Abstract: A closed loop brain-machine interface is disclosed. The closed loop brain-machine interface translates one or more neural signals into a movement, or a series of movements, performed by a machine. The close-loop brain-machine interface also provides sensory feedback to the subject. Methods of employing the closed loop brain-machine interface are also disclosed.

Abstract: A practical control device having up to eight independent channels of communication for simultaneously operating a plurality of electromechanical devices or for simultaneously performing a plurality of independent functions on an electromechanical device, such as a prosthetic hand, includes a foot-operated controller and a microprocessor. The foot-controller includes a plurality of pressure sensors mounted at selected locations on a substrate. The microprocessor converts sensor inputs from the foot-operated controller into commands for a controllable electromechanical device such as a prosthetic hand. Commands may be communicated via a radio transmitter or via hard-wiring.

Abstract: An artificial hand includes a finger group which is pivotally connected to a thumb. The finger group and thumb are resiliently biased toward one another. The finger group and thumb have hooked articulated distal ends. When the artificial hand and the object are brought together, the finger-group and the thumb part to allow the object to pass into a capture zone. The articulated distal ends bend inwardly to assist in the passage of the object. Once in the capture zone the finger group and thumb close about the object thereby holding it is place. The hooked distal ends also serve to retain the object within the capture zone. In another aspect of the invention the finger group includes two finger subgroups which are also resiliently biased together to hold objects.

Abstract: A transcutaneous prosthesis is disclosed comprising a first component (1) shaped for implantation into a bone (2), a second component (4) intended for location between the bone (2) and the skin, and a third component (5) intended for location exterior to the skin surface, having a low surface energy which deters bacterial adhesion. The second component (4) may carry an adhesion-promoting protein.

Abstract: A soft and elastic prosthetic liner blank for customizing to an individual user is formed from thermoplastic material and molded to a hollow, generally rotation symmetric shape having at least one radial dimension. The liner blank has an open proximal end for insertion of the residuum of an amputee's arm or leg and a closed distal end, and the liner blank further having a material composition allowing thermo-forming of the liner blank while maintaining elasticity in the thermally applied shape. The radius of the liner blank is dimensioned to accommodate and to adopt, through plastic deformation, any sectional profile included in the positive copy.

Abstract: A gripper device comprising at least two portions which are coupled together and which can be moved towards one another to effect a gripping action and away from one another to effect a release action. An electrical motor is arranged to effect such movement, and a battery is connected to supply electrical current to the motor. A capacitor device is also connected to be capable of supplying electrical current to the electrical motor. A control device is arranged to cause the capacitor device to supply electrical current to the electrical motor after supply of electrical current to the electrical motor by the battery, to increase the strength of the gripping action.

Abstract: The present invention relates to a system for the control and monitoring of functional devices for the disabled with energy from outside the body, comprising actuator element(s), data-processing element(s), and control element(s) connected to the actuator element(s) to the processing element(s). The system further comprises a sensor element which is connected to the control element(s) and can transmit one or more signals for the control and monitoring of functional devices for the disabled. The present invention also relates to the procedures necessary for the remote control and monitoring of the system.

Abstract: A bandage which may be used for the forearm or as an upper arm triple traction bandage includes a bandage strap (3) that engages a ring (2) to form a loop. At least one elastic bandage strap (4) engages the ring (2) and encloses a cable (6) which at one end is secured to the ring (2) and has a fastening device at its other end (4a). The fastening device is formed by a strap connector (11, 12, 13) having a flat lower part (11) which is adapted to the strap width. The upper side is covered by a flat upper part (12) onto which a clamp slide (13) is pushed that engages under the lower part (11) and firmly presses the lower part and upper part together with the strap end (4a) lying between them. The strap connector (11, 12, 13) has a clamp-free cable passage (14, 15, 16) and a bracket (19) for securing the strap connector (11, 12, 13) to a prosthesis part.

Abstract: A golf prosthesis assisting an upper extremity amputee to swing a golf club. In one embodiment, the prosthesis comprises first and second prosthetic sockets in which the amputee's limbs are received. An extension pylon extends from the first prosthetic socket towards the golf club. The second prosthetic socket is attached to the extension pylon, thereby assisting the amputee in keeping shoulders, back and hips in proper alignment during back swing and return swing. There is also a more complete transfer of energy into the swing from the shoulders, back and legs. A wrist terminal device connects the extension pylon to the golf club. The wrist terminal device emulates cocking and release of the wrists during a conventional golf swing. The wrist terminal device provides a club holder firmly holding the golf club, and a rotary joint advantageously restrained from rotation in all but a preselected plane.

Abstract: Artificial muscle analog 1000 is located within hollow exoskeletal bone 10. Muscle 1000 comprises inflatable bladder 120, cable 130, roller 140, anchor point 150, and connection means 160 whereby said bladder may be inflated and deflated. Bladder 120 is affixed to the interior surface of said bone. Cable 130, attached to bone 10 at point 150, passes over bladder 120 and through roller 140. Cable 130, if unobstructed and taut, takes a shortest path from point 150 to roller 140. When inflated, bladder 120 forces cable 130 to deviate from this shortest path, pulling cable 130 in through said roller, under tension. In their paired opposing muscle form 2000, the artificial muscles synergistically assist each other when used in opposition. Paired muscles 2000 may actuate a robotic arm 3000, and are easily controlled by the associated simple low-cost control systems 100a,b,c of the present invention.

Abstract: It is sought to provide a body part substitute, which can be held mounted without feel of uncomfortability and be held mounted continuously for long time without possibility of occasional detachment, and a method of mounting the same. A thin film having breathable property, flexibility and extensible-contractible property is attached to the corresponding portion of the body part substitute to be held in close contact with the human body. Alternatively, the thin film is bonded to the human body, and then the corresponding portion of the body part substitute is bonded to the thin film. By preparing the thin film as a transparent film, the skin of the human body can be seen through the thin film, and more natural feel is thus obtainable.

Abstract: The present invention is directed to state-of-the-art medical devices using smart materials and related emerging technologies under development for robotics. In particular, the present invention is directed to the development of rehabilitative (i.e. prosthetic, orthotic, surgical) devices actuated by smart material artificial muscles to increase the dexterity and agility of an artificial limb or a dysfunctional body part, so that movement of the limb more accurately simulates movement of a human appendage. A kinetic assistive device is provided is provided which is constructed of a lightweight material (such as aluminum) and has a plurality of smart material actuators attached thereto. A system for detecting environmental stimulation of the device is provided in electrical communication with such actuators to effect movement of said device in response to detection signals produced thereby.

Abstract: Methods for reproducing a 3D object surface are provided. A preferred method according to this invention includes (1) identifying a real object surface, (2) acquiring at least a 3D data set with a 3D surface imaging device, (3) acquiring at least a 2D data set using a 2D surface imaging device with a surface resolution of at least about 0.1 mm2, (4) synthesizing a 3D composite data set by orienting a first virtual image of the first data set and a second virtual image of the second data set to form a composite virtual image that corresponds to the composite data set, and (5) making a reproduction of the object surface with the composite data set. Orientation of the virtual images is relative to each other and without substantial loss of surface resolution.

Abstract: A method of constructing an artificial limb from individual components comprising providing a plurality of logical unit tables (2A, 2B) arranged to contain data related to a respective class of the components, providing a plurality of component records (4A, 4B) located in at least one of the logical unit tables (2A, 2B) arranged to hold data related to a respective plurality of components of the same class providing an interface field (6A, 6B) located in each respective component record (4A, 4B) arranged to hold data related to an interface of the component to which the component record relates, selecting a component record (4A, 4B) generating a list of compatible component records from a logical unit table (2A, 2B) other than the logical unit table containing the selected component record (4A, 4B), which are compatible with the selected component taking account of the information contained in the interface fields (6A, 6B) of the selected component record (4A, 4B) and the component records in the other logica

Abstract: The present invention relates to improved controllers for externally powered prosthetic limb devices or similar extension devices such as orthotic devices or a sensor probe device. The improved controller operates a highly-efficient, compact, reliable and low-maintenance tactile force feedback system for translating a sensed pressure force from a prosthesis contacting an object or surface into a tactile sensory feedback pressure force to the user. The tactile force feedback system comprises at least one contact-responsive transducer which translates a sensed contact pressure from a portion of an extension device which contacts an object or surface into a corresponding electrical signal. The electrical signal is received by a microprocessor and processed into a proportional output voltage for producing a proportional torque from a motor.

Abstract: In one aspect, the present invention is directed to a kit for constructing a biomechanical model of a lever system selected from a first class lever system, a second class lever system, and a third class lever system, comprising a base, a support structure attachable to the base, at least one lever assembly attachable to the support structure, and at least one cord assembly attachable to the lever assembly. The present invention is also directed to first, second and third class lever system models useful for teaching and demonstration purposes.

Abstract: An arm socket and attached hand prosthesis. The socket has a gate in an anterior wall making the socket easy to put on and allowing the user to adjust the pads on the interior of the socket to changes in the shape of the residuum or the amount of padding required over a scar or bony area. The hand prosthesis includes an artificial hand and a connector. The artificial hand has a stationary jaw and a movable jaw with a slidable ratchet bar connected at one end to the movable jaw for moving the movable jaw towards the stationary jaw and at the other to a cable, a pair of pawls in mesh with the ratchet bar for holding the movable jaw in selected position.

Abstract: A voluntary closing prosthetic prehensor includes a locking mechanism which may be locked into any position, and released with a small amount of force. With locking enabled, the prehensor opens and closes normally until the user applies sufficient tension to the prehensor cable after the prehensor has closed upon an object. Then, a lever arm attached to the cable rotates, pulling a second cable which causes an elliptical cam to rotate such that its wider portion presses against a pawl, causing the pawl to rotate into engagement with a toothed sector, locking the prehensor closed. When the user releases the force on the cable, the lever arm is biased to return to its normal position, but the prehensor stays closed because the pawl remains engaged with the sector. The cam includes a ratcheting drum which takes up the slack in the second cable. To release the prehensor, the user applies a small amount of force to the first cable, moving the lever arm and pulling the second cable, which rotates the cam.

Abstract: A forearm lifter for assisting in the articulation of a mating forearm part of an arm prosthesis with respect to a mating upper arm part about at least one elbow axis is disclosed. The forearm lifter includes: (i) a spring element; (ii) a mechanism having an input and an output, with the spring element directly or indirectly applying a tensile force to the input of the mechanism; and (iii) a tension element having one end acted upon by the output of the mechanism, and having another end which can be fastened at a fixed point on said mating upper arm part. The fixed point and the elbow axis define a torque lever, such that the force that is transmitted through the mechanism from the spring element applies torque to the mating upper arm part in such a manner that the curve of the torque acting at the fixed point, plotted against the angle of articulation of said forearm part, is approximately parabolic. The torque has its minimum values in both the forearm extended position and at maximum forearm bending.

Abstract: A visco-elastic polymer liner and sleeve for prosthetic devices utilize the liner for donning over a residual limb and fitting within the socket of an artificial limb. The sleeve is rolled on over the top of the artificial limb and onto the amputee's remaining stump. The liner is shaped to have its cavity formed with a volume and shape less than a volume and shape of the residual limb for both tension and tissue configuration relief while the liner has an outer surface formed with a volume and shape greater than the volume and shape of the artificial limb socket for relief of certain tissue configurations and to create weight bearing, relief and compression areas on and in the liner to absorb and dissipate shock, shear and mechanical forces through the liner otherwise transmitted to the residual limb. The sleeve is shaped like a tube.

Abstract: A computerized electronic hand prosthesis apparatus and method utilizing input, feedback, control, and operating systems configurable to provide precise control and gripping forces corresponding to the particular capabilities and requirements of an individual wearer. An articulated prosthesis is capable of exerting a mechanical gripping force and contains a programmable microcomputer. Electrodes on the prosthesis contact muscles of the remnant portion of a limb and produce an electric command signal responsive to the myoelectric signal created by the wearer contracting and relaxing the muscles in the remnant portion. A drive motor in the prosthesis causes the prosthesis to exert a mechanical gripping force responsive and proportional to the electric command signal. Force sensors in the digits of the prosthesis detect the force exerted and produce an electric sensor signal responsive and proportional thereto.

Abstract: An artificial manually positionable elbow joint for use in an upper extremity, above-elbow, prosthetic which provides a locking feature that is easily controlled by the wearer. The instant elbow joint is very strong and durable to withstand the repeated heavy loadings encountered by a wearer who works in an industrial, construction, farming or similar environment. The elbow joint of the present invention comprises a turntable, a frame, a forearm and a locking assembly. The frame generally includes a housing for the locking assembly and two protruding ears. The forearm includes an elongated beam having a cup-shaped cylindrical member at one end and a locking wheel having a plurality of holes along a circular arc on its other end with a central bore for pivotal attachment to the protruding ears of the frame.

Abstract: A form-fitting residual limb socket or shell comprises, at least in part, a lightweight resinous material. This form-fitting residual limb socket or shell defines a mounting end and an open end. A metal-mounting member is secured to the mounting end and adapted to receive a conventional prosthetic coupling member. A plurality of metal support anchors are secured to the mounting member and extend into the resinous material of the residual limb socket or shell.

Abstract: A sensory input discrimination system for use with a prosthetic limb such as the prosthetic lower arm includes touch pressure transducers such that information regarding pressure upon portions of the prosthesis, temperature therein, and changes in position of joints thereof will result in a sonic frequencies of characteristic pattern. Such characteristic sonic frequency patterns are communicated to the sonic proximity vibratory receptors existent upon a bone stump of an amputation site correspondent to the connection of the prosthetic limb. Such receptors will resulting generate neural impulses having a signal pattern correlating to the sonic output patterns of a system power unit that will travel from the stump to the posterior columns of the spinal cord and, therefrom, to the brain. Discrimination of such impulses will be accomplished to enable recognition of pressure, upon the prosthesis.

Abstract: A prosthesis for attachment with an adjustable fitting clearance to an amputation stump in which optionally, the fit therebetween can be diminished by connectors threadably engaged with each other one thread at a time, or the fit totally released by correspondingly releasing the threaded engagment of the connectors.

Abstract: A hand prosthesis utilizing wrist movement and capable of securely grasping both large objects and small objects.

Abstract: A bi-directionally operable terminal device for an upper limb prosthesis is provided having a frame that includes a rigid finger portion which, to simulate the fingers of a natural hand, is partially curled in a manner generally corresponding in configuration and location to the normal relaxed finger condition of the natural hand; this rigid finger portion of said frame effectively constituting a first gripping jaw means. To said frame is attached a thumb-like unit that is adapted to swing towards and away from said rigid finger portion of the frame; this thumb-like unit including its immediately adjacent frame support structure effectively constituting a second jaw means. Operatively disposed between said thumb-like unit and said rigid finger portion of the frame, for bi-directional gripping movement, is the hooked forward end of a finger slide that is movably carried by said frame; this hooked forward end of said finger slide effectively constituting a third or central jaw means.

Abstract: A device that is pivotally mounted to a socket of a prosthesis has a top part that bears against the residual limb above a bone to suspend the socket from the limb. As the knee is bent, the device pivots about its pivot point and therefore remains in contact with the limb throughout the entire range of motion of the limb so that the socket does not come off. A convexity is formed in the top part of the device, and that convexity bears against the residual limb just above the medial femoral condyle. Another curvature in the top part allows it to at least partially extend around the medial part of the residual limb. The device is substantially rigid but flexible enough to allow it to conform itself to the contour of the residual limb so that the device will fit numerous individuals having differing bone structures. Use of the device eliminates the need to form the convexity into the socket itself.

Abstract: Attachment devices for joining endoskeletal, prosthesis to prosthetic sockets on a person's stump are disclosed. The couplers have a peripheral notch on their side surfaces which define a void into which material can be molded to effectively secure the coupler to the socket. A depression is provided in the top surface of the device to facilitate fitting to a prosthetic socket.

Abstract: A prosthetic limb (10) for a below-the-elbow amputee is constructed having a removable effector (16) removably mounted in a mount (18) having semicircular bands (20) set by "hand lapped" construction in sides of a body (12) near a closed end (22) thereof. The effector (16) is offset from the body (12) and is provided with supports (60, 62), each having a C-shaped slot (64, 66) for receiving a horizontally oriented bar, such as that on a chainsaw. A pair of semi-circular gripping members (68, 70) are pivotally mounted by pins (72, 74) near a closed end of the slots (64, 66) and are biased closed by a C-shaped leaf spring (90) disposed about an outer periphery of the members (68, 70).

Abstract: A covering device for a jointed artificial limb includes a covering layer covering the artificial limb. The covering layer can be made of semirigid PU foam. The covering layer has a screen-like flexible portion adjacent to the joint of the artificial limb. The flexible portion includes a plurality of slits.

Abstract: This invention relates to an improved construction and arrangement for a hand prosthesis wherein cooperating finger-like and thumb-like units are adapted to be yieldably biased towards a closed condition and are capable of being opened simply by pressing the prosthesis against an external object for reception of an item to be held. In operation one or both of the finger and/or thumb-like units are adapted to conform to the general profile of the contacted surfaces of the item to be grasped. Further a normally inoperative supplemental gripping force generating means is provided which is capable, when actuated, of applying a large separate additional gripping force over and above that which is normally applied by the said yieldable biasing action. Also one of said units is adapted to be selectively positioned in at least two different fixed positions relative to the other unit in order to make possible the gripping of different ranges of sizes of items to be held.

Abstract: A prosthetic device for duplicating biomechanical action of the human body is disclosed. The device is mountable on a prosthetic appendage such as a prosthetic arm and is particularly suited for use in vigorous activities such as athletics and the like. Various embodiments of the device including a flexible prosthetic hand, a flexible prosthetic joint module and a prosthetic shock absorber device as well as various modifications and combinations thereof are described.

Abstract: An apparatus is arranged for slidingly mounting over an individual's natural limb to include a tubular sleeve member, including a hand portion mounted at a forward end thereof. The sleeve member is arranged to include an inner and outer tube, with the outer tube of porous construction to excrete an itemized fluid perfume mixture directed into pneumatic chamber defined between the inner and outer tube of the organization. A pump member is arranged to direct the itemized fluid through a fluid conduit into the chamber.

Abstract: An artificial nail includes an acrylic top layer mounted on a collagen support layer in the form of a mesh. The proximal end of the nail includes a plurality of anchor points, preferably three semi-circular anchor points. The proper size nail is selected by use of sizers. The toe or finger is prepared for implantation of the artificial nail by a puncturing tool which has a pattern of tines on its flat base.

Abstract: A modular dexterous grasping hand comprises three rotatable fingers mounted on the mounting plate of a Stewart platform for rotation about parallel axes extending perpendicular to the mounting plate. The fingers have a generally L shape so that the grasping elements at the distal ends of the fingers are spaced from the rotational axes. The grasping elements can thus be positioned along the arcs of circles centered on the rotational axes, and so form grasping triangles of variable shapes and sizes. The fingers are independently driven by motors mounted to the mounting plate. Positional encoders and pressure sensors may be included in the motor drive control system.

Abstract: A planetary friction transmission, especially for miniature application as in prosthetic joints and the like, has cylindrical periphery planet wheels pressed by a stationary ring against a conical portion of the drive shaft, the ring being axially shiftable relative to the shaft and on a support. The planet carrier is connected to the planet wheels by pins which extend into the holes of the planet wheels with play.

Abstract: An artificial hand has its finger gripper swingable about an axis which includes an angle of 30.degree. to 70.degree. with a plane normal to axis of a prosthesis connector and its fingers inclined at an acute angle to the finger carrier to provide a more natural orientation of the hand for picking up objects at pick-up surfaces located above a support surface for the object.

Abstract: The present invention is a prosthetic prehensor with two members extending in the same direction. One of the members rotates about a parallel axis removed from the first member until it contacts the first member. In the preferred embodiment, the two members are curved plates, one simulating a thumb and the other being wider and simulating a palm. The thumb plate rotates around a base plate which is coupled to the end of an arm. The thumb plate can contact the palm plate in either of two directions. This allows two types of gripping for fine objects and larger objects. The use of plates that are curved allows for a more aesthetic design than metal hooks.

Abstract: This disclosure describes a wrist capable of the range of motion and function of a human wrist, composed of a basic ball and socket joint, with the ball portion segmented vertically into as many flat portions as there are fingers to allow the first segment of each finger to attach to each ball segment, allowing independant up-down motion of the fingers, while retaining dependant motion of the fingers in the back-and-forth direction.

Abstract: A sleeve member (1) for enclosing and being fixed to a body part, such as an amputation stump, has a substantially frusto-conical shape with the truncated end thereof completely closed and at least slightly rounded and is made of an airtight material. The sleeve member (1) is characterized in that it substantially is made of an elastic material, at least the distal portion thereof exhibiting such anisotropy with regard to the elasticity that it has a relatively high elasticity in a radial direction and is substantially inelastic axially.

Abstract: A prosthesis drive, especially for a hand prosthesis, can rapidly approach the grippers until resistance is sensed and then apply an increased force to the object. For this purpose, two electric motors drive selectively the respective planetary gearing in an arrangement in which the planet wheels of the two gearings engage a common gear between the sun and ring gear of one planetary gearing or the sun and ring gear of the other planetary gearing, the gearings being coaxial with one another and with the motors. A circuit responding to an increase in the current of the high speed motor above a threshold value is provided to control the switchover.

Abstract: A prosthesis sleeve for attaching a prosthesis to a partially amputated limb of the body which is made of an elastomeric material which may have a tube shape and having concentric annular ribbing on an inside surface of one end to engage the remaining portion of the limb, thereby creating a suction-type seal therebetween to suspend the prosthesis. Another end of the sleeve has a smooth inside surface which engages the prosthesis forming a seal therebetween. The combination of seals creates an air tight junction and secure attachment of the prosthesis to the limb for rigorous activity such as athletics for persons requiring prostheses.

Abstract: The invention embodies the construction and implementation of synthetic muscle elements into numerous prosthetic devices. The aforesaid synthetic muscle elements consist of piezoelectric Gels; which function to motivate artificial limbs, rotate artificial joints, institute peristaltic motion in synthetic muscle systems and perform other activities consistant with the operation of organic muscle tissue. Sensory elements and ancillary systems embodied within said synthetic muscle means are responsive to evoked potentials generated by the neurons or other impulse conducting structures of the user. The aforesaid synthetic muscle has the additional capacity to sense, measure and act in a compensatory fashion to adjust their operation to biochemicals emitted by the user including, neural humoral secretions, endocrine levels, the formation of metabolites and the tension or partial pressures of gases such as CO.sub.2, O.sub.2, or other substances.

Abstract: The function and advantages of a split hook and a mechanical hand are combined into a single unit obviating the complex and difficult process of interchanging hook and hand units while at the same time providing the dexterity of a hook for grasping and manipulating small objects and the prehensile function of an operable locking thumb including extending holding times without the need for cable manipulation. Covering the split hook members with finger-shaped material and adding rigid fingers enhances the cosmetic appeal of the unit.

Abstract: Reconstructive orthopedic prosthesis devices for cadavers comprised of plastic tubing, elbows and fasteners, for use by undertakers and morticians. The devices are used in cadavers whose bones have been harvested for bone banks, in order to give the cadaver a normal appearance.

Abstract: An inner hand as an orthopedic fitting part of thermoplastic for accommodating a hand mechanism is disclosed. The inner hand has an annular groove which is made on the end portion of the hand and into which a ring which fixes the inner hand on the hand mechanism is inserted. To improve the functioning of the inner hand, a two-component sandwich design is proposed, the utilization region of at least the thumb and index finger being harder than the remaining hand element.

Abstract: The present invention relates to an integral elastic suspension sleeve for use with an artificial limb prosthetic device. Specifically, the invention is an integral flexible elastic support sleeve having two circular ends which encloses and securely grips the residual lower extremity portion of a human being who has had a below the knee (or below the elbow) amputation and also encloses and securely grips the top outer surface of the socket of a shin and foot (or forearm and hand) prosthetic device. The suspension sleeve has a smaller internal cylindrical-like panel which has a fabric surface having a low coefficient of friction. This fabric surface is in contact with the outer intersection line between the prosthetic device and the limb extremity of the human being. This sleeve is at between about 5.degree. and 45.degree. angle, and the described configuration results in improved mobility, decreased dermatological irritation to the wearer and enhances the longevity of the elastic suspension sleeve.

Abstract: The invention relates to an artificial hand or prosthesis with a carcase, a palm and a finger pair, a thumb and a link (20). Distinguishing for the invention is that the movement pattern of the thumb in relation to the movement of the finger pair, the pattern being provided by the palm on which the thumb is rigidly attached being pivotably connected to the carcase about a wrist turning point (B) and by the finger pair being connected to the palm via the finger joint turning point (A). A link mechanism comprising four joints (inter alia 29, A, B) controls the gripping movements of the prosthesis, and is driven by an electric motor located in the palm in the preferred embodiment.

Abstract: A sensory input discrimination system for use with a prosthetic limb such as a prosthetic hand having five digits. The discrimination system includes pairs of sonic frequency generators in electrical communication with pressure transducers which are disposed proximally to each other and within the extremity of corresponding digits of the prosthetic hand, the frequency generators having discrete sonic frequencies. The electrical communication between each frequency generator and the pressure sensor is open in the absence of contact pressure, and closed in the presence of contact pressure. Such closure generates a discrete sonic frequency output from the digit to which the contact pressure has been applied. In the prosthesis, a power unit amplifies the frequency outputs and provides power for the operation of the frequency generators and pressure transducers. The power unit exhibits an output including a voltage and a sonic frequency.