SOFIE, the Smart Bike for Seniors

To keep fit and enjoy an active lifestyle, seniors are encouraged to use green transportation. Cycling is particularly recommended because it helps to maintain good mental and physical health. Some people are deprived of this pleasure because of loss of balance or an elevated risk of falling due to vision disorder, age-related fragile bones or disease. A team of researchers created an electric bicycle to help seniors avoid the risk of falling.

The smart bike was named SOFIE, an acronym for the Dutch term Slimme Ondersteunende Fiets, which stands for intelligent supported bicycle. It is intended for the elderly who are able to pedal, allowing for safe and comfortable riding. The researchers provided solutions to the four main risk factors of falls:

1. Existing saddles are too high, forcing riders to be on tiptoe to get on and off the bicycle, increasing the risk of losing their balance.
2. The height of the saddle is also a problem when stopping.
3. Seniors do not have enough strength to propel the bike at the start at a speed that will help stabilize it. This can cause the bike to wobble.
4. The reaction time of seniors is slower, making it more difficult to counter the bicycle’s instability in time to prevent a fall.

These difficulties, exacerbated by riding discomfort, can stress cyclists and increase the risk of falling.

Intuitive and Adaptable Design

Rosemary Dubbeldam, Jaap H. Buurke and Chris Baten, researchers at the Rehabilitation Technology Department of the Roessingh Research and Development Center, and Johan S. Rietman of the Department of Biomechanical Engineering at Twente University in the Netherlands, designed a SOFIE prototype. The prototype was presented in a study entitled “SOFIE, a bicycle that supports older cyclists?” published in ScienceDirect in August 2017.

Rosemary Dubbeldam, Jaap H. Buurke et Chris Baten, chercheurs au Rehabilitation Technology Department du centre Roessingh Research and Development et Johan S. Rietman du Department of Biomechanical Engineering de l’Université Twente aux Pays-Bas ont conçu un prototype de SOFIE. Celui-ci a été présenté dans une étude intitulée « SOFIE, a Bicycle that Supports Older Cyclists? », parue dans la revue ScienceDirect au mois d’août 2017.

In addition to providing a reliable and safe solution, the aim of this research is to study human balance on a bike, dynamics of the bicycle system, interaction between the cyclist and the environment, and specific techniques that can support the production of this type of product. In particular, the aim is to create a new test environment called the Fiets Stabiliteits Simulator (FSS – bicycle stability simulator).

The smart bike stability simulator

SOFIE’s design features front and rear wheels that are closer together. The size of the wheels was also reduced in order to limit the speed to 18 km/h. The system makes it possible to achieve speeds that will give faster starts to propel and stabilize the smart bike. When the cyclist presses on the pedal, the electric assistance is activated and makes it possible to:

1. Lower the saddle so that the cyclist can sit on it more easily.
2. Increase the bike’s speed automatically with the assistance of a small motor.
3. Raise the saddle to allow the cyclist to pedal comfortably.
4. Lower the saddle when the bicycle slows down to a stop, allowing the cyclist to dismount safely.

Tested Effectiveness of SOFIE

In their article, the researchers present the technical characteristics, design of SOFIE and results from a comparative study with the prototype. Nine riders between the ages of 65 and 80 tried the prototype and a regular bicycle in a parking lot—to avoid road traffic and interaction with other vehicles.

The following actions were analyzed during the tests:

1. Pedalling at low speeds and at normal speeds
2. Avoiding obstacles
3. Getting on and off the bicycle

Bicycle and cyclist movements were recorded with ten inertial measurement units and two video cameras. The FUSION software (LABVIEW) was used to evaluate kinematic parameters. A subjective analysis of the different driving stages was made based on the video images. Differences in the kinematic parameters of cyclists, normal bicycles and SOFIE were studied in all driving stages.

The tests confirmed the safety effectiveness of SOFIE smart bike compared to regular bicycles.