Table 2. Summary of all known designs of SMART spinal implants available across all sources i.e., primary, secondary academic literature, commercial website, patents etc.
| Source | Design | Power system | Sensor | Intended location |
|---|---|---|---|---|
| Rohlmann et al. | Modified Dick internal fixator | Wireless inductive coupling (passive) | Strain-gauge | Rods/posterior fixators |
| Contains six load sensors, eight-channel telemetry unit, inductive power coil and an antenna | ||||
| Rohlmann et al. | Modified VBR | Wireless inductive coupling (passive) | Strain-gauge | VBR |
| Contains six load sensors, nine-channel telemetry unit, inductive power coil and an antenna | ||||
| Smith et al. | Modified cannulated pedicle screws | Wired | Strain-gauge | Pedicle screws |
| Contains strain gauges and wires within the neck and proximal end of the screw | ||||
| Janna et al. | Cylindrical accelerometer design able to inserted into narrow nails and screws | Undefined | Accelerometer | Orthopaedic nails and screws |
| Contains at least one sensor and microelectronic components including memory device, power supply and communications components | ||||
| Intellirod SpineTM | Titanium/zirconia ceramic, single use strain sensor with radio-frequency transmission | Wireless inductive coupling (passive) | Strain-gauge | Rods |
| Clamps onto rods during kyphotic correction | ||||
| Anderson et al. | Modified tire pressure sensor | Wireless inductive coupling (passive) | Pressure-sensor | Interbody cage |
| MEMS-based technology | Accelerometer | |||
| Compactly contains a load sensor, a two-axis accelerometer, a thermometer and a radio-frequency transmitter | Longevity of 1 year in standby mode | Thermometer | ||
| Barri et al. | Fowler-Nordheim sensor-data-logger attached to polymer model of the spine | Self-powered energy harvesting system based on Fowler-Nordheim quantum tunnelling | Strain-gauge | Rods |
VBR, vertebral body replacement.