biodex NxSTEP 950-485 User manual

NxSTEP™ UNWEIGHING SYSTEM
INSTRUCTIONS FOR USE AND ASSEMBLY
950-485
945-480
FN: 16-136CLR Rev C 5/19

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NxStepTM Unweighing System
This instructions for use document covers safe operation of the NxStep Unweighing System –
950-485 and 945-480.
Additional information and resources are available upon request or directly from the Biodex
website, www.biodex.com.
If the desired information is not found, please feel free to contact a local distributor or Biodex
directly at [email protected]
Thank you,
Biodex Medical Systems, Inc.
Contact information
Manufactured by:
Biodex Medical Systems, Inc.
20 Ramsey Road, Shirley, New York, 11967-4704
Tel: [phone] (Int’l 631-924-9000)
Fax: [phone]
email: [email protected]
www.biodex.com

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Table of Contents
Contact information ................................................................................................................ 2!
Definition of Symbols................................................................................................................ 4!
Before Proceeding ..................................................................................................................... 5!
Product Certifications and Classifications.................................................................................. 6!
Important Safety Information .................................................................................................... 7!
1.!Introduction ........................................................................................................................ 8!
2.!Assembly Instructions ....................................................................................................... 11!
Assembly Procedure ........................................................................................................ 11!
3.!NxStep Unweighing System Operation ............................................................................... 12!
The Hand-Held Controller ............................................................................................ 16!
The Battery Pack .......................................................................................................... 16!
Positioning NxStep for Use with the Biodex Gait Trainer or Treadmill ........................... 17!
Free Wheeling.............................................................................................................. 18!
Jogging........................................................................................................................ 18!
Pelvic Stabilization Straps (Retention Cords)................................................................. 19!
Using the Unweighing Harness..................................................................................... 19!
Safety Tether Operation............................................................................................... 20!
Determination of Body Weight Support ........................................................................ 21!
Unloading Patient Weight............................................................................................. 21!
Patient Unloading Procedure ........................................................................................ 21!
4.!Maintenance and Safety Inspection.................................................................................... 24!
5.!References and Bibliography ............................................................................................. 25!
6.!Specifications .................................................................................................................... 26!

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Definition of Symbols
The following symbols and their associated definitions are used and implied throughout this
manual.

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Before Proceeding
Before you get started with any of the setups described in this manual, there
are a few preliminary points to consider which will help ensure safe and
smooth operation of your NxStep Unweighing System.
Be aware that use of Biodex products requires professional expertise for
discerning appropriate treatment techniques. Each subject’s unique situation
should be taken into account before beginning any type of testing or
rehabilitation program. Be sure you fully comprehend these operating
instructions before attempting to treat a subject for testing or exercise.
Practice setups and positioning with a healthy subject before attempting to
treat an injured patient.
NOTE: Service should be provided by qualified personnel only. Please do not
attempt installation or repair on your own. Call Biodex Customer Service for
assistance.
WARNING: The NxStep Unweighing System must be thoroughly inspected every time
prior to each usage with a patient to ensure safe operation. Refer to the Maintenance
and Safety Inspection section for details.
CAUTION: The NxStep Unweighing System should not be used if an issue
requiring service by Biodex personnel is detected during inspection.
CAUTION: Ensure that the support rope safety stop does not come in contact
with the support bar pulley when either a Biodex supplied harness or other
manufacturer’s harness is used to support the patient.
CAUTION: When service is required, the NxStep Unweighing System should
only be serviced by personnel authorized by Biodex Medical Systems, Inc.
Failure to do so will void the warranty and no longer ensure safe operation.
CAUTION: Modifications to this product are only permitted by the
manufacturer. Unauthorized modification of the product can result in hazards
to the operator and patient, and will void the manufacturer’s warranty. Do not
modify this equipment without authorization from the manufacturer.
For additional technical advice, service or education information, please contact:
Biodex Medical Systems, Inc., 20 Ramsey Road, Shirley, New York 11967-4704;
1-800-224-6339 (Int’l 631-924-9000) or [e-mail].

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Product Certifications and Classifications
The NxStep Unweighing System has received the following certifications, and falls within the
following classifications:
●ANSI ES 60601-1
●IEC 60601-1
●IEC 60601-1-2
●CAN/CSA C22.2 No. 60601-1:2014
●FDA Class I Equipment
●EU Class I Product
●CE Marked.
●Type B Applied Part
●Electromagnetic Compatibility: This equipment complies with the Medical Equipment ICC
60601-2 EMC Standard.
NOTE:Complete information on the Electromagnetic Compatibility for the NxStep system
can be found in the Compliance Supplement located on the Biodex website (www.biodex.com)
or can be obtained by contacting Biodex Customer Service (see Contact information).
Authorized European Community Representative:
Emergo Europe
Prinsessegracht 20
2514 AP, The Hague
The Netherlands

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Important Safety Information
CAUTION: Federal Law restricts this device to sale by, or on the order of a
medical practitioner. When prescribed for therapeutic purpose, a physician
should clearly define the parameters of use (i.e., total work, maximum heart
rate, etc.) to reduce the risk of patient injury.
Follow the assembly and installation instructions document.
Before using this device, read the entire operation manual carefully. Failure
to read the manual may result in user error or inaccurate data. Be sure to
save all provided documents for future reference.
Make certain to understand all warning and caution labels as explained in
the Before Proceeding section of this manual.
This product should be used only as specified in the operation manual.
WARNING: The Biodex NxStep Unweighing System is designed for use in a
patient environment.
For product specifications, refer to the Table of Contents.
For Cleaning and Maintenance instructions, refer to the Table of Contents.
CAUTION: Battery Operation: 115 V or 230 V wall adapter for battery
charging.
WARNING: Use approved wall pack adapters.
User Capacity
•Height: up to 78 inches (6 ft, 3 in) (191 cm)
•Weight: up to 400 lb
Biodex Warranty
Refer to the warranty card included with the product or contact Biodex Support Services.

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1. Introduction
Intended Use
•The NxStep Unweighing System is used for Partial Body-Weight Support with the
capability to unload up to 30-40 percent weight bearing for patients with gait
impairments.
•It is a versatile product, providing capabilities for patients with lower extremity
weakness, core strength deficits, neurological and musculoskeletal disorders.
•It is intended to be used as a training tool to assist patients with gait performance with
a goal for remediation of ambulation activity.
Indications for Use
The NxStep Unweighing System is used with patients who may be deconditioned due to
weakness or diagnosed with disease processes such as Parkinson’s disease, incomplete spinal
cord injuries, multiple sclerosis, LE amputees, Cerebral Palsy, Traumatic Brain Injury, and all
other patients with movement disorders effecting gait.
Contraindications for Use
The NxStep Unweighing System is not to be used for patients with any of the following:
•Severe osteoporosis
•Non-union fractures
•Bariatric patients greater than 400 lb
•Patients with poor safety awareness/cognition
•Acute conditions such as pulmonary embolus, thrombus
•Acute Myocardial Infraction
•Acute fractures
•BP over 180/110 Hg
•Severe debilitating dizziness
Precautions
Precautions should be taken with patients that have poor safety awareness/cognition, global
weakness, a history of hazardous falls, and/or severe fatigue. Patients less than 30 lb may not
register the appropriate loading weight.

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Figure 1.1. The NxStep Unweighing System parts and adjustments include:
Standard Parts and Adjustments:
1. Safety Tether
2. Support Bar with Donut
3. Main Column
4. Allen Wrench (stored in slot near battery pack)
5. 5" Locking Casters (4)
6. Cross Tube
7. Coupling Pull Pin
8. Handrail Release Buttons (one for each side)
9. Handrails
10. Unweighing Scale
11. Quick Release Vest Clips
12. Patient Harness Bar with Bumper
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11
12
13
3
2
9
6
4
7
8
5
14
1
13. Hand-Held Controller
14. Therapist Stool
Not shown:
Battery Pack
AC power adapter(s) (115 VAC adapter for US
customers, 115 and 230 VAC adapters for
customers outside of the US)
Pelvic Stabilization Straps (945-462, two included)
Optional:
Additional Therapist Stool (950-486)

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Training
Biodex supplements on-site training with many training resources.
For detailed information on the NxStep System:
•Visit www.biodex.com and register for the NxStep eLearning course by navigating to:
Physical Medicine/Education & Training/Training: Interactive eLearning.
https://www.biodex.com/physical-medicine/biodex-
university/training-interactive-elearning
NOTE: There are also courses for clinical applications of Biodex
products for Stroke, Parkinson’s, and Peripheral Neuropathy.
NOTE: Scanning the code may require the Articulate app
to be downloaded.
Figure 1.2. NxStep eLearning Course
•Browse the NxStep Unweighing System videos available on the Biodex website:
https://www.biodex.com/physicalmedicine/products/pbws/
nxstep/videos-0

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Figure 2.1. The Biodex NxStep in the
fully compressed
position.
2. Assembly Instructions
NOTE:The Assembly Instructions are detailed in the Unpacking and Assembly Prep segment of
the NxStep eLearning course.
Assembling the NxStep Unweighing System
The system should arrive at your facility fully
assembled. It is shipped in a compressed position
with the support bar tilted down and the cross
tube c ompressed. Initial use will require fully
expanding the cross tube and setting the support
bar to the fully raised position.
NOTE: If the system needs to be transported
through a doorway, hallway, etc., the cross tube
can be compressed and the support bar lowered
to make moving the system easier. Fully
compressed, the system will fit through a 36”
wide opening.
WARNING: At least two people are required
to complete the following procedure. Ensure that
the NxStep will be assembled on a level surface.
Ensure that there is enough room to easily move
around the NxStep frame during installation.
Assembly Procedure
The entire assembly procedure is covered in the NxStep eLearning Course. To watch the video
detailing the assembly process, please register for the course.

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3. NxStep Unweighing System Operation
NOTE:System Operation instructions are detailed in the Using the Unweighing System segment
of the NxStep eLearning course. This includes an Operational Overview and a separate segment
on using the hand-held controller.
CAUTION: Never leave a patient unattended on this device. Check all cables,
harness and fittings before each use.
CAUTION: The system uses a special harness to support the patient. It is vital
that the harness fits properly on the patient. Refer to the video available on
the Biodex website.
Straight Hanger Bar with Quick Disconnect
The straight hanger bar is illustrated in Figure 3.1 below.
Figure 3.1. Straight Hanger Bar with Quick Release
The straight hanger bar features a quick disconnect that allows the use of a single point
harness when the intention is slight support or safety from falling during activity.
The Quick Release pin (see Figure 3.2) is used to disconnect the hanger bar from the clevis. It
can be reconnected to a Single Point Support harness either directly or a carabiner can be used.
NOTE: The Straight Hanger Bar with quick disconnect can also be used with the FreeStep Rail
System.

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Figure 3.2. Quick Disconnect Apparatus Illustrating Quick Release Pin.
Reconnect to the Single Point harness either directly or using a carabiner.
Figure 3.3. Direct Connection to a Single Point Harness.

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Steering Casters
The NxStep has four locking casters. The rear casters have two lever positions:
• Lever down: the wheel is locked.
• Lever up: wheel is unlocked and rolls and swivels in any direction.
The front casters have three lever positions:
• Lever down: the wheel is locked.
• Lever up halfway: wheel is unlocked, and therefore rolls and swivels in any direction.
• Lever all the way up: Wheel rolls, but only in the direction it is set (it will not swivel.)
Steering tends to be easiest when the two rear casters are unlocked and the front casters
are directionally locked in the ‘forward’ orientation.
Figure 3.4. The front casters have three setting: completely locked, completely unlocked,
and directionally locked.

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Installing and Removing the Handrails
Figure 3.5. The handrail release button.
The handrails can be used to assist the patient, or removed to provide more of a challenge.
To install or remove the handrails, push in on the appropriate handrail release button.
The Therapist Stool
NOTE:Setting up the Therapist Stool, Hand-Held Controller, and Battery Pack, are all fully
explained in the Preparing the NxStep for First Use segment of the NxStep eLearning Course.
One Therapist Stool comes standard on each NxStep. An additional stool can be purchased
separately (catalog product code: 950-486). While seated on the stool, a clinician can easily
observe or assist patients with foot placement and weight shifting.
• To remove the therapist stool, simply lift it up. To install the therapist stool, fit the stool
support into either of the two positioning holes along each support bar. The seat can face
either in or out from the subject, and the height of the seat can be adjusted by moving the
bolt into any of the six holes in the stool post.
Figure 3.6. The Therapist Stool.

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The Hand-Held Controller
The hand-held controller is used to easily raise or lower the patient harness bar, adjust the
amount of weight to unload from the patient, or to turn the auto unload feature ON or OFF for
unweighing activities. The controller is magnetic, allowing for easy-to-reach positioning
anywhere along the main column when not being held by the therapist.
• To raise or lower the patient harness bar, press on the Bar Adjustment <UP> or <DOWN>
buttons until the desired bar height is achieved.
• To raise or lower the amount of weight to be unloaded from the patient, press on the
Unweigh Load <UP> or <DOWN> buttons until the desired amount to be unloaded from the
patient is centered in the appropriate zone of the UNWEIGHING LOAD scale.
• The Auto Unload Feature allows the system to automatically adjust the unweighing load as
the patient progresses through unweighing activities to compensate for any slight loosening
of the harness as the patient moves. To turn Auto Load on or off, press on the Auto Load
<ON> or <OFF> button. A green indicator light will illuminate next to the LOAD RANGE scale
when Auto Unload is activated.
Figure 3.7. The Hand-Held Controller.
The Battery Pack
The battery pack attaches to the main column. Slide the battery pack onto the support posts.
The plug and cord are located beneath the lower battery. To charge the batteries, plug the
charging cord into a wall socket.
•While the battery is being charged, one of two LED lights is illuminated: A green light
means the battery is fully charged and an amber light means it is currently charging.
•The red button on the battery is a safety button. Pushing it in removes all power to the
device. If it is pulled out, the device will be powered for normal use.
NOTE: The battery can also be charged with a remote charger (part #: C10396). If battery
power is drained, the device can still be used with the battery plugged in and charging.

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Positioning NxStep for Use with the Biodex Gait Trainer or
Treadmill
NOTE:Instructions for Positioning the NxStep for use with a treadmill and the use of the
Therapist Stool are detailed in the Clinical Applications Overview: Treadmill Training segment
of the NxStep eLearning course.
Figure 3.8. The NxStep ready for use with the Biodex Gait Trainer.
The NxStep can be positioned for use with treadmills to 38" w and 13.5'' h (97 x 34 cm).
1. Remove handrails (if treadmill has its own handrails) and unlock all casters.
2. Roll the NxStep into position ensuring the patient harness bar is closest to the control
panel end of the treadmill. The treadmill control panel should be easily accessible.
3. Position the patient in the center of the treadmill belt and closer to the front than the back
of the treadmill deck.
4. Lock all four casters and proceed with treadmill use.
CAUTION:When using the NxStep Unweighing System with a treadmill, the
steering casters should be positioned at the rear of thetreadmill.Thiswill makeit
easier tomaneuver around the treadmill deck .

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Free Wheeling
Figure 3.9. The NxStep ready for free-wheeling across the floor.
The NxStep can be used over the floor or with other exercise devices. Be aware of the
adjustments required when moving from one device to another. For example, when stepping
down from a treadmill, the step-up height of the treadmill must be taken into account; the
harness bar will need to be lowered. The opposite is true when going from the floor to the
treadmill.
When traveling across the floor there is no need to spin the entire unweighing system around
when the patient runs out of floor space. Simply turn the patient around and move in the
opposite direction.
CAUTION:When using the NxStep with a treadmill, the steering casters should be
positioned at the rear of thetreadmill.Thiswill makeit easier to maneuver around
the treadmill deck .
Jogging
The dynamic suspension provides ample dynamics to allow patients to walk briskly or even
jog while attached to the NxStep.

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Pelvic Stabilization Straps (Retention Cords)
NOTE:Using the Biodex Standard Unweighing Harness for additional pelvic support is covered
in a video that is offered at www.biodex.com/harness.
If desired, use the two included pelvic stabilization straps for additional support during partial
body weight support activities. Place the strap loops around the handrails and place the hooks
in the rings on the patient harness.
Figure 3.10. Retention Cords hooked into harness ring.
Using the Unweighing Harness
CAUTION: The NxStep uses a special harness to support the patient. It is vital
that the harness fits properly on the patient. Refer to the video available at
www.biodex.com/harness.
The NxStep can be used with most two-point harnesses. The harness that is supplied with
your NxStep provides maximum support for patients needing consistent body weight
unloading. It also provides increased trunk stability. A two-panel design allows for a wide
range of adjustability and easy application in sitting and supine positions, while a unique
pelvic support piece prevents excessive pressure in the groin area. The harness fits most
patients (waist size 24-54".) Maximum weight capacity is 300 lbs (136 kg).

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Standing Harness Application
NOTE:Applying the harness while the patient is in a standing position is covered in the NxStep
eLearning course and a video that is offered at www.biodex.com/harness.
Sitting Harness Application
NOTE:Applying the harness while the patient is in a seated position is covered in the NxStep
eLearning course and a video that is offered at www.biodex.com/harness.
Safety Tether Operation
CAUTION: To ensure patient safety, it is vital that the safety tether is attached.
The Figure 3.11. The safety tether (the rippled elastic cord) attaches to the center of the patient
harness bar.
The safety tether is factory installed, but a few simple adjustments may be required to ensure
proper operation during device usage. The tether strap is elastic, but its maximum stretched
length is about 25 inches.