8.5.2 Technologies Assisting Disorders

Question 1

Hearing Aids

Hearing Loss Technologies

Answer 1

Small electrical devices that sit behind the ear to take arriving sound waves and increase their volume into the ear.

• Consist of a microphone, amplifier, receiver and speaker that detect sound waves, transform it into electrical energy and then back into sound waves that are amplified into the auditory canal
• Useful when there has been damage to the outer and middle ear but not the inner ear
• Cheaper and less risk than surgical treatments
• Amplify all sounds in the environment, not necessarily leading to better hearing since background noise can also be amplified, but recent technology has introduced that ability to screen out noise

Question 2

Cochlear Implants

Hearing Loss Technologies

Answer 2

(AKA “the bionic ear”) Consists of external and surgically implanted parts to return a sense of hearing to damaged middle or inner ears.

• External parts include a microphone, speech processor and transmitter that picks up sound waves and send them to a speech processor (behind ear or in pocket) to convert into an electrical signal. The digitised sound can then be sent through the transmitter coil to the implanted receiver to transmit the signals to electrodes in the cochlea to the brain.
• Particularly useful for middle ear damage in people who do not benefit from traditional hearing aids as it directly stimulates the auditory nerve to bypass the hair cells
• Does not help all people as it is different from actual hearing, require a learned interpretation of the signals/sensations and takes time and experience, as well as surgical risks of anaesthetic, damage to facial nerves and infection

Question 3

Bone Conduction Implants

Hearing Loss Techbologies

Answer 3

Medical device that transmits sound by direct conduction through bone to inner ear, bypassing the outer and middle ear entirely.

• Consists of a small titanium implant, abutment (support) and sound processor, which transmit vibrations to the implant through the bone

Question 4

Kidney Dialysis (Haemodialysis)

Answer 4

Kidney dialysis is the preferred treatment in most cases of kidney failure as it is less risky that a transplant. It is a life prolonging treatment, the most common form being haemodialysis.

Haemodialysis is a treatment used to filter the waste and water from your blood in place of your natural kidney function, allowing for increased control of blood pressure and concentration of important minerals. This occurs by running the blood through a dialyzer, a machine outside of the body. This runs it through many thin, hollow fibres with a prescribed dialysis solution moving in the opposite direction. The altered blood can then flow back into the body.

Question 5

Kidney Transplants

Answer 5

Living donor kidney surgery is known as nephrectomy, and involves a surgeon removing a kidney from a living donor to transplanting it into someone in need. It is a rigorous surgery that occurs over three to four hours and requires significant pain medicine to occur. There are two types:

1. Laparoscopic nephrectomy: the use of a laparoscope (wand camera) to pass through small incision and scope out the abdominal area before removing the kidney
2. Robotic nephrectomy: the use of surgeon-controlled robot arms to remove the kidney through a small incision along the bikini line

Question 6

Eye Technologies

Answer 6

Professional eye tests can be conducted to detect refractive eye errors or other abnormalities.

1. Spectacles use convex and concave lenses that are shaped to correct the refracting light entering the eye.
2. Contact lenses perform the same function but are worn directly on the surface of the cornea.
3. Intraocular lens surgery is used to treat cataracts by replacing the natural lens with a small plastic lens.
4. Photorefractive keratectomy (PRK) involves the removal of the epithelium and reshaping of the upper surface of the cornea.
5. Laser eye surgery uses a laser beam to change the shape of the cornea.

Question 7

LASIK

Eey Technologies

Answer 7

LASIK is an abbreviated term to refer to laser in situ keratomileusis, a common laser eye surgery procedure performed to correct vision.

It involves a two step method that is performed under the effect of anaesthetic drops or another mild sedative.

1. A femtosecond laser set to the patient’s precise refractive measurements creates a thin flap of corneal tissue.
2. The excimer laser reshapes the corneal bed, using high power UV output to precisely remove the tissue of the stroma.
3. The corneal flap can then be repositioned and it naturally adheres into place.
4. Recovery occurs over the next week and involves fluctuations in vision but will quickly stabilise.