Methods and ultrasonic devices and systems for vessel sealing

#The present disclosure relates to a method and an ultrasonic surgical device or system for sealing a vessel. More particularly, the present disclosure relates to a method and an ultrasonic surgical device or system that controls delivery of electrical energy to seal the vessel based on a size of the vessel.

#Ultrasonic surgical devices are used for treating many medical conditions, such as removal of tissue and cauterization and sealing of vessels. Ultrasonic surgical devices utilize ultrasonic energy to generate vibrations with an ultrasonic transducer along a longitudinal axis of a cutting blade. Unlike electrosurgical devices, which require electrical current to flow through a patient, ultrasonic surgical devices operate by applying mechanical action of a transducer that is driven at a mechanical resonant frequency. By placing a resonant wave along the length of the blade, high-speed longitudinal mechanical movement is produced at the end of the blade. Ultrasonic surgical devices are advantageous because the mechanical vibrations transmitted to the end of the blade are effective at treating tissue using the heat energy produced by the mechanical movements. Ultrasonic surgical devices are particularly well suited for minimally invasive procedures, such as endoscopic or laparoscopic procedures, where the blade is passed through a trocar to reach the surgical site. Further, ultrasonic surgical devices have been demonstrated to achieve hemostasis and sealing of tissue with minimal lateral thermal damage and low smoke generation.

#Since vessels differ in size, treating different vessels with a single treatment approach may not provide ideal results. Accordingly, there is continuing interest in improving treatment of vessels to account for the size of the target vessel.

#The present disclosure may be understood by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:

#FIG. 1A is a side elevation view of an ultrasonic surgical device in accordance with embodiments of the present disclosure;

#FIG. 1B is a perspective view of parts separated, which shows the left portion of a handle, a transducer, and the right portion of the ultrasonic surgical device of FIG. 1A in accordance with embodiments of the present disclosure;

#Generally, the present disclosure provides an ultrasonic surgical device and system and a method for controlling a heating rate of a vessel based on the size of the vessel. In accordance with aspects of the present disclosure, the ultrasonic surgical device estimates a size of a vessel to be sealed. Based on the estimated size of the vessel, the ultrasonic surgical device controls a heating rate of the vessel to seal the vessel. An ultrasonic surgical device includes a transducer that provides and couples mechanical motion to an end effector. When the transducer is driven at a resonant frequency, the end effector achieves maximum motion for a particular input energy. Various factors can affect the resonant frequency of a transducer and cause it to drift or shift, including temperature. Thus, there is a relationship between temperature and the resonant frequency of an ultrasonic transducer. In accordance with aspects of the present disclosure, an ultrasonic surgical device can achieve an appropriate heating rate of a vessel by monitoring changes in the resonant frequency of the transducer over time and controlling the electrical energy supplied to the ultrasonic surgical device based on the changes in resonant frequency. By using these various controls, the ultrasonic surgical device provides controlled ultrasonic mechanical motions to seal various vessels in accordance with embodiments of the present disclosure.

#With reference to FIGS. 1A and 1B, an ultrasonic surgical device 100 for treating tissue is illustrated. The ultrasonic surgical device 100 includes a power source 110, a housing 130, a transducer 150, and an ultrasonic probe 190. The power source 110 provides DC power to the transducer 150. In various embodiments, the power source 110 may be a portable power source, such as a battery, that can be carried to provide DC power at any place. In a further embodiment, the power source 110 may be insertable or integrated into the housing 130 so that the ultrasonic surgical device 100 may be portably carried without disturbances of any cable. In yet another embodiment, the power source 110 may be rechargeable so that the power source 110 may be reusable. In yet another embodiment, the power source 110 may receive power from a wall outlet.

#In another embodiment, the power source 110 may include a converter that is connected to an alternating current (AC) power source and converts the AC power to DC power. The AC power source may be of a relatively low frequency, such as about 60 hertz (Hz), while the ultrasonic surgical device 100 operates at a higher frequency. Thus, the power source 110 may convert the low frequency AC power to DC power so that the DC power may then be inverted to AC power having a frequency suitable to cause the transducer 150 to generate ultrasonic mechanical motions.