Studies validate ergonomic pipette design

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Studies validate ergonomic pipette design

  1. 1. Studies Validate Design Objectives and Ergonomic Science behind the Ovation BioNatural Pipette Richard E. Scordato, VistaLab Technologies, Inc.Abstract Axial style pipettesThe Ovation Pipette (Fig. 1) was introduced in 2002 and has received Traditional laboratory pipettes are designed andsubstantial attention due to its innovative design approach. Numerous constructed along a single axis of operation (Fig. 2).evaluations of the Ovation have occurred and thousands of scientists and The axis is defined by the plunger, the handle andtechnicians now use the Ovation pipette on a daily basis. The purpose of the pipette tip. This style of design originated overthis paper is to discuss three particularly important studies performed since 40 years ago, primarily because it is a simple andthe launch of the Ovation. straightforward way of making a pipette. While the science of ergonomics has advanced substantiallyThe first study was performed by the U.S. National Institute of during this time period, the axial pipette design isOccupational Safety and Health (NIOSH) (1). In this study very detailed essentially unchanged.measurements were taken of forces and postures during pipetting. This The axial style pipette requires the user to employinformation was then analyzed for MSD risk factors. The study concluded posture(s) that increase the risk of MSD’s. Forthat the Ovation “showed a significant reduction in the most important example, Figures 3a & 3b show typical pipettingMSD (musculoskeletal disorder) risk factors for pipetting.” postures when using axial pipettes. These posturesThe second study was done at Duke University (2). This study supplied violate many recommendations for minimizing MSD Figure 2: TraditionalOvation pipettes to randomly selected participants in order to assess the risk (8), however the axial design often makes Axial-Designcomfort and utility of using the Ovation on a daily basis. This study found an compliance with these recommendations“Overwhelming preference for the Ovation in terms of ‘comfort’” and a physically impossible.“Strong preference for the Ovation in terms of ‘Accuracy’ and ‘General use Figure 3a: Elevated, “winged elbow”throughout the workday.’” The average human arm weighs approximately 6% of the total body weight. Holding a pipette asAnd finally, results are presented from VistaLab’s surveys of Ovation users. shown places the weight of the arm onto the neckIn these surveys users report a significant reduction in discomfort after and shoulder muscles causing stress and fatigue.switching to the Ovation from their previous axial pipette. They also report For a 70Kg (150 lbs) person, the arm weighs 4Kg (9 lbs). This is many times heavier than the pipette -great satisfaction with the Ovation and highly recommend it to their peers. so a “light weight” pipette doesn’t solve the ergonomic problem. The real issue is the weight of the arm, not the pipette.Introduction Figure 3b: Over-rotated forearm and wristSignificant risk factors for musculoskeletal disorders (MSDs) due to pipetting Rotation of the forearm in a supinated positionhave been well documented by governmental agencies and scientific (palm up) and/or wrist flexion increases the fluidorganizations(3,4,5,6,7). The problems cited are not limited to just the pressure in the carpal tunnel. This increased pres-thumb or hand, showing recurrent prevalence for other upper extremity sure can result in compression of soft tissues like nerves, tendons and blood vessels, causinginjury. A commonly cited study(6) found that 58% of laboratory workers numbness in the thumb and fingers.reported shoulder problems, 44% reported neck problems and 44% reportedhand problems associated with pipetting. In VistaLab research, 45% of labpersonnel experienced measurable discomfort at least occasionally whilepipetting. The effects of even A recent report (9) compared five commercially available axial style pipettes.minor injuries are cumulative, The study included models that have been available for many years, as welland therefore represent as newer pipettes that claim to be“ergonomic” with features such as lowersignificant risk to the plunger forces and improved grip. The report concluded that all the pipettesindividual over time. “strained the shoulder muscle, the finger flexor and the short thumb flexor toNumerous organizations (8) the same extent” and that “the tested 1-channel pipettes caused more thumbhave recognized these risks muscle electrical activity and higher wrist extension (bending towards the backassociated with pipetting, or the hand) angles than those recommended by the relevant norms” (9).and have developed The evidence affirms that traditional axial design pipettes are fundamentallyguidelines as a method to flawed by their geometry. Improvements to the axial design such aslimit the user’s exposure. lowering plunger forces and improving the grips do not fundamentally Figure 1: Ovation BioNatural Pipette change key risk factors for MSD’s posed by axial pipettes.
  2. 2. Ovation National Institute of Occupational Safety and Health (NIOSH)The Ovation BioNatural Pipette (Fig. 1) is the result of several years of An independent study of the Ovation pipette was conducted in 2004 byresearch into the ergonomics of pipetting. A team of ergonomists, engineers, Min Lung (Jack) Lu, PhD, of the National Institute of Occupational Safety andand industrial designers studied existing pipettes, the lab environment and Health (NIOSH) (1). NIOSH is the U.S. government agency responsible forscientific literature. Unlike other pipettes in the marketplace, the Ovation research and recommendations for the prevention of work-related injuriesteam started without any arbitrary design constraints, and invented the and illness. The research project was part of the National Occupational“BioNatural” design in order to remedy the deficiencies of the traditional Research Agenda (NORA), which has identified the 21 most importantaxial pipette style (10). The BioNatural design allows the user’s hands to areas of research for occupational safety and health.stay low to the lab bench, the elbows and arms to stay close to the body,and the forearm to be rotated inward (pronated). The grip was designed to The NIOSH researchers observed laboratoryminimize contact stress on the hand and thumb (Fig. 4a & 4b). workers performing lab functions and then devised a simulation of the lab activity. TheFigure 4a usage of the Ovation pipette and twoThe pipette’s contoured shape provides maximum traditional axial-design pipettes was thenstability and minimal contact pressure for the hand. randomized and a battery of ergonomicA loose, relaxed grip increases available strength inthe hand, improving endurance and productivity dur- measurements was taken during theing pipetting. Rounded plunger and tip ejection simulation. Finger force was measured frombuttons with reduced forces minimize contact stress. 19 sensors in a glove worn during the trial (Fig. 5). Wrist posture and forearm rotation Figure 5: Flexiform glove were measured using a twin axis goniometer, with force transducers and shoulder elevation was measured usingFigure 4b video task analysis software. Measurement data was collected during theThe user’s arm elevation remains low, minimizingstress to the elbow, shoulder and neck. The elbow full cycle of pipette use: (a) picking up a pipette, (b) acquisition of a tip,remains close to the body in a neutral posture to (c) aspiration, (d) dispensing and overblow, and (d) ejection of a tip.maximize available arm strength. The wrist remainsin a pronated position and neutral range of motion The total finger force data from the NIOSH study are summarized in Figure 6,throughout all pipetting operations, eliminating and represent the sum of forces from all 19 sensors on the “glove” wornrepetitive twisting of the forearm and reducing pres-sure on the carpal tunnel. during pipetting. Finger forces required to pipette with the Ovation were significantly lower in each of the five steps of the pipetting process. In fact, the axial pipettes required as much as five times greater total finger forcesBalance and weight were carefully considered, and an adjustable hook during the pipetting process than the Ovation. These low force requirementsenables the pipette to fit a wide range of hand sizes. A unique tip are a result of Ovation’s “BioNatural” shape which eliminates the high gripacquisition system “clicks” when the tip is acquired, and an eject button forces necessary when using an axial pipette. Lower forces lead to moreactivates a discard mechanism that pushes the tip off with minimal user comfort, less fatigue and lower MSD risk.effort. The pipette’s form allows it to stand independently on a countersurface, making it easier to pick up and put down, and eliminates therepetitive twisting of the forearm that occurs when picking up or puttingdown a traditional pipette.The Ovation pipette employs a unique digital volume selection system. Thisallows fast adjustment, precise setting of the volume, and memory presetsfor fast recall of commonly used settings. The Ovation design has receivedseveral patents (11) and was awarded the prestigious gold award by theIndustrial Design Society of America for best product design (12).Ovation Study ResultsThe Ovation pipette was tested extensively during the design process forminimization of ergonomic risk. In testing by ergonomists fromErgonomics Technologies Corporation (13), the Ovation was the only Figure 6: Total Finger Forcepipette that was below the recommended limits for arm flexion andextension, wrist flexion, and maximum muscle activity during tip ejection While total finger force requirements provide a much more comprehensive(14). It was also the only pipette that enables the forearm to be in the picture of MSD risk than just the forces required from the thumb alone,pronated position which has been shown to provide substantially lower isolated measurements of thumb activity were also performed as shown incarpal tunnel pressure (15). Subsequent to introduction, the Ovation Figure 7. The Ovation showed significantly lowered thumb force require-pipette has been further studied by VistaLab Technologies and several ments at each pipetting step when compared with the traditional pipettes.independent groups.
  3. 3. Figure 7: Thumb Force Figure 9: Forearm RotationWrist deviation was also significantly lower with the Ovation while picking 70up the pipette, acquiring tips and during aspiration (Fig. 8). The datashowed statistically equivalent results during the overblow step, but higher 60 0 deg MCP Carpal Tunnel Pressure (mmHg) 45 deg MCPdeviation during tip ejection. The observed higher wrist deviation is directly 50 90 deg MCPattributed to a quirk in the simulation where the tip disposal bin remained at 40the same elevation as used in prior lab practice (16). The Ovation pipette is 30designed to eject the tips downward into a waste bin. If the disposal bin 20had been placed as recommended, the wrist deviation data would have beensignificantly lower during this step of pipetting as well. 10 0 Full 45˚ 0˚ 45˚ Full Pronation Supination Figure 10: Carpal Tunnel Pressure Reference: Rempel D, Bach J, Gordon L, Yuen S. “Effects of Forearm Pronation/Supination on Carpal Tunnel Pressure”, Journal of Hand Surgery 1998; 23A:38-42 Figure 11 shows a measurement of the percent of time that the shoulder was elevated more than 45 degrees. In all cases Ovation was the lowest. Once again, placement of the tip disposal bin below the counter height would significantly lower the shoulder elevation observed with the Ovation during tip ejection. Figure 8: Wrist DeviationForearm rotation is shown in Figure 9. This graph represents pronation(turning inward) and supination (turning outward) on the samemeasurement scale. In the case of Ovation, rotation is pronated, while foran axial pipette the rotation is supinated (Fig. 3 & 4). Research has shownthat carpal tunnel pressure is substantially higher when forearm rotation issupinated (Fig. 10). Pronated rotation leads to posture with lower carpaltunnel pressure, and lower risk for MSD’s. Figure 10: Shoulder Elevation The NIOSH study is an extremely detailed study conducted by an independent government agency dedicated to the study of workplace ergonomics. The conclusion they reached after analysis of the data was: “The re-designed, low force pipette (Ovation) showed a significant reduction in the most important MSD (musculoskeletal disorder) risk factors for pipetting, as compared to two other traditional axial-design pipettes” (1).
  4. 4. Duke University Study Customer SurveysThe Duke University Department of Ergonomics evaluated the pipetting In order to assess how well the Ovation meets customer needs, VistaLabexperiences of 61 laboratory workers. Each participant in the study performed extensive surveys of Ovation users. These surveys werecompleted an extensive questionnaire about their work habits, and the administered to randomly selected customers and represent customers wholocation, severity and frequency of any discomfort they experience due to have used the Ovation for time periods ranging from a few weeks to twopipetting. A summary of the discomfort data is shown in Figure 12. These years. The data was analyzed by the author.data show a substantial amount of discomfort reported by laboratory One of the most important objectives of the survey was to determine if Ovationworkers. The most frequent areas of discomfort were the neck (56%), reduced the pain and discomfort from pipetting. Participants who reportedlower back, right shoulder (33%), right wrist (26%) and right hand (25%). they had experienced pain or discomfort from pipetting prior to using OvationThe thumb, which users frequently associate with pipetting discomfort, were asked how that pain had changed since using the Ovation. 94% reportedwas the sixth most frequently noted discomfort area. that the Ovation had reduced their pain and the majority experiencedHalf of the study participants were provided Ovation pipettes to use complete elimination or significant reduction of their discomfort (Fig. 14).exclusively in their normal lab work for six weeks. These workers had noprior experience with the Ovation. At the end of the study the Ovation How has Ovation affected your pain? 60users were queried about their experience with the Ovation in comparisonto the pipette they used previously. The study reports: 50 45• “Overwhelming preference for Ovation in terms of “Comfort’” 40 % 30• Strong preference for Ovation in terms of “Accuracy” and “General Use 19 Throughout Workday” 20 15 14 10 6 0 No effect Some Moderate Significant Completely Reduction Reduction Reduction Eliminated Figure 14: Affect on Pain Customers were also queried about their overall satisfaction with the Ovation. Very high levels of satisfaction were reported (Fig. 15) and 96% reported that they recommend the Ovation to their peers. Customers were also very satisfied with the support they received from VistaLab Technical Support. Figure 12: Summary of Discomfort Data How satisfied are you with the Ovation? 60 48 50One unexpected finding from the Duke Study was that users with small 41 40hands found it difficult to open a microcentrifuge tube whilesimultaneously holding the Ovation. They had to put down the Ovation to % 30open the tube. This is not necessary with a traditional axial pipette– even 20though this can cause considerable discomfort due to the high contact 10 6pressure on the finger tips. 3 2 0To address this issue, a cap opener 1 2 3 4 5 Not Satisfied Very Satisfiedaccessory (Fig. 13) was developed thatcan easily be added to the base of theOvation. The cap opener greatly facilitatesopening microcentrifuge tubes and Figure 15: Overall User Satisfactioneliminates the high contact pressure onthe finger tips. The tubes can be quicklyopened while still holding the Ovation, soproductivity is significantly improved. Figure 13: Cap Opener
  5. 5. Additional Products SummaryFollowing the success of the original Ovation pipette, a multichannel Ovation is a novel design approach to hand-held pipettes. It fundamentallymodel has been introduced (Fig. 18). Conventional multichannel pipettes alters postures used to pipette in order to lower the risk of MSD’s. A majorcan cause significantly greater ergonomic problems because the forces study by Lu et al of NIOSH analyzed the Ovation in comparison to traditionalrequired to acquire tips, eject tips, aspirate and dispense are multiplied. axial-design pipettes and concluded that the Ovation “showed a significantIt is also common to use multichannel pipettes for long periods of time. reduction in the most important MSD risk factors for pipetting.” James et al of Duke University studied the Ovation when used by a group of lab workers performing their routine work. These workers had an “overwhelming preference” for the comfort of the Ovation and had a “strong preference” for using it throughout the day. VistaLab surveyed Ovation users in order to determine their satisfaction with this pipette. 97% of customers express satisfaction with the Ovation and 96% recommend it to their peers. Of those who have previously experienced pipetting discomfort, 94% reported improvement. In summary, this data shows that: Figure 18: Ovation 8 and 12 channel models • the Ovation pipette reduces the risk factors for MSD’s • users find the Ovation more comfortable to useThe design of the Ovation • users prefer to use the Ovation during the dayMultichannel lowers the force • 94% report reduction in pain or discomfort while pipettingrequired to acquire tips and alsoallows both hands to be used, • Ovation users have an extraordinarily high rate of satisfactionfurther reducing stress to aspecific muscle group (Fig. 19). • 96% of Ovation users recommend it to their peersAn audible “click” indicates thatall tips are sealed so excessiveforce is not applied. A very lowforce ejection button discards alltips simultaneously without effort. Figure 19: Tip AcquisitionThe Ovation Multichannel is fully electronic, because the forces required todepress the plungers manually are excessive. The electronic features alsoimprove productivity by enabling automatic multidispensing, dilution and mixing.Footnotes 1. NIOSH Special Session – Ergonomic Intervention Studies, Presented by Ming-Lun (Jack) Lu, Ph.D, Research 9. Maija Lintula, Nina Nevala-Puranen, “Testing the ergonomics and usability of liquid dosage pipettes”, Kuopio Ergonomist, Division of Applied Research & Technology Regional Institute of Occupational Health. 2. “A comparison of traditional and alternative pipettes - comfort and preference” Presented by Tamara 10. Calhoun et al., “Development and Evaluation of an Ergonomic Pipette to Reduce Musculoskeletal Injuries in James, MS CPE, Ergonomics Director, Duke University and Medical Center. Laboratory Workers”, Pittsburgh Conference 2002; McKean et al., “Pipette Design and Cumulative Stress Disorders: Radical Ergonomic Improvements needed to Prevent Injury, Pittsburgh Conference 2002 3. David G., Buckle P., “A questionnaire survey of the ergonomic problems associated with pipettes and their usage with specific reference to work-related upper limb disorders”, Appl Ergonomics. 1997;28(4):257-262. 11. US6749812; US6601433; USD460193; US20020095998A1 (pending). 4. Baker P., Cooper C., Upper limb disorder due to manual pipetting. Occup Med. 1995;48(2):133-134. 12. Industrial Designers Society of America, 2001 Gold Winner for Industrial Design Excellence. 5. Fredriksson K., “Laboratory work with automatic pipettes: a study on how pipetting affects the thumb”, Ergonomics. 1995;38:1067-1073. 13. Costello, Kevin J, The Evolution and Ergonomics of Pipetting. Laboratory Medicine 2005; 36 (9):533-536. 6. Bjorksten, M.G.; Almby, B; and Jansson, E.S., Hand and shoulder ailments among laboratory technicians 14. Various published VistaLab data sheets. using modern plunger-operated pipettes. related upper limb disorders”, Appl Ergonomics. 1994;25(2):88-94. 15. Rempel D, Bach J, Gordon L, Yuen S., Effects of Forearm Pronation/Supination on Carpal Tunnel Pressure. 7. National Institute of Environmental Health Sciences (NIEHS), US Department of Health and Human Services - Journal of Hand Surgery 1998; 23A:38-42 Centers for Disease Control and Prevention (CDC), US Department of Labor - Occupational Safety & Health 16. NIOSH Special Session – Ergonomic Intervention Studies, Presented by Ming-Lun (Jack) Lu, Ph.D, Research Administration (OSHA), National Institute of Occupational Safety and Health (NIOSH), numerous Ergonomist, Division of Applied Research & Technology. Oral comments by Dr Lu. universities including Cornell University, University of Florida, University of Minnesota, University of Michigan, University of California, University of Vermont, University of Rochester, University of Queensland. 8. NIEHS, CDC, NIOSH OSHA (http://www.niehs.nih.gov/odhsb/ergoguid/home.htm; http://www.cdc.gov/od/ohs /Ergonomics/labergo.htm; http://odp.od.nih.gov/whpp/ergonomics/ergonomics.html; http://www.osha.gov/SLTC/ergonomics; http://www.isber.org/MeetingArchive/00WorkshopNotes/barr.pdf
  6. 6. VistaLab Technologies, Inc.27 Radio Circle Drive ©2005 VistaLab Technologies, Inc. All rights reserved.Mt. Kisco, NY 10549 USA Ovation is a trademark of VistaLab Technologies, Inc.(888) 652-6520 or (914) 244-6226

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