Polaris Tool Types
To meet the requirements of unique applications, NDI offers three types of optical tracking technologies: passive, active, and active wireless. Passive and active wireless tools are tracked by either the Polaris Vicra® or the passive Polaris Spectra® systems, while passive, active wireless, and active tools are tracked by the hybrid Polaris Spectra®.
NDI can help you determine the best technology for your application, while considering the following key points and differences of each tool.
Passive
Passive tools use spherical, retro-reflective markers that reflect infrared light emitted by the illuminators on the position sensor- Tools are wireless
- Offers simple tool construction
- Requires each tool have a unique marker geometry resulting in larger tool sizes
- Passive spheres need to be replaced after single use
- Difficult to clean passive spheres intra-operatively
Active
- Active tools incorporate infrared-emitting markers that are activated by an electrical current
- Tools are wired to the system
- More complex to build than passive tools
- Tools can be small since the same geometry can be used multiple times
- Markers have limited life and are not replaceable
- Markers can be cleaned easily
- Can incorporate switches and visible LEDs
- Tool Definition File can be programmed into tool
Active Wireless
- Active wireless tools incorporate infrared-emitting markers that are activated by an electrical current
- Tools are wireless
- Markers can be cleaned easily
- Tools can be powered by the device to which they are connected
- Requires each tool have a unique marker geometry resulting in larger tool sizes
- Using batteries can create challenges with sterilization and disposal
- Requires extra hardware such as a micro-controller
- The most complex to build
