Parts List
| Component Type | Component Name | Description | Quantity | |
|---|---|---|---|---|
| BUS / Interface | I2C or SPI | Inter-Integrated Circuit Communications Protocol or Serial Peripheral Interface Communications Protocol | 1 | |
| Direct Attach Type | SMD | Surface Mount Device Connection Type | 1 | |
| Wireless Technology | Bluetooth/BLE | Bluetooth / Bluetooth Low Energy v4+ | 1 | |
| Sound | 94dB-20Hz to 20kHz | Standard (94dB max) + High Quality (down to 20 Hz) + Audible Range (up to 20 kHz) | 1 | |
| Pressure | 24bit-110kPA +/- .05kPA | High Resolution (24 bit) + Standard Atmospheric (110 kPa) + High Accuracy (± 0.05%) | 1 | |
| Magnetometer | 16-bit | High Resolution (16 bit) | 1 | |
| Gyroscope | 3 Axes | 3 Axes - Eg. Pitch / Yaw / Rotation | 1 | |
| Accelerometer | High Res - Medium Duty | High Resolution (16 bit) + Medium Duty (± 8.0 G) | 1 | |
| Colour | RGB | 450 to 750nm | 1 | |
| Light | Visible Spectrum | Visible spectrum (peak wavelength 750nm) | 1 | |
| Temperature | Standard Accuracy | Standard Accuracy (±2°C) from -40°C to 105°C | 1 |
Background
I spend many hours a day sitting behind a desk. So do many of my friends and colleagues. Some of them do one or more sport activities before/after work, but a lot of them don't. This is how I got the idea to use a device that would encourage the owner to move in a bit entertaining way. To relief the strain, change body position, stretch and relax.
I have noticed a recent expansion of fitness trackers, but most of them are smart watches
attached to a hand. They tend to track the whole person, which could be limiting. I was thinking about something of a tennis ball size, that would include the sensor board, host MCU and a battery. Small form factor of all the electronics is the only way this could ever be made - ideally with a center of gravity in the intersection of X,Y and Z axis.
Here are some ideas for elementary functions:
The device could detect movement using an on-board accelerometer, a gyroscope and a magnetometer:
- detection of a rotational movement - while holding in hand, rotating your wrist, elbow or the whole arm using a shoulder
- compass heading
- detection of a free fall - throw the ball in the air and catch it
- click and double click detection - start and stop the exercise
On-board pressure sensor is able to provide a pressure difference in time:
- detection of an altitude difference - for example exercise consisting of climbing 100 stairs.
I am not a fan of too complicated devices. However, it might be useful to signal some exercise states. Let's say the ball could be made out of some semi-transparent plastic. An RGB LED provides simple state information (changing colour from red to green during the progress) in addition to a small vibration motor (force feedback for every repetition) and an audio output with instructions.
BLE would be the only data connection to the outside world. A paired cell phone with an application would have to store all the exercise definitions and probably collect the results.
The question is whether all the sensor data and its precision could be used for real therapy applications or just for having some fun. I don't think that any electronics can currently replace a physiotherapist, however, there are always more people with health problems than can be treated. I guess the only way to find out is to run a proper clinical trial.