Audible frequency vibration of puncture-access medical devices

https://doi.org/10.1016/j.medengphy.2013.12.011Get rights and content

Abstract

Ultrasonic vibration has been proven to help scalpels and puncture devices cut and cauterize, but creates a damaged tissue zone that may not be desirable. We have found that audible frequency vibration applied to a needle not only reduces puncture force more than ultrasonic vibration; it does not cause significant immediate tissue damage. Here we thus present a method for decreasing the force required to insert a puncture-access medical device and an analytical model for predicting performance of a hypodermic needle, which correlates well with tests and shows that needle insertion force is lowered not only by decreasing the outer diameter of the needle, but also by driving the device at its free state resonant (amplitude-maximizing) frequency. Finally, an in vivo histology study is conducted and suggests that audible frequency vibration results in the same degree of immediate local tissue damage as simple manually inserted needles, but that it causes significantly less immediate local tissue damage than ultrasonic vibration.

Section snippets

Introduction and background

Numerous procedures in nearly every field of medicine require the insertion of an access device into a tissue medium along an axial path. Hypodermic needles, laparoscopic trocars, and other similar devices require an axial force to be applied by the user in order to penetrate various tissue layers. This force is determined not only by the geometry of the device itself but also by the mechanical properties of the tissue medium that it penetrates. Due to the complexity and variability of the

Concept

The concept proposed in this study is to drive a needle-like device to oscillate linearly along its longitudinal axis at audible frequencies. This concept is intended to lower the force required to insert a needle-like device by lowering both the frictional and tip forces. The device should oscillate at a frequency below a maximum value such that the insertion force is significantly lowered but there is not sufficient frictional heating for local residual tissue damage to occur. The concept is

Existing devices

The idea of applying vibration to medical instruments is highly prevalent in both patent literature and current medical practice. Ultrasonic cutting devices are common in many surgical specialties including laparoscopy and cosmetic surgery. Although ultrasonic instruments employ vibration to decrease cutting or insertion force, their function relies on frictional heating and cavitation to denature proteins and vaporize intracellular fluid [6]. Depending on the amplitude and frequency at which

Proof of concept: experimental methods

To test the analytical model and concept proposed above, three needle configurations were constructed. The “NN” configuration was a standard 3.81 cm long 16 gauge lancet-tip hypodermic needle (BD 305198). The “VN” configuration was a standard 3.81 cm long 16 gauge lancet-tip hypodermic needle that was driven to oscillate linearly along its long axis at 150 Hz. The needle was fixed to the dust cap of a Jameco 135812 5W voice coil speaker driven by a function generator and power amplifier. The

Proof of concept: results and discussion

Table 1 shows the parameter values used to construct the theoretical insertion force as a function of insertion depth for a standard 16 gauge needle inserted into ballistics gel, corresponding to the NN configuration, given by (6). All possible values of cutting coefficient B are considered.

Fig. 1 shows the axial insertion force as a function of insertion depth for all 15 test repetitions, as well as the theoretical axial insertion force as a function of insertion depth for the parameter values

Device parameters: experimental methods

Once the VN configuration was shown to require the least insertion force, an experiment to determine the effect on insertion force of varying needle diameter, vibration frequency, and peak to peak input voltage amplitude was conducted. A similar test setup to the proof of concept experiment was employed. The VN configuration was made to vibrate at a given parameter configuration. Axial force was recorded as the needle was driven into a block of ballistics gel at a rate of 0.0508 cm per second.

Device parameters: results and discussion

Table 2 shows the parameter values, as well as the measured free-vibration needle-tip peak-to-peak stroke length, for each parameter configuration. Note that as per our earlier assumption, increasing the input signal amplitude with other parameters held constant always resulted in a higher measured needle stroke amplitude. In addition, with other parameters held constant, a frequency of 150 Hz consistently produced the greatest needle-stroke amplitude. This is likely due to the needle apparatus

Frequency range effect on insertion force

In order to validate and differentiate the use of audible frequency vibration from widely available ultrasonic devices, comparative studies of insertion force and local tissue damage were conducted. To evaluate insertion force effects, the required force for a 16 gauge hypodermic needle to puncture deceased porcine skin was measured for non-vibrating, audible frequency vibration, and ultrasonic frequency vibration needle configurations. To achieve ultrasonic frequency oscillation, a needle was

Immediate local tissue effects

It is important in designing medical devices that a new method or instrument does not significantly increase risk to the patient. The immediate effect of linear oscillation of the cutting tip on local tissue damage was observed in an in vivo histology study.1 For comparison and frequency range validation, a device oscillating at ultrasonic frequency was also included. Flat surgical blades were fixed to the

Conclusions and recommendations

Applying axial vibration to a hypodermic needle, specifically within the 50–500 Hz frequency range, lowers both the frictional and tip forces experienced by the needle, and subsequently results in a lower force required to advance the needle into tissue; in addition significantly less immediate tissue damage occurs than if ultrasonic vibration were used. By reducing the force necessary to advance the needle, the probability that the needle will advance too far and cause damage or other

Funding

None.

Conflict of interest

None declared.

Ethical approval

Not required.

Acknowledgments

The authors of this paper would like to thank the MIT Precision Engineering Research Group staff; S. Gallagan and Branson Ultrasonics; Dr. E. Edelman, Dr. R. Marini, M. St-Pierre, Y. Miller, and the MIT Division of Comparative Medicine; The MIT Koch Institute Histology Core Center; Dr. R.T. Bronson; Dr. C. Hogan, Professor I. Hunter, and the MIT Bioinstrumentation Lab; and Dr. J. Bales and the MIT Edgerton Center; for their guidance and generosity in helping with the completion of this study.

References (14)

  • S.P. Davis et al.

    Insertion of microneedles into skin: measurement and prediction of insertion force and needle fracture force

    Journal of Biomechanics

    (2004)
  • A. Slocum

    Precision machine design

    (1992)
  • H. Kataoka et al.

    Measurement of the tip and friction force acting on a needle during penetration

  • A.M. Okamura et al.

    Force modeling for needle insertion into soft tissue

    IEEE Transactions on Biomedical Engineering

    (2004)
  • P. Desai

    Recent trends in obstetrics and gynecology

    (2007)
  • Harmonic®, Ethicon endo-surgery. Available: http://www.ees.com/clinicians/products/energy-devices%23!harmonic-portfolio...
  • Y. Song et al.

    Ultrasound-mediated DNA transfer for bacteria

    Nucleic Acids Research

    (2007)
There are more references available in the full text version of this article.

Cited by (25)

  • Effect of microneedles shape on skin penetration and transdermal drug administration

    2022, Biomaterials Advances
    Citation Excerpt :

    Data emerged that the compressive force required for the needle indentation was reduced, increasing the number of polygon base vertices. It was probably due to the corners in the cross section of the needle body that might effectively reduce the frictional resistance because of the contact area between the skin and the needle was limited to the corners [49,50]. As a result, sqMN and sMN penetrated inside the skin easier than other geometries.

  • Effect of vibration frequency on frictional resistance of brain tissue during vibration-assisted needle insertion

    2020, Medical Engineering and Physics
    Citation Excerpt :

    The pre-treated porcine brain tissue was naturally placed on the acrylic cube box to prevent the material from developing internal stress before the experiment. Because ultrasound-assisted insertion generates more heat during the insertion process, the risk of local tissue burns and postoperative infections increases greatly [26]. Due to the limitations of the experimental equipment, this paper used acoustic vibrations as the auxiliary insertion vibration.

  • Study on design and cutting parameters of rotating needles for core biopsy

    2018, Journal of the Mechanical Behavior of Biomedical Materials
  • Effect of vibration frequency on biopsy needle insertion force

    2017, Medical Engineering and Physics
    Citation Excerpt :

    Begg and Slocum advanced the needle into tissue using a hypodermic needle with axial vibration. The results indicate that a lower insertion force is obtained at the correct frequency and that immediate tissue damage is reduced compared with insertions using ultrasonic vibration [9]. Vibratory fascicle insertion into human skin is also a common phenomenon.

View all citing articles on Scopus
View full text