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Investigation of vibration parameters for needle insertion force reduction

Investigation of vibration parameters for needle insertion force reduction DE GRUYTER Current Directions in Biomedical Engineering 2020;6(3): 20203155 Dennis Rehling*, Jan Liu, Frank Schiele, Kent W. Stewart, Peter P. Pott Investigation of vibration parameters for needle insertion force reduction Abstract: Many medical interventions in therapy and an axial vibration can reduce the required needle insertion diagnostics require needle insertion into tissue. Common forces [3–5]. complications such as increased pain and formation of Begg and Slocum have worked on the concept of an haematoma are caused by wrong needle positioning. It has axial oscillating vibration in the range of audible frequencies. been shown that pain experience and needle positioning can They pierced into gelatine phantoms and investigated the be improved by a reduction of insertion force, which can be reduction of the insertion force in relation to the insertion achieved by vibrating the needle axially. An experimental depth. A vibration with the actuator’s resonant frequency at setup has been designed to investigate the influences of 150 Hz, which resulted in the largest vibration amplitude, different combinations of vibration frequencies (10, 100, and showed the lowest insertion forces [6]. Tan et al. also used 200 Hz) and vibration amplitudes (20, 100, and 500 µm) gelatine phantoms and investigated the additional force during needle insertion into thin sheets of polyethylene generated by a vibration. They claimed that a vibration with terephthalate (PET). A customary 20 W loudspeaker was 500 Hz creates a 17.9 % higher additional force compared to used to generate the vibration. The results indicate a a vibration with 50 Hz [7]. Barnett investigated the puncture maximum reduction of 73 % in puncture force and up to a force when piercing into porcine skin. He examined 100 % reduction in shaft friction force. However, the frequencies from 100 Hz to 2000 Hz and amplitudes from additional vibration force generated by the vibration 5 µm to 50 µm and achieved a maximum reduction of 35 % movement has to be high enough to generate positive effects in puncture force. This was achieved by applying a vibration in terms of force reduction. with 500 Hz and an amplitude of 25 µm [5]. However, no investigation of the influences of frequency and amplitude on Keywords: venepuncture, vibratory needle insertion, different phases during insertion has been conducted. insertion force, force reduction, pain reduction This paper, therefore, investigates different combinations of vibration frequencies and vibration amplitudes and the https://doi.org/10.1515/cdbme-2020-3155 influences on different insertion phases. A sinusoidal vibration movement is used. Combinations of 10, 100, and 200 Hz vibrations and peak-to-peak amplitudes of 20, 100, 1 Introduction 500 µm are investigated. For this purpose, a setup is built consisting of a vibration actuator, a force sensor, and a linear Drawing of blood for diagnostic testing is one of the most motor. This allows the measurement of forces during needle common invasive procedure performed in healthcare [1]. insertion with and without vibration. The force values are Despite the frequency and importance of venepuncture, analysed in respect to puncture force and friction force. complications such as severe pain and formation of haematoma caused by positioning errors of the needle occur frequently [2]. Different studies correlate an improved pain 2 Material and methods experience and a more accurate needle positioning with a reduction of insertion force. It has been shown that applying 2.1 Experimental setup ______ *Corresponding author: A 20 W loudspeaker (FR 10 HMP, VISATON GmbH & Co. Dennis Rehling: Institute of Medical Device Technology, KG, Haan, DE) was used to generate sinusoidal vibrations. University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, To transfer the vibrations to the needle, a PMMA plate was Germany, e-mail: dennis.rehling@googlemail.com glued onto the dust cap of the speaker. A Luer adapter was Jan Liu, Kent W. Stewart, Peter P. Pott: Institute of Medical screwed into the center of the plate to provide an interface for Device Technology, Stuttgart, Germany Frank Schiele: Institute for Design and Manufacturing in the 21 G hypodermic needle used. Precision Engineering, Stuttgart, Germany Open Access. © 2020 Dennis Rehling et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 License. Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 2 Figure 1: Experimental setup. The speaker stays stationary during the experiments and is moves the sample towards the needle at a constant speed of fixated on an optical breadboard. The excitation signal was 1 mm/s [9]. During the whole process, the force data of the delivered by a function generator (PeakTech® 4060 MV, load cell was recorded by the measuring amplifier with the PeakTech Prüf- und Messtechnik GmbH, Ahrensburg, DE) in maximum sampling rate of 625 Hz. After 15 seconds in conjunction with an amplifier (KS-DR3002, JVC which the needle pierced the sample, the forward movement KENWOOD Corporation, Yokohoma, JP). ends and the linear motor returns to the starting position at A laser Doppler vibrometer (OFV-3001, POLYTEC the same speed after a pause of 1 s. Finally, the recording of GmbH, Waldbronn, DE) was used to identify the required the measured force values is ended. Each parameter excitation voltage to achieve the desired free vibration combination was run five times. amplitudes (20, 100, and 500 µm) and frequencies (10, 100, In this setup, the total force comprised of insertion force and 200 Hz). Free vibration amplitude describes the and vibration force was measured by the sensor during peak-to-peak amplitude of the needle if moving freely in contact. To isolate the insertion force required to advance the space. needle through the sample, the forces generated by the nd The sample was fixed to a 5 N load cell (KD40s, vibration had to be filtered. A digital 2 order notch filter ME-Meßsysteme GmbH, Hennigsdorf, Germany) with an was used to suppress the vibration frequency as well as the nd rd adapter. The load cell itself has an accuracy class of 0.1 % 2 and 3 harmonic. Also, a moving average filter with a and a resonant frequency of 2 kHz without added mass. It is window size of 10 was applied to better expose the desired connected to a measuring amplifier (GSV-2TSD-DI, ME- signal. The force curves resulting from the filtering then only Meßsysteme GmbH, Hennigsdorf, DE) which forwards the provide information about the actual force needed to advance signal to a control PC via USB. The adapter clamped the the needle. Exemplary force curves and the power spectra sample, a 125 µm thin sheet of PET, between two plates, prior and after filtering can be seen in Figure 2. both with a centred 10 mm diameter hole, which allows the To determine the puncture force, the maximum force needle to pierce the sample completely. PET is commonly value was determined from the filtered curves. To obtain the used as blood vessel replacement [8]. The connection of load value for the shaft friction, the average value over the period cell and sample holder was mounted to a linear motor (VA of time in which the constant shaft friction was effective was LINAX® Lxc 80F40, Jenny Science AG, Rain, CH) that determined. This time period (depicted by E in Figure 2) is set moved the arrangement of load cell and sample towards the manually. Two-sample t-tests with a significance level of α = stationary speaker vibrating the needle. The experimental 5 % were conducted to compare the identified forces with setup can be seen in Figure 1. vibration to the ones for the non-vibrating mode. 2.2 Measurements At the beginning of each measurement, the sample out of PET is loaded into the sample holder. The linear motor Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 3 Figure 2: Exemplary force data of a measurement with a 10 Hz – 500 µm vibration mode. The blue line indicates the original data. Force oscillations induced by the vibration can be clearly seen. To remove this force component, a notch filter with the respective vibration frequency is used. The resulting curve after notch filtering and after application of a moving average can be seen in orange and yellow, respectively. In the power spectrum in the lower graph, the increased signal amplitude at 10, 20, and 30 Hz is visible. The orange and the yellow signal show the effectivity of the notch filter and the moving average, respectively. Table 1: Overview of results for shaft friction force and puncture force: Force values are given in Newton and the deviations from the control insertion are given in percentage 3 Results (square brackets). Values that are significantly different are marked with an asterisk. Recorded force curves show characteristic points and phases during puncture. This can be seen in the upper graph of Puncture force Figure 2. The rising deflection force, the initial puncture 0 Hz 10 Hz 100 Hz 200 Hz force as well as the cutting forces induced by the secondary and primary bevel can be seen. In addition, a phase with a 1.768 0 µm ± 0.046 - - - constant very low insertion force can be seen which is [0.00 %] characteristic for shaft friction acting only. In the lower graph 1.821 1.790 1.852* of Figure 2, the power spectrum of the signal can be seen. 20 µm - ± 0.028 ± 0.033 ± 0.031 [+3.04 %] [+1.26 %] [+4.76 %] The signal amplitude is increased at the respective vibration 1.794 1.852* 1.527* frequency and from the associated harmonics, as a 100 µm - ± 0.038 ± 0.049 ± 0.016 consequence of the vibratory movement of the needle. [+1.52 %] [+4.79 %] [-13.62 %] Results for puncture force reduction can be seen in the 1.737 0.483* 0.582* upper part of Table 1. Puncture force is increased at 100 Hz - 500 µm - ± 0.035 ± 0.014 ± 0.047 [-1.71 %] [-72.69 %] [-67.09 %] 100 µm (p = 0.033) and 200 Hz - 20 µm (p = 0.010) by Shaft friction force about 5 %. At 100 Hz - 500 µm (p < 0.001) and 200 Hz - 0.103 500 µm (p < 0.001), puncture force is significantly reduced 0 µm ± 0.005 - - - by 73 % and 67 %, respectively. [0.00] Results for shaft friction force reduction can be seen in 0.119* 0.122* 0.170* the lower part of Table 1. Shaft friction is significantly 20 µm - ± 0.004 ± 0.006 ± 0.002 [+14.72 %] [+17.91 %] [+63.83 %] reduced or increased at all frequencies and amplitudes, except for 200 Hz – 100 µm. An amplitude of 100 µm 0.112* 0.062* 0.108 100 µm - ± 0.004 ± 0.005 ± 0.006 reduces shaft friction at 100 Hz by more than [+8.09 %] [-40.44 %] [+4.39 %] 40 % (p < 0.001). By applying an amplitude of 500 µm, shaft 0.027* -0.018* -0.026* friction is significantly reduced by 74 % at 10 Hz (p < 0.001) 500 µm - ± 0.007 ± 0.002 ± 0.002 and up to 100 % at 100 Hz (p < 0.001) and [-74.00 %] [≥ -100.0 %] [≥ -100.00 %] 200 Hz (p < 0.001). Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 4 to implement an active control of the vibration mode to 4 Discussion maintain the desired vibration. In this setup, the loudspeaker was driven open loop. Future works will, therefore, focus on It has been shown that the insertion force required when actively controlling the vibration movement. Also, an inserting a needle through a thin sample is reduced by the additional bearing of the needle is to be integrated to ensure a application of specific vibration parameter combinations. The purely axial vibration movement. Finally, the resonance effect of reduction can be seen in both shaft friction force and frequency of the load cell with added mass should be puncture force. An amplitude of 500 µm led to shaft friction investigated to exclude negative effects on measurements. force reductions by up to 100 %. By applying vibrations of 500 µm and 100 Hz or 200 Hz, the vibration reduces the Author Statement insertion force needed to puncture the sample by 73 % Research funding: The author state no funding involved. and 67 %, respectively. However, also negative effects were Conflict of interest: Authors state no conflict of interest. observed. A higher friction force during vibration could be due to the partial forward stroke of the needle in direction of the References load cell and the inability to complete the forward stroke. At 10 Hz - 100 µm, this effect also occurs but to a lesser extent. [1] I. Lavery and P. Ingram, “Venepuncture: best practice,” For vibrations at 100 µm and 100 Hz or 200 Hz, the Nursing standard, vol. 19, no. 49, 55-65; quiz 66, combination of frequency and amplitude is strong enough to generate constant back and forward movements of the needle [2] O. Y. Buowari, “Complications of venepuncture,” shaft. As a result, shaft friction forces are significantly lower ABB, vol. 04, no. 01, pp. 126–128, 2013. here. [3] J. Liu, K. W. Stewart, and P. P. Pott, “Towards This also applies to vibrations with an amplitude of automated and painless venipuncture – vibratory needle 500 µm. Reductions up to 100 % could be observed here. insertion techniques,” Current Directions in This rather unexpected value could be a measurement Biomedical Engineering, vol. 5, no. 1, pp. 157–160, artefact resulting from errors of the force sensor since the measured forces are rather small. This is also supported by [4] D. Bi and Y. Lin, “Vibrating needle insertion for the fact that the same force values occur when the needle is trajectory optimization,” in 7th World Congress on retracted. Intelligent Control and Automation: WCICA 2008; 25 - In summary, it must be assumed that the speaker is not 27 June 2008, Chongqing, China, 2008, pp. 7444-7448. able to maintain the vibration in the desired manner when the [5] A. C. Barnett, “Tissue cutting mechanics of dynamic needle comes into contact with the sample. needle insertion,” 2015. The slight increases in the measured puncture force [6] N. D. M. Begg and A. H. Slocum, “Audible frequency during vibration at 100 Hz - 100 µm and 200 Hz - 20 µm can vibration of puncture-access medical devices,” Medical be explained by the fact that the vibration increases the Engineering & Physics, vol. 36, no. 3, pp. 371–377, generated force of the needle tip for a short time. However, the vibration force is still too weak to penetrate the sample. [7] L. Tan et al., “Effect of vibration frequency on biopsy Filtering took place after sampling at a frequency of needle insertion force,” Medical Engineering & 625 Hz. When vibrating at 10 Hz and sampling at 625 Hz, it Physics, vol. 43, pp. 71–76, 2017. was found that the harmonics are of too low amplitude to [8] V. Catto, S. Farè, G. Freddi, and M. C. Tanzi, create pronounced aliasing effects and influence the “Vascular Tissue Engineering: Recent Advances in measurement result. It was therefore assumed that this also Small Diameter Blood Vessel Regeneration,” ISRN applies to higher vibration frequencies, which is why these Vascular Medicine, vol. 2014, pp. 1–27, 2014. measurements were also sampled at 625 Hz. [9] S. P. DiMaio and S. E. Salcudean, “Simulated In further experiments, more combinations of interactive needle insertion,” in Proceedings 10th frequencies and amplitudes have to be tested as well as the Symposium on Haptic Interfaces for Virtual force progression in complete tissue phantoms. The here Environment and Teleoperator Systems. HAPTICS presented results indicate positive effects on insertion forces. 2002, Orlando, FL, USA, Mar. 2002, pp. 344–351. However, to further investigate the influence of frequency and the influence of amplitude, it is important and necessary http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Current Directions in Biomedical Engineering de Gruyter

Investigation of vibration parameters for needle insertion force reduction

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Abstract

DE GRUYTER Current Directions in Biomedical Engineering 2020;6(3): 20203155 Dennis Rehling*, Jan Liu, Frank Schiele, Kent W. Stewart, Peter P. Pott Investigation of vibration parameters for needle insertion force reduction Abstract: Many medical interventions in therapy and an axial vibration can reduce the required needle insertion diagnostics require needle insertion into tissue. Common forces [3–5]. complications such as increased pain and formation of Begg and Slocum have worked on the concept of an haematoma are caused by wrong needle positioning. It has axial oscillating vibration in the range of audible frequencies. been shown that pain experience and needle positioning can They pierced into gelatine phantoms and investigated the be improved by a reduction of insertion force, which can be reduction of the insertion force in relation to the insertion achieved by vibrating the needle axially. An experimental depth. A vibration with the actuator’s resonant frequency at setup has been designed to investigate the influences of 150 Hz, which resulted in the largest vibration amplitude, different combinations of vibration frequencies (10, 100, and showed the lowest insertion forces [6]. Tan et al. also used 200 Hz) and vibration amplitudes (20, 100, and 500 µm) gelatine phantoms and investigated the additional force during needle insertion into thin sheets of polyethylene generated by a vibration. They claimed that a vibration with terephthalate (PET). A customary 20 W loudspeaker was 500 Hz creates a 17.9 % higher additional force compared to used to generate the vibration. The results indicate a a vibration with 50 Hz [7]. Barnett investigated the puncture maximum reduction of 73 % in puncture force and up to a force when piercing into porcine skin. He examined 100 % reduction in shaft friction force. However, the frequencies from 100 Hz to 2000 Hz and amplitudes from additional vibration force generated by the vibration 5 µm to 50 µm and achieved a maximum reduction of 35 % movement has to be high enough to generate positive effects in puncture force. This was achieved by applying a vibration in terms of force reduction. with 500 Hz and an amplitude of 25 µm [5]. However, no investigation of the influences of frequency and amplitude on Keywords: venepuncture, vibratory needle insertion, different phases during insertion has been conducted. insertion force, force reduction, pain reduction This paper, therefore, investigates different combinations of vibration frequencies and vibration amplitudes and the https://doi.org/10.1515/cdbme-2020-3155 influences on different insertion phases. A sinusoidal vibration movement is used. Combinations of 10, 100, and 200 Hz vibrations and peak-to-peak amplitudes of 20, 100, 1 Introduction 500 µm are investigated. For this purpose, a setup is built consisting of a vibration actuator, a force sensor, and a linear Drawing of blood for diagnostic testing is one of the most motor. This allows the measurement of forces during needle common invasive procedure performed in healthcare [1]. insertion with and without vibration. The force values are Despite the frequency and importance of venepuncture, analysed in respect to puncture force and friction force. complications such as severe pain and formation of haematoma caused by positioning errors of the needle occur frequently [2]. Different studies correlate an improved pain 2 Material and methods experience and a more accurate needle positioning with a reduction of insertion force. It has been shown that applying 2.1 Experimental setup ______ *Corresponding author: A 20 W loudspeaker (FR 10 HMP, VISATON GmbH & Co. Dennis Rehling: Institute of Medical Device Technology, KG, Haan, DE) was used to generate sinusoidal vibrations. University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, To transfer the vibrations to the needle, a PMMA plate was Germany, e-mail: dennis.rehling@googlemail.com glued onto the dust cap of the speaker. A Luer adapter was Jan Liu, Kent W. Stewart, Peter P. Pott: Institute of Medical screwed into the center of the plate to provide an interface for Device Technology, Stuttgart, Germany Frank Schiele: Institute for Design and Manufacturing in the 21 G hypodermic needle used. Precision Engineering, Stuttgart, Germany Open Access. © 2020 Dennis Rehling et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 License. Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 2 Figure 1: Experimental setup. The speaker stays stationary during the experiments and is moves the sample towards the needle at a constant speed of fixated on an optical breadboard. The excitation signal was 1 mm/s [9]. During the whole process, the force data of the delivered by a function generator (PeakTech® 4060 MV, load cell was recorded by the measuring amplifier with the PeakTech Prüf- und Messtechnik GmbH, Ahrensburg, DE) in maximum sampling rate of 625 Hz. After 15 seconds in conjunction with an amplifier (KS-DR3002, JVC which the needle pierced the sample, the forward movement KENWOOD Corporation, Yokohoma, JP). ends and the linear motor returns to the starting position at A laser Doppler vibrometer (OFV-3001, POLYTEC the same speed after a pause of 1 s. Finally, the recording of GmbH, Waldbronn, DE) was used to identify the required the measured force values is ended. Each parameter excitation voltage to achieve the desired free vibration combination was run five times. amplitudes (20, 100, and 500 µm) and frequencies (10, 100, In this setup, the total force comprised of insertion force and 200 Hz). Free vibration amplitude describes the and vibration force was measured by the sensor during peak-to-peak amplitude of the needle if moving freely in contact. To isolate the insertion force required to advance the space. needle through the sample, the forces generated by the nd The sample was fixed to a 5 N load cell (KD40s, vibration had to be filtered. A digital 2 order notch filter ME-Meßsysteme GmbH, Hennigsdorf, Germany) with an was used to suppress the vibration frequency as well as the nd rd adapter. The load cell itself has an accuracy class of 0.1 % 2 and 3 harmonic. Also, a moving average filter with a and a resonant frequency of 2 kHz without added mass. It is window size of 10 was applied to better expose the desired connected to a measuring amplifier (GSV-2TSD-DI, ME- signal. The force curves resulting from the filtering then only Meßsysteme GmbH, Hennigsdorf, DE) which forwards the provide information about the actual force needed to advance signal to a control PC via USB. The adapter clamped the the needle. Exemplary force curves and the power spectra sample, a 125 µm thin sheet of PET, between two plates, prior and after filtering can be seen in Figure 2. both with a centred 10 mm diameter hole, which allows the To determine the puncture force, the maximum force needle to pierce the sample completely. PET is commonly value was determined from the filtered curves. To obtain the used as blood vessel replacement [8]. The connection of load value for the shaft friction, the average value over the period cell and sample holder was mounted to a linear motor (VA of time in which the constant shaft friction was effective was LINAX® Lxc 80F40, Jenny Science AG, Rain, CH) that determined. This time period (depicted by E in Figure 2) is set moved the arrangement of load cell and sample towards the manually. Two-sample t-tests with a significance level of α = stationary speaker vibrating the needle. The experimental 5 % were conducted to compare the identified forces with setup can be seen in Figure 1. vibration to the ones for the non-vibrating mode. 2.2 Measurements At the beginning of each measurement, the sample out of PET is loaded into the sample holder. The linear motor Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 3 Figure 2: Exemplary force data of a measurement with a 10 Hz – 500 µm vibration mode. The blue line indicates the original data. Force oscillations induced by the vibration can be clearly seen. To remove this force component, a notch filter with the respective vibration frequency is used. The resulting curve after notch filtering and after application of a moving average can be seen in orange and yellow, respectively. In the power spectrum in the lower graph, the increased signal amplitude at 10, 20, and 30 Hz is visible. The orange and the yellow signal show the effectivity of the notch filter and the moving average, respectively. Table 1: Overview of results for shaft friction force and puncture force: Force values are given in Newton and the deviations from the control insertion are given in percentage 3 Results (square brackets). Values that are significantly different are marked with an asterisk. Recorded force curves show characteristic points and phases during puncture. This can be seen in the upper graph of Puncture force Figure 2. The rising deflection force, the initial puncture 0 Hz 10 Hz 100 Hz 200 Hz force as well as the cutting forces induced by the secondary and primary bevel can be seen. In addition, a phase with a 1.768 0 µm ± 0.046 - - - constant very low insertion force can be seen which is [0.00 %] characteristic for shaft friction acting only. In the lower graph 1.821 1.790 1.852* of Figure 2, the power spectrum of the signal can be seen. 20 µm - ± 0.028 ± 0.033 ± 0.031 [+3.04 %] [+1.26 %] [+4.76 %] The signal amplitude is increased at the respective vibration 1.794 1.852* 1.527* frequency and from the associated harmonics, as a 100 µm - ± 0.038 ± 0.049 ± 0.016 consequence of the vibratory movement of the needle. [+1.52 %] [+4.79 %] [-13.62 %] Results for puncture force reduction can be seen in the 1.737 0.483* 0.582* upper part of Table 1. Puncture force is increased at 100 Hz - 500 µm - ± 0.035 ± 0.014 ± 0.047 [-1.71 %] [-72.69 %] [-67.09 %] 100 µm (p = 0.033) and 200 Hz - 20 µm (p = 0.010) by Shaft friction force about 5 %. At 100 Hz - 500 µm (p < 0.001) and 200 Hz - 0.103 500 µm (p < 0.001), puncture force is significantly reduced 0 µm ± 0.005 - - - by 73 % and 67 %, respectively. [0.00] Results for shaft friction force reduction can be seen in 0.119* 0.122* 0.170* the lower part of Table 1. Shaft friction is significantly 20 µm - ± 0.004 ± 0.006 ± 0.002 [+14.72 %] [+17.91 %] [+63.83 %] reduced or increased at all frequencies and amplitudes, except for 200 Hz – 100 µm. An amplitude of 100 µm 0.112* 0.062* 0.108 100 µm - ± 0.004 ± 0.005 ± 0.006 reduces shaft friction at 100 Hz by more than [+8.09 %] [-40.44 %] [+4.39 %] 40 % (p < 0.001). By applying an amplitude of 500 µm, shaft 0.027* -0.018* -0.026* friction is significantly reduced by 74 % at 10 Hz (p < 0.001) 500 µm - ± 0.007 ± 0.002 ± 0.002 and up to 100 % at 100 Hz (p < 0.001) and [-74.00 %] [≥ -100.0 %] [≥ -100.00 %] 200 Hz (p < 0.001). Dennis Rehling et al., Investigation of vibration parameters for needle insertion force reduction — 4 to implement an active control of the vibration mode to 4 Discussion maintain the desired vibration. In this setup, the loudspeaker was driven open loop. Future works will, therefore, focus on It has been shown that the insertion force required when actively controlling the vibration movement. Also, an inserting a needle through a thin sample is reduced by the additional bearing of the needle is to be integrated to ensure a application of specific vibration parameter combinations. The purely axial vibration movement. Finally, the resonance effect of reduction can be seen in both shaft friction force and frequency of the load cell with added mass should be puncture force. An amplitude of 500 µm led to shaft friction investigated to exclude negative effects on measurements. force reductions by up to 100 %. By applying vibrations of 500 µm and 100 Hz or 200 Hz, the vibration reduces the Author Statement insertion force needed to puncture the sample by 73 % Research funding: The author state no funding involved. and 67 %, respectively. However, also negative effects were Conflict of interest: Authors state no conflict of interest. observed. A higher friction force during vibration could be due to the partial forward stroke of the needle in direction of the References load cell and the inability to complete the forward stroke. At 10 Hz - 100 µm, this effect also occurs but to a lesser extent. [1] I. Lavery and P. Ingram, “Venepuncture: best practice,” For vibrations at 100 µm and 100 Hz or 200 Hz, the Nursing standard, vol. 19, no. 49, 55-65; quiz 66, combination of frequency and amplitude is strong enough to generate constant back and forward movements of the needle [2] O. Y. Buowari, “Complications of venepuncture,” shaft. As a result, shaft friction forces are significantly lower ABB, vol. 04, no. 01, pp. 126–128, 2013. here. [3] J. Liu, K. W. Stewart, and P. P. Pott, “Towards This also applies to vibrations with an amplitude of automated and painless venipuncture – vibratory needle 500 µm. Reductions up to 100 % could be observed here. insertion techniques,” Current Directions in This rather unexpected value could be a measurement Biomedical Engineering, vol. 5, no. 1, pp. 157–160, artefact resulting from errors of the force sensor since the measured forces are rather small. This is also supported by [4] D. Bi and Y. Lin, “Vibrating needle insertion for the fact that the same force values occur when the needle is trajectory optimization,” in 7th World Congress on retracted. Intelligent Control and Automation: WCICA 2008; 25 - In summary, it must be assumed that the speaker is not 27 June 2008, Chongqing, China, 2008, pp. 7444-7448. able to maintain the vibration in the desired manner when the [5] A. C. Barnett, “Tissue cutting mechanics of dynamic needle comes into contact with the sample. needle insertion,” 2015. The slight increases in the measured puncture force [6] N. D. M. Begg and A. H. Slocum, “Audible frequency during vibration at 100 Hz - 100 µm and 200 Hz - 20 µm can vibration of puncture-access medical devices,” Medical be explained by the fact that the vibration increases the Engineering & Physics, vol. 36, no. 3, pp. 371–377, generated force of the needle tip for a short time. However, the vibration force is still too weak to penetrate the sample. [7] L. Tan et al., “Effect of vibration frequency on biopsy Filtering took place after sampling at a frequency of needle insertion force,” Medical Engineering & 625 Hz. When vibrating at 10 Hz and sampling at 625 Hz, it Physics, vol. 43, pp. 71–76, 2017. was found that the harmonics are of too low amplitude to [8] V. Catto, S. Farè, G. Freddi, and M. C. Tanzi, create pronounced aliasing effects and influence the “Vascular Tissue Engineering: Recent Advances in measurement result. It was therefore assumed that this also Small Diameter Blood Vessel Regeneration,” ISRN applies to higher vibration frequencies, which is why these Vascular Medicine, vol. 2014, pp. 1–27, 2014. measurements were also sampled at 625 Hz. [9] S. P. DiMaio and S. E. Salcudean, “Simulated In further experiments, more combinations of interactive needle insertion,” in Proceedings 10th frequencies and amplitudes have to be tested as well as the Symposium on Haptic Interfaces for Virtual force progression in complete tissue phantoms. The here Environment and Teleoperator Systems. HAPTICS presented results indicate positive effects on insertion forces. 2002, Orlando, FL, USA, Mar. 2002, pp. 344–351. However, to further investigate the influence of frequency and the influence of amplitude, it is important and necessary

Journal

Current Directions in Biomedical Engineering – de Gruyter

Published: Sep 1, 2020

Keywords: venepuncture; vibratory needle insertion; insertion force; force reduction; pain reduction

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