E- Health (HCI 316) Week 9 Chapter 8: 3D Printing & Chapter 11: Drones in Healthcare
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Students Resources: – Chapter 8: 3D Printing
– Chapter 11: Drones in Health care
Objectives: (a) Understand the Three-dimensional printing for a variety of medical applications .
(b) Identify the already used 3D printed models for educational and training purposes as well as for planning of complex surgical intervention.
(c) Understand the manufacturing process of patient- specific implants.
(d) Discuss the bio-printing technologies applied, utilizing living cells.
(e) Introduction to Drones in Healthcare.
Week 9
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Additive manufacturing (AM), also referred to as 3D printing, describes a class of manufacturing technologies in which material is added in a layer-by-layer fashion to directly produce a three-dimensional object.
Prerequisite is a digital dataset that defines the dimensions of the object and, for the manufacturing process itself, additional information about the step-wise assembly process.
AM, therefore, can be seen as a further development of technologies like computer numerical controlled (CNC) milling, which are still subtractive methods, but already make use of the principles of computer aided design/computer aided manufacturing (CAD/CAM).
Basics of Additive Manufacturing
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AM was first introduced in the field of prototype development (and, therefore, called “rapid prototyping”) in mechanical engineering and design but evolved into a class of production technologies applied to all kinds of industries, including the biomedical field, in the meantime.
In medicine, digital data describing the patient’s anatomy that can be used for the CAD/CAM process is commonly available as computed tomography (CT) and 3D magnetic resonance imaging (MRI), which have emerged as standard medical imaging techniques.
Basics of Additive Manufacturing
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AM is an umbrella term for a variety of technologies covering a whole range of materials (metals, ceramics, polymers, and living cells suspended in soft hydrogels) as well as dimensions.
Nowadays, instruments for the production of parts measuring 1 are available as well as high-precision “printers” that achieve sub-micron resolution.
The advantage of AM is that in most cases, less raw material is needed (which is of great importance if the raw material is expensive as in the case of most medical implants or devices) and no tools specific for the part to be manufactured are needed.
Basics of Additive Manufacturing
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As soon as the digital dataset of the object is available, the production process can begin.
Another benefit is that with AM, various geometries can be realized (e.g., those with internal, closed cavities), which are not possible using conventional methods.
3D printers are available nowadays to manufacture very small to very large objects from all types of materials.
Each AM technology has advantages and disadvantages; therefore, a proper selection has to be done depending on the proposed application.
Basics of Additive Manufacturing
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For objects to be utilized in medicine, aspects like material selection, reproducibility, and accuracy of the manufacturing process are of special importance.
In addition, if possible, one-step technologies, like selective laser sintering/melting (SLS/SLM), are applied in which layer-by-layer material deposition and formation of the final product are combined in a single process.
Basics of Additive Manufacturing
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In principle, 3D printing could be used for producing most of the devices, implants, and even tissue engineering constructs utilized in medical education and clinical practice today.
However, AM is only cost- effective for small quantities, whereas the cost per unit is significantly lower if identical parts are produced in large amounts by conventional manufacturing technologies.
On the other hand, the particular strength of AM is that the complexity of the part does not significantly influence the production costs.
Present Landscape of 3D Printing in Healthcare
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Therefore, it is unlikely that AM will replace conventional, established technologies for production of large quantities of identical parts, but will be used especially for small quantities or for manufacturing very complex structures.
As usual for new medical applications and technologies, gaining approvals is a time-consuming process that delays their translation into clinical practice.
Present Landscape of 3D Printing in Healthcare
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In the case of AM and patient-specific implants and devices, the U.S. Food and Drug Administration (FDA) issued a first draft on “Technical Considerations for Additive Manufactured Devices” in May 2016, which is only the first step of a long-lasting procedure.
In many countries, selected AM-based technologies have already been implemented in clinical applications like manufacturing of Patient-Specific Implants (PSI) made of approved materials like titanium.
Present Landscape of 3D Printing in Healthcare
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Probably the fastest growing field in 3D printing applications in medicine is currently that of 3D models for medical education and surgical planning.
Both can be described together as the only significant difference is that for medical education, standardized, or at least typical, anatomical models are produced, whereas for surgical planning, patient-specific and, therefore, unique units are fabricated.
Ethical concerns exist regarding the utilization of formalin-preserved cadavers and exposure of staff and students to toxic gaseous formaldehyde.
3D Printing in Medical Education and Surgical Planning
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Therefore, the use of anatomically correct, 3D printed models made of polymers might offer a practical alternative.
It was pointed out that AM allows for the fast and easy manufacture of realistic, multi-colored models of any anatomical object with high accuracy and reproducibility, whereas embalmment as well as plastination processes are very time-consuming.
In addition, with 3D printing, as many copies as needed can be produced for very small and/or complex objects.
Given the prices for 3D printers and printed models will likely present an interesting alternative from a financial point of view.
3D Printing in Medical Education and Surgical Planning
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In contrast, 3D printed models for surgical planning do not replace any established methodology, but rather are a clear add-on to existing procedures.
These models are used like a touchable 3D image to facilitate defining the strategy of a surgical intervention in case of very complex or risky treatments.
The other type of model is used already to test the applicability of the surgical intervention by, e.g., probing the width and geometry of blood vessels concerning the optimal size of a catheter or stent.
3D Printing in Medical Education and Surgical Planning
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Real 3D models not only facilitate discussion between the surgeons, but also help inform the patient by showing what is intended to be done and the possible risks of the intervention.
AM technologies, commercially available printers, and the software needed for translation of the DICOM dataset (coming from medical 3D imaging like CT or MRI) to a CAD file format, suitable for the 3D printing process.
3D Printing in Medical Education and Surgical Planning
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For the implementation of 3D printed models for surgical planning in clinical practice, two general options are available: digital data processing and (or) printing can either be outsourced to a commercial service or established in-house.
As a function of size, complexity, and detail of the model, the full process, including data processing and manufacturing, requires between a few hours and 1–3 days.
With increasing printing speeds, this period will decrease further.
3D Printing in Medical Education and Surgical Planning
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In principle, the workflow for PSI manufacturing is similar to that used for the printing of surgical models; however, in case of implanted parts, a thorough preoperative validation has to be performed.
The typical workflow of PSI planning, manufacturing, validation, and utilization.
Check the following image for a real clinical case in which a customized metal implant for a cancer patient suffering from a pelvic tumor was applied.
Patient-Specific Implants (PSI) and Devices
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The disadvantages is mainly the deviations between the virtual model and the real 3D object, the long time needed for the whole process, and additional costs.
As already discussed AM is only cost-effective for small lot sizes or the fabrication of very complex objects.
Patient-Specific Implants (PSI) and Devices
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Tissue engineering (TE) describes the formation of living tissue outside of a living organism, i.e., in a tissue culture lab (in vitro).
In most cases, a 3D scaffold is seeded with cells and then further cultivated until cell and tissue differentiation occur.
If a clinical application is intended, then the scaffold should consist of a biodegradable material to act as an artificial extracellular matrix only for a limited period of time, but then give space for the regenerating new tissue.
3D Bio-printing
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However, conventional cell seeding has several limitations; in particular, only one cell type or mixture of cells can be seeded onto one construct.
In contrast, 3D bio-printing allows for the inclusion of multiple cell types with high spatial resolution as the cells are mixed with the respective biomaterial prior to printing.
During the AM process, therefore, biomaterial(s) and cells are positioned together, which enables the fabrication of complex tissue models.
3D Bio-printing
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Two main classes of technique can be distinguished:
Spherical cell/biomaterial droplets or cell aggregates are used as building blocks, or
Cells are suspended in a hydrogel and extruded continuously in a strand-like fashion.
Mostly inkjet printing technologies are used for the first type of application, whereas extrusion-based bio-printing (also called 3D plotting, direct writing, or robotic dispension) is achieved by pneumatic or mechanical extrusion.
Both groups of technologies have advantages and disadvantages.
3D Bio-printing
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3D bio-printing is currently developing as a distinct research field, having strong interactions with AM, TE, microfluidics, and organ-on- a-chip technologies.
The development of vascularized and fully functional tissue/organ models is currently under intensive investigation, but it is still unclear when bio-printing will be introduced into clinical practice.
3D Bio-printing
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As 3D printing has evolved to a very innovative and fast-growing field of research, it is difficult to predict its future direction.
Currently, there is intensive investigation by researchers from all over the world as well as rapid progress concerning hardware and software development.
Already, companies in industrialized countries are producing PSI and models for preoperative planning based on CT or MRI data from specific patients.
3D printing will definitely play a stronger role; however, the velocity and degree of translation will be restricted by financial as well as regulatory issues.
Future Predictions of 3D Printing
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Watch the Video and Learn with Joy.. !
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The most common term used in the media today to describe an “unmanned aerial vehicle” is a drone.
Drones have generated great interest in recent years due to their industrial, commercial, and recreational potential.
Drones have locomotion capacities, the ability to move from one side to another.
However, drones are differentiated from other air vehicles in that they do not need to be manned by a human.
Their remote pilots can control them from varying distances, dependent on their automation and autonomy.
Drones in Health Care
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Drones contain cameras, GPS, and diverse sensors that allow greater autonomy and efficient flights.
Additionally, new lithium batteries are allowing drones to cover greater distance.
Furthermore, mobile phone or tablet software increases accuracy in tracking and navigation.
Civilian drones with commercial-grade low-cost technology have already been used for various rescue tasks and natural disasters around the world.
Drones in Health Care
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Although this technology is already available and ready to be used, technology advances much faster than the laws themselves.
One of the main reasons that airspace regulatory agencies block or restrict certain uses of these aircrafts is to preserve air safety of manned aircrafts and people on the ground by gradually analyzing the risks and knowing the modes of operation and then slowly deciding restrictions and operating laws.
Due to these limitations, there is very limited research on the use of drones in the health industry.
Drones in Health Care
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Next Week
Chapter 9: Augmenting Behavioral Healthcare: Mobilizing Services with Virtual Reality and Augmented Reality
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Chapter 10 : How Serious Games Will Improve Healthcare