Rocker switch provides variable-speed, bidirectional control of bone saw.

Dental unit features special actuators to provide 10 control functions in a small footprint.

Surgery units feature conductive foot pads and special color pedals per IEC Standard.

Foot controls found in industrial and commercial environments are functional, rugged, and wrong for medical devices and equipment applications. From the bottom pads that contact the floor, to the mating connector for controlled medical devices such as electrosurgical generators and orthopedic shavers, the design requirements for a medical-grade foot control are significantly different from those for an “industrial-grade” or “commercial-grade” unit. In fact, many critical parameters for designing foot controls for medical applications are unimportant for industrial or commercial applications. Among these:

• Weight must be optimized for stability during use and relocation. The designer must find a balance between satisfying the functional control requirements in a unit that is heavy enough to remain stationary during use, and light enough to be lifted during a procedure (sometimes by the user lifting the unit with their instep), and/or between procedures ,for movement to a different OR or for periodic cleaning.

• Cleanability is accomplished by providing geometric details and a surface finish for easy and effective cleaning. Design variables to consider include:

— Shape and contours of the unit.
— Clearance spacing between the actuators and between the actuators and their host console.
— Drainage of the surfaces.
— Level of sealing integrity (IP ratings typically of IP X6 to IP X8).
— Surface “texture” of the various elements of the unit, such as the console, pedal covers, base plate, and other actuators.
— Use of powder-coating and molded-in colors instead of painted surfaces that can crack, peel, or flake.
— Use of stainless steel hardware.

• Storage and mobility are important because the foot control console must be small enough to fit into a storage and docking station and/or capable of being moved from place-to-place during or between procedures. In addition to weight, the implications of frequent movement on other design attributes must be considered. These include:

— Strain relief integrity to withstand incorrect transport of the foot control when lifted by its cable; tight winding of the cable around the foot control for storage; and the use of the cable as a “tether” to pull the foot control to a new location.
— Characteristics of the foot pads must optimize the balance between the need for the unit to remain stationary during use, yet allow it to be moved during the procedure without lifting it from the floor.
— Optional fixed or collapsible “handle” allows lifting without undue strain and damage at the cable gland. This also lets users pick up the unit using their insteps for repositioning during procedures.
— Overall dimensions for storage considerations need to fit docking stations, equipment carts, etc.).

• Ingress protection must provide effective drainage during the procedure or cleaning and sealing integrity in order to tolerate and withstand bioliquids, cleaning solutions, disinfectants, and possible total immersion. Present IEC standards require foot controls to have a minimum ingress protection (IP) rating of IP X5. With the impending enactment of the Third Edition of IEC 60601, this minimum rating is expected to increase to IP X6. In addition, many applications require sealing to meet the submersibility requirements of IP X8. Where the cost of the foot control is significant (e.g. a multifunction unit for urology tables, cataract surgery, or orthopedic surgery), meeting the sealing requirements while allowing for servicing and repair requires critical consideration of subassembly dimensional tolerances, gasket design and material integrity, and specific servicing requirements.

• Compliance with standards such as IEC 60601, UL 2601, CSA 22.2, and for wireless designs assorted local standards such as the United States’ FCC Part 15.247/IC RSS-210 2.4 GHz; Europe’s (IEC 60601-1, IEC 60601-1-2, EN 60950 (2006), EN 50371 (2002), EN 300 440-1 V1.3.1 (2001-09), EN 300 440-2 V1.1.2 (2004-07), EN 301 489-1 V1.6.1 (2005-09), EN 301 489-3 V1.4.1 (2002-08); and Japan’s (J60950).

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