The MJS system is the grassroots model of the line Multi Joint System. Like every models of the line MJS, the system 401 is geared with an anthropomorphic mechanic arm with a three-dimensional movement placed in parallel with the patient's arm. The load component is managed by a only power regulator ( unlike the model MJS 403 P which has three independent power regulators).
The arm of the Multi-Joint System, that is positioned so that it is parallel to the patient’s limb, is actually a good and proper anthropomorphic arm, engineered according to the principles of cybernetics. As it is provided with four “freedom” ranges, this mechanical arm gives the patient freedom of jointmovement in a three-dimensional joint-space. Simultaneously, every single movement is detected. As in the past, the patient is required to follow predetermined trajectories on a computer screen in order to be able to explore the most complex joint movements but, in addition, the movements will be traced and recorded for subsequent assessment and comparison with a set of reference indexes, that will help the operator to build up a correctly personalised rehabilitation protocol.
The three fundamental axes of movement (Anterior-Posterior, Adduction-Abduction, Internal rotation-External rotation) are much too important to be controlled and adjusted with the same force intensities. The muscles that are responsible for the anterior- posterior movement of the shoulder, such as the deltoid or the biceps brachii muscle, develop a force that is by far inferior compared to the muscles that are responsible for Adduction- Abduction movement (e.g. the pectoralis major muscle). Therefore, in order to differentiate the intervention modes on the different muscle sections correctly and also in order to expand the MJS implementation potential, the MJS has been provided with three, completely independent force control and adjustment units. One unit is for Anterior-Posterior movements, one is for Adduction-Abduction movements and, finally, one is for Internal rotation-External rotation of the shoulder. For monitoring completeness, without any compromise to the perfect control of motorial exercises.
MJS has three different force controls taht allow to change the force: Force 1 changes the resistance in horizontal flex extension, Force 2 changes the resistance in anteposition elevation (Light-G) and Force 3 changes the resistance in intra extra rotation. The three forces are bidirectional, in fact they can be helpful, neutral or in against-resistance.
The Light-G function is also particularly useful as it relieves the joints of the weight of the arm. When in Light-G mode, the system gently and gradually thrusts upwards, enabling the patient to work even during the acute phase.
This rehabilitation method is often used in water too, where the patient is subject to a hydrostatic thrust exerted by the submersion of the body.
The MJS system uses the same principle to help the operator regulate the necessary articular load with extreme sensitivity and precision in relation to the muscular intervention requested for the patient.
For a good stability it’s necessary to restore an equilibrium between the extra and the intra-rotary musculature. Bend the injured arm to a corner on 90 degree and using the F3 engine it’s possible to set a training of this delicate muscular area in a very gradual and precise way.
The software of the system allows to show several information like the dynamic R.O.M., the number of the sequences, the angular speed and many other information.
MJS is equipped with a button of pain signaling. During the test execution the patient can signal the pain of the under consideration arm and the software will register immediately this information in real time. The therapeutic and evaluative aim is to recall the same test in the aftermath and repeat the test, verify if the patient feels pain again in the same position.
The system foresees an inertial sensor for the movements control of the patient's arm. It can be single (arm) or double (arm and forearm). In the first case it is possible control all the shoulder movement, in the second case also the prono-supination of the wrist and the flexion of the elbow and the hand pressure, useful for the occupational therapy. The advantage of this device is the free movement of the limb, untied from the system anthropometrical arm.
The MJS system has the possibility to use the electromyography, synchronized with the limb movement, to allow the assessment of the muscular activation. It has four canals and it connect itself to the PC by Bluetooth.
The occupational therapy with MJS 614 P is possible thanks to a sensor of pressure that assess the pressure which is set by the patient's hand, allow to catch the virtual object.
Different from the MJS 614, this system foresees also the wrist prono-supination control. Thanks to a ferrule you can either lock the wrist in specific angular positions.
|PC control with display 20"|
|Anthropomorphic arm with three degrees of freedom|
|Electro-pneumatic system for power adjustment in a differed way (F1 – F2 – F3)|
|Horizontal and vertical adjustment of the sitting|
|Elbow support for exercise in intra-extra rotation|
|Dimension||L: 2000 mm D: 1100 mm H: 1600 mm|
|Elevation range||0 - 180 °|
|Horizontal inflection extension range||-45 / 120 °|
|Intra-extra rotation range||-90 ° / 90°|
|Prono-supination range||-90 ° / 90°|
|Angular adjustement||0.1 °|
|Power modulation||On three movement axis with an electro-pneumatic system|
|F1 - Inflection-extension||50 Nm (100 PSI)|
|F2 - Elevation||50 Nm (100 PSI)|
|F3 - Intra-extra||30 Nm (100 PSI)|
|Adjustments||Adjustment function of the articular load|
|Functions||Pain button, button for the activation of the loads , hand pressure module (MJS614P)|
|Trunk inclinations (MJS614P)||
Flex-extension -30° +30°, lateral -30° + 30° resolution 0.1 °
|Sampling frequency||20 hz|
EN 60601-1 III ° edition
After an initial assessment phase, the MJS system enable the operator to select specific “Rehabilitation Tracing” functions, that can make the “Global” rehab approach considerably easier.
As in the past, the operator here can design some specific tracings of movement on the computer screen, in a completely free and threedimensional way.
In this way the patient, comparing in real time the right track with that of the reference ,It has a powerful feedback that can help in the refinement of their motor gesture.
The Assessment Module provides for threedimensional exploration of the shoulder, related to the range of motion that is detected. The test gives the operator a set of indicators such as proprioceptive sensitivity, joint mobility or the developed strength in isometric mode.
This program module gives a clear and legible display of the three-dimensional movement of the shoulder, either in flat-view mode, in graphic mode or in anatomic mode.
The fact that during the joint exploration process the patient has the option of signalling the points of pain by pressing on the “pain pushbutton”, is particularly useful. The coordinate data of the points of pain are stored by the system and can be accessed at later dates for further verification.
The Rehabilitation Tracing module is also particularly useful both for correct proprioceptive training sessions and for accurate, local assessments.
The coloured spheres represent the compulsory or enforced transit points (Joint Position Sense), whereas the red line represents the ideal kinaesthetic path.
The program provides continuous display of the gap between the ideal kinaesthetic line and the patient’s trace line. In this way, the patient’s proprioceptive sensitivity is quantified.
This programme reconstructs everyday environments virtually and gives the patient a chance to concentrate on overall motor function as opposed to individual movements. The programmes also allow significant motivational involvement by noticeably accelerating and improving the rehabilitation process.