Diatermiasavun analysointiin perustuva leikkauksenaikainen tervekudosmarginaalin tunnistava mittausjärjestelmä

In this thesis, a method and system capable of intraoperative cancer margin detection, with potential to improve the current methodology, is introduced, tested and validated. The system is based on diathermy smoke analysis by differential ion mobility spectrometry (DMS). Three large measurement sets with different objectives were executed. The first measurement set concentrated on validating the function of a novel filtration device, which is an essential part of the full system proposed in this thesis, and was patented during the thesis work. In the second measurement set, a proof-of-concept study with porcine tissues was conducted to elucidate, whether healthy tissue identification with the system is possible. The third measurement set was a pilot test with two types of clinical human brain tumor samples, with the aim to achieve actual reliable cancer identification with the proposed system. Regarding the objectives, all the three measurement sets were successful. Based on the results, we state that the patented filtration solution works with a high efficiency without compromising tissue identification, and that cancer detection based on the ion mobility spectrometer analysis of tissue smoke can be achieved with our system

Yüksek frekans akım transformatörsüz elektrocerrahi jeneratörü tasarımı ve gerçeklemesi

x, 32 sayfa29 cm. 1 CDÖZETBu tezde yüksek frekans akım (YFA) transformatörü kullanılmayan elektrocerrahi jeneratör (ECJ) tasarımı ve gerçeklemesi yapılmıştır. ECJ’ler cerrahi operasyonlarda dokuların kesilmesi ve koterizasyonu işlemleri için kullanılırlar. Mevcut ECJ’lerde YFA katında kullanılan radyo frekans (RF) transformatörü ile yüksek frekans anahtarlaması yaparak çıkış gücü düzenlemesi yaparlar. Ancak, yüksek frekansla anahtarlama RF transformatörü çıkışında zıt elektromotor kuvveti etkileri ile oluşan yüksek genlikli ani gerilim değerlerine ve elektrocerrahi kesim kipi işleminde cihaz ucunda alev uzamalarına neden olmaktadır. Bu da cerrahi operasyonlarda istenilmeyen yanık veya doku hasarına neden olabilir. Bu tezde, YFA transformatörü kullanılmadan yüksek gerilimli doğru akım devresi ve anahtarlaması ile çalışan yeni bir ECJ cihazı tasarımı ve gerçeklemesi yapılmıştır.ABSTRACTThe electrosurgical generators (ECJ) are used for cutting and cauterization of tissues in surgical operations. Available ECJs make high frequency switching to regulate the output power with the radio frequency (RF) transformer used in the high-frequency current (HFC) stage. However, this high-frequency switching causes not only high amplitude instantaneous voltage values owing to the effects of opposite electromotive force at the RF transformer output, but also flame elongation at the end of the device in electrosurgical cutting mode. These unwanted results may cause undesirable burns or tissue damage in surgical operations. In this thesis, a new ECJ device has been designed without using an HFC transformer via the developed high voltage direct current circuit. The developed ECJ has been implemented without RF transformer as the monopolar type ve the required direct current source design has been designed for HFC

Feasibility of on/at line methods to determine boar taint and boar taint compounds: An overview

Classification of carcasses at the slaughter line allows an optimisation of its processing and differentiated payment to producers. Boar taint is a quality characteristic that is evaluated in some slaughter plants. This odour and flavour is mostly present in entire males and perceived generally by sensitive consumers as unpleasant. In the present work, the methodologies currently used in slaughter plants for boar taint classification (colorimetric method and sensory quality control-human nose) and the methodologies that have the potential to be implemented on/at the slaughter line (mass spectrometry, Raman and biosensors) have been summarized. Their main characteristics are presented and an analysis of strengths, weaknesses, opportunities and threats (SWOT) has been carried out. From this, we can conclude that, apart from human nose, the technology that arises as very promising and available on the market, and that will probably become a substitute for the colorimetric method, is the tandem between the laser diode thermal desorption ion source and the mass spectrometry (LDTD-MS/MS) with automation of the sampling and sample pre-treatment, because it is able to work at the slaughter line, is fast and robust, and measures both androstenone and skatole.info:eu-repo/semantics/publishedVersio

The Landscape Across the Continuum of Invasive Cervical Cancer Prevention: A Geospatial Approach

In the United States (U.S.) over the past decade, approximately 40,000 women have died from a disease that is mostly preventable, invasive cervical cancer (ICC). Since the 1950’s, with the introduction of the Papanicolaou (Pap) screening test, there has been a ≥ 60% decline in the incidence rate. Screening is highly effective in reducing the incidence of ICC, but it is only one component of the multi-step process of the “continuum of care” (i.e. screening, diagnosis, and treatment). There is increasing concern about why women in the U.S. are still dying from ICC and why minority women are disproportionately burdened with higher mortality rates. To address these concerns, a multidisciplinary approach informed by theoretical frameworks and methods in GISHealth, health geography, epidemiology, and sociology were used to examine three aims: (1) characterize the effort to manually geocode healthcare facilities that provided invasive cervical cancer preventive services; (2) examine if geographic accessibility, defined as travel time and travel distance, differs for women who live in rural areas as opposed to women who live in non-rural areas; and (3) determine if socioeconomic status, acculturation, race/ethnicity, and geography are associated with ICC through the examination of main effects and interactions using a case-control research design. I found that there was a 90% improvement in geocode quality type and a corresponding spatial shift that ranged from 0.02 to 151,368 meters after manual intervention of geocoding of healthcare facilities, which took 42 hours of processing time. The Mann-Whitney test confirmed that there was a significant (P < 0.001) difference in travel time for all services across the ICC continuum of care comparing women who resided in rural areas to women who resided in non-rural areas. Multivariable conditional logistic regression results showed that female-headed households, not having health insurance, being a Hispanic woman, being a non-Hispanic white woman, travel time to a cervical cancer screening facility, living in a rural area as opposed to a non-rural area, and low educational attainment had increased odds while living in poverty and “speaking Spanish but not speaking English well” had decreased odds with ICC (statistically significant at P < 0.050)

The Use of Predicates in FDA Regulation of Medical Devices: A Case Study of Robotic Surgical Devices

In the last decade, a number of high profile medical device recalls have drawn attention to the regulatory approval process, particularly the streamlined process for devices considered “lower risk” known as the 510(k). Approval of medical devices through the 510(k) Process is not based on clinical data, but rather on “substantial equivalence” to predicate devices approved pre-1976 or legally marketed thereafter. A predicate device is one that shares the same intended use as the new device and technological characteristics which are either the same or different without introducing new safety hazards. Many scholars believe that the premise of approving medical devices based on similarity to existing devices is inherently flawed. In particular, there is worry that presence of technology creep between predicate devices can lead to the approval of medical devices which ultimately do not resemble the original device for which clinical evidence exists, even as that evidence is used to validate device safety. Given these concerns about the safety of the established regulatory process, this thesis explored the impact of predicate creep within the 510(k) Process through a case study of a Robotic Assisted Surgery (RAS) devices, with particular focus on the Intuitive Surgical Da Vinci Surgical System. Through the development of new methodologies using publicly available data to measure predicate creep, this research traces the predicate ancestry of several RAS devices to assess the current impact and implications of predicate creep on the current regulatory process. The study concludes that there is significant evidence of predicate creep within the approval process and recommend new guidelines for classifying device risk and subsequent evidentiary requirements within the 510(k) Process, to reduce the number of devices with high levels of potential risk to public safety released onto the market

Organization and management of maintenance indexed to risk factors in healthcare environment

Currently, in a similar way to the policies adopted by the organizations, the hospitals lay an enormous effort in the search of the maximum efficiency of the organizational flows. This results in the improvement of the provided services and patient safety, taking into account the profitability of the physical resources and economic conditions. To achieve these goals, it is necessary not only to increase the efficiency of medical equipment throughout their life cycle, but also to prevent the risks associated with their handling, with emphasis on patient safety. The concepts of maintenance management and risk assessment have been evolving towards the adequacy of the policies most adapted to the nature of the facilities and equipment, whether by economic, functional or other classification. The concept of risk in a hospital environment is very diverse. There are physical, chemical, biological and psychosocial risks. Although all risks are important for the safety and well-being of patients, this dissertation/project focuses mainly on biological risks (infections due to viruses, fungi, bacteria and parasites), and physical risks with a special focus on electrical risk. These risks can be partially indexed to the organization and management of the maintenance of hospital facilities and equipment, as this can help to prevent risks; However, with a good evaluation and management of these, maintenance costs can be reduced and unexpected interventions can be avoided. In this context, this article analyzes the main electrical and biological risks, in order to establish a cause-effect relationship with the maintenance policies carried out by the institutions

Advances in mass spectrometry-based cancer research and analysis: from cancer proteomics to clinical diagnostics

Introduction: The last 20 years have seen significant improvements in the analytical capabilities of biological mass spectrometry. Studies using advanced mass spectrometry (MS) have resulted in new insights into cell biology and the aetiology of diseases as well as its use in clinical applications. Areas Covered: This review will discuss recent developments in MS-based technologies and their cancer-related applications with a focus on proteomics. It will also discuss the issues around translating the research findings to the clinic and provide an outline of where the field is moving. Expert Opinion: Proteomics has been problematic to adapt for the clinical setting. However, MS-based techniques continue to demonstrate potential in novel clinical uses beyond classical cancer proteomics

Tissue Identification by Differential Mobility Spectrometry

Perimämme muuttuu jatkuvasti luonnollisten mutaatioiden sekä ulkoisten tekijöiden vaikutuksesta. Muutosten kumuloituessa elämämme aikana hallitsemattomasti jakaantuvien ja ympäröiviin kudoksiin sekä lymfaattiseen järjestelmään ja verenkiertoon tunkeutuvien solujen syntymisen todennäköisyys kasvaa. Tämän tyyppistä pahanlaatuista solukasvua kutsutaan syöväksi. Syöpä vaikuttaa joko suoraan tai epäsuorasti suurimpaan osaan ihmisistä yhtenä yleisimmistä kuolinsyistä. Syöpä on monimuotoinen tauti, joka voi syntyä käytännössä mihin kehon osaan tahansa. Riippuen syövän kohdekudoksesta ja kasvun aggressiivisuudesta mahdolliset hoitomuodot, selviytymisennusteet ja kuolleisuus vaihtelevat huomattavasti. Yleisesti syövän rooli kuolinsyynä kuitenkin korostuu jatkuvasti, ja huomattavasta rahallisesta panostuksesta ja vuosikymmenten tutkimustyöstä huolimatta uusille ja paremmille hoito- ja diagnosointimenetelmille on jatkuva tarve. Kiinteiden syöpien leikkaushoito on yksi erityisalue, joka hyötyisi uusista, hoitoa tehostavista innovaatioista. Syövän leikkaushoidossa on yleisesti tavoitteena poistaa kasvain elimistöstä täydellisesti ja täten saavuttaa negatiivinen tervekudosmarginaali. Huomattavassa osassa syöpäleikkauksia poisto on kuitenkin epätäydellinen. Tällöin potilaaseen jääneet syöpäsolut vaativat jatkohoitotoimenpiteitä, joihin yleensä sisältyy myös syövän uusintaleikkaus. Uusintaleikkauksen tarve on erittäin vahingollista potilaan yleiselle hyvinvoinnille ja tuo mukanaan huomattavia lisäterveydenhuoltokustannuksia. Jos vältettävissä olevien uusintaleikkausten määrä voitaisiin puolittaa nykyisestä, säästöjä mitattaisiin jo miljardeissa. Selkeästä säästöpotentiaalista huolimatta syöpien turhat uusintaleikkaukset ovat edelleen ratkaisematon ongelma johtuen etenkin leikkauksenaikaisista haasteista erottaa hyvänlaatuinen kudos pahanlaatuisesta. Solujen rakenteen ja toiminnan määräävä molekulaarinen sisältö eroaa riippuen solujen syntykudoksesta, ja samankaltaisia eroja havaitaan myös pahanlaatuisten ja hyvänlaatuisten solujen välillä. Biomolekyylejä, jotka mahdollistavat kudostyyppien erojen havaitsemisen, kutsutaan biomarkkereiksi tai bioilmaisimiksi, ja tutkimuksissa onkin löydetty satoja proteiineja, rasva-aineita ja aineenvaihduntatuotteita, joiden pitoisuus solussa vaihtelee hyvänlaatuisen ja pahanlaatuisen kudoksen välillä. Tiettyjen biomarkkereiden pitoisuuksien vaihteluvälit hyvänlaatuisissa ja pahanlaatuisissa kudoksissa ovat kuitenkin erittäin suuria, ja molekyylitason erot kudosten välillä aiheuttavat harvoin selkeää makroskooppisesti näkyvää muutosta. Siksi syöpäkudoksen ja tervekudoksen välisen rajan silmämääräinen arvioiminen on erittäin haastavaa. Silti lähes kaikki syöpäkirurgit käyttävät ainoastaan visuaalista arviointia ja tunnustelua operaatiotilanteessa. Lisää haasteellisuutta syövän kokonaispoistoon tuovat myös nykysuositukset, joiden mukaan syövän ympäriltä poistetun tervekudoksen määrä pyritään minimoimaan. Tämä tavoite ja rajan subjektiivinen arviointi johtavat suureen hajontaan eri maiden ja sairaaloiden positiivisten marginaalien määrissä sekä yleisesti korkeaan uusintaleikkausten määrään. Positiivisista tervekudosmarginaalilöydöksistä johtuvia uusintaleikkauksia on pyritty vähentämään tutkimalla ja ottamalla käyttöön useita erilaisia leikkauksenaikaista kudostunnistusta auttavia menetelmiä, mutta niiden kliininen käyttö on ollut rajallista johtuen kunkin menetelmän rajoitteista ja haitoista. Tässä väitöskirjassa esitellään kudostunnistusjärjestelmä, jota voidaan mahdollisesti tulevaisuudessa hyödyntää leikkauksenaikaisessa tervekudosmarginaalin arvioinnissa. Järjestelmän kehitystä ja soveltuvuutta kudostunnistukseen tarkastellaan viiden osatyön kautta. Järjestelmä pohjautuu sähkökirurgiassa tuotetun kudossavun mittaamiseen liikkuvuuserospektrometrialla (differential mobility spectrometry, DMS). DMS on normaali-ilmanpaineessa toimiva mittausteknologia, joka tuottaa informaatiota kaasumaisen näytteen molekulaarisesta rakenteesta erottamalla ionisoidut molekyylit toisistaan voimakkaassa, epäsymmetrisesti muuttuvassa sähkökentässä. DMS vertautuu massaspektrometriaan (MS) mutta on analyyttiseltä suorituskyvyltään sitä heikompi. DMS-teknologian etuna on kuitenkin sen yksinkertaisuus, pienempi koko sekä pienemmät kustannukset MS-teknologiaan verrattuna. DMS-teknologiaa on aiemmin käytetty itsenäisenä mittausmenetelmänä erilaisissa kaasumittaussovelluksissa sekä biolääketieteellisessä käytössä muun muassa hengitysilman mittaamiseen. Nämä sovellukset ovat kuitenkin aina sallineet kontrolloidun ympäristön ja suhteellisen pitkän mittauksen keston. Siksi reaaliaikainen DMS-pohjainen sovellus vaatii ympärilleen lisälaitteistoa ja järjestelmän parametrien optimointia. Lisäksi DMS-data ei suoraan tuota määrällistä tietoa näytteessä olevista biomolekyyleista vaan luo pikemminkin kokonaiskuvan näytteen sisältämien aineiden seoksesta. Spektrin tulkinta ja kudostyypin määritys ei siis ole suoraviivaista, ja yhdestä näytteestä saatavan suuren datamäärän vuoksi analysointi soveltuu parhaiten koneoppimismenetelmille. Järjestelmän poikkitieteellinen näkökulma sekä kokonaisuuden toiminnan ja suorituskyvyn tutkiminen kudostunnistuksessa ovat tämän väitöskirjan pääsisältö. Väitöskirjan kolmessa ensimmäisessä osatyössä tavoitteena oli tutkia menetelmän soveltuvuutta kudostunnistukseen eläinkudosnäytteillä sekä ihmisen rintasyöpänäytteillä. Tulokset laboratorio-olosuhteissa hallitulla näytteentuotolla olivat lupaavia, ja diagnostinen suorituskyky osoitti teknologian potentiaalin kudostunnistuksessa. Neljännessä osatyössä laitteistoa muokattiin mahdollistamaan reaaliaikaiset mittaukset sekä luokittelutuloksen esitys välittömästi mittauksen jälkeen. Tulokset osoittivat, että järjestelmä soveltuu reaaliaikaiseen kudostunnistukseen vähintään eläinnäytteillä laboratorio-olosuhteissa. Viidennessä osatyössä järjestelmää käytettiin rintasyöpäleikkauksissa. Diagnostisen suorituskyvyn osalta tulokset eivät olleet vertailukelpoisia laboratoriotutkimuksiin, mutta tutkimus osoitti, että järjestelmän integroiminen osaksi syöpäkirurgiaa onnistuu käyttäjiä häiritsemättä ja että se pystyy tuottamaan informaatiota leikatusta kudoksesta operaation aikana. Kokonaisuudessaan väitöskirjatutkimuksen tulokset osoittavat DMS-pohjaisen kudostunnistusjärjestelmän potentiaalin ja soveltuvuuden reaaliaikaiseen käyttöön riittävällä diagnostisella suorituskyvyllä. Tulevaisuudessa tässä työssä esitetty järjestelmä voi jatkokehityksen jälkeen toimia syöpäkirurgin apuna tervekudosmarginaalin tunnistuksessa ja auttaa suojelemaan syöpäpotilaiden hyvinvointia vähentämällä tarpeettomia syövän uusintaleikkauksia.The human genome is constantly changing due to natural mutations and environmental exposure. As these changes accumulate over our lifetime, it increases the likelihood of the creation of cells that proliferate uncontrollably and ultimately invade surrounding tissue and the blood circulation or the lymphatic system. This type of malignant neoplasm, more commonly known as cancer, is a disease that either directly or indirectly affects the majority of the population as one of the leading causes of death. Cancer is a versatile disease that can affect practically any part of the body. Depending on the tissue of origin and the aggressiveness of the malignancy, the treatment options, prognosis and mortality rates can vary significantly. In general, the role of cancer as a cause of death is constantly increasing, and despite significant global financial investments and decades of research, new and better methods of treatment and diagnosis are in continuous demand. One particular area that requires more attention and innovation is the surgical treatment of solid cancers. The general aim of surgical treatment is to remove all malignant cells from the patient’s body – that is to say, to achieve a negative surgical margin. The resected tumour has a negative margin, when the outermost surface area has no cancerous cells. However, in a considerable number of surgeries, the removal is incomplete. The resulting residual cancer almost always triggers additional treatment steps, which often involve a reoperation. The need for a reoperation is a major detriment for the well-being of the patient, and the added healthcare costs are substantial. If the number of avoidable reoperations could be halved from their current level, the saving potential in annual global healthcare costs would already be measured in billions of dollars. The reason why the problem of reoperations persists despite the notable financial incentives lies in the difficulty of discriminating malignant tissue from benign, especially during a surgical procedure. The molecular contents that define the structure and function of a cell are different depending on the organ of origin, and similar differences are also present between malignant and benign cells. The biomolecules that enable the identification of the types of tissues are called biomarkers, and the research on this area has revealed hundreds of proteins, fatty acids and metabolic products that exhibit differences in quantities based on tissue malignancy. However, the variation of specific marker molecules is often high, and the molecular differences rarely translate into clear macroscopic differences. This means that visual assessment of the margin between benign and cancerous tissue is extremely challenging. Still, almost all surgeons rely only on visual assessment and palpation in cancer surgeries. The challenge of complete excision is further accentuated by the current resection guidelines that instruct surgeons to preserve as much non-cancerous tissue as possible. This aim and its subjective execution lead not only to high variation in positive margin rates between institutions and regions, but also to a high number of required reoperations in general. To reduce the reoperations caused by positive surgical margins, several technologies have been studied and introduced to aid in intraoperative tissue identification, but the clinical adoption has been limited due to various impeding factors involved in their use. In this thesis, a concept that could potentially be used in the assessment of the intraoperative surgical margin is introduced through five scientific publications that concentrate on the evolution and feasibility of the technology in tissue identification. The basis of the technology is the measurement of surgical smoke with differential mobility spectrometry (DMS). DMS is a measurement technology that provides information on the molecular content of a gaseous sample in atmospheric pressure by means of ionisation and subsequent differentiation of the ions in a high-strength asymmetric electric field. DMS is comparable to mass spectrometry (MS), and even though the analytical performance of MS is better, the reduced complexity, smaller size and lower cost of DMS make it an advantageous option. DMS has been used as a standalone measurement instrument in many types of general gas measurement applications and in some biomedical applications, such as breath analysis, but the context of use has always permitted a controlled environment and a relatively long measurement duration. Thus, the real-time application of surgical smoke measurement requires additional hardware and parameter optimisation. In addition, raw DMS measurement data do not provide directly quantifiable information on certain biomolecules, but rather a comprehensive spectrum of all contents in the sample combined. This means that the interpretation and identification of tissue type from the DMS output spectra is not trivial and involves a high number of dimensions that are most effectively analysed by means of machine learning. The interdisciplinary aspects of the system and their combined function and performance in tissue identification are the focus of this thesis. In the first three publications included in the thesis, the focus was on studying the overall feasibility of tissue identification and its possibilities with animal tissues and clinically relevant breast cancer samples. The results in laboratory conditions with controlled sampling were promising, and the diagnostic performance demonstrated the potential of the technology in tissue identification. In Publication IV, the system was modified to accommodate real-time measurements and to relay the classification information immediately after the measurement. The results demonstrated the feasibility of real-time tissue identification with the system, albeit in laboratory conditions and in a porcine model. In the final study, a prototype system was used intraoperatively during breast cancer surgeries. The results of this study were not comparable to the laboratory results in respect to diagnostic performance but indicated that the system can be adapted to the surgical workflow with minimal intrusiveness to provide information on the operated tissue. Overall, the results of this study indicate that a DMS-based tissue identification system has the potential to be used in real-time applications to identify tissue types with adequate diagnostic performance. With further development, the system presented in this thesis could fulfil the need for a surgical margin assessment device that would reduce avoidable reoperations of solid cancers and thus protect the well-being of cancer patients

Elektromagnetische velden in arbeidssituaties

NB Nederlandstalige versie verschenen onder nummer 610015001N De EU heeft richtlijn 2004/40/EG uitgevaardigd om de werknemer te beschermen tegen gezondheidsrisico's door blootstelling aan elektromagnetische velden op het werk. Deze richtlijn moet uiterlijk 30 april 2008 zijn omgezet in nationale wetgeving. Ter voorbereiding hiervan heeft het RIVM in opdracht van het Ministerie van SZW de blootstelling in Nederlandse arbeidssituaties geinventariseerd en geanalyseerd. Het doel van dit rapport is de werkgevers een handreiking te geven om vast te stellen of aan de eisen uit de richtlijn wordt voldaan en om de risico-inventarisatie en -evaluatie (RI&E) voor elektromagnetische velden op te stellen. Totdat er geharmoniseerde Europese normen van het Europees Comiti voor elektrotechnische normalisatie (CENELEC) beschikbaar zijn voor alle situaties die moeten worden beoordeeld, gemeten en berekend, mag dit rapport als richtsnoer gebruikt worden. Gebruik van dit rapport is dus geen verplichting. Voor de meeste werkgevers is het voldoende om de eerste twee hoofdstukken door te nemen. De volgende drie hoofdstukken bevatten voor een aantal arbeidssituaties informatie over de blootstelling, de rekenregels waarmee de situatie kan worden ingeschat en de mogelijke beheersmaatregelen. Het laatste hoofdstuk geeft een overzicht van de kosten die met invoering van de richtlijn samenhangen. Om te kunnen toetsen of de blootstelling onder de limieten van de richtlijn blijft, moeten CENELEC-normen worden gebruikt, voor zover ze bestaan. Deze normen zijn zonder specialistische kennis niet eenvoudig toe te passen. Ook hoeft niet alle apparatuur even uitgebreid beoordeeld te worden of zijn even zware maatregelen nodig. Om de beoordeling te vergemakkelijken geeft dit rapport een beoordelingsschema en tabellen met een indeling van alle relevante werkomgevingen in drie categorieen. Voor iedere categorie geldt een ander beoordelingstraject.The EU has issued Directive 2004/40/EC on the protection of workers from health and safety risks arising from exposure to electromagnetic fields in the workplace. This directive must be implemented in national legislation no later than 30 April 2008. To prepare for implementation, RIVM has, on commission of the Ministry of Social Affairs and Employment, investigated and analysed the exposure in Dutch working environments. The purpose of this report is to provide assistance to employers to assess whether compliance is met and to carry out the inventory and evaluation of risks (RI&E) due to electromagnetic fields. Until harmonised European standards from CENELEC cover all relevant assessment, measurement and calculation situations, this report may serve as a guide. It is not mandatory to use this report. It will be sufficient for most of the employers to confine themselves to the first two chapters. Subsequent chapters deal with the exposure found in several working environments and provide guidelines for assessing risks and possible measures in these working environments. Costs for implementing the directive are discussed in the last chapter. CENELEC standards, if available, are mandatory for assessing whether exposure occurs below the limits in the directive. However, these standards are not easy to use without specialist knowledge. Furthermore, not all equipment needs to be assessed to the same extent nor are the same measures needed. A flow chart and tables of relevant working environments, classified into three categories, are provided to facilitate the assessment. Each category has its own assessment path.SZ