Final Flashcards
What’s the function of the fair-lead cable?
Allows it to control multiple functions
Used for elbow flexion/ opening and closing hook
Where is the Fair-Lead cable split?
Split at the elbow
Since the housing is split the tension on the control cable flexes the elbow when elbow is _________ and opens the TD when elbow is ___________.
Flexes elbow when elbow is unlock
Opens TD when elbow is locked
What is required when the elbow flexion attachment point is close to the mechanical elbow axis?
Less cable excursion required to make it work
More force required
What is required when the elbow flexion attachment point is far from the mechanical elbow axis?
More cable excursion required
Less force required
Where should the elbow flexion attachment point be placed?
1 1/4” distal to elbow axis
1” anterior to elbow axis
How much excursion is required for a Transradial?
5cm (2”)
How much excursion is required for a trans humeral?
11.3 cm (4.5”)
What are the components of a figure 8 harness?
A. Axilla loop B. Anterior support strap C. Lateral support strap D. Control strap E. Elbow lock control strap
Where is the cross point located?
Just to non-amputated side
Distal to C7
Axilla loop
Anchor for other harness components
Some straps attach for suspension
Some straps attach for control
Attaches to the cross point
True or False
The northwestern ring is used less frequently for TH as it gives too much freedom - lose excursion
True
What is the anterior support strap also known as?
Elastic suspension strap anterior suspension strap
Where is the anterior support/suspension strap located?
Originates at cross point
Crosses through delto-pectoral groove
Attaches in the distal anterior humeral section
Elastic distal 2/3
What is the purpose of the anterior support/suspension strap?
Helps suspend prosthesis (limited due to elastic)
Helps prevent external rotation
Helps “cock” the elbow lock
Where is the elbow lock strap located?
Originates on the upper non-elastic portion of the anterior support strap?
The elbow lock strap requires how much excursion?
1.3 cm
Where is the lateral support strap located?
Originates just posterior to the highest point of the Axilla strap
Stitched to the anterior support strap
Lateral end passes just anterior to acromion
Attaches close to proximal socket trim line
What does the lateral support strap do?
Suspends
Helps limit external rotation when control cable engaged
Where is the control cable located?
Originates at the cross point
Runs obliquely downward across the back, mid scapula
What happens when the control cable is too high?
Not enough cable excursion to operate elbow and TD
What happens when the control cable is too low?
Requires too much force to operate
What is the purpose of the cross-back strap?
Helps reduce the vertically directed force of the axillary loop
Helps prevent superior migration of cross point -keeping inferior to c7
Helps keep the control cable in the mid-scapula position
True or false
The shoulder saddle harness is more challenging due to the required need for excursion in trans humeral
True
When should a shoulder saddle harness being used?
Can be used if really need to distribute the forces caused by unusually heavy use
What is the type of harness used for bilateral transhumeral harnessing?
Figure 8 harness without axillary loop
Cross back strap is essential for bilateral TH
Over the shoulder strap- stitches to control strap, lateral strap and anterior support strap
What are the Trans humeral control motions?
Gleno-humeral flexion
Bi- scapular abduction
What are the elbow lock control motions?
Slight glenohumeral extension
Slight Gleno-humeral abduction and
Slight shoulder depression
What are the control motion for shoulder disarticulation?
Bi-scapular abduction
Best harnessed by chest strap
Where is the chest strap located?
~Buckle an anterior surface of shoulder cap
~Runs horizontally across chest
~Runs inferior to the Axilla of non amputated side
~Terminates Posteriorly on the proximal end of the elbow flexion/terminal device control cable
Where is the elastic suspension strap located?
~Posteriorly attaches to the horizontal strap about midline
~Passes over the shoulder along a diagonal path
~Anteriorly attaches to the proximal surface of the socket shoulder cap
What is a excursion Amplifier?
Provides increased excursion
Bi-scapular abduction has good power but little excursion
Where is the excursion amplifier located?
~Control cable originates posterior surface of the socket.
~Passes through a small pulley that is attached to the posterior horizontal harness strap via a hanger
~cable enter the proximal opening of the split housing
2.5 cm bi-scapular abduction produces ____cm excursion
5cm
Requires increased force
The external friction (w/o rotation unit) provides what?
Provides constant friction
Positioning in elbow flexion/extension
Who is the external friction (w/o rotation unit) indicated for?
For someone who can’t learn lock/unlock action
What is a disadvantage of the external friction (w/o rotation unit)?
Won’t hold position for heavy objects
Adds ML bulk
What does the internal friction (w rotation unit) provides?
Adjustable constant friction flexion/extension, IR/ER
Who is the internal friction (w rotation unit) indicated for?
For someone who can’t learn lock/unlock action
What is a disadvantage of the internal friction (w rotation unit)?
Won’t hold position for heavy objects
Less bulky than external joints
Where is the external locking joint located?
On medial side
Following joint lateral
The Hosmer small, medium, and large have how many locking positions?
7 lock positions
The Hosmer heavy duty has how many locking positions?
5 lock positions
Alternating one pull lock, one pull unlock
Where is the external locking forearm lift assist located?
On lateral side
Which of the following apply to the external locking joint? Small
A. difficult for children under 5 to operate
B. Decreased power and excursion
C. Complicated to learn at that development age
D. All of the above
E. None of the above
D. All of the above
Where is the Otto Bock external locking joint located?
Locking joint on medial side
Following joint lateral
Less bulky than Hosmer
What is an disadvantage of the Otto Bock external locking?
Can’t use the Hosmer lift assist on lateral
How many locking positions does the Hosmer small (child) internal locking have?
10 locking positions
Called E- 50
How many locking positions does the Hosmer medium internal locking have and called?
11 locking positions
E- 200
How many locking positions does the Hosmer large internal locking have or called?
11 locking positions
E-400
How many locking positions does the Hosmer large heavy duty internal locking have or called?
8 locking positions
E- 400
What classes of the TH is the Hosmer internal locking joint used for?
For class II and III
What does the forearm lift assist?
Counter balance the weight of the TD and other objects
Allows you to adjust the cabling to increase ROM
Lateral side- Adjustable tension
What is a advantage of the X- Finger?
Great ROM
What is a disadvantage of the X- finger?
Insecure hold ( purchase) Long wait
What is an advantage of the BPF (finger)?
Decreased ROM
What are the three types of trans-phalangeal mechanical fingers?
X- finger
BPF
M-fingers
True or False A myoelectric prosthesis functions when a patient generates a voluntary muscle contraction to create an EMG that can be read by an electrode
True
True or False
EMG travels in the direction of the muscle fibers. However, it Is not necessary for the contact points of the electrode to be aligned in the direction of the fibers to achieve an optimal signal
False
An electrode performs 3 functions to an EMG signal. What are they?
Amplifies, rectifies and filters
What psychological activity or signal is measured or detected by the electrode?
Action potential
Which one of the statements below is correct?
A. All ottobock electrodes have 3 main components
B. 2 differential inputs (one at each end)
C. A center reference input or ground
D. All of the above
D. All of the above
How much signal is required to operate a Digital hand at full speed?
A “high” level signal, any signal just above the “on” threshold & 0.54V
How much signal is required to operate a DMC hand at full speed
A high level signal, the maximum signal the system can read & 1.5V
True or false
An amputee controls grip force in a digital hand by maintaining a signal above the “on” threshold until the desired grip force is achieved?
True
What does the “first signal wins” principle in myo-testing mean?
Whenever two signals are generated simultaneously, the first signal to cross the “on” threshold is the “winner”, only the winning signal is allowed to operate the system; all other signals are ignored.
True or false
The goal of myo-testing is to find the strongest signal available then, amplify it as necessary to get the signal as close to the “high” classification as possible ?
True
True or False
It is safe to charge a lithium ion battery when it’s not completely charged?
True
True or false
It is safe to charge a NiMH battery when it’s not completely charged?
False
True or false
Each time the myo-Select tool is used to adjust the hand, it is reset to the NiMH technology?
True
Identify the appropriate scenarios from the list below in which you could use a switch?
A. When you need to use switches to introduce additional inputs for higher levels of amputation
B. Immediately postoperatively w/an externally powered prosthesis by combining the switch with a harness
C. When the patient has no detectable EMG signal
D. When a patient is transferred from a body-powered to an externally powered system
E. All of the above
E. All of the above
When you need to use switches to introduce additional inputs for higher levels of amputation;
Immediately postoperatively w/an externally powered prosthesis by combining the switch with a harness; When the patient has no detectable EMG signal; When a patient is transferred from a body-powered to an externally powered system
When would you use a linear transducer?
Linear transducers replace a single electrode; when you need to allow for proportional control; when you need to combine a linear transducer with an electrode site can be found
Which linear transducer is more robust and more resistant to damage?
9 x 52
Which linear transducer is more suitable for retro-fitting?
9 x 50
True or false
The Myoselect can be used to program all ottobock programmable components.
False
True or false
After making all programmable changes using the Myoselect, you know that all changes are set when you hear an audible beep after holding the jog dial in
True
What functions are performed by the Myoselect?
It automatically returns components to NiCd and NiMH battery mode; choose a program option from available program options for a component; adjust settings (maximum, speed, thresholds)
Identify the appropriate scenerios in which you could use a switch?
A. When you need to use switches to introduce additional inputs for higher levels of amputation
B. Immediately postoperatively w/an externally powered prosthesis by combining the switch with a harness
C. When the patient has no detectable EMG signal
D. When a patient is transferred from a body-powered to an externally powered system
True or false
Due to their ability to monitor and optimize power management, microprocessors are able to increase the operating time of a prosthetic system.
True
True or false
Closed loop control of all components is made possible by microprocessors which enable improved efficiency and support more smooth and natural movements with the prosthesis
True
Microprocessor control is unable to over-ride electromagnetic interferences in the environment
False
True or false
The DMC plus feature of the SensorHand speed is a built in safety feature that prevents the prosthetic hand from inadvertently opening and losing grasp of an object.
True
What type of control is available in the SensorHand speed?
Proportional control and digital control
How does the clinician decide which SensorHand speed program should be used to achieve maximum benefit and performance for the patient?
The clinician need to combine knowledge of the patients EMG signals with the type of input device they intend to use before determining which program to use
For the SensorHand program numbers in the left column, select the corresponding number of inputs required from the right hand column?
Programs #’s 1, 2, 5, & 6 = 2 inputs; programs #3 & 4 = 1 input
The device used to control the SensorHand speed’s 6 programming options is the Myoselect ?
True
SensorHand speed has the following unique features
Autograsps, ability to activate and de-activate the thumb & flexi-grip
How can you tell by looking at the hand whether or not you are holding a SensorHand speed?
The coaxial ring is always orange
True or False
All programs in the Greifer and Myohand vs variplus speed offer proportional control for both speed and grip force
False
True or false
You can adjust the speed of the Greifer
False
True or false You can adjust the speed of the Myohand variplus speed?
True
Which switching method offers immediate control of either the wrist or hand?
Program #1 (Channel control)
Which kind of control does the MyoRotronic offer for wrist or hand?
Both proportional and digital
True or false
It is possible to control hand open/close and supination/ pronation with only one electrode
True
True or False
The automatic switchback timer caused function to switch from the rotator to the terminal device. The timer only works from hand to rotator, not rotator to hand
Fals
Identify a fitting challenge that could best be addressed by the trans carpal hand
The patient presents w/a short limb
Under what conditions would you use a 13E180 switch block
Used for wired hands
What control options are available for the transcarpal hand or a size 7 hand?
DMC & digital
How many versions of pediatric limb systems are available from ottobock?
Two
Which children’s system uses the MyoEnergy integral Lilon battery system?
7.4V
Identify the improvements the 7.4V children’s system has over the 4.8V children’s system?
The 7.4V children’s system can be adjusted using software and Bluetooth connection to optimize these system for the users needs; the 7 in 1 controller system has up to date electronic components which reduces the size of the unit; the 7.4V children’s system allows for battery installation within the prosthesis to reduce bulk and improve cosmesis
Which electrode should be used in a child’s hand system?
13E202 suction electrode= when the patient presents enough residual limb volume, length, and circumference; 13E200 standard electrode= when the patient presents very small limbs! small radii, or insufficient space
True or false
The Myoselect can be used to change the programs in the Ergoarm 12k50
True
Of the 7 programs available for use with the ErgoArm, programs 1(uses an external switch to lock and unlock the elbow) and 2 (uses co-contraction of the patients EMG signals to lock and unlock the elbow) are the most commonly used programs
True
True or false
The adjustable forearm Balance (AFB) should be adjusted by the prosthetist only?
False
True or false
The automatic forearm balance (AFB) is a complex mechanism that allows for varied flexion assistance and resistance throughout the range of elbow joint motion
True
True or false
Proportional control of the elbow, wrist and terminal device is possible with the dynamic arm
True
True or false
The “elbow soft) software program is the only means of programming the dynamic arm
True
What is the maximum live lift capacity of the dynamic arm?
13.2 lbs.
True or False
Simultaneous control of the elbow and either the hand or rotator is possible through programming the dynamic arm
True
True or false
To lock or unlock the dynamic arms elbow joint, a separate signal is needed?
False
What is the movement range of the dynamic arm?
15 degrees - 145 degrees
When does the dynamic arm need to be switched off ?
When exchanging the terminal device; when donning and doffing the dynamic arm; when not in use; when dismounting the dynamic arm from the socket
What happens if the locked dynamic arm measures a positive load greater than 6kg or a negative load greater than 1kg and a control signal to flex/extend the elbow is sent?
The elbow will not unlock; a warning beep and vibration will be emitted
True or false
Mechanical locking and unlocking is only engaged when the dynamic arm is turned off, or when the power down sequence has started
True
True or false
Locking of the elbow is carried out automatically after elbow movement and unlocking is carried out automatically before elbow movement
True
What steps should you follow in adjusting the automatic forearm balance (AFB)
Flex the elbow fully then turn the finger wheel in a clockwise direction; the AFB is adjusted correctly when the elbow can be held at 90 degrees
True or False
The linear transducer can be used to directly control the movement of the dynamic arm in combination with another input device to control the movement of the terminal device, thus allowing simultaneous control of the elbow and terminal device
True
True or false
All input devices for the dynamic arm will be plugged into one of the ports on the easy plug connection and are opposite for right versus left.
False
What are the characteristics of the harness, cable, rocker, and pressure switches
Provide digital control of the component; produce maximum signal when activated; most often used for sequential switching
True or false
All components and tools needed to assemble the dynamic arm are included in the package, including the terminal device and the electric wrist rotator?
False
True or false
When aligning the dynamic arm to the check socket with the alignment tool, the elbow turntable must be horizontal to the floor to ensure proper elbow function.
True
What is the correct procedure for calibrating the dynamic arm?
Manually flex forearm once just short of the flexion stop and manually extend forearm until reaching the extension stop; after manually extending the forearm to the extension stop, click the “end calibration” button
How do you activate “training mode” for the dynamic arm?
Switch over to training mode by Unchecking the box beside “active mode”
True or false
By default the dynamic arm is delivered with the maximum speed set at 31%
True
True or false
After loading the control and switching parameters of one of the 9 standard programs into the dynamic arm, you still have the opportunity to further customize the programs
True
What steps do you take to program the dynamic arm for simultaneous control?
Choose 1-POS for the control mode in the elbow column; check the box beside the word “ simultaneous”
What are the recommended steps to charge the dynamic arm?
Extend the dynamic arm, switch if off and lock the elbow; connect barging plug to charging port of the dynamic arm, then connect power cable to power outlet
True or false
When the charger is connected to the dynamic arm the elbow will not move and will be locked, but the terminal device and rotator remain active
False
True or false
The battery management system monitors battery capacity and initiates a power down sequence, beginning with the dynamic arm
True
True or false
You will hear an acoustic signal when the dynamic arm is turned ON and OFF
False
True or fAlse
If you turn the dynamic arm On after the charging port, you will hear an acoustic signal.
True
