Biomedical subjects

W W Cimino

Publications and source records attributed to W W Cimino.

4 recordsLinked to original sources

PubMed1999

The physics of soft tissue fragmentation using ultrasonic frequency vibration of metal probes.

The physics of soft tissue fragmentation using ultrasonic frequency vibration of metal probes has been discussed, including a comparison and contrast of ultrasound radiation and ultrasonic surgery and a brief history of ultrasonic surgery. Three theories of interaction and an assessment of power flow have been presented. Many unanswered questions remain concerning the physics of soft tissue fragmentation using ultrasonic frequency vibratory energy. This effort has hopefully contributed to a better understanding of the general principles involved.

Adipose Tissue↗

PubMed1996

Physics of ultrasonic surgery using tissue fragmentation.

The ultrasonic surgical aspirator employs a vibrating metal tip to fragment tissue and then aspirates the debris through the hollow center of the tip. The mechanism of interaction has been stated to be poorly understood, most likely related to cavitation, possibly acting in concert with other mechanical actions. The role of stroke, suction, frequency, tissue type, and tip area have been examined with regard to tissue fragmentation rate. Suction is shown to make a significant contribution to the interaction. Photographic and acoustic data from experiments in water and on a range of fresh pig tissues are used to investigate the fragmentation effect. A model for the primary mechanism for tissue fragmentation is presented. This involves the horn-tip impact and other mechanical forces, operating in combination with hydrodynamic forces applied to the tissue on the forward stroke in each cycle. No evidence of cavitation in tissue was observed.

Acoustics↗

PubMed1996

Physics of ultrasonic surgery using tissue fragmentation: Part I.

The ultrasonic surgical aspirator employs a vibrating metal tip to fragment tissue and then aspirates the debris through the hollow center of the tip. The mechanism of interaction has been stated to be poorly understood, most likely related to cavitation, possibly in concert with other mechanical actions. In Part I (of two parts), the role of stroke, suction, frequency, tissue type and tip area are examined with regard to tissue fragmentation rate. A tissue quantifier which can be used to relate the performance of the ultrasonic aspirator and a selected tissue is described. Suction is shown to make a significant contribution to the interaction. Thermal and tip load experiments are used to estimate the acoustic pressures and powers at the tip. In Part II, photographic and acoustic data from experiments in water and on a range of fresh pig tissues are used to further investigate the fragmentation effect.

Animals↗

PubMed1996

Physics of ultrasonic surgery using tissue fragmentation: Part II.

Ultrasonic surgical aspirators typically operate at a frequency between 20 and 60 kHz. A vibrating hollow horn moves against the tissue and suction is applied. The interaction causes tissue to fragment; the fragmented material is then aspirated. However, the mechanism of interaction is poorly understood: the most common view relates it to cavitation, probably active in concert with other mechanisms, including the direct jack-hammer effect, shock-induced stress, acoustic microstreaming and shearing stress. It has also been attributed to chopping, which will produce emulsification. This article reports a study that collected and analyzed ultrasonic, high-speed photographic, visual/optical and electrical data for a 23-kHz unit operating in water and a range of fresh pig tissues. The primary mechanism for tissue fragmentation is shown to be horn-tip impact and other mechanical forces, operating in combination with hydrodynamic forces applied to the tissue on the forward stroke in each cycle. No evidence of cavitation in tissue was observed.

Animals↗