System and method for skin rejuvenation using impedance monitoring

An apparatus for treating tissue, comprising:

• a first treatment applicator head including a first plurality of needles;
• an applicator body having a first end connected to the first treatment applicator head;
• and
• a control system;
• wherein the applicator body includes a second end in communication with a radio frequency (RF) power source and the control system;
• wherein the first treatment applicator head, when connected to the applicator body, is electrically connected with the RF power source in communication with the second end;
• wherein the control system is configured to:
• detect an initial increase in impedance
• determine, while monitoring impedance changes while the first plurality of needles contact a portion of the tissue, that an impedance drop has occurred that meets or exceeds an expected threshold impedance drop following the initial increase in impedance, and
• initiate a treatment time period in response to the determining that the impedance drop has occurred that meets or exceeds the expected threshold impedance drop following the initial increase in impedance, wherein the monitored impedance changes correspond to impedance changes in the portion of the tissue, wherein a timer for the treatment with RF energy is set by the control system in response to the impedance drop being detected following the initial increase in impedance,
• wherein the first plurality of needles is configured to deliver treatment energy during the treatment time period,
• wherein the control system terminates tissue treatment at end of the treatment time period.

A method of treating tissue comprising:

• applying radio frequency (RF) power to tissue through a plurality of electrodes, the plurality of electrodes contacting a portion of the tissue, wherein each electrode is a needle in electrical communication with a control system;
• during the application of the RF power, monitoring impedance changes of the plurality of electrodes over time;
• detecting a first impedance value of the plurality of electrodes before or during monitoring impedances of the plurality of electrodes over time wherein the first impedance value is detected while monitoring the impedances of the electrode array over time;
• following the detection of the first impedance value, continuing monitoring changes to the impedance of the electrode array contacting the portion of tissue over time detect an initial increase in impedance;
• determining, while continuing monitoring impedance changes, that an impedance drop has occurred that meets or exceeds an expected threshold impedance drop while each needle is in contact with the portion of tissue, wherein the monitored impedance changes correspond to impedance changes in a portion of the tissue following the initial increase in impedance;
• controlling the application of RF power based on the monitored impedance changes;
• initiating a treatment time period in response to the determining that the impedance drop has occurred that meets or exceeds the expected threshold impedance drop following the initial increase in impedance, wherein the monitored impedance changes of the plurality of electrodes over time correspond to impedance changes in the portion of the tissue over time;
• delivering treatment energy during the treatment time period using the plurality of electrodes, wherein delivery of the treatment energy is initiated by detecting that the impedance drop has occurred that meets or exceeds the expected threshold impedance following the initial increase in impedance;
• and
• terminating application of the treatment energy at the end of the treatment time period.