| PASSIVE SOLUTIONS | |||
 | |||
| |||
| |||
| Human to machine interface and machine to machine interface requirements | |||
Choosing potentiometers, panel controllers and rotary encoders for control purposes in medical applications requires not only selection of the right type of component but also of a suitable shaft/bushing configuration. Correct selection will produce optimum performance in the two major types of application: Human-to-Machine Interfaces (HMI) and Machine-to-Machine Interfaces (MMI). HMI implementations are required on the majority of end products, and are most commonly implemented as front panel controllers or adjusters. Such devices are typically mounted to a panel with a sleeve bushing and have a knob mounted on the end of the shaft. Typical applications are defibrillators using digital contacting encoders such as Bourns’ ECW series; dialysis equipment, patient monitoring and MRI scanner implementations equipped with an EM14 rotary optical encoder with switch; ultrasound and plastic surgery equipment that makes use of the Model 51 sealed square panel control; CT scanner equipment using the Model 92 single turn panel control; infusion pump equipment requiring a precision potentiometer such as the 3545 device.  In these applications, high speed rotation and side loads of the shaft are normally not encountered but designers need to keep these to a minimum when choosing the device. On some encoder models such as the ENT series, a front ball-bearing is available should the designer wish to have a very low shaft torque for use in tracker-ball and menu-selection applications. Many MMI applications are position sensors in which adjustments are made by a mechanical interface. Position sensor designs include linear actuators used in hospital beds (precision potentiometers such as the 3540 device), x-ray equipment (3500 or 6639 potentiometers), CT and MMR scanners (3541, 6538 and 6657 potentiometers and ENA-series optical encoders).  The Bourns EN-type optical encoder sensors can also be used to count rotations of a motor via a mechanical coupling device. In MMI applications, a high speed of rotation may be encountered along with a shaft side-load exerted by either a pulley or gear system. For these applications, the front ball-bearing option or front and rear ball-bearing option and servo-mount configuration is highly recommended. Configurations made for MMI applications may be used in HMI applications where the designer requires additional robustness and extended rotational life. However, configurations made for HMI applications are not recommended for use in MMI applications. Suitable Products
Applications
|
 |
 |
 |
 |
 |
|
 |
 |
||||
 |
 |
 |
 |
 |
|
|
 |
|
|||
 |
 |
 |
 |
 |
|
