Sustainability in the medical field: Medical implants muscling their way towards imitating the human body

Medical implants: the ins and outs

Medical implants are devices usually positioned inside the body for medical purposes for prolonged periods of time. They are generally contrived out of synthetic materials and are utilized to replace body parts, provide medication, monitor and regulate body functions, and additionally deliver support to organs and tissues. These devices can ultimately be life-saving: for instance, cardiac pacemakers can aid in preventing life-threatening cases and implants can restore mobility and improve quality of life. Generally, their use can diminish the need for regular treatment for users, thus reducing the costs of handicaps over time; this is done through remote monitoring facilitated by active implants, which allows for less hospital visits (Source: Nuffield Council on Bioethics). Some more potential applications for these devices are shown in Figure 1

However, because of the progress being made in the nanoelectronics sector, they are consistently becoming smaller and simultaneously more efficient in a manner that allows for more comfort for the user. As a result, conversations are being opened up on new, innovative ways to design and manufacture the next generation of these devices (Source: Imec). In the EU, nearly half a million medical devices have been approved for use– however, the demand for many types of medical implants is presumed to increase given the world’s aging population (Source: Nuffield Council on Bioethics). 

Figure 1: Potential applications of implantables (Source: Imec). 

Taking the sustainable road

As part of the UN’s 2030 Agenda for sustainable development, member states established 17 goals which, along with the EU’s Green Deal, aims to address issues in the sustainability field. As a result, measures have been gradually implemented in a variety of sectors– however, this shift has not yet had significant influence in the medical technology industry. According to industry association MedTech Europe, taking action towards sustainability in this sector is vital, as good health and well-being directly impact consumption and production. The medical technology industry specifically can benefit substantially from such measures, as it encompasses a considerably large range of interests and fields (Source: Johner Institut). 

The definitive individual measures that can be taken on a large scale in the medical technology sector are discussed further below. 

However, in this scope, it is important to identify the main limitations obstructing medical implants from making more progress towards the green advancement. In this case, it is their characteristic need for an external power source which poses a significant hindrance– the goal with these devices is therefore to utilize power in a more efficient way. Particularly the extensive sensing and actuation capabilities of the chips that these devices contain require more power and therefore more frequent battery replacements (Dagdeviren, 2019). This means that patients subsequently must undergo multiple surgical procedures, with each carrying associated health risks and costs; therefore, it is necessary to take the steps to reach a balance between reducing their power consumption and simultaneously supplying more power when it is needed (Source: Imec). 

Nevertheless, there is a wide variety of options available in the scientific field to combat these constraints, some of which are for instance utilized by research and innovation program Horizon Europe’s INTEGRATE project, which is coordinated by Veltha and is set to begin on June 1st of this year. The aim of this venture is to make use of newly available technology to build soft actuating devices that utilize metabolic energy to eliminate the need for external power sources. An introduction to some of these options are found below. 

3D Printing: A different dimension for medical implants

One of the possible solutions to the hindrances to medical implants’ sustainability is presented by 3D printing. This procedure is a set of various processes that utilize a 3D model of other electronic data sources to create three-dimensional objects, and the adoption of this practice is occurring at the most rapid rate in the medical industry, as further shown by its projected global market growth illustrated in Figure 2. At the moment, there are numerous medical applications of 3D bioprinting, which are moreover being analyzed and researched for further use – however, this practice has already been in use extensively to print implants that are patient-specific and other devices for medical purposes (Source: Disabled World). However, this practice has proven to be useful not only in the production of prototypes and other large parts, but also in the creation of the materials used within the larger implant parts. Particularly 3D cell printing with a microfluidic approach, which allows for the use of less volume of samples, has created momentous advancements in vascularizing engineering tissues (Source: Elveflow)– through the use of biomaterials, human tissues can now be replicated at remarkably precise lengths (Source: Medical Device Network). 

Figure 2: 3D printing medical implants market size, 2020 to 2030 (USD million) (Source: Precedence Research). 

Generally, the general 3D printing technique exhibits more circular characteristics over customary manufacturing approaches. Overall, conventional methods of manufacturing use up extensive amounts of energy as well as raw materials. With 3D printing, the manufacturing process itself not only becomes more efficient with faster prototyping, but this approach additionally removes the need for large-scale transportation and storage, which subsequently trims production costs (Source: TCT Magazine). 

Carbon dioxide emissions are also consequently reduced and the product’s energy consumption is lowered over its lifecycle– correspondingly, a Michigan Technological University study found that 3D printing items takes up around 40-65% less energy than manufacturing it traditionally due to the fewer amount of materials required (Source: AZOM). This process is moreover able to aid in minimizing the issue of vast energy usage as it constructs the product layer by layer rather than manufacturing it from a large piece of metal or plastic, which leads to significantly less leftover waste. As mentioned above, the manufacturing process is also facilitated by the integral use of computers in the design stages: updated computer simulations allow for the identification of improvement areas, which call for fewer required prototypes and by extension, less waste.  

Concerns

Even though the prototyping and production of new products can be made faster through 3D printing, this simultaneously means that this technique still plays a role in producing more readily available consumer items that have a high probability of winding up in landfills, meaning that it is not a completely circular practice. It must also be taken into account that 3D printing additionally requires post-processing for larger parts during production, lengthening their production time, and failed parts then get thrown into the mix, which create more waste (Source: The Welding Institute). 

Other additional aspects to consider that concern sustainability are for instance the disposal of the backings used to prevent deformation during the printing process. This means that even when raw materials are being used, there is still excess plastic waste being created. Overall, 3D printing can be a considerably expensive procedure which also causes small-scale harmful emissions throughout the process (Source: For 3D Print).   

Energy harvesting

A further solution which would aid in making these bionic muscles more circular is the process of energy harvesting. As previously mentioned, one of the problems is that the chips utilized in these devices use up large amounts of power. This subsequently means that these implantable devices ultimately have a relatively limited lifespan. In addition to this, conventional power sources for these medical devices are rigid and bulky (Dagdeviren, 2019). To this end, there is a possible solution available which would utilize the human body’s various natural sources of energy towards powering these devices: scientists have found an approach that would harvest moving organs’ mechanical energy and convert it into stored electricity (Zou et al., 2021). 

Since the early 20th century, researchers and developers have been aiming to utilize the human body’s energy as a source for renewable energy– and it has since been found that the thermal energy radiating off the human body is equivalent to that generated by a 100-watt lamp (Source: SWI). All activities, from thinking, to each heartbeat, to every footstep, involve energy exchanges: Figure 3 below shows various possible ways in which energy from the human body can be harvested to power different devices for different purposes. 

Figure 3: Strategies for interaction between various energy harvesting devices and the human body (Source: link). 

Energy harvesters can provide power to parallely extend the battery lifetime of wearable or implantable devices, and can even function as a lone power supply on its own (Dagdeviren, 2019).  Correspondingly, there are a number of harvesting methods that can be utilized to power devices from the body’s energy. Among these are piezoelectricity, which involves the conversion of mechanical energy into electrical energy, and vice versa; thermal energy extracted from the body’s natural temperature changes; and electromagnetic energy which converts movement into electric power (Paulo & Gaspar, 2010). 

Future Outlook

The concept of sustainability looks different in different sectors. Particularly in the case of medical devices, it is vital to follow the regulatory requirements set in place for both safety and performance, which means that environmental sustainability aspects may often have to take a back seat– the UN’s standards for sustainability include aspects concerning public health along with the environmental factors. There are thus numerous legal aspects that these medical companies must keep in mind: the legally protected right to human life takes priority over environmental sustainability considerations. This means that in the case of no available environmentally friendly option that is safe and performs its functions appropriately, a less sustainable option will have to be implemented (Source: Johner Institute). 

However, the technological advancements being made in the medical science sector in recent years provide an array of options to continue a shift towards greener operations in this field. There are numerous other existing options aside from 3D printing and energy-harvesting organs that could also effectively contribute to an increasingly circular economy. Regardless of the method used, a way for med-tech companies to continue to prioritize the circularity of their devices would for instance be the inclusion of sustainability measures in their corporate strategy and considering end-of-life use at the design stage (Source: Johner Institute). With this in mind, circularity in the medical field is a notion that, through additional research and institutional changes, is a viable possibility that can see continued growth moving forward.  

References

  1. Dagdeviren, C. (2016). The future of bionic dynamos. Science, 354(6316), 1109–1109. https://doi.org/10.1126/science.aal2190 
  2. Disabled World. (2022, April 9). Medical 3D printing applications, news and product accomplishments. Disabled World. Retrieved from https://www.disabled-world.com/news/research/3d-printing/
  3. Edwards, C. (2022, March 25). Materials used in medical implants: How is the industry breaking the mould? Medical Device Network. Retrieved April 21, 2022, from https://www.medicaldevice-network.com/analysis/materials-used-medical-implants-industry/ 
  4. Elveflow (2021, June 30). Microfluidics: A general overview of Microfluidics. Elveflow. Retrieved from https://www.elveflow.com/microfluidic-reviews/general-microfluidics/a-general-overview-of-microfluidics/ 
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  9. Paulo, J., & Gaspar, P. D. (2010). Review and Future Trend of Energy Harvesting Methods for Portable Medical Devices. Proceedings of the World Congress on Engineering 2010, Volume II. ISSN: 2078-0966. 
  10. Precedence Research. (n.d.). 3D printing medical implants market 2022 – 2030. Precedence Research. Retrieved from https://www.precedenceresearch.com/3d-printing-medical-implants-market  
  11. Reichental, A. (2020, August 17). When it comes to 3D printing, how much sustainability is enough? TCT Magazine. Retrieved from https://www.tctmagazine.com/additive-manufacturing-3d-printing-industry-insights/3d-printing-how-much-sustainability-is-enough/  
  12. ​​Svenning Berg, R. (2019, June 19). Medical implants: Bioethics briefing note. Nuffield Council on Bioethics. Retrieved April 21, 2022, from https://www.nuffieldbioethics.org/publications/medical-implants  
  13. Taylor-Smith, K. (2021, January 12). How is 3D printing a sustainable manufacturing method? AZOM.com. Retrieved from https://www.azom.com/article.aspx?ArticleID=20017  
  14. TWI. (2022). What are the advantages and disadvantages of 3D printing? The Welding Institution. Retrieved from https://www.twi-global.com/technical-knowledge/faqs/what-is-3d-printing/pros-and-cons 
  15. Zou, Y., Bo, L., & Li, Z. (2021). Recent progress in human body energy harvesting for Smart bioelectronic system. Fundamental Research, 1(3), 364–385. https://doi.org/10.1016/j.fmre.2021.05.002 

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