Applications and Advancements in Biomechanical Engineering

1
Applications and Advancements in Biomechanical
Engineering

• A sub-field of Bio-medical Engineering

Riyad Mohammed
2
The Discipline of Biomechanical Engineering

• Officially defined as the application of
  mechanical engineering principles, and the use of
  new materials to biology, especially to surgery
  and prosthetics.

3
The Components of Biomechanical Engineering

• Consists of applying concepts of mechanical
  engineering to the medical field, such as
• Thermodynamics - the study of energy conversion
  between heat and mechanical work
• Fluid Mechanics - the study of how fluids move
  and the forces which act on them
• Solid mechanics - the behavior of solid matter
  under external actions.

4
Applications

• The application of mechanics to biological
  systems has allowed society to produce
  breakthroughs in areas such as
• Artificial organs and human limb prostheses
• Medical instrumentation
• Biomaterials
• Cellular mechanics and Tissue Engineering

5
Advancements (the interesting part)1. Surgical
Implants

• Surgical Implants devices which are manufactured
  in order to replace, support, or improve an
  existing biological structure.
• (Im)plants are man-made, whereas a (trans)plant
  is more likely to be made up of human or animal
  tissue.
• Surgical implants which will contact tissue
  consists of materials guaranteed to not cause
  rejection or infection in the body, such as
• - Titanium
• - Silicone
• - Apatite (a major component of tooth enamel and
  bone mineral)

6
2. Artificial Organs

• The application of Mechanical Engineering to
  human biology has resulted in the creation of
  revolutionary devices, which mimic the functions
  of a human organ.
• Types include, but are not limited to Artificial
  hearts and pacemakers, artificial lungs, and
  dialysis machines for the filtration functions of
  the human kidney. Cochlear implants are used to
  treat those with There are even Brain pacemakers
  which use electrical signals to treat people who
  suffer from epilepsy, Parkinson's disease, major
  depression and other diseases.

7
The Artificial Heart

• Two successful manufacturers
• 1. Syncardia (formerly Jarvik) temporary
  CardioWest Total Artificial Heart
• - Used as a bridge between hearts for patients
  on organ waiting lists.
• - more than 800 implants
• - 79 of patients survived to transplant
• - sports the highest bridge-to-transplant rate
  for any heart device in the world

8
The Artificial Heart

• 2. AbioCor replacement heart
• - the Massachusetts based company AbioMed has
  produced the AbioCor artificial heart.
• - It is fully implantable within a patient,
  meaning that no wires or tubes penetrate the
  skin, thus reducing the risk of infection.
• - used in patients with severe end-stage heart
  disease, who have become ineligible for heart
  transplant and have no other treatment options.
• - To date, 15 patients have been implanted with
  the AbioCor, with one patient living for 512 days
  with the AbioCor.

9
The AbioCor artificial heart How does it work?

• External battery - This battery is worn on a
  Velcro-belt pack around the patient's waist. Each
  rechargeable battery offers about four to five
  hours of power.

10
The AbioCor artificial heart How does it work?

• Wireless energy-transfer system - Officially
  called the Transcutaneous Energy Transfer (TET),
  this system consists of two coils, one internal
  and one external, which transmit power via
  magnetic force from an external battery across
  the skin. The internal coil receives the power
  transmitted from the external coil and sends it
  to the internal battery and controller device.

11
The AbioCor artificial heart How does it work?

• Internal battery - A rechargeable battery is
  implanted inside the patient's abdomen. This
  gives a patient 30 to 40 minutes to perform
  certain activities, such as showering, while
  disconnected from the main battery pack.

12
The AbioCor artificial heart How does it work?

• Internal Controller - This small electronic
  device is implanted in the patient's abdominal
  wall. It monitors and controls the pumping speed
  of the heart.

13
The AbioCor artificial heart How does it work?

• The AbioCor heart, also referred to as the
  Thoracic Unit, connects to four locations
• - Right atrium
• - Left atrium
• - Aorta
• - Pulmonary artery
• The entire system weighs about 2 pounds (0.9 kg
  and is composed of titanium and plastic.

14
The AbioCor artificial heart How does it work?

• Hydraulic pump - A gear inside the pump spins at
  10,000 revolutions per minute (rpm) to create
  pressure.
• Porting valve - This valve opens and closes to
  let hydraulic fluid flow from one side of the
  artificial heart to the other. When the fluid
  moves to the right, blood gets pumped to the
  lungs through an artificial ventricle. When the
  fluid moves to the left, blood gets pumped to the
  rest of the body.

15
2. Artificial Organs (Continued) The
artificial Lung

• Currently in the last stages of development, the
  MC3 Company has introduced the BioLung.
• The BioLung is designed to replace the gas
  exchange function of a persons native lungs
  during recovery from injury or illness, or until
  donor lungs are available for transplantation.
• Expected to be marketed commercially through
  various biomedical firms, including the
  partially MC3-owned Novalung, a German company
  dedicated to providing devices to treat lung
  failure.

16
The Cochlear Implant

• Frequently called the bionic ear, a cochlear
  implant is a surgically implanted electronic
  device that provides sound to a person who is
  profoundly deaf or severely hard of hearing.

17
The Cochlear Implant - Components

• i) a microphone which picks up sound from the
  environment
• ii) a speech processor which filters sound to
  pick up audible speech.

18
The Cochlear Implant - Components

• iii) A transmitter, which is held in position by
  a magnet placed behind the external ear.
  Electrical sound signals are sent through a thin
  cable to the transmitter, and the processed sound
  signals to
• iv) A receiver and stimulator, which are secured
  in bone beneath the skin. This converts the
  signals into electric impulses and sends them
  through an internal cable to
• v) Electrodes wound inside the cochlea, which
  send the impulses through the auditory nerve
  system to the brain stem.

19
The End Results

• The development of the artificial heart has
  allowed many critical patients to survive during
  the waiting period of an organ transplant.
• Surgical Implants have allowed those crippled by
  injury or suffering from degenerative diseases to
  be able to return to their everyday lives.
• In the most recent worldwide census,
  approximately 188,000 people worldwide had
  received cochlear implants so far. This means
  that 188,000 people considered permanently deaf
  have been given the ability to hear sound.
• The applications and advancements made through
  biomechanical engineering have given countless
  human beings not only relief from illness and
  discomfort, but also a second chance at life.

20
Sources

• "NEJM -- Cardiac Replacement with a Total
  Artificial Heart as a Bridge to Transplantation."
  The New England Journal of Medicine Research
  Review Articles on Diseases Clinical Practice.
  Web. 24 Feb. 2010. lthttp//content.nejm.org/cgi/co
  ntent/short/351/9/859gt.
• MSN Encarta Online Dictionary. Encarta, 2009.
  Web. 22 Feb. 2010. lthttp//encarta.msn.com/diction
  ary_561536710/biomechanical_engineering.htmlgt.
• "Biomaterial." Wikipedia, the Free Encyclopedia.
  Web. 22 Feb. 2010. lthttp//en.wikipedia.org/wiki/B
  iomedical_materialgt.
• "Artificial Lung (Biolung)." Medical Device
  Design and Development MC3. Web. 22 Feb. 2010.
  lthttp//www.mc3corp.com/case_studies/artificial_lu
  ng_bio/gt.
• "HeartReplacement.com Abiocore."
  HeartReplacement.com Index. Web. 22 Feb. 2010.
  lthttp//www.heartreplacement.com/abiocore.htmlgt.