The invention relates to an instrument for the manipulation of fine structures, said instrument detecting hand tremor and compensating for this hand tremor by effecting counter-movements of the working tip. The main area of application will probably lie in the field of microsurgery, since the operations performed in said field can be made difficult by the hand tremor of the operating surgeon. Here, the tremor is detected by movement sensors, by repeated analysis of the position of the handheld part ( 1 ) of the instrument, or by deriving electromyographic signals from the forearm of the operator. Intentional and unintentional movements are differentiated from one another on the basis of one or more criteria, such as movement amplitude, speed, frequency and direction. To compensate for undesired movements, signals are sent to an arrangement of actuators ( 3 ) which cause deflections of the movable part ( 4 ) of the instrument, which deflections at the tip of the instrument compensate for the hand tremor. When the instrument is used as a needle holder in surgery, the actuators ( 3 ) can also be controlled by push button in such a way that, by oscillations, they facilitate the penetration of the suture needle into the area being worked on.

Instrument for compensating for hand tremor during the manipulation of fine structures

Apparatus for reducing acoustic background noise for use with a telephone handset (10) or a boom microphone device (100) or a boom headset (401) or the like. The apparatus includes first (12) and second (14) microphones which are arranged such that the first microphone (12) receives a desired speech input and the background noise present in the vicinity of the speech, and the second microphone (14) receives substantially only the background noise. The background noise from the second microphone (14) is converted into a corresponding electrical signal and substracted (16) from a signal corresponding to the speech and background noise obtained from the first microphone (12) so as to produce a signal representing substantially the speech.

Noise cancellation apparatus

An active vibration isolation system (10) includes a plurality of stiff actuators, such as piezoelectric motors (12a-c; 284, 350) which support a small mass (18) inside of a case (300). A passive isolator (20) is interposed between the small mass (18) and the payload mass (Mp). In the instance where the stiff actuators are piezoelectric motors, the sidewalls of the case (300) are used to provide compressive force along the variable length of each of the horizontal piezoelectric motor elements (284, 350) to prevent damage to same. Compensation circuitry (24) is connected between velocity sensors (17) and the stiff actuators to control the variable length thereof in this move-out-of-the-way system (10) and to compensate for resonating modes. Optionally, a payload mass velocity sensor (26) and associated circuitry may be used to provide additional control. Shear decouplers (282a-c; 352, 360) are used in conjunction with the piezoelectric motor elements (12a-c; 284, 350) to minimize the amount of shear force acting on the motor elements.

Stiff actuator active vibration isolation system

A sensor array (10 sub.1-N) receiving system which incorporates one or more filters (16 sub.1-N) that are capable of adaptive and/or fixed operation. The filters are defined by a multiple of coefficients and the coefficients are set so as to maximize the signal to noise ratio of the receiving array's output. In one preferred embodiment, the filter coefficients are adaptively determined and are faded into a predetermined group of fixed values upon the occurrence of a specified event. Thereby, allowing the sensor array (10 sub.1-N) to operate in both the adaptive and fixed modes, and providing the array with the ability to employ the mode most favorable for a given operating environment. In another preferred embodiment, the filter coefficients are set to a fixed group of values which are determined to be optimal for a predefined noise environment.

Super directional beamforming design and implementation

A vibration control system comprising an actuator, and a sensor useful for controlling vibrations in systems for fabricating electronics equipment The actuator may comprise one or more plates or elements of electroactive material bonded to an electroded sheet

Method and device for vibration control

A method of and a system for active vibration control of an extended mechanical structure having a point or region at which unwanted vibrations are to be reduced or suppressed, wherein a plurality of uni-axial inertial actuators (4, 5) are disposed to act on a rigid intermediate part such as a flange (1) attached to the point or region of the structure. The actuators may be controlled by an electronic controller (35, FIG. 3) to which are fed control signals from accelerometer sensors (27, 28) adjacent the flange (11).

Active vibration control

A method of and system for active vibration control in an elongate member such as a pipe (2), wherein an actuator which comprises at least one constrictive element (3) capable of changing its length is attached between flanges (1) spaced along the member and is controlled to produce deformations of the member which inhibit the transmission of unwanted vibration from the member to one side of the attached actuator to the other side.

Mark Francis Lucien Harper

Papers

Active vibration control

Active control of vibration