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Level One

The standard device is battery operated, completely portable, and features a microprocessor based LCD display. This display module shows peak strength in pounds or kilograms and can store and recall up to nine patients' average grip values, keyed to patient ID numbers. Optional software and cable are available for downloading data to an IBM-PC compatible computer for long term storage, statistical analysis, or printed reports.

 Level Two

To step up to Level Two, simply remove the display module and connect the DIGIT-Grip to any IBM-PC compatible computer. As an option, Level Two performance gives you the ability to measure the contribution of the middle/index fingers and ring/little fingers, as well as total grip. The package includes the NK DAQ2001 computer interface module and assessment software.

Level Three

Level Three provides the ability to accurately measure the contribution of each individual digit, as well as total grip. This upgrade includes the four sensor DIGITS-Grip handle, and associated software.

TECHNICAL SPECIFICATIONS

Measurement Range	+/-100 Kg (+/-220 Lb)
Accuracy	+/- 1% F.S.
Resolution	40 G
Temperature Compensation Range	5-50oC (41-122oF)
Maximum Excitation	5 Volts
Input Resistance	>500 Ohms
Output Resistance	>500 Ohms
Resistance to Ground	Infinite
Bridge Output	1.7 mV/V (100 Kg) (Nominal)
Non-Linearity	<0.5% F.S.
Hysteresis	<0.5% F.S.
Zero Shift	<0.5% F.S.
Calibration Intervals	3 Years
Instrument Weight	330 G (0.73 Lb)
Height	7.1 Cm (3.8 In)
Width	3.2 Cm (1.25 In)
Length	20.3 Cm (8.0 In)

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The NK DIGITS-Grip Device Model DGR001 Level Three  

The NK DIGIT-Grip Level Three device allows measurement of the contribution of each digit, as well as total grip strength. The Level Three Handle (shown here), contains four sensors and replaces the removable handle included in Level Two, and may be used in DIGIT-Grip positions 3-5.  Optionally, a slip-on adapter may be used with the Level Three handle for testing in a single fixed position.

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DIGIT-Grip Level three Impulse test results. Contribution of index, middle, ring, and little fingers plus total for three trials and average 

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DIGIT-Grip Level Three sustained test results. 

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The NK GRASP STRENGTH Device U.S. Patent No. 5,125,270 Model GR001

• The GRASP device is designed to provide accurate and repeatable hand grip strength measurement data, providing researchers and practitioners alike the ability to obtain reliable valid grasp strength data - a prerequisite for establishing a patient's baseline, assessing the need for surgical intervention, planning and evaluating rehabilitation programs, comparing to normal values, and calculating permanent impairments.

DEVICE FEATURES Small and lightweight, providing the ability to evaluate hand function without discomfort in even the most severely disabled. Unique, one piece design Three handle sizes are easily changed and maintain a snug fit. Accurate measurement regardless of position of hand on device. Custom designed handles are available. Calibration is traceable to NIST. Computerized device with data acquisition  software.

 

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DESIGN CONCEPT

• The GRASP Force Measurement Device incorporates a unique electro-mechanical concept that utilizes specially designed flexures which deform predictably under shear loading on its handles. The change in calibration coefficients due to the position of the load on the handles in not greater than 0.25 % of full scale.

  The mechanical design of this device is that of a one piece body, with the upper and lower handles being part of that body. This design concept eliminates assembly joints, resulting in better overall performance with respect to repeatability, linearity, zero shift, hysteresis, and change in calibration coefficient.
   

  TECHNICAL SPECIFICATIONS

  Measurement Range	0-70 Kg (0-155 Lb)
  Accuracy	+/- 0.25 % F.S.
  Resolution	40 G
  Temperature Compensation Range	5-50oC (41-122oF)
  Maximum Excitation	10 Volts
  Input Resistance	>500 Ohms (Nominal)
  Output Resistance	>500 Ohms (Nominal)
  Resistance to Ground	Infinite
  Bridge Output	3.8 mV/V (60 Kg) (Nominal)
  Non-Linearity	<0.10% F.S.
  Hysteresis	<0.10% F.S.
  Zero Shift	<0.10% F.S.
  Calibration Intervals	3 Years
  Instrument Weight	390 G (0.86 Lb)
  Height	8.9 Cm (3.5 In)
  Width	2.4 Cm (0.95 In)
  Length	17.8 Cm (7.0 In)

The NK PINCH Device

Model PF002  

PINCH STRENGTH DATA  Impulse Tests (Squeeze and Release) Sustained Tests (Squeeze over time) Left-Right Tests Baseline data for each patient Normal data comparison Visit-to-visit comparison Data analysis (Peak, Average, Coefficient of Variation, Reaction time, etc.) Test Protocols (Key, Tripod, Index Finger Tip, Middle Finger Tip, Index Finger Pulp, Middle Finger Pulp) Computerized device with data acquisition software

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Examples of Sustained and Impulse data charts 

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Example of visit-to-visit comparison chart 

TECHNICAL SPECIFICATIONS

Measurement Range	0-20 Kg (0-44 Lb)
Accuracy (Centerline loading)	+/- 2.0% F.S.
Resolution	10 G
Temperature Compensation Range	0-50oC (32-122oF)
Maximum Excitation	10 Volts
Input Resistance	<500 Ohms (Nominal)
Output Resistance	<500 Ohms (Nominal)
Resistance to Ground	Infinite
Bridge Output	3.3 mV/V (20 Kg) (Nominal)
Non-Linearity	<0.5% F.S.
Hysteresis	<0.5% F.S.
Zero Shift	<0.5% F.S.
Calibration Intervals	3 Years
Instrument Weight	35 G (0.08 Lb)
Height	1.4 Cm (0.55 In)
Width	3.8 Cm (1.5 In)
Length	5.7 Cm (2.25 In)

• DESIGN CONCEPT

  The PINCH ADJUSTABLE (Fingertip) Force Measurement Device incorporates a unique electromechanical concept that utilizes specially designed flexures which deform predictably under shear loading along its platforms.

  The mechanical design is that of a two piece body with the bottom platform being an integral part of the main body. The top platform has a mechanism allowing for continual adjustment of the distance between the two platforms to accommodate different pinch strength applications. The design concept, which minimizes the number of assembly joints, results in better overall performance with respect to repeatability, linearity, zero shift, hysteresis, and change in calibration coefficients.

  
   

  DEVICE FEATURES  Small and lightweight, providing the ability to evaluate hand function without discomfort, even in the most severely disabled patients Unique design Measures pinch strength accurately regardless of where force is applied on the platforms Platforms have a continuous adjustment feature, allowing for pinch strength measurement any distance apart within the range of 0.8 to 3.3 centimeters Calibration traceable to NIST

  
  

  APPLICATIONS  The PINCH ADJUSTABLE (Fingertip) Device accurately measures all pinch protocols, including tip, pulp, tripod, and key. It is designed to be held by the examiner and is recommended for measuring pinch strength in young children and severely disabled individuals. The device provides real time measurement and graphical display when even a very minimal amount of force is applied.

  TECHNICAL SPECIFICATIONS

  Measurement Range	0-10 Kg (0-22 Lb)
  Accuracy	+/- 0.25% F.S.
  Resolution	5 G
  Temperature Compensation Range	0-50oC (32-122oF)
  Maximum Excitation	10 Volts
  Input Resistance	<500 Ohms
  Output Resistance	<500 Ohms
  Resistance to Ground	Infinite
  Bridge Output	3.5 mV/V (10 Kg)
  Non-Linearity	<0.25% F.S.
  Hysteresis	<0.25% F.S.
  Zero Shift	<0.25% F.S.
  Calibration Intervals	2 Years
  Instrument Weight	155 G (0.34 Lb)
  Height	6.6 Cm (2.6 In)
  Width	1.9 Cm (0.75 In)
  Length	14.7 Cm (5.80 In)

• The Deviation Force Measurement Device incorporates a unique electromechanical concept that utilizes specially designed flexures which exclusively measure shear force.

  The device can be adjusted with respect to its height and the angle of inclination of its input arm, allowing proper alignment, even in the case of a severly deformed joint.