Question 16
Falls at home are a major cause of injury and hospital admission for older people, and many older people lose their independence after a fall. Families and health services need ways to help older people keep living safely in their own homes.
Explain how biomechanical engineers have used their expertise in mechanics, materials science and control technology to develop a device that reduces the risk of falls for older people living at home. Include two benefits to the community in your response.
An exoskeleton that steps with you and locks when you stumble
Watch one device do all three jobs. The frame is the materials science, the sensors and microcontroller are the control technology, and the gears at the knee are the mechanics.
The device acts before a fall happens. That is what makes it a falls-prevention device and not just an alarm.
Plan your answer: one device, three fields, two benefits
Pick a device. The planner shows what would earn each field mark for that device, and what would not. Then pick two community benefits and see whether both marks land.
Nothing planned yet. Start with the device. Everything else in your answer hangs off it.
No benefits picked yet. The question asks for two, and each earns its own mark.
Work through the model response one mark at a time
Write your own sentence for each mark before you reveal it. The cards follow the marking guide’s order.
Name one device and say what it does to stop a fall happening. Everything after this sentence explains this device.
Biomechanical engineers have developed powered lower-limb exoskeletons that help older people stand up, walk and climb stairs.
Names a valid device (powered exoskeleton) and what it does to prevent falls.
Devices/machines include: powered exoskeletons, smart walkers with automatic braking, stair lifts, fall-detection systems with automatic lighting, patient hoists or ceiling lifts, powered sit-to-stand chairs, motorised mobility scooters, powered wheelchairs, or other suitable response consistent with a reasonable understanding.
Marker: identifies a valid device or machine that reduces the risk of falls
Say what the sensors detect and what the microcontroller does with that signal.
In control technology, sensors at the hip and knee detect the user’s movement, and a microcontroller switches the motors on to assist each step and locks the joints if a fall is detected.
Sensors plus microcontroller controlling motors and joint locking: control technology applied.
Control technology: sensors, microcontrollers, logic gate circuits, remote controls including smartphones, fall detection alarms, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in control technology
Give the materials, the property that matters and why the device needs it.
In materials science, engineers have used strong, lightweight aluminium alloys and carbon-fibre composites for the frame, so it supports the user without being too heavy to wear.
High strength-to-weight frame materials, linked to wearability.
Materials science: strength-to-weight ratio, durability, corrosion resistance, biocompatible or skin-safe materials, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in materials science
Give the mechanism and what it achieves for the user.
In mechanics, motors drive gear trains at each joint, providing a mechanical advantage so small motors can help lift the user’s body weight.
Gear trains giving mechanical advantage, linked to lifting body weight.
Mechanics: gears, pulleys, screws, levers, linear actuators, motion, mechanical advantage, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in mechanics
A benefit that reaches beyond the user. The stimulus hands you this one: “many older people lose their independence after a fall”.
Exoskeletons allow older people to keep living independently in their own homes,
Independent living at home.
Benefits: independent living, fewer falls and hospital admissions, reduced demand on health services and carers, older people remain in their own homes and community, or other suitable response consistent with a reasonable understanding.
Marker: includes one benefit to the community
A second benefit that is about something different from the first. The model response finishes the same sentence.
and fewer falls means fewer hospital admissions and less demand on health services.
Fewer hospital admissions and reduced demand on health services: distinct from the first benefit.
Benefits: independent living, fewer falls and hospital admissions, reduced demand on health services and carers, older people remain in their own homes and community, or other suitable response consistent with a reasonable understanding.
A second benefit that repeats the first is not awarded a mark.
Biomechanical engineers have developed powered lower-limb exoskeletons that help older people stand up, walk and climb stairs. Mark 1
In control technology, sensors at the hip and knee detect the user’s movement, and a microcontroller switches the motors on to assist each step and locks the joints if a fall is detected. Mark 2
In materials science, engineers have used strong, lightweight aluminium alloys and carbon-fibre composites for the frame, so it supports the user without being too heavy to wear. Mark 3
In mechanics, motors drive gear trains at each joint, providing a mechanical advantage so small motors can help lift the user’s body weight. Mark 4
Exoskeletons allow older people to keep living independently in their own homes, Mark 5 and fewer falls means fewer hospital admissions and less demand on health services. Mark 6
Six marks in 125 words, inside the 150-word limit. One sentence per mark makes each mark easy for the marker to find.
Marker: includes a second benefit to the community
Each phrase of the question gave you something
If I had to guess where you might lose marks…
- A device that only responds after a fall. An alert pendant calls for help once the person is already on the floor. If you describe one, you still have to explain how it reduces the risk of falls, or the device mark is at risk. A device that steadies, supports or lights the way before a fall is the safer choice.
- Listing features instead of explaining them. “Uses sensors” and “made of aluminium” are features. Say how each one makes the device work or reduces the fall risk: what the sensors detect and what the microcontroller then does, or why a strong, light frame matters to someone wearing it.
- Benefits to the user only. Comfort and confidence are good for the person using the device, but the question asks for benefits to the community. Independent living at home and less demand on health services and carers are community benefits.
- Two benefits that say the same thing. “Fewer hospital visits” and “less pressure on hospitals” are one benefit written twice, so the second earns no mark. Make the second benefit about something different, such as older people living independently in their own homes.
The past QCAA questions this one was modelled on
Only mark this done when you could do it without help. Reading the solution does not count.
A Tangent Tuition mock exam question. It is not a past QCAA question, and Tangent Tuition is not affiliated with the QCAA.
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