Please enable JavaScript.
Coggle requires JavaScript to display documents.
Biomedical Engineering - Coggle Diagram
Biomedical Engineering
Tissue engineering
Cells
Induced Pluripotent Stem Cells (iPSCs): These are mature cells that scientists “reprogram” to behave like stem cells. They’re very useful because they can be derived from a patient’s own body, reducing the chances of rejection.
Mature/Post-Mitotic Cells: These are specialised cells that can’t divide further but can still perform specific tasks, like muscle or nerve cells
Stem Cells: These are "blank slate" cells that can turn into many different types of specialized cells (e.g., bone, muscle, skin).
Aims to restore, maintain, or improve the function of damaged tissues in the body.
Scaffold (structural framework)
They provide a surface where cells can grow and organize themselves, like bricks forming a building.
Scaffolds create a platform similar to natural tissue, making it easier for the body to regenerate.
Liver Cirrhosis
Liver cirrhosis causes permanent scarring in the liver tissue
Removes functionality of cells leading to liver failure
Possible biomaterials to use
Liver tissue engineering is a promising alternative to organ transplants
Decellularised Extracellular Matrix (dECM)
PLGA (cultures hepatocytes)
Is tissue engineering possible?
To create the engineered tissue, it needs:
Functional cells derivable from healthy adult tissue (hepatocyte)
A biocompatible scaffold
Active bio molecules
Ethics and Socially responsible engineering
Engineers Australia Code of Ethics
Exercise leadership
Practise competently
Promote sustainability
Demonstrate integrity
Microethics
Whistleblowing
Corporate responsibilities and loyalties
Respecting intellectual property
Falsifying records
Macroethics
Environmental responsibility
Techno responsibility
Customer/stakeholder/social responsibility
Ethical theories
Duty ethics
Right ethics
Utilitarianism
Ethical Egoism
Virtue ethics
Tomography
Examples
MRI scans
Uses strong magnetic fields and radio waves to generate detailed images of the organs and tissues inside the body.
Energy : Magnetic fields and radio waves
No ionisation radiation used
Best for: Imaging soft tissues like the brain, muscles, heart, and cancers.
PET
Injects a small amount of radioactive material into the body, which highlights areas of high chemical activity, often corresponding to disease processes.
Energy : Gamma rays (from radioactive tracers)
Exposure to radioactive material
Injects a radioactive tracer that emits positrons → when positrons interact with electrons in the body, they produce gamma rays, which are detected by the PET scanner to create images of metabolic activity.
Best for: Detecting cancer, evaluating brain function, and assessing heart diseases.
CT scans
Utilises X-rays to create detailed cross-sectional images of the body's internal structures.
Best for: Evaluating bone injuries, diagnosing lung and chest problems, detecting cancers.
Energy : X - rays
Exposure to ionising radiation can be harmful overtime
SPECT
Similar to PET but uses gamma rays to create 3D images after injecting a radioactive tracer.
Evaluating blood flow to organs and tissues, particularly the heart and brain.
Energy : Gamma rays (from tracers)
SPECT detects single photons emitted from a radioactive tracer injected into the body. The scanner rotates around the patient to capture images and create 3D reconstructions.
Motion correction
Excluding corrupted data (e.g. if motion exceeds threshold)
Gating (grouping data collected at regular time intervals)
Used when the motion is periodic
Event-by-event based compensation
Each PET event (line-of-response) is adjusted based on the measured motion
Image registration (image alignment)
Eg : instead of doing a 60 min head scan, doing 10 x 6 minutes head scans and aligning them together
Anatomy and physiology
Bone anatomy
Distribution of the cortical and spongy bone
Spongy bone
Found in greater proportion at the epiphysis (near the joints)→ to be able to withstand any pressure from any direction
Haphazard arrangement → distributed all over the place
Cortical bone
Found along the diaphysis
Stronger → the layers that makes up the cortical bone is parallel to each other can absorb stress really well in a longitudinal way but not any other axis
Osteoblast
Create a new bone matrix after the osteoclasts have resorbed damaged bone. They rebuild the bone structure, completing the remodeling cycle.
Osteocytes
Bone remodeling cycle by sensing mechanical load, micro-damage, or responding to hormonal signals
Osteoclasts
Responsible for breaking down (resorbing) the bone matrix.
Release calcium into the bloodstream while resorbing bone, helping maintain calcium levels when needed.
Effects of aging
Osteoporosis
Osteoblast activity falls down
Osteoclast activity does not change
The net bone loses over time. This process weakens bones, making them more prone to fractures, particularly in weight-bearing areas like the hip and spine. It becomes harder to build bones
Cardiovascular system
Joints
Cartilaginous joints - slight movement
Eg: pelvis
Synovial joints - free movement
Eg: finger, shoulders
Fibrous joints - no/very slight movement
Osteoarthritis (OA)
Degeneration of cartilage (wear and tear overtime)
Muscular system
Biomaterials
Types
Bioceramics
Metals
Biocomposite
Polymers
Biologically derived materials
Rejection of biomaterials
When a biomaterial is placed inside the body, it disrupts the normal healing process. The immune system sees it as foreign and tries to protect the body by forming a barrier (like a scab).
Dental implant failure
Implants can produce debris and corrosion. The byproducts might be toxic, damaging the body, or trigger an inflammatory response, which leads to rejection.
Mechanobiology
Create new treatment for diseases such as arthritis, osteoarthritis, osteoporosis.
Examples
Hip and knee replacements
Heart valves
Contact lenses
Artificial skin
Nanomaterials
Nanoparticles
Can be used to deliver drugs more efficiently
Quantum dots : type of nanoparticle
The behaviour is influenced by their size and the wavelength of light that they are exposed to
Smaller dots emitting shorter wavelengths (e.g., blue) and larger dots emitting longer wavelengths (e.g., red).
These color emissions make quantum dots particularly useful for applications like imaging and diagnostics.
They can act as fluorescent markers in biological research, helping visualise cellular processes or detect diseases
Uncontrolled exposure to uncontrolled nanoparticles (NP) is dangerous
Inhalation of asbestos and metal oxide NP
Buildup of NP in artificial joints
1 to 100 nanometers in size
Nanoparticles will also attract proteins in the bloodstream
Proteins called opsonin (includes antibodies, complement proteins, plasma proteins) will attach to the surface of the NP
Gold nanoparticles
The colour of nano-gold is not gold, but RED
You dissolve the gold nano in a solvent and depending on the size of the gold nanoparticle, you can get different colours
Biomaterials
Interactions with the body
Cell penetration - can enter cells and interact with organs
Targeting capabilities - can target specific proteins and exploit small cellular gaps
Potential risks - uncontrolled exposure can be harmful
Engineering in disability and bioelectronics
Cerebral Palsy
17 million people has cerebral palsy
A physical disability that affects movement and postures that is caused by brain damage
Assistive technology
Bioelectronics
Probes and Electrical Impedance Tomography
Cell membranes are held together with electric charges.
Physical Modelling – Gel and ex-vivo tissue Phantoms
Computational Modelling
Newborn composition and health technology
Portable and low cost
Non-invasive body composition measurement
Motivation
Stunted growth - impact physical and cognitive development
Undernutrition
Measures fat thickness
Stem cells
Smart toys
Implants
Cochlear implants
Esports
Telehealth
Brain computer interface
Reduce re-calibrations
Increase privacy
Direct eye communication
Context dependent
Focuses not on fixing individuals but empowering them to do what they want.
Soft exoskeletons technology and soft robotics
Microfluids
Droplet microfluidics
Cell encapsulation
Cell sorting
Individual cells can be identified and sorted after being encapsulated in droplets
Specific cells are recognised by their fluorescent signal
A set of electrodes charge the surface of the droplets
Only specific droplets are sorted at high-throughput (>10 kHz)
Continuous droplet PCR
Organ-on-a-chip models
Microfluidic device - a small laboratory on a chip, using small channels (typically micron-sized) to precisely manipulate fluids, enabling applications in various fields like medicine, chemistry, and biology
Laminar and Turbulent flow
Laminar flow - where a fluid flows in parallel layers, with no disruption between the layers
Advantages and disadvantages - allows for precise control of fluid movement, hence predictable. However poor mixing will require slow diffusion
2 or more fluids can flow side by side without mixing except through slow diffusion
Turbulence flow - unsteady vortices appear on many scales and interact with each other
Brownian motion
particles smaller than 1micrometer by optical microscopy, the particles are observed to undergo random motion
Droplet manipulation
Merging
Splitting
Benefits : very small sample/volume needed, cost effective and reduces the need for animal testing
It is also optically transparents, uses biocompatible materials
Computational modelling
In vitro - any biological process or experiment conducted outside a living organism, often in a laboratory setting like a test tube or petri dish
In vivo - biological process or experiments conducted within the organism
In silco - experiment performed on a computer or via computer simulation software
Workflow for Biomedical Modelling
Solid modelling
Segmentation & Reconstruction
Typical Workflow
Create surface model
Generate solid model
Apply smoothing filter and/or fit curves
Separate into different tissue types or parts
Import
image stack
Numerical analysis
Data acquisition
Digitalised Imaging Techniques
X-rays
Bones contain much calcium, which due to its relatively high atomic number absorbs x-rays efficiently. This reduces the amount of X-rays reaching the detector in the shadow of the bones, making them clearly visible on the radiograph
The lungs and trapped gas also show
up clearly because of lower absorption compared to tissue
Differences between tissue types are much harder to see
CT scans
Ultrasound scans
Ultrasound is sound waves with frequencies which are higher than those
audible to humans
Ultrasonic images also known as sonograms are made by sending pulses of ultrasound into tissue using a probe. The sound echoes off the tissue; with different tissues reflecting varying degrees of sound.
MRI
Medical scan data
Digital Imaging and Communications in Medicine (DICOM) - a standard for handling, storing, printing, and transmitting information in medical imaging. It includes a file format definition and a network communications protocol
Implantable bionics
Main neuro-device modalities
Pacing
Deep brain simulation
Cochlear prostheses
Spinal cord stimulation
Neuromodulation
Nervous system
CN
Brain and the spinal cord
Spinal chord performs some signal processing (not
just a conductor)
Brain : white matter is mainly myelinated axons (conductive connectors), grey matter is cell bodies (decision makers)
PN
Nerves connecting the CN to the rest of the body
Sensory (afferent) nerves carry information from
sense organs to the CNS
Motor (efferent) nerves carry information from the
brain to the effector organs
Axons
Information flows as a result of “action potentials” or waves of ionic transfer across the cell wall at the “Nodes of Ranvier”
Bionic Devices
Four therapeutic applications
of Bionic devices
Management of Parkinson Disease
Parkinson's disease deep brain stimulation
Stimulation of the sub-thalamic nucleus
(STN) increases dopamine production
Chronic degenerative condition affecting central nervous system
Could be due to reduced levels of Dopamine being produced
Relief of Chronic Pain
Spinal cord stimulation (SCS)
Monitoring & Prediction of Epileptic Seizures
Epileptic seizures can cause temporary loss of awareness and affect movement,
sensation and mood.
Urinary and Faecal Incontinence
Sacral nerve stimulation
129k (70.9%) in Residential Aged Care
(RAC) have urinary incontinence (UI) and/or faecal incontinence (FI).
Cochlear implants
Ear anatomy
Outer ear and eardrum enhance
sound levels at eardrum
Eardrum and 3 small bones transfer sound vibrations to the cochlea via the oval window
Cochlea
Three chambers
Spiral ganglion cells
Basilar Membrane and hair cells
Biomanufacturing (Regulatory affairs)
Poly Implant
Prosthese (PIP)
Around 300,000 women in 65 countries have received PIP implants.
The implants had double the rupture rate of other implants, but were not found to be toxic or carcinogenic
The CEO was sentenced to four years in prison and forced to pay a fine of €75,000 for fraud.
The PIP implants have been a subject of controversy due to the use of non-medical-grade silicone in their construction, leading to a recall and potential health concerns
ISO 13485
Medical devices - Quality management systems - Requirements for regulatory purposes.
Management Responsibility, Quality System, Contract Review, Design Control, Document and Data Control
Purchasing, Control of Customer-supplied Product, Product Identification and Traceability, Process Control, Inspection and Testing, Control of Inspection, Measuring and Test Equipment, Inspection and Test Status, Control of Non-conforming Product
Corrective and Preventive Action, Handling, Storage, Packaging, Preservation and Delivery, Control of, Quality Records, Internal Quality Audits, Training, Servicing, Statistical Techniques
International standardisation bodies
CEN - European Committee for Standardization
DIN - German Institute for Standardization
ISO - International Organization for Standardization
Regulatory bodies
U.S. Food and Drug Administration (FDA)
CE mark (European Union)
Australian Government Department of Health Therapeutic Goods Administration (TGA)
Regulatory Affairs
Medical devices
Instruments, apparatus, implement, machine, appliance, implant, in
vitro reagent or calibrator, software, material designed for medical purposes
Intended to be used for diagnosis or treatment of a diseases or disability.
How do we regulate
Regulatory process
Preview market
Evaluate device design and safety
Manufacture
Controls
Ensure consistent quality
Postmarket
Monitoring
Tracking device performance and address potential issues
Corrective
Actions
Design and verification
Verficiation standards
Using the international standards for testing and compliance
Clinical evidence
Combining data + Expert review
Data
Risk assessment
Post market data
Clinical trials
Lit reviews
Preclinical studies
Expert review
Balance
Completeness
Scope
Expertise
Design input
Converting general requirements into measurable specifications
Why regulate?
Prevent potential failures and to ensure safety to the public.
Asymmetry of Information and
Power - Seller knows much more about
the good than the buyer
Post marketing and pre marketing regulations
Sleep
Sleep apnoea is a disorder characterised by interruptions of breathing during
sleep.
What is sleep?
naturally-occurring state
periodic and recurring
involves both the mind and body
involves the temporary suspension of consciousness
involves the relaxation and inactivity of muscles
involves reduced responsiveness to external stimuli
How does it work?
Circadian rhythm (Process C)
Regulated by body clock (suprachiasmatic nucleus) located in the hypothalamus of the brain
Sleep-wake homeostasis (Process S)
Generates sleep drive or sleep pressure
Longer we have been awake, the stronger the desire to sleep
Stages
NREM or non-REM
REM or rapid eye movement
Night of sleep comprises 4 to 6 cycles through these stages, each cycle
around 90 min
Reduced sleep efficiency with
age
Takes longer to fall asleep (longer sleep latency)
More waking at night (greater wake after sleep onset)
Disorders
– Insomnia
– Sleep Related Breathing Disorders (Obstructive sleep apnoea)
– Central Disorders of Hypersomnolence (Narcolepsy)
– Circadian Rhythm Sleep-Wake Disorders (Shiftwork disorder)
– Parasomnias (Sleep-walking)
– Sleep Related Movement Disorders (Restless legs syndrome)
Innovation on technology
for sleep measurements
Home sleep testing
Portable home sleep monitoring devices
Eg : ApneaLink (ResMed), SleepScout (9ch), SleepView(8ch) (CleveMed), Somte PSG(25ch) (Compumedics)
Advantages : familiar environment for patients, no waiting list, multi-night studies, remote monitoring capability, convenient sensor set-up
Disadvantages : suitable for only some, can be less accurate
Wearables in sleep
Measurements
Sleep tracking
Heart rate
Many available and constantly changing
Therapy monitoring
ResLink (ResMed)
Non-invasive monitoring
Records patient’s response during therapy
Stores data on a memory card
and more than 30 sessions (days)
Smart phone apps
Examples
Sleep cycle (iOS, Android)
Sleepbot (iOS, Android)
Smart Alarm clock (iOS, Android)
SleepTime+ (iOS, Android)
MotionX 24/7 (iOS, Android)
Advantages
Popular, familiar
Convenient
Readily adopted by people
Low cost
Empowering people to manage their health
Cloud based data collection
Providing feedback / motivation for change
Anatomy
Cardiovascular system
Heart is a double pump
Receives and pumps oxygenated and deoxygenated blood
Complex directional blood flow