Article - Wheelchair Options/Accessories - Policy Article (A52504)

POWER WHEELCHAIR DRIVE CONTROL SYSTEMS:The term interface in the code narrative and definitions describes the mechanism for controlling the movement of a power wheelchair. Examples of interfaces include, but are not limited to, joystick, sip and puff, chin control, head control, etc. (Note: In the Power Mobility Devices policy, the term "control input device" is used instead of "interface".)A proportional interface is one in which the direction and amount of movement by the beneficiary controls the direction and speed of the wheelchair. One example of a proportional interface is a standard joystick.A non-proportional interface is one which involves a number of switches. Selecting a particular switch determines the direction of the wheelchair, but the speed is pre-programmed. One example of a non-proportional interface is a sip-and-puff mechanism.The term controller describes the microprocessor and other related electronics that receive and interpret input from the joystick (or other drive control interface) and convert that input into power output which controls speed and direction. A high power wire harness connects the controller to the motor and gears.A non-expandable controller has the following features:May have the ability to control up to 2 power seating actuators through the drive control (for example, seat elevator and single actuator power elevating legrests). (Note: Control of the power seating actuators though the Control Input Device would require the use of an additional component, E2310 or E2311.)Can accommodate only an integral joystick or a standard proportional remote joystickMay allow for the incorporation of an attendant controlAn expandable controller is capable of accommodating one or more of the following additional functions:Other types of proportional input devices (e.g., mini-proportional or compact joysticks, touchpads, chin control, head control, etc.)Non-proportional input devices (e.g., sip and puff, head array, etc.)Operate 3 or more powered seating actuators through the drive control. (Note: Control of the power seating actuators though the Control Input Device would require the use of an additional component, E2310 or E2311.)An expandable controller may also be able to operate one or more of the following:A separate display (i.e., for alternate control devices)Other electronic devices (e.g., control of an augmentative speech device or computer through the chair's drive control)An attendant controlFor power wheelchairs which are capable of being upgraded to an expandable controller (K0835, K0836, K0837, K0838, K0839, K0840, K0841, K0842, K0843, K0848, K0849, K0850, K0851, K0852, K0853, K0854, K0855, K0856 K0857, K0858, K0859, K0860, K0861 K0862, K0863, K0864, K0868, K0869, K0870, K0871, K0877, K0878, K0879, K0880, K0884, K0885, K0886, K0890,K0891), E2377 is used if an expandable controller is provided at the time of initial issue. Code E2376 is used with complete replacement of an expandable controller.A harness (E2313) describes all of the wires, fuse boxes, fuses, circuits, switches, etc. that are required for the operation of an expandable controller. It also includes all the necessary fasteners, connectors, and mounting hardware. Code E2313 is separately billable in addition to an expandable controller both at initial issue and with complete replacement of the expandable controller. Code K0108 must not be used for any component or feature of an expandable controller at the time of initial issue. The reimbursement for any type of complete expandable controller is included in the allowance for codes E2377/E2376 plus E2313. However, if individual components of the harness are replaced, code K0108 should be used.A switch is an electronic device which turns power to a particular function either "on" or "off". The external component of a switch may be either mechanical or non-mechanical. Mechanical switches involve physical contact in order to be activated. Examples of the external components of mechanical switches include, but are not limited to, toggle, button, ribbon, etc. Examples of the external components of non-mechanical switches include, but are not limited to, proximity, infrared, etc. Some of the codes include multiple switches. In those situations, each functional switch may have its own external component or multiple functional switches may be integrated into a single external switch component or multiple functional switches may be integrated into the wheelchair control interface without having a distinct external switch component.A stop switch allows for an emergency stop when a wheelchair with a non-proportional interface is operating in the latched mode. (Latched mode is when the wheelchair continues to move without the beneficiary having to continually activate the interface.) This switch is sometimes referred to as a kill switch.A direction change switch allows the beneficiary to change the direction that is controlled by another separate switch or by a mechanical proportional head control interface. For example, it allows a switch to initiate forward movement one time and backward movement another time.A function selection switch allows the beneficiary to determine what operation is being controlled by the interface at any particular time. Operations may include, but are not limited to, drive forward, drive backward, tilt forward, recline backward, etc.An integrated proportional joystick and controller is an electronics package in which a joystick and controller electronics are in a single box, which is mounted on the arm of the wheelchair.The interfaces described by codes E2312, E2321, E2322, E2325, E2327, E2328, E2329, E2330, E2373, E2374, E2375, E2376, E2377 must have programmable control parameters for speed adjustment, tremor dampening, acceleration control, and braking.A remote joystick is one in which the joystick is in one box that is typically mounted on the arm of the wheelchair and the controller electronics are located in a different box that is typically located under the seat of the wheelchair. The joystick is connected to the controller through a low power wire harness. A remote joystick may be used for either hand control, chin control, or attendant control.A standard proportional remote joystick is one which requires approximately 340 grams of force to activate and which has an excursion (length of throw) of approximately 25 mm from neutral position. It can be used with a non-expandable or an expandable controller. There is no separate billing for a standard proportional remote joystick when it is provided at the time of initial issue of a power wheelchair whether it is used for hand or chin control by the beneficiary or whether it is used as an attendant control in place of a beneficiary-operated drive control interface.A mini-proportional (short throw) remote joystick (E2312) is one which can be activated by a very low force (approximately 25 grams) and which has a very short displacement (a maximum excursion of approximately 5 mm from neutral). It can only be used with an expandable controller. It can be used for hand or chin control or control by other body part (e.g., tongue, lip, fingertip, etc.). There is no separate billing for control buttons, displays, switches, etc. There is no separate billing for fixed mounting hardware, regardless of the body part used to activate the joystick.A compact proportional remote joystick (E2373) is one which has a maximum excursion of about 15 mm from neutral position but requires approximately 340 grams of force to activate. It can only be used with an expandable controller. It can be used for hand or chin control or control by other body part (e.g., foot, amputee stump, etc.). There is no separate billing for control buttons, displays, switches, etc. There is no separate billing for fixed mounting hardware, regardless of the body part used to activate the joystick.A touchpad is an interface similar to the pad-type mouse found on portable computers. It is billed with code K0108.Code E2321 is used for a non-proportional remote joystick, regardless of whether it is used for hand or chin control.When code E2312, E2321, E2373, or E2374 is used for a chin control interface, the chin cup is billed separately with code E2324.Code E2322 describes a system of 3-5 mechanical switches which are activated by the beneficiary touching the switch. The switch that is selected determines the direction of the wheelchair. A mechanical stop switch and a mechanical direction change switch, if provided, are included in the allowance for the code.Code E2323 includes prefabricated joystick handles that have shapes other than a straight stick - e.g., U shape or T shape - or that have some other nonstandard feature - e.g., flexible shaft.A sip and puff interface (E2325) is a non-proportional interface in which the beneficiary holds a tube in their mouth and controls the wheelchair by either sucking in (sip) or blowing out (puff). A mechanical stop switch is included in the allowance for the code. E2325 does not include the breath tube kit which is described by code E2326.A proportional, mechanical head control interface (E2327) is one in which a headrest is attached to a joystick-like device. The direction and amount of movement of the beneficiary's head pressing on the headrest control the direction and speed of the wheelchair. A mechanical direction control switch is included in the code.A proportional, electronic head control interface (E2328) is one in which a beneficiary's head movements are sensed by a box placed behind the beneficiary's head. The direction and amount of movement of the beneficiary's head (which does not come in contact with the box) control the direction and speed of the wheelchair. A proportional, electronic extremity control interface (E2328) is one in which the direction and amount of movement of the beneficiary's arm or leg control the direction and speed of the wheelchair.A non-proportional, contact switch head control interface (E2329) is one in which a beneficiary activates one of three mechanical switches placed around the back and sides of their head. These switches are activated by pressure of the head against the switch. The switch that is selected determines the direction of the wheelchair. A mechanical stop switch and a mechanical direction change switch are included in the allowance for the code.A non-proportional, proximity switch head control interface (E2330) is one in which a beneficiary activates one of three switches placed around the back and sides of their head. These switches are activated by movement of the head toward the switch, though the head does not touch the switch. The switch that is selected determines the direction of the wheelchair. A mechanical stop switch and a mechanical direction change switch is included in the allowance for the code.An attendant control is one which allows a caregiver to drive the wheelchair instead of the beneficiary. The attendant control is usually mounted on one of the rear canes of the wheelchair. This code is limited to proportional control devices, usually a joystick. Code E2331 is used when an attendant control is provided in addition to a beneficiary-operated drive control interface.Codes E2374, E2375, E2376 describe components of drive control systems. They may only be used for replacements other than at the time of initial issue.Code K0108 is appropriately used at the time of initial issue only when the drive control interface that is provided is not included in the base code and there is no specific E code which describes it. K0108 must not be used for additional features of a joystick.Code K0108 is appropriately used at the time of replacement in the following situations:An integrated proportional joystick and controller box are being replaced due to damage; orAn interface other than a remote joystick (e.g. sip and puff, head control) is being replaced but the controller is not being replaced; orThere is no specific E code which describes the type of drive control interface system which is provided.The KC modifier (replacement of special power wheelchair interface) is used in the following situations:Due to a change in the beneficiary's condition an integrated joystick and controller is being replaced by another drive control interface - e.g., remote joystick, head control, sip and puff, etc.; orThe beneficiary had a drive control interface described by codes E2321, E2322, E2325, E2327, E2328, E2329, E2330, or E2373 and both the interface (e.g., joystick, head control, sip and puff) and the controller electronics are being replaced due to irreparable damage.The KC modifier would never be used at the time of initial issue of a wheelchair. The KC modifier specifically states replacement, therefore, the RB modifier is not required.OTHER POWER WHEELCHAIR ACCESSORIES:A drive wheel is one which is directly controlled by the motor of the power wheelchair. It may be either a rear wheel, mid wheel, or front wheel, depending on the model of the power wheelchair.A caster is a smaller wheel that is in contact with the ground during normal operation of the wheelchair and which not directly controlled by the motor. It may be in the front and/or rear, depending on the location of the drive wheel.A pneumatic tire (E2381, E2384) is a rubber tire which is used in conjunction with a separate tube (E2382, E2385) which is filled with air.A flat free insert (E2383) is a removable ring of firm material that is placed inside of a pneumatic tire to allow the wheelchair to continue to move if the pneumatic tire is punctured. This code may not be used for a foam filled tire.A foam filled tire (E2386, E2387) is one in which a rubber tire shell has been filled with foam which is non-removable.