Method And Apparatus For Pressure Detection

Abstract

A device may include a first locking mechanism configured to connect a first end of the device to a needle, a second locking mechanism configured to connect a second end of the device to a syringe, a pressure transducer, a microprocessor and a light emitting diode. The pressure transducer may be configured to measure a first pressure at a first time and a second pressure at a second time. The microprocessor may be configured to receive the first pressure and the second pressure from the pressure transducer, determine a pressure difference between the first pressure and the second pressure, and determine a time difference between the first time and the second time. The light emitting diode may be configured to signal when the needle is properly situated based on the pressure difference and the time difference.

1 . A device comprising:
 a first locking mechanism configured to connect a first end of the device to a needle;   a second locking mechanism configured to connect a second end of the device to a syringe;   a pressure transducer configured to measure a first pressure at a first time and a second pressure at a second time;   a microprocessor configured to:
 receive the first pressure and the second pressure from the pressure transducer, 
 determine a pressure difference between the first pressure and the second pressure, and 
 determine a time difference between the first time and the second time; and 
   a light emitting diode configured to signal when the needle is properly situated based on the pressure difference and the time difference.   
   
   
       2 . The device of  claim 1 , further comprising:
 a microsensor configured to produce an electrical signal.   
   
   
       3 . The device of  claim 1 , further comprising:
 a power source configured to power the pressure transducer and the microprocessor.   
   
   
       4 . The device of  claim 1 , further comprising:
 an external housing made from a biocompatible plastic.   
   
   
       5 . The device of  claim 1 , further comprising:
 a user interface configured to display the first pressure and the second pressure.   
   
   
       6 . The device of  claim 1 , further comprising one or more of the following:
 the pressure transducer further configured to output a voltage signal;   an amplifier configured to amplify the output voltage signal;   a filter configured to reduce system noise from the pressure transducer; and   signal processing circuitry configured to ensure that the output voltage signal is compatible with the microprocessor.   
   
   
       7 . The device of  claim 1  wherein the device is disposable. 
   
   
       8 . A syringe comprising:
 a pressure detection device embedded in the syringe, the pressure detection device comprising:
 a pressure transducer configured to measure a first pressure at a first time and a second pressure at a second time, 
 a microprocessor configured to:
 receive the first pressure and the second pressure from the pressure transducer, 
 determine a pressure difference between the first pressure and the second pressure, and 
 determine a time difference between the first time and the second time; and 
 
   a light emitting diode configured to signal when the needle is properly situated based on the pressure difference and the time difference.   
   
   
       9 . The syringe of  claim 8 , further comprising:
 a power source configured to power the pressure transducer and the microprocessor in the pressure detection device.   
   
   
       10 . A method of using a pressure detection device comprising:
 obtaining a first pressure at a first time and a second pressure at a second time in real time via a pressure transducer;   determining a pressure difference between the first pressure and the second pressure;   determining a time difference between the first time and the second time;   performing a first determination to determine whether the pressure difference divided by the time difference is less than a slope threshold; and   signaling whether the needle is properly situated based on the first determination.   
   
   
       11 . The method of  claim 10  wherein the pressure detection device is positioned between a syringe and an injection needle hub. 
   
   
       12 . The method of  claim 10  wherein the first pressure is an atmospheric pressure and the second pressure is a cavity pressure. 
   
   
       13 . The method of  claim 10  wherein signaling whether the needle is properly situated comprises one or more of the following:
 displaying a light from a light emitting diode, and   producing an audible sound.   
   
   
       14 . The method of  claim 10 , further comprising:
 storing the first pressure; and   retrieving the stored first pressure to display on a user interface.   
   
   
       15 . The method of  claim 10 , further comprising:
 performing a pressure threshold determination to determine whether the pressure difference exceeds a pressure threshold;   performing a time threshold determination to determine whether the time difference is less than a time threshold;   wherein signaling whether the needle is properly situated is further based on the pressure threshold determination and the time threshold determination.   
   
   
       16 . The method of  claim 15 , further comprising:
 determining whether the second pressure is less than a pressure value,   wherein signaling whether the needle is properly situated is further based on whether the second pressure is less than the pressure value.   
   
   
       17 . The method of  claim 10 , further comprising:
 determining an internal air volume inside the pressure detection device, wherein the internal air volume is less than 0.5 mL.   
   
   
       18 . The method of  claim 10  wherein the slope threshold is approximately −1.5. 
   
   
       19 . The method of  claim 10 , further comprising:
 obtaining a third pressure at a third time;   performing a second determination to determine whether the third pressure is less than a pressure threshold; and   performing a third determination to determine whether a second time difference between the second time and the third time is greater than a time threshold,   wherein signaling whether the needle is properly situated is further based on the second determination and the third determination.   
   
   
       20 . The method of  claim 19  wherein the time threshold is approximately 0.1 seconds. 
   
   
       21 . The method of  claim 19  wherein the pressure threshold is approximately −0.2 mmHg. 
   
   
       22 . A system comprising:
 a device comprising:
 a first locking mechanism configured to connect a first end of the device to a needle, 
 a second locking mechanism configured to connect a second end of the device to a syringe, and 
 a pressure transducer configured to measure a first pressure at a first time and a second pressure at a second time; and 
   a computing system configured to:
 receive the first pressure and the second pressure from the pressure transducer, 
 determine a pressure difference, and 
 perform a second determination to determine a time difference.