Biomedical Devices Design and Troubleshooting (BME520) Chapter 3 PDF

Biomedical Devices Design and Troubleshooting (BME520 ) Chapter 3: Biomedical Engineering Design Claudio Becchetti, 1th Edition Dr. Qasem Qananwah 11/13/2022...

Biomedical Devices Design and Troubleshooting (BME520 ) Chapter 3: Biomedical Engineering Design Claudio Becchetti, 1th Edition Dr. Qasem Qananwah 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 1  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations In general terms, the presence of a measuring system will represent an increased risk (for patients and operators), that needs to be fully taken into account when designing an instrument intended for clinical applications. The key concept is ‘acceptable risk’ 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 2  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations In general terms, the following key factors have to be addressed, when designing biomedical instrumentation: 1. patients’ and operators’ safety, in order to make direct risk associated acceptable when using instrument, in normal conditions, and in fault or abnormal conditions 2. instrument quality and performance, in order to minimize the effects of an increased indirect risk, associated with the use of the instrument. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 3  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations The technical standard series IEC/EN 60601 is specifically devoted to safety and effectiveness requirements. The standard was first published in 1977, and now it represents a de facto constraint when a medical electrical instrument needs to be designed and placed on the market. The standard is composed of a general part, IEC/EN 60601-1, with ten different collateral sections, and numerous vertical standards that address specific medical instruments. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 4  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations Table 1: EU medical device classes 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 5  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations In the design phase, a risk analysis is needed to identify possible harms to patients or operators and to introduce control measures to minimize the effects. These measures will be implemented to minimize the probability of having a harm due to specific event (such as an accident) “prevention measures” the severity of that harm “protection measures”. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 6  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations In general, risk analysis is synthesized by an ‘acceptability matrix’, where harm probability is categorized into probability levels (e.g., rare, improbable, remote, probable, frequent). Harm severity is associated to specific levels: negligible, marginal, serious, critical. Risk Management standard— ISO 14971 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 7  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations Corrective and Preventive Actions (CAPA) There are Corrective action procedure (set of points) and preventive action procedures (set of points) adopted by the ISO 14971 standard. risk analysis synthesized by an ‘acceptability matrix’, 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 8  Chapter 3: Biomedical Engineering Design Part I: Theory Design Principles and Regulations 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 9  Chapter 3: Biomedical Engineering Design Part I: Theory General Design System Model Figure : Medical instrument architecture. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 10  Chapter 3: Biomedical Engineering Design Part I: Theory Pressure and Flow Instruments Example: Module for pressure measurements Figure : Acquisition module for pressure measurements. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 11  Chapter 3: Biomedical Engineering Design Part I: Theory Example: Measuring Oxygen Saturation Figure : Pulse oximeter design scheme. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 12  Chapter 3: Biomedical Engineering Design Part I: Theory Biopotential Instruments Example: Biopotential Instruments - Electroencephalographs Figure : Conceptual representation of an EEG device 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 13  Chapter 3: Biomedical Engineering Design Part I: Theory Biopotential Instruments Example: Biopotential Instruments - Electroencephalographs Figure : EEG conceptual single channel scheme. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 14  Chapter 3: Biomedical Engineering Design Part I: Theory Biopotential Instruments Example: Biopotential Instruments - Electromyographs Figure : Instrumentation amplifier for EMG recordings. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 15  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process The use of a design process is recommended in any product development to improve quality and reduce risks and costs of reworking Many design techniques are available in the scientific literature. However, design cannot be considered a standard activity applicable to any class of products Design standards and guidelines mainly suggest frameworks that have to be tailored according to the product context and the applicable requirements. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 16  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process In this chapter, the design process will be based mainly on the MIL 498 standard (template document ). Supported by the US Food and Drug Administration (FDA) The design process includes the activities to obtain design outputs from inputs. Figure : Design process scheme based on MIL 498 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 17  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process The conceptual design process is performed to clarify device features and to assess product feasibility. In product design: ‘the earlier the errors are detected, the less the effort spent to fix them’, According to Brook’s ‘law’ Figure : Design process scheme based on MIL 498 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 18  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process The design output may include functional performance, interface specifications, drawing, processes and procedures for manufacturing and delivery, software documentation, source code…etc. In the USA, the FDA requires a ‘design history file’ containing most of these information. The design history file is very important and employed for certification Figure : Design process scheme based on MIL 498 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 19  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process Risk management is a process that has to be performed in parallel with the design. Risks have to be assessed, evaluated and controlled continuously throughout the design. Therefore, it is a dynamic process that is continuously iterated throughout the product life cycle, including the design step. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 20  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process Risk management implies 1. risk analysis, identifying hazards, considering all the combinations of events that may produce harm, defining the severity of harm and the probability of occurrence 2. risk evaluation, assessing the acceptability of risks and deciding whether protection measures are required 3. risk control that focuses on the implementation of protection measures for unacceptable risks 4. risk monitoring, where risks are assessed periodically to evidence any changes (new risks, different estimation etc.) 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 21  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process Figure : The risk management process. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 22  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process The evidence of the risk managements process is included in the ‘risk management files’ which, for each product, contains all the records and documents generated by the process. Usually, the company which design specific product establish and maintain a systematic procedure to review information obtained by medical devices or similar devices in post-production. These data must be evaluated for safety significance. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 23  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process The post-production information must evidence if there are hazards not previously recognized if estimated risks, related to a specific hazard, are no longer acceptable if the original assessment is in any case to be invalidated. If one of the above conditions is satisfied, the outcomes must be reported as input elements of the process of risk management revision 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 24  Chapter 3: Biomedical Engineering Design Part I: Theory The Design Process In particular, the risk management file will be updated in the following cases: change or introduction of new legislation evidence from scientific publications that additional methods exist for reducing risks introduction of new technologies changes in process, material or critical suppliers Complaints reporting of accidents or ‘near misses’. 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 25  And this concludes… 11/13/2022 BME520: Biomedical Devices Design and Troubleshooting Biomedical Systems and Informatics Engineering Department 26