To understand what is going on in this post, take 5 minutes to read this one. It’s an introduction to the concept of Biomimicry Biweekly Challenge. Besides, you all are very brave to have read my incoherent thoughts this far. Stay strong! You can get through this!
Of birthdays, arteries, and Möbius strips
It all comes down to my husband, again. Well, to him and his bookshelf. Have you ever heard of a book “Imagining the Tenth Dimension” by Rob Bryanton? I highly recommend reading it, if you are into mind-expanding exercises.
According to Rob, as we move through the fourth dimension – time – we are very much like an ant on a Möbius strip. To us, time feels like a straight line, moving from past to the future. But as we move along the straight line, our choices are constantly branching in the fifth dimension. When we look back in time, it feels like a straight line to us moving in the fourth dimension, but that straight line is an illusion.
As you read this post, your fifth-dimensional self might now have two main branches – one would be the version of you that continues reading into the next paragraph, while another would be the one who decides to take a break and go do something else.
Hello to all those fifth-dimensional selves, who have chosen to tread onto the next paragraph! Let me introduce you to Mykola and Max.
Myk is a computer scientist, specializing in game programming. This particular choice of branch was influenced by his father, who specializes in cybernetics, by Myk’s exposure to computers and games at a very early age, and many other factors. He is also surrounded by the multitude of paths, one of which might as well lead him to become a surgeon. This has been his dream for many years. In the future – if chance, choice, and the actions of others permits – Myk will achieve his dream, regardless of how improbable it may seem at the moment.
On one of his birthdays, Myk was given a book – titled “The Human Body” – with beautiful illustrations explaining the structure, functions, and malfunctions of the machine we operate. This action, in principle, led me to my first Biomimicry Challenge.
Max is an incredibly talented surgeon in Cambridge, England, specializing in throat cancer. He is also fascinated by the world of design and is constantly thinking of ways to improve medical equipment for the benefit of his patients. During one of our conversations, he mentioned a problem with administering nutrition to throat cancer patients.
Percutaneous endoscopic gastrostomy (PEG) is a safe and effective way to provide nutrition and medications directly into the patient’s stomach. The procedure is usually done for throat cancer patients, who have just undergone a surgery.
During the procedure, a physician places an endoscope (a long, thin, flexible instrument about 1/2 inch in diameter) into the patient’s mouth. The endoscope is then advanced through an esophagus and into a stomach. The endoscope is used to ensure correct positioning of the PEG tube. The PEG tube rests in the stomach and exits through the skin of the abdomen. Some of the main problems with this design are:
- High level of leakage, causing infections;
- Possibility of dislodgment;
- Seeding of cancer cells into a stomach.
Of tentacles and arteries
Max asked me a question: what are the alternative ways of carrying food to the stomach, bypassing a mouth and esophagus?
This question made me think of a paragraph I read in a book – titled Incredible Biology by Igor Akimushkin – some ten years ago. Pogonophora have fascinated me ever since.
These beard worms have a complex closed circulatory system and a well-developed nervous system, but as adults, they completely lack a mouth, gut and anus. So, how do these creatures feed? Most of a pogonophoran’s nutrition is provided by symbiotic bacteria living inside the worm. But I was interested in their tentacles that absorb nutrients directly from water.
It is thought that some pogonophorans feed by extending their tentacles from the mouth of the tube to gather organic detritus and plankton. Suspended particles of food may be trapped on the pinnules, and cilia are thought to drive water from anterior to posterior through the cylinder or funnel made by the tentacles.
Definitely, worth exploring.
However, one of the important conditions that I wanted to observe was “being locally attuned” – beard worms reside in a deep sea, and are not planning to visit Ottawa any time soon. Is my body local enough? As I was leafing through Myk’s book, I noticed an illustration of an artery section with the following accompanying sentence:
An artery narrows when the heart relaxes, helping push blood onward.
As I began to dig deeper, I found a great article titled Three-Dimensional Polymer Constructs Exhibiting a Tunable Negative Poisson’s Ratio by David Y. Fozdar and others. Here’s the excerpt:
A scaffold made out of an auxetic material would expand and contract in tandem with the strains resulting from the cyclical pressures from pulsatile blood ﬂow. Thus, an auxetic scaffold that exhibits concurrent axial and transverse expansion (contraction) would likely better integrate with native tissues and better promote clinical tissue regeneration.
First level of biomimicry: Form
The reason for a high level of leakage – and, thus, infections – is due to a constant movement and dislodging of the tube. So, if there was a mesh around the structure that would expand, whenever it is tugged on?
The reason for seeding cancer cells into a stomach is due to the oral administering of endoscope to secure the tube internally. You simply can’t go around it, unless, there is a tube that expands as soon as it is administered through an abdomen, bypassing the esophagus altogether. What if the Ni-Ti mushroom, covered with the mesh expanded not unlike flower petals in the morning, as soon as it entered the inside of the abdomen?
As soon as it is expanded, it is secured in place through a negative Poisson’s behaviour. To take the tube out, a nurse tugs on a string that causes the Ni Ti structure to collapse and withdraws it from the abdomen.
Now, I’m curious, if the fifth dimension me were to go off and explore the beard worm anatomy, what solution would I end up with? Comments and criticism are very much welcomed, as the necropsy of what worked, and what didn’t is waiting to be written! Max, as well, would be interested in the feedback on our design.