Patch sensor for measuring blood pressure without a cuff

Abstract

A monitoring device, method and system for monitoring vital signs of a patient over a wireless network are disclosed herein. The monitoring device includes an adhesive patch sensor, typically mounted on a patient's head, and a processing component. The adhesive patch sensor typically includes an optical system that generates an optical waveform, and an electrode that generates an electrical waveform. The processing component processes the optical and electrical waveforms, along with a calibration table, to determine the patient's vital signs.

1 . A system for measuring vital signs from a patient, the system comprising: 
 an adhesive patch sensor comprising    1) an optical system comprising a first LED which emits a first optical wavelength, a second LED which emits a second optical wavelength, and a photodetector that detects reflected radiation from at least one of the first LED and the second LED to generate at least one radiation-induced photocurrent,    2) an electrical system comprising an electrode that generates an electrical impulse, and    3) an adhesive component for adhering the adhesive patch sensor to the patient's skin; and    a controller in electrical communication with the adhesive patch sensor, the controller comprising    1) means to convert the at least one radiation-induced photocurrent into an optical waveform,    2) a microcontroller comprising means to generate an electrical waveform from the electrical impulse, the microcontroller configured to operate a computer algorithm that determines a blood pressure value and at least one other vital sign by processing i) a time-dependent property of the optical waveform, ii) a time-dependent property of the electrical waveform, iii) a time delay between the optical waveform and the electrical waveform, and iv) at least one calibration parameter.    
     
     
         2 . The system of  claim 1 , wherein the computer algorithm of the microcontroller further comprises: 
 a first step for measuring a first amplitude of the optical waveform;    a second step for measuring a second amplitude of the electrical waveform; and    a third step for measuring a time delay between the first amplitude of the optical waveform and the second amplitude of the electrical waveform.    
     
     
         3 . The system of  claim 2 , wherein the computer algorithm of the microcontroller processes the time delay and the at least one calibration parameter to determine a blood pressure value for the patient.  
     
     
         4 . The system of  claim 3 , wherein the computer algorithm of the microcontroller processes: the electrical waveform to determine a heart rate of the patient; the optical waveform and a second optical waveform generated from a second radiation-induced photocurrent from the photodetector to determine a pulse oximetry value for the patient; and the optical waveform and the electrical waveform to determine a blood pressure value of the patient.  
     
     
         5 . The system of  claim 1 , further comprising a cable to connect the adhesive patch sensor to the controller.  
     
     
         6 . The system of  claim 1 , wherein both the controller and adhesive patch sensor each comprise a wireless component.  
     
     
         7 . The system of  claim 6 , further comprising a wireless interface between the separate wireless components.  
     
     
         8 . The system of  claim 1 , further comprising a component configured to connect to the Internet.  
     
     
         9 . The system of  claim 1 , further comprising an Internet-accessible website configured to display the blood pressure of the patient and the at least one other vital sign.  
     
     
         10 . The system of  claim 1 , wherein the adhesive component is further configured to attach on or near the patient's head.  
     
     
         11 . A method for measuring vital signs from a patient, the method comprising the following steps: 
 attaching an adhesive patch sensor on or near a patient's head, the adhesive patch sensor comprising    1) an optical system comprising a first LED which emits a first optical wavelength, a second LED which emits a second optical wavelength, and a photodetector that detects reflected radiation from at least one of the first LED and the second LED to generate at least one radiation-induced photocurrent,    2) an electrical system comprising an electrode that generates an electrical impulse, and    3) an adhesive component for adhering the adhesive patch sensor to the patient's skin;    generating an optical waveform from the at least one radiation-induced photocurrent;    generating an electrical waveform from the electrical impulse; 
 processing the optical waveform and electrical waveform with a controller in communication with the adhesive patch sensor, the controller comprising a microcontroller configured to operate a computer algorithm that determines a blood pressure value and at least one other vital sign by processing i) a time-dependent property of the optical waveform, ii) a time delay between the optical waveform and the electrical waveform, and iii) at least one calibration parameter.  
   
     
     
         12 . The method of  claim 11 , further comprising: 
 a step for measuring a first amplitude of the optical waveform;    a step for measuring a second amplitude of the electrical waveform; and    a step for measuring a time delay between the first amplitude of the optical waveform and the second amplitude of the electrical waveform.    
     
     
         13 . The method of  claim 12 , further comprising a step for processing the time delay and the at least one calibration parameter to determine a blood pressure value for the patient.  
     
     
         14 . The method of  claim 13 , further comprising: 
 a step for processing the electrical waveform to determine a heart rate for the patient;    a step for processing the optical waveform and a second optical waveform generated from a second radiation-induced photocurrent from the photodetector to determine a pulse oximetry value for the patient; and    a step for processing the optical waveform and the electrical waveform to determine a blood pressure value for the patient.    
     
     
         15 . The method of  claim 11 , further comprising a step of transmitting the blood pressure value of the patient and the at least one vital sign value of the patient to an Internet-accessible website.  
     
     
         16 . The method of  claim 15 , further comprising a step of displaying the blood pressure value of the patient and the at least one vital sign value of the patient on the Internet-accessible website.  
     
     
         17 . A method for measuring vital signs from a patient, the method comprising the following steps: 
 attaching a vital sign-measuring system on or near a patient's head, the system comprising:    an adhesive patch sensor comprising    1) an optical system comprising a first LED which emits a first optical wavelength, a second LED which emits a second optical wavelength, and a photodetector that detects reflected radiation from at least one of the first LED and the second LED to generate at least one radiation-induced photocurrent,    2) an electrical system comprising an electrode that generates an electrical impulse, and    3) an adhesive component for adhering the adhesive patch sensor to the patient's skin;    generating an optical waveform from the at least one radiation-induced photocurrent;    generating an electrical waveform from the electrical impulse;    processing the optical waveform and the electrical waveform with a controller in communication with the adhesive patch sensor, the controller comprising    a microcontroller configured to operate an algorithm that determines a blood pressure value of the patient and at least one other vital sign using the following steps, i) determining a time-dependent property of the optical waveform using a first numerical fitting algorithm, ii) determining a time-dependent property of the electrical waveform using a second numerical fitting algorithm, iii) comparing the time-dependent properties of the optical and electrical waveform to determine a time delay, and iv) comparing the time delay to at least one calibration parameter to determine the blood pressure value of the patient.    
     
     
         18 . A method for measuring vital signs from a patient, the method comprising the following steps: 
 attaching a vital sign-measuring system on or near a patient's head, the vital-sign measuring system comprising    1) an optical system comprising a first LED which emits a first optical wavelength, a second LED which emits a second optical wavelength, and a photodetector that detects reflected radiation from at least one of the first LED and the second LED to generate at least one radiation-induced photocurrent,    2) an electrical system comprising an electrode that generates an electrical impulse, and    3) an adhesive component for adhering the adhesive patch sensor to the patient's skin;    generating an optical waveform from the at least one radiation-induced photocurrent;    generating an electrical waveform from the electrical impulse; and    processing the optical waveform and the electrical waveform with a controller in communication with the vital sign measuring system, the controller comprising    a microcontroller configured to operate an algorithm that determines a blood pressure value for the patient and at least one other vital sign of the patient using the following steps i) determining a local maximum value of the optical waveform, ii) determining a local maximum value of the electrical waveform, iii) comparing the local maximum value of the optical waveform and the local maximum value of the electrical waveform to determine a time delay between the optical waveform and the electrical waveform, and iv) comparing the time delay to at least one calibration parameter to determine the blood pressure value of the patient.