Abstract: Apparatus for measuring forces on a load-carrying element comprises optical sensors mounted to the load-carrying element. Each optical sensor includes a light source, a photosensor and an opaque mask positioned in a light path between the light source and the photosensor. The mask has a window that is movable relative to the photosensor and is located such that light from the light source that passes through the window forms an illuminated region on the photosensor. Each of the optical sensors has a first part which includes the light source and the photosensor that is coupled to the load-carrying element at a first location and a second part that includes the mask that is attached to the load-carrying element at a second location spaced apart from the first location.

Abstract: Apparatus for measuring forces and/or moments on a load-carrying element comprises plural optical sensors mounted to the load-carrying element. Each of the optical sensors includes a light source, a photosensor and an opaque mask positioned in a light path between the light source and the photosensor. The photosensor comprises first and second light sensitive elements separated by a boundary. The mask has a window that is movable relative to the photosensor and is located such that light from the light source that passes through the window forms an illuminated region on the photosensor. The illuminated region includes at least part of the boundary and parts of each of the first and second light sensitive elements.

Abstract: An intra-operative ultrasound probe for use with a robotic and laparoscopic surgical systems that allows for direct surgeon control over the position and orientation of the ultrasound image is presented. The transducer is designed to interface with the laparoscopic grasper so that it is easy to pick up in a locking, self-aligning and repeatable manner. The transducer is tracked in space using either forward kinematics or electromagnetic sensing, allowing multiple 2D images to be combined in order to create 3D ultrasound volumes. The 3D volumes can be further processed and displayed on the surgeon's console, or used to register and display acquired pre-operative images at the correct spatial location within the patient.

Abstract: An intra-operative ultrasound probe for use with a robotic and laparoscopic surgical systems that allows for direct surgeon control over the position and orientation of the ultrasound image is presented. The transducer is designed to interface with the laparoscopic grasper so that it is easy to pick up in a locking, self-aligning and repeatable manner. The transducer is tracked in space using either forward kinematics or electromagnetic sensing, allowing multiple 2D images to be combined in order to create 3D ultrasound volumes. The 3D volumes can be further processed and displayed on the surgeon's console, or used to register and display acquired pre-operative images at the correct spatial location within the patient.

Abstract: Described herein are a method and apparatus for determining viscoelastic parameters of a tissue. A vibration signal is applied to the tissue and displacements at a plurality of locations within the tissue are measured at a plurality of times. The viscoelastic parameters of the tissue, including elasticity and viscosity, can then be determined by fitting a finite element model of the tissue to the vibration signal and the measured displacements and by solving for the viscoelastic parameters of the model. A value for density of each element of the model is selected and the absolute values for the viscoelastic parameters of each of the elements in the model is determined. Alternatively, the difference in relaxation-times between two locations within the tissue can be determined from the difference in phases of the strains at the two locations.

Abstract: Described herein are a method and apparatus for determining viscoelastic parameters of a tissue. A vibration signal is applied to the tissue and displacements at a plurality of locations within the tissue are measured at a plurality of times. The viscoelastic parameters of the tissue, including elasticity and viscosity, can then be determined by fitting a finite element model of the tissue to the vibration signal and the measured displacements and by solving for the viscoelastic parameters of the model. A value for density of each element of the model is selected and the absolute values for the viscoelastic parameters of each of the elements in the model is determined. Alternatively, the difference in relaxation-times between two locations within the tissue can be determined from the difference in phases of the strains at the two locations.

Abstract: The characterization of tissue viscoelastic properties requires the measurement of tissue displacements over a region of interest at frequencies that exceed significantly the frame rates of conventional medical imaging devices. The present invention involves using bandpass sampling to track high-frequency tissue displacements. With this approach, high frequency signals limited to a frequency bandwidth can be sampled and reconstructed without aliasing at a sampling frequency that is lower than the Nyquist rate. With bandpass sampling, it is feasible to use conventional beam-forming on diagnostic ultrasound machines to perform high frequency dynamic elastography. The method is simple to implement as it does not require beam interleaving, additional hardware or synchronization and can be applied to magnetic resonance elastography.

Abstract: A method and apparatus for processing ultrasonic image signals is disclosed. The method involves receiving a plurality of input sample values representing reflected sound waves in a ultrasonic system, exponentiating each input sample to produce a plurality of respective exponentiated sample values, conditioning the exponentiated sample values to produce conditioned exponentiated sample values for receipt by an imageformer, and causing the imageformer to produce an image representing the ultrasonic sound waves in response to the conditioned exponentiated sample values.

Abstract: Described herein are a method and apparatus for determining viscoelastic parameters of a tissue. A vibration signal is applied to the tissue and displacements at a plurality of locations within the tissue are measured at a plurality of times. The viscoelastic parameters of the tissue, including elasticity and viscosity, can then be determined by fitting a finite element model of the tissue to the vibration signal and the measured displacements and by solving for the viscoelastic parameters of the model. A value for density of each element of the model is selected and the absolute values for the viscoelastic parameters of each of the elements in the model is determined. Alternatively, the difference in relaxation-times between two locations within the tissue can be determined from the difference in phases of the strains at the two locations.

Abstract: An imaging system comprises a device to excite mechanical waves in elastic tissue, a device for measuring the resulting tissue motion at a plurality of locations interior to the tissue at a number of time instances, a computing device to calculate the mechanical properties of tissue from the measurements, and a display to show the properties according to their location. A parameter identification method for calculating the mechanical properties is based on fitting a lumped dynamic parametric model of the tissue dynamics to their measurements. Alternatively, the mechanical properties are calculated from transfer functions computed from measurements at adjacent locations in the tissue. The excitation can be produced by mechanical vibrators, medical needles or structures supporting the patient. The measurements may be performed by a conventional ultrasound imaging system and the resulting properties displayed as semi-transparent overlays on the ultrasound images.

Abstract: The invention relates to a needle guidance system provided by a needle with a steerable tip. The needle has a cannula and a stylet. The stylet adjacent to its tip has a naturally curved portion. The stylet is movable in two degrees of freedom with respect to the cannula—axial translation and axial rotation with respect to the cannula axis. When extended, the stylet curves off-axis and provides cannula tip steering. Driving and/or steering systems may be provided to the orientation and relatively move the stylet.

Abstract: The invention relates to a needle guidance system provided by a needle with a steerable tip. The needle has a cannula and a stylet. The stylet adjacent to its tip has a naturally curved portion The stylet is movable in two degrees of freedom with respect to the cannula—axial translation and axial rotation with respect to the cannula axis. When extended, the stylet curves off-axis and provides cannula tip steering. Driving and/or steering systems may be provided to the orientation and relatively move the stylet.

Abstract: A system for medical ultrasound in which the ultrasound probe is positioned by a robot arm under the shared control of the ultrasound operator and the computer is proposed. The system comprises a robot arm design suitable for diagnostic ultrasound, a passive or active hand-controller, and a computer system to co-ordinate the motion and forces of the robot and hand-controller as a function of operator input, sensed parameters and ultrasound images.

Abstract: A joystick composed of a stator formed by an outer cage forming an inner cubic compartment containing an inner cube oriented with its wall spaced from and substantially parallel corresponding wall of the compartment. Opposed magnets are position in cooperating relationship on opposed walls of the compartment and cube and define a gap therebetween. A floater formed by a plurality of flat actuating coils, one positioned in each gap and each thinner than the width of the gap in which it is received. Preferably the ratio of coil thickness to gap width is at least 1:3. Preferably an optical position sensor is used to monitor the relative position of the flotor and stator and is composed of at least one linear light position sensor mounted on one of the stator and flotor and a plurality of planar light beams arranged at an angle to each other on the other of the stator and flotor and directed to the linear light position sensor(s) so that the light beams traverse the linear light position sensor(s).

Abstract: A pair of five-bar mechanisms having their pivotal axes parallel are each mounted at one end to a base and are interconnected at their other ends by a crankshaft to obtain a manipulator generating three degrees of freedom planar motion of an end-effector. Redundant actuation may be used to generate an unlimited rotation range and an extensible link in the crankshaft may be used to provide adjustable torque capabilities during operation.

Abstract: A joystick composed of a stator formed by an outer cage forming an inner cubic compartment containing an inner cube oriented with its wall spaced from and substantially parallel corresponding wall of the compartment. Opposed magnets are position in cooperating relationship on opposed walls of the compartment and cube and define a gap therebetween. A floater formed by a plurality of flat actuating coils, one positioned in each gap and each thinner than the width of the gap in which it is received. Preferably the ratio of coil thickness to gap width is at least 1:3. Preferably an optical position sensor is used to monitor the relative position of the flotor and stator and is composed of at least one linear light position sensor mounted on one of the stator and flotor and a plurality of planar light beams arranged at an angle to each other on the other of the stator and flotor and directed to the linear light position sensor(s) so that the light beams traverse the linear light position sensor(s).

Abstract: This invention is related to a novel passive medical device that can be used in surgery to stabilize tissue for anastomosis or other surgical work. More particularly, the tissue stabilization device and surgical arm stabilizes cardiac tissue which enables coronary artery bypass grafting surgeries to proceed while the heart is beating, or during other surgical procedures that require holding or retraction of tissue and arresting blood flow. A surgical arm comprising: (a) a first hollow link; (b) a second hollow link; (c) a hollow universal joint connecting an end of the first link with an end of the second link; (d) a support mount for the first link, the universal joint and the second link; and (e) a hollow tissue stabilizer connected to an end of a hollow link opposite to the hollow link that is proximate the support mount.

Abstract: A joystick composed of a stator formed by an outer cage forming an inner cubic compartment containing an inner cube oriented with its wall spaced from and substantially parallel corresponding wall of the compartment. Opposed magnets are position in cooperating relationship on opposed walls of the compartment and cube and define a gap therebetween. A floater formed by a plurality of flat actuating coils, one positioned in each gap and each thinner than the width of the gap in which it is received. Preferably the ratio of coil thickness to gap width is at least 1:3. Preferably an optical position sensor is used to monitor the relative position of the flotor and stator and is composed of at least one linear light position sensor mounted on one of the stator and flotor and a plurality of planar light beams arranged at an angle to each other on the other of the stator and flotor and directed to the linear light position sensor(s) so that the light beams traverse the linear light position sensor(s).

Abstract: A six degree of freedom structure forming a robotic manipulator, consisting of two five-bar linkages (30 and 80) set on rotatable base linkages (18 and 58); the output points (44 and 94) of the five-bar linkages (30 and 80) are attached to a rigid payload platform (48) by universal joints (46 and 96), respectively. Each linkage (30 and 80) on its rotatable bass can position its output point in three degrees of freedom, but since the two five-bar linkages (30 and 80) are tied together at the platform (48), five degree of freedom motion of the platform (48) results--three degrees of freedom in translation, and two of rotation. A seventh motor (100), mounted for example on one of the five bar linkages, provides power to rotate the platform about the axis defined by the two universal joints (46 and 96). The rotational torque is coupled through one of the universal joints (46 or 96).

Abstract: Apparatus for evaluating the stability of the shoulder joint of a human subject includes a rotatable, elbow-holding assembly that has sensors and associated processing components for producing an indication of the rotational angle of the long axis of the humerus of the subject relative to a reference. Sensors measure muscle activity as the humerus is rotated. Changes in the muscle activity measurement are processed to produce an indication of the changes in the subject's apprehension as the humerus is moved. The apparatus may include a clock that indicates the times when muscle activity occurs. The levels of muscle activity may be recorded at different times and indicated to the operator. Pressure can be applied in a direction normal to the long axis of the humerus, and sensors produce an indication of the level of the applied pressure and corresponding apprehension of the subject. Also available is an indication of the level of muscle activity that occurs when such pressure is applied.