In Vitro, In Vivo, In Silico? – What these technical terms mean, and how and where are they used
In the span of medical history, researchers have always relied on various testing methods to confirm their hypotheses. This started with performing tests on living organisms and cadavers, the so called in vivo approach. This has led to many great medical achievements and advances in performing various surgeries. With the introduction of in vitro testing – or testing in a petri dish or test tube, we were able to see innovations not only in the medical field, but also within the pharmaceutical industry.
Today we are witnesses to a new revolutionary wave of testing methods – those performed on a computer. In the following post, we will discuss those three methods in more detail, and explain why adopting the newest technologies will help accelerate and disrupt the medical device industry.
In vitro vs. in vivo methods
The term in vitro is used when referring to processes outside of a living organism. Literally translated, in vitro means “in a glass”. Thus, organisms and structures are studied under experimental conditions rather than in their natural context. The counterpart to in vitro investigations are in vivo experiments. Here, processes are tested and carried out on living organisms.
There are some advantages of in vitro testing over in vivo. Firstly, the physical and chemical environment in medical examinations that are carried out in vitro can be better controlled.
This means that various conditions can be influenced more easily and individually. In addition, the cost for such research is significantly less than for in vivo testing. Another big factor is the opportunity to reduce the number of animals and humans used for testing purposes. However, it is important to know that experiments conducted outside of a living organism cannot always be directly transferred and applied to the living organism, because cells in the isolated environment might not behave identically to those in living ones. Therefore, in vitro studies are often verified with another series of experiments on a living organism.
The recent introduction of in silico methods brings new opportunities and advantages into the mix. It is now possible to test on a large number of patients, without risking their lives, and reduce the costs and time needed.
In silico methods
In short, in silico describes processes and experiments that take place in the computer. Especially in the world of medical simulations, the term in silico is often found. What this means is that using special programs and algorithms, processes are simulated on the computer. The origin of the term in silico is due to the fact that most computer chips are manufactured on the basis of the chemical element silicon.
In silico methods are proving to be extremely useful for testing on multiple patients. Medical device developers are able to construct their target patient group based on different physiological and pathological variability, and make sure their device will behave as predicted in that specific environment. Using in silico methods can therefore greatly speed up the development and enable developers to find out problems with their device fit early on and adjust the design.
Simulations and computer-driven clinical trials
A simulation refers to the most realistic possible replication of real scenarios. More precisely, a simulation imitates the functioning of real processes and systems with the inclusion of models. While the model shows the main features of a process, the simulation shows how the model evolves over time. Simulations are performed for a wide variety of purposes and reasons. For example, simulations can be used for education, entertainment, or analysis. In the context of medicine, simulations are performed to test existing problems, recreate surgical situations, and theoretically identify treatments that can solve existing problems in reality. Simulation is an important method of analysis that can be easily verified. They also provide a safe and more cost-effective method of recreating actual problems to test how they can be solved in reality.
With our software v-Patients.com, you can take our digital twins to the next level and explore the interaction of your medical device with physically accurate modelling of the anatomy. Our simulation feature enables you to accurately deal with the complexity of the human and animal anatomy and physiology, while at the same time receiving fast, reproducible, and well-visualized results.
We readily integrate our extensive database in our simulation pipeline to provide you with the desired information based on your choice of cohort. Relying on our battle-tested meshless simulation engine, we can perform robust simulation for any geometries you might additionally input to validate your device. Operating at such scale allows you to rapidly refine the design of your device to fit your objectives with respect to the selected population.
Acceptance of in silico methods as digital evidence
In the context of computer-driven clinical trials, a lot of progress was made in recent years. Digital evidence as a substitute for traditional clinical evidence is becoming more and more accepted and increasingly the standard. Notably, the FDA and ASME have published several documents relating to reporting and validation activities around digital evidence, which is key to such developments. A big step forward will be the Good Simulation Practice that a dedicated community is working on at the moment in collaboration with the FDA and the Avicenna Alliance. This will allow for a more standardized process for the submission and approval of digital evidence.
To find out more about in silico methods and medical simulations, don’t hesitate to contact us.