted data in a data store associated with the patient from which the vital sign data was obtained. For example, the data may be stored in an EMR record associated with the patient. 
     It should be appreciate that a patient, as referenced throughout the description herein, may include a human or any suitable animal for which it may be desirable to collect vital sign data. 
     It should be appreciated that the third-party computing device  110  of  FIG. 1 , including a user interface, may be any suitable form such as a smart watch, an electronic display, a mobile application on a smart phone, tablet, or any other smart device, or an application on any personal computing device. The user interface of the patent computing device may contain information such as the patient&#39;s name, medical condition (if any), current medications, age, the number of calories burned, the number of steps taken, weight, usage time, blood pressure, blood oxygen saturation, heart rate, or body temperature. Physicians, family, friends, or other third parties can also be issued a user interface via a third-party computing device and be given access to patient information or be alerted when vital signs are outside of a normal range of the patient. Additionally, the user interface will contain software to translate the signals acquired from the wearable measurement devices. Thus, the wearable measurement device is solely designed to acquire the signal while the user interface portion of the patient computing device is designed to translate the signals into meaningful data such as blood pressure or heart rate. In one example, the wearable measurement device may be configured to translate or manipulate the acquired data before transmitting the data to the patient computing device. 
       FIG. 19  is a schematic diagram of an example computer  1900  for implementing the example third-party computing device  110  of  FIG. 1 . Computer  1900  includes a processor  1902 , memory  1904 , a storage device  1906 , and a communication port  1908  operably connected by an interface  1910  via a bus  1912 . Processor  1902  processes instructions, via memory  1904 , for execution within computer  1900 . In an example embodiment, multiple processors along with multiple memories may be used. 
     Memory  1904  may be volatile memory or non-volatile memory. Memory  1904  may be a computer-readable medium, such as a magnetic disk or optical disk, solid-state drive (SSD), Random Access Memory, disk drive or tape drive device. Storage device  1906  may be a computer-readable medium, such as floppy disk devices, a hard disk device, optical disk device, a tape device, a flash memory, phase change memory, or other similar solid state memory device, or an array of devices, including devices in a storage area network of other configurations. In one example, the storage device  1906  includes dual solid state disk drives. A computer program product can be tangibly embodied in a computer-readable medium such as memory  1904  or storage device  1906 . 
     To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use, See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or components. 
     While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.