Real time ultrasound thermal dose monitoring system for tumor ablation therapy

An ultrasound transmitter of an interventional tool, the ultrasound transmitter, comprising:

• a liquid cell for securing to the interventional tool;
• an optical fiber having a transmitting end coupled to the liquid cell such that the transmitting end is fixed within an interior space defined by the liquid cell, the interior space containing a fluid;
• and
• a laser optically coupled to the optical fiber, the optical fiber being configured to propagate a laser beam generated by the laser to the transmitting end of the optical fiber,
• wherein the fluid is selected to absorb the laser beam generated by the laser at the transmitting end of the optical fiber and wherein the liquid cell comprises an expandable portion that is free to expand and transmit acoustic energy generated by the fluid due to thermal expansion and phase change of the fluid when contained within the liquid cell and while the fluid is being exposed to energy from the laser beam to induce a Giant Photo-Acoustic Effect of the fluid and generate the acoustic energy.

An interventional system with real-time ablation thermal dose monitoring, comprising:

• an interventional tool including an ultrasound transmitter configured to be arranged proximate a region of tissue while undergoing an ablation procedure, wherein the ultrasound transmitter comprises:
• a liquid cell including a fluid containing a suspension of carbon particles;
• and
• an optical fiber having a transmitting end coupled to the liquid cell such that the transmitting end is fixed within an interior space defined by the liquid cell, wherein the optical fiber is configured to be optically coupled to a laser, the optical fiber being configured to propagate a laser beam generated by the laser to the transmitting end of the optical fiber,
• wherein the fluid is selected to absorb the laser beam generated by the laser at the transmitting end of the optical fiber and wherein the liquid cell comprises an expandable portion that is free to expand and transmit acoustic energy generated by the fluid due to thermal expansion and phase change of the fluid when contained within the liquid cell and while the fluid is being exposed to energy from the laser beam to induce a Giant Photo-Acoustic Effect of the fluid and generate the acoustic energy;
• an ultrasound receiver configured to be arranged proximate the region of tissue such that the region of tissue is between the ultrasound transmitter and the ultrasound receiver, the ultrasound receiver being further configured to receive ultrasound signals from the ultrasound transmitter after transmission through the region of tissue;
• and
• a signal processing system configured to communicate with the ultrasound transmitter to obtain information concerning ultrasound pulse transmission times, and the signal processing system configured to communicate with the ultrasound receiver to receive the detection signals and to calculate, based on the detection signals, a thermal dose delivered to the region of tissue in real time during the ablation procedure,
• wherein the ultrasound receiver provides information concerning reference detection times of pulses with known transmission times and provides corresponding detection times of detection signals from a thermal ablation zone of a tissue, and
• wherein the signal processing system is configured to calculate the thermal dose based on time of flight information using the reference detection times and based on time of flight information using the corresponding detection times of the detection signals from the thermal ablation zone.