View this video (6:11) which provides an overview of human factors:
| Medisense MedEd. (2017, October 10). Human Factors: A Quick Guide. Retrieved from https://www.youtube.com/watch?v=aGZz3w5Hy8Y |
Human-Centered Design
View these videos (3:11 & 2:55) below to learn about what it means to design products and systems with users in mind. The speaker is Donald Norman, noted researcher and author of the book “The Design of Everyday Things”.
NNgroup. (2017, October 13). Design for How People Think (Don Norman).
Retrieved from https://www.youtube.com/watch?v=vdDwe0bM4U4
NNgroup. (2018, August 10). Principles of Human-Centered Design (Don Norman).
Retrieved from https://www.youtube.com/watch?v=rmM0kRf8Dbk
Human Factors Engineering & Patient Safety
Read the following materials to gain a clear understanding of the scientific discipline of human factors engineering and its critical role in helping improve patient safety:
- Agency for Healthcare Research and Quality. (2019, September). Human Factors Engineering. Retrieved from https://psnet.ahrq.gov/primer/human-factors-engineering
- Johns Hopkins Medicine. (n.d.). Human Factors in Health Care. Retrieved from https://www.hopkinsmedicine.org/armstrong_institute/centers/human_factors_engineering/human_factors_in_health_care.html
This video (5:21) provides a summary of the incident:
| NRCGov. (2013, April 8). Moments in NRC History: Three Mile Island – March 28,1979. Retrieved from https://www.youtube.com/watch?v=SUct_69kNpQ |
This infographic shows how the incident occurred:
Padilla R., Loehrke J., & Petras G. (2019, September 20). Three Mile Island: How America’s worst nuclear accident unfolded. Retrieved from https://www.usatoday.com/in-depth/news/2019/09/20/three-mile-nuclear-meltdown-graphics/2344134001/
Read the following materials to learn about the Therac-25 incidents:
- Thompson, R. C. (1987, December 1). Faulty therapy machines cause radiation overdoses. FDA Consumer, 21(10), 37+. Retrieved from https://link.gale.com/apps/doc/A6245245/AONE?u=esc&sid=AONE&xid=4b42abed
- Leveson, N. G. (2017, November). The Therac-25: 30 years later. Computer, 50(11), 8-11. Retrieved from http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8102762&isnumber=8102264
- The incident that took place at the East Texas Cancer Center in March of 1986 (we will focus on this incident for our collaborative project). The following excerpt is taken from Wang, J. X. (2017, January 2). Therac-25 and industrial design engineering of socio-technical systems. Retrieved from https://www.crcpress.com/authors/news/i3158-therac-25-and-industrial-design-
Another Therac-25 accident, the fourth in the series, developed at the East Texas Cancer Center in March of 1986. A male patient was to receive therapy on his upper back. The Therac-25 operator had typed in incorrect treatment information by indicating X-ray mode instead of electron mode. She merely used the “cursor up” key to edit the mode entry and then quickly pressed “enter” (one of the user-friendly features), and started treatment. The machine shut down with treatment pause, and a “malfunction 54” error message was displayed on the screen. This error message indicated that either a dose too high or a dose too low had been delivered. Since an underdose value appeared on the screen and the operator was used to quirks in the machine, she hit the “P” key to continue with the treatment. The machine repeated the “Malfunction 54” error message and indicated the same underdose was delivered. The operator had no contact with the patient, because the usual audio and video monitors were not working properly. After the first attempt at treatment, the patient felt an “electric shock” or as if “someone had poured hot coffee” on his back. He knew this was not normal and began to get up from the treatment table when the second treatment was delivered. The patient felt a tremendous shock in his arm, and felt that “his hand was leaving his body”. He had to pound on the treatment room door to get the operator’s attention. The patient eventually loss the use of his left arm and both legs, was unable to speak, and had several other complications. He died from complications five months later.
Review the following if you are not familiar with medical linear accelators and radiation therapy sessions:
- Medical Linear Accelators
RadiologyInfo.org. (2019, February 20). Linear Accelator. Retrieved from https://www.radiologyinfo.org/en/info.cfm?pg=linac
- Radiation Therapy
This is a short video (3:32) on what a radiation therapy session looks like:
Accelerated Education Program (AEP). (2014, July 2). What to Expect: Radiation Therapy 101.
Retrieved from https://www.youtube.com/watch?v=t8Q23XhqAhc
The following excerpt is taken from Wang, J. X. (2017, January 2). Therac-25 and industrial design engineering of socio-technical systems.
(The excerpt below has all the information we need from this source for our project, and there is no other information about this incident included Wang’s book referenced above. If you would like to find out more about the incident, you can search online with these keywords: “Therac-25, East Texas Cancer Center”.)
The safety of the Therac-25 is not really a property of the machine alone. Accidents that go unreported contribute to (or at least fail to stop) later accidents. When the TV camera in the room is unplugged, the operator cannot see that the patient is in trouble. So safety is really a property of the entire technical and social system (socio-technical system).
The Therac-25 Medical Linear Accelerator is a large machine that sits in a room designed just for it. We may think of the machine itself or the machine-in-the-room as the system. But the larger system, or the Socio-Technical system, that we need to think about includes:
- Hardware: The mechanics of the machine itself, including its associated computer
- Software: the operating system of the computer and the operating system of the machine
- Physical surroundings: the room with its shielding, cameras, locking doors, etc.
- People: operators, medical physicists, doctors, engineers, salespeople, managers at AECL, regulators
- Institutions: AECL, regulators, each medical facility, associations of operators, etc.
- Procedures
- Management models: AECL’s model of how risk is managed
- Reporting relationships: who was required to report accidents to whom
- Documentation requirements: for the software, for the facilities, for the government regulators
- Data flow: how different parts of AECL shared information, how information was shared among agencies and organizations, how data was used by the Therac software.
- Rules & norms: what patients are “normally” told, what operator & physicist responsibilities are, expectations set for the programmer
- Laws and regulations: Reporting requirements, regulators enforcement mechanisms, medical liability law
- Data: data was collected in regulators’ approval process, use of data in Therac software,
The following table presents some of these items in a schematic form.
| Therac-25: The Socio-Technical System | |
| The Machine Supporting Systems (video, audio, etc.) Hardware Software Systems | Hospitals and Clinics Doctors, Medical Physicists Management, User Groups Operators, Reporting Procedures |
| Atomic Energy Canada, Limited Management, Reporting Procedures, Design Teams, Sales Staff, Support and Field Engineers | Medical Device Regulation Regulators Reporting Procedures |
When addressing complex societal problems, Industrial Design Engineering has been recognized in literature as a solution likely to achieve better and more sustainable results than a traditional product design approach. Industrial Design Engineering considers different system hierarchies within a particular socio-technical system. A socio-technical system is a number of clustered elements, such as technology, policies, user practices, markets, culture and infrastructure, which are linked together to attain a specific functionality in a system. By broadening the scope and complexity of design practice, Industrial Design Engineering increases the capacity of the (socio-technical) system to address its function.
Industrial Design Engineering [https://www.crcpress.com/Industrial-Design-Engineering-Inventive-Problem-Solving/Wang/p/book/9781498709590] understands that solely (re)designing products to be affordable is not enough to guarantee their adoption and thus render the function of the system to be comprehensively accomplished. As such, it develops the design of a coherent combination of processes and products that together fulfill the function of the system. For designers this means handling a larger degree of complexity and making a more sustainable change by considering value creation through a long-term timeframe and the involvement of a larger network of stakeholders. Therefore, relying on existing product development knowledge (i.e. methods, tools and techniques) restricts the design process creating an inability to understand the local context. Using Industrial Design Engineering encourages designers to consider aspects beyond technology, related to business, lifecycle and stakeholders motivations. Because designers and researchers are typically educated to apply traditional product development, in this novel innovation network, universities increasingly gain relevance as essential partners for system change.
Here is another short video (5:26) of Don Norman on socio-technical systems: NNgroup. (2017, December 22). Don’t Drop The Patient! Examine the Entire System (Don Norman).
Retrieved from https://www.youtube.com/watch?v=xfOpgyGqgx8
