AMNIUS: Advancing Tissue Adaptivity with Additively Manufactured Nitinol Ultrasonic Transducers in Robot-Assisted Surgery

Ultrasonic cutting instruments, widespread in surgical procedures today for operations on both soft and hard tissues, use high-energy ultrasonic oscillations in the 0.1 mm range to effectively remove soft tissue, seal vessels, or dissect bone tissue depending on the resonance frequency.

Advantages of ultrasonic surgery include the ability to cut and dissect bone or soft tissue with precision and selectivity, with minimal damage to delicate tissue structures like nerves, muscles, blood vessels and ligaments. This results in improved patient outcomes, with evidence of lower levels of tissue necrosis and faster recovery times.

However, there remain some key technology limitations of ultrasonic surgical devices which are limiting future development.

The first is that these cutting devices tend to be single use, designed either for operations on soft tissues and coagulation procedures, or for the surgical cutting of harder mineralised tissue such as bone.

Secondly, the supporting instrumentation required can be expensive, such as the power generators for the ultrasonic transducers, and the handpieces necessary to undertake the surgery.

This project aims to address these technological shortcomings, and barriers to future innovation, to enable the development of a multifunctional tissue-selective ultrasonic instrument for cutting and coagulation of soft tissue, also able to undertake surgical cutting of bone.

The prototype ultrasonic cutting device will incorporate a nickel-titanium, Nitinol, shape memory alloy, whose tuneable material properties can be used to actively adjust the dynamic performance of the transducer.

This material will be additively manufactured, to provide flexibility in the design approach and to optimise the integration of the material with an ultrasonic transducer.

It is anticipated that the prototype ultrasonic surgical device will be scalable to be inexpensive in comparison to the current requirement to acquire separate instruments for bone and soft tissue interventions.