INHERENTLY SAFE DESIGN OF A PRACTICABLE MEDICAL LASER HANDPIECE - - PowerPoint PPT Presentation

Lewis C. R. Jones1, Mark Parry1, John R. Tyrer1, Jason Britton2

1 Loughborough University. 2 Leeds General Infirmary

INHERENTLY SAFE DESIGN OF A PRACTICABLE MEDICAL LASER HANDPIECE

24.5th Laser Safety Forum 2020

Contents

The rationale for a new design

• Growing concerns with surgical smoke; Key findings from the literature
• Legal movement in USA

Experimental testing

• Our approach to inherently safe design
• Testing of design concept
• Identification of surgical smoke hazards
• Integrated handpiece optical filters and extraction

The rationale for a new design

• Design proposal
• Conclusions and Further work

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Laser Generated Surgical Smoke

Changing legal position in USA

• The state of Rhode Island has effective, from January 1st 2019, legislation

(RI Gen L § 23-17-49.1 2018) requiring action for surgical smoke.

• Colorado has passed legislation (Colo. Rev. Stat. § 25-3-120 2019) that

will become effective May 1st 2021,

• The states of New Jersey, Oregon, Utah, Kentucky, Georgia, and

Tennessee have bills under various stages of review.

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Recognition of the hazard

• Surgical smoke is linked to respiratory irritation, the transmission of infectious and cancer cells, and

genotoxicity [1–7].

• Cases of laser-generated surgical smoke causing infection in a surgeon [8] and a nurse [9].
• One gram of laser-generated surgical smoke contains 40 mg of smoke condensates, with an equivalent

mutagenic potential of 3 cigarettes [10].

Recommended Risk Management

• No specific legal requirement in UK using smoke evacuation [11]. Medical and Healthcare Products

Regulatory Agency (MHRA) recommends to use masks and Local Exhaust Ventilation (LEV) [12] to meet the Control of Substances Hazardous to Health Regulations (COSHH) (SI 2002/2677) requirements.

• The recommendations from research on risk control for surgical smoke includes the use of LEV and

surgical masks [1–4,7,13–15]

Current Risk Management

• Current LEV systems are highly reliant on the operator, policies and administrative procedures [4,16].
• Collection nozzle is very sensitive to position [17].

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a) b) Handheld extraction nozzle Local Exhaust Ventilation Unit Laser fibre, control, and cryogen umbilical Laser handpiece

Our ‘generic’ example The underlying problem

Use varies: 1. 47% (n = 1315) of laser surgeries used LEV, and 31% of procedures never used LEV [6]. 2. 66% (n = 50) of plastic surgery theatres had specialised smoke extractors [13]. 3. 43% (n = 67) of surgical consultants used smoke evacuators [18].

Inherently safe design

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Elimination Substitution Engineering controls Administrative controls PPE

Most Effective Least Effective

Engineering Controls

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Integrated Extraction Out to filter Air flow in clears smoke Existing laser handpiece body, fibre delivery and focusing optics Endoscope camera magnifying target image Extraction tip provides focal standoff Tip seals to skin and makes electrical contact for safety interlock Annular flow of extraction from source

Method

External Extraction Condition Face Velocity Measurement (m/s) Volumetric Flow Rate (L/min) Face Velocity Conversion (ft/min) Low 2.1 419 414 Medium 5 996 985 High 13.2 2629 2599

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Biolitec diode laser Fibre delivery Porcine skin sample Stationary fibre support External Extraction 150mm Plume sample hose TSI 3330 Optical Particle Sizer 30mm Removable handpiece extraction Air flow in Integrated Extraction Sample height measurement

Results

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1000 2000 3000 4000 0.300 - 0.374 0.374 - 0.465 0.465 - 0.579 0.579 - 0.721 0.721 - 0.897 0.897 - 1.117 1.117 - 1.391 1.391 - 1.732 1.732 - 2.156 2.156 - 2.685 2.685 - 3.343 3.343 - 4.162 4.162 - 5.182 5.182 - 6.451 6.451 - 8.031 8.031 - 10.00 Total particle count Optical Particle Size - Sample Collection Channels (µm)

← PM2.5

PM2.5 is associated to an increase in daily mortality [19,20] and linked to pulmonary diseases [14,15]. The World Health Organisation (WHO) annual mean exposure guidelines for PM2.5 is 10 µg/m3 [21].

10 20 30 40 50 60

• 40
• 20

20 40 60 80 100 120 140 PM 2.5 Concetration (µg/m3) Time (s) Background Background (M ± 1SD) Laser with No Extraction (±5% Error) + 9

Start of Laser sequence End of Laser sequence Pre-sample collection time Peak concentration from laser Residual unextracted particulate generated by test

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10 20 30 40 50 60 5 10 15 20 25 30 PM 2.5 Concetration (µg/m3) Time (s)

Design Proposal

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Conclusions and Further Work

• Identified reduction in respirable hazard of PM2.5 but it is

know that surgical smoke has unique toxicology and infection risk. [8,10,22–24].

• Method to ensure safety through engineering controls.
• Potentially eliminated both fume and radiation hazards to

staff

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• Peak PM =2.5 concentrations without

extraction

55.86 ± 2.79 µg/m3

• 16% reduction with typical extraction

47.07 ± 2.35 µg/m3.

• With device – only safe background reading

2.19 ± 0.68 µg/m3

References

[1] Barrett WL, Garber SM. Surgical smoke: a review of the literature. Surg Endosc 2003;17:979–87. https://doi.org/10.1007/s00464-002-8584-5. [2] Fan JK-M, Chan FS-Y, Chu K-M. Surgical Smoke. Asian J Surg 2009;32:253–7. https://doi.org/10.1016/S1015-9584(09)60403-6. [3] Alp E, Bijl D, Bleichrodt RP, Hansson B, Voss A. Surgical smoke and infection control. J Hosp Infect 2006;62:1–5. https://doi.org/10.1016/j.jhin.2005.01.014. [4] Tan E, Russell KP. Surgical plume and its implications: A review of the risk and barriers to a safe work place. J Perioper Nurs 2017;30:33–9. https://doi.org/10.26550/2209-1092.1019. [5] Pierce JS, Lacey SE, Lippert JF, Lopez R, Franke JE. Laser-Generated Air Contaminants from Medical Laser Applications: A State-of-the-Science Review of Exposure Characterization, Health Effects, and Control. J Occup Environ Hyg 2011;8:447–66. https://doi.org/10.1080/15459624.2011.585888. [6] Steege AL, Boiano JM, Sweeney MH. Secondhand smoke in the operating room? Precautionary practices lacking for surgical smoke. Am J Ind Med 2016;59:1020–31. https://doi.org/10.1002/ajim.22614. [7] Ulmer BC. The Hazards of Surgical Smoke. AORN J 2008;87:721–38. https://doi.org/10.1016/j.aorn.2007.10.012. [8] Hallmo P, Naess O. Laryngeal papillomatosis with human papillomavirus DNA contracted by a laser surgeon. Eur Arch Oto-Rhino-Laryngology 1991;248:425–7. [9] Calero L, Brusis T. Laryngeal papillomatosis - first recognition in Germany as an occupational disease in an operating room nurse. Laryngo-Rhino-Otologie 2003;82:790–3. https://doi.org/10.1055/s-2003-44546. [10] Yoshifumi T, Shigenobu M, Kazuto N, Setsuo U, Masakazu F, Minoru H, et al. Mutagenicity of smoke condensates induced by CO2-laser irradiation and electrocauterization. Mutat Res Toxicol 1981;89:145–9. https://doi.org/https://doi.org/10.1016/0165-1218(81)90120-8. [11] Beswick AJ, Evans G. RR922 - Evidence for exposure and harmful effects of diathermy plumes (surgical smoke). 2012. [12]

• MHRA. Lasers, intense light source systems and LEDs – guidance for safe use in medical, surgical, dental and aesthetic practices. 2015.

[13] Hill DS, O’Neill JK, Powell RJ, Oliver DW. Surgical smoke – A health hazard in the operating theatre: A study to quantify exposure and a survey of the use of smoke extractor systems in UK plastic surgery units. J Plast Reconstr Aesthetic Surg 2012;65:911–6. https://doi.org/10.1016/j.bjps.2012.02.012. [14] Liu Y, Song Y, Hu X, Yan L, Zhu X. Awareness of surgical smoke hazards and enhancement of surgical smoke prevention among the gynecologists. J Cancer 2019;10. https://doi.org/10.7150/jca.31464. [15] Lewin JM, Brauer JA, Ostad A. Surgical smoke and the dermatologist. J Am Acad Dermatol 2011. https://doi.org/10.1016/j.jaad.2010.11.017. [16] Stanley K. Diathermy smoke shown to be hazardous, so why are we not protecting ourselves? J Perioper Pract 2018;28:145–51. https://doi.org/10.1177/1750458918767582. [17]

• NIOSH. (HC11) Control of Smoke From Laser/Electric Surgical Procedures. 1998. https://doi.org/10.1080/104732299303205.

[18] Spearman J, Tsavellas G, Nichols P. Current attitudes and practiees towards diathermy smoke. Ann R Coll Surg Engl 2007;89:162–5. https://doi.org/10.1308/003588407X155752. [19] Schwartz J, Dockery DW, Neas LM. Is Daily Mortality Associated Specifically with Fine Particles? J Air Waste Manag Assoc 1996;46:927–39. https://doi.org/10.1080/10473289.1996.10467528. [20] Xing YF, Xu YH, Shi MH, Lian YX. The impact of PM2.5 on the human respiratory system. J Thorac Dis 2016;8:E69–74. https://doi.org/10.3978/j.issn.2072-1439.2016.01.19. [21] World Health Organisation. WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide. 2005. [22] Tyrer J, Jones LCR, Edwards J, Beswick A, Bard D, Britton J. Viable pathogen aerosols produced during laser dermatology surgery – A quantified analysis. Int. Laser Saf. Conf., vol. 1, Kissimmee, FL, USA: Laser Institute of America; 2019, p. MP602. https://doi.org/10.2351/1.5118631. [23] Sisler JD, Shaffer J, Soo JC, Lebouf RF, Harper M, Qian Y, et al. In vitro toxicological evaluation of surgical smoke from human tissue. J Occup Med Toxicol 2018;13:1–11. https://doi.org/10.1186/s12995-018-0193-x. [24] Sawchuk WS, Weber PJ, Lowy DR, Dzubow LM. Infectious papillomavirus in the vapor of warts treated with carbon dioxide laser or electrocoagulation: Detection and protection. J Am Acad Dermatol 1989;21:41–9. https://doi.org/10.1016/S0190-9622(89)70146-8.

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Thank you for listening Lewis Jones PhD MEng FHEA Lecturer in Engineering Product Design Wolfson School of Mechanical, Electrical and Manufacturing Engineering Loughborough University Tel: +44 1509 227594 E-Mail: L.Jones@lboro.ac.uk

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