Sub-epidermal electric warning device

Abstract

A sub-epidermal electric warning device has electrodes penetrating through the patient's epidermis and bipolar electric warning signals are transmitted to the sub-epidermal tissue by these electrodes. A device for surveillance of vital signs, analyte levels, or treatment parameters is using a sub-epidermal electric warning device for notifying the patient in situations requiring intervention.

1 . A sub-epidermal electric warning device, comprising:
 electrodes to penetrate through a patient's epidermis into sub-epidermal tissue; and   circuitry to transmit unipolar voltage pulses to the electrodes, the unipolar voltage pulses to create bipolar current pulses of alternating positive and negative polarity in the sub-epidermal tissue.   
     
     
         2 . The sub-epidermal warning device according to  claim 1 , wherein:
 the electrodes are electrically connected to each other to have a same potential during a portion of the unipolar voltage pulses.   
     
     
         3 . The sub-epidermal warning device according to  claim 2 , wherein:
 one of the electrodes is grounded, and another of the electrodes is electrically connected to a power source during another portion of the unipolar voltage pulses which is different than said portion of the unipolar voltage pulses.   
     
     
         4 . The sub-epidermal warning device according to  claim 3 , wherein:
 the unipolar voltage pulses include a rising edge and a falling edge,   when the unipolar voltage pulses are at the rising edge, the bipolar current pulses have a first polarity, and   when the unipolar voltage pulses are at the falling edge, the bipolar current pulses transition to a second polarity that is opposite to the first polarity.   
     
     
         5 . The sub-epidermal warning device according to  claim 1 , wherein:
 the unipolar voltage pulses include a rising edge and a falling edge,   when the unipolar voltage pulses are at the rising edge, the bipolar current pulses have a first polarity, and   when the unipolar voltage pulses are at the falling edge, the bipolar current pulses transition to a second polarity that is opposite to the first polarity.   
     
     
         6 . The sub-epidermal warning device according to  claim 1 , wherein:
 the unipolar voltage pulses are 2 volts or more away from zero volts, and   the unipolar voltage pulses are 9 volts or less away from zero volts.   
     
     
         7 . The sub-epidermal warning device according to  claim 1 , wherein:
 a duration of the unipolar voltage pulses is 1 to 100 milliseconds.   
     
     
         8 . The sub-epidermal warning device according to  claim 1 , wherein:
 a period from a rising edge of one of the unipolar voltage pulses until a rising edge of a next of the unipolar voltage pulses is of the order of 1 second.   
     
     
         9 . The sub-epidermal warning device according to  claim 6 , wherein:
 a duration of the unipolar voltage pulses is 1 to 100 milliseconds.   
     
     
         10 . The sub-epidermal warning device according to  claim 9 , wherein:
 a period from a rising edge of one of the unipolar voltage pulses until a rising edge of a next of the unipolar voltage pulses is of the order of 1 second.   
     
     
         11 . The sub-epidermal warning device according to  claim 1 , wherein:
 a number of the electrodes is 2.   
     
     
         12 . The sub-epidermal warning device according to  claim 1 , wherein the circuitry includes:
 a pulse generator including a DC-DC converter and a controller.   
     
     
         13 . The sub-epidermal warning device according to  claim 1 , wherein the circuitry includes:
 an electronic switch, which connects and disconnects one of the electrodes to a voltage which generates the unipolar voltage pulses.   
     
     
         14 . The sub-epidermal warning device according to  claim 13 , wherein:
 another of the electrodes is always connected to ground.   
     
     
         15 . The sub-epidermal warning device according to  claim 1 , wherein:
 one of the electrodes is always connected to ground.   
     
     
         16 . The sub-epidermal warning device according to  claim 1 , further comprising:
 an inserter to provide sub-epidermal insertion of the electrodes into the skin, wherein the inserter is configured such that that in a ready-to-use position, the inserter keeps the skin away from contacting a tip of the electrodes which are fixedly positioned by a bottom of a casing of the device and, upon activation, pulls the skin towards the tip of the electrodes with a velocity to effect piercing of the skin and sub-epidermal insertion of the electrodes.   
     
     
         17 . The sub-epidermal electric warning device according to  claim 1 , wherein the electric warning signal is delivered with increasing intensity over time until the electric warning signal is recognized and confirmed by the patient. 
     
     
         18 . The sub-epidermal electric warning device according to  claim 17 , wherein the electric warning signal is delivered with different rhythm for different warning messages. 
     
     
         19 . The sub-epidermal electric warning device according to  claim 1 , further comprising:
 at least one sensor system configured such that when abnormal values for vital signs are measured by the at least one sensor system, the at least one sensor system transmits the input signals to the circuitry to generate the unipolar voltage pulses.   
     
     
         20 . The sub-epidermal electric warning device according to  claim 19 , wherein the at least one sensor system comprises subcutaneously implanted sensors to provide determination of analyte concentrations.