Abstract: The present invention relates to a model based positioning system that includes a positioning device having at least one transmitter configured to be in a tracking environment, e.g. inserted into a body, a receiver having a plurality of receiver elements arranged outside the tracking environment, a control unit configured to measure amplitude and/or phase information of a signal transmitted from the at least one transmitter and received at each receiving element, and a memory unit M for storing a model for each receiving element. The control unit is also configured to estimate the position P of the positioning device by comparing the model for each receiving element with the measured received signal for each receiving element.

Abstract: A subject-specific skeletal model of a body is created, and an intended path of a catheter within the body is defined in the model. While the probe is inserted into the body electrical currents are passed through the body between at least one electrode in the probe and through respective electroconductive location pads that are disposed at a plurality of locations on the body surface along the intended path. Based on respective characteristics of the currents passing through the plurality of locations, position coordinates of the probe are iteratively determined. The actual path of the probe is tracked with reference to in the model using the iteratively determined position coordinates to determine whether the actual path corresponds to the intended path.

Abstract: In Magnetic Particle Imaging (MPI) the reconstruction requires the knowledge of a so called system function. This function describes the relation between spatial position and frequency response and is currently measured once for a scanner set-up and a tracer material. For reasonable resolutions and fields of view the system function becomes quite large, resulting in large acquisition times to obtain reasonable signal-to-noise. However, the system function has a number of properties which can be used to improve signal-to-noise. According to the present invention use is made of the spatial symmetry and/or identical responses at different frequencies for this purpose.

Abstract: A new and improved method for tracking and/or spatial localization of an invasive device in Magnetic Resonance Imaging (MRI) is provided. The invention includes providing an invasive device including a marker having a chemically shifted signal source with a resonant frequency different from the chemical species of the subject to be imaged, applying a pulse sequence, detecting the resulting RF magnetic resonance signals, and determining the 3D coordinates of the marker. The invention also includes generating scan planes and reconstructing an image from the detected signals to generate an image having the marker contrasted from the subject. The invasive device includes a marker having a chemically shifted signal source which has a resonant frequency different from the chemical species of the subject to be imaged for use in tracking the device during imaging.

Abstract: The present disclosure describes system and methods for detecting and amplifying weak magnetic fields generated by anatomical structures. The disclosure describes an implantable magnetic reporter system. The magnetic reporter system includes a magnetic reporter. The magnetic reporter includes a platform coupled to a support structure by a plurality of torsional flexures. A magnet is disposed on the platform, and the magnet and platform rotate when exposed to a magnetic field. The rotation of the magnet generates a stronger magnet field that is detectable external to the patient.

Abstract: Apparatus and methods which enable the stimulation of neurons oriented in all directions within a biological structure using applied magnetic fields.

Abstract: An apparatus, including a bus having electrical power and data lines, and a plurality of location pads, which are positionable at different, respective locations with respect to a body cavity in which the object is located, and which are connected to the bus in series so as to receive electrical power and exchange data signals over the bus. Each location pad includes multiple radiator coils and driving circuitry configured to select, responsively to the data signals, different respective driving frequencies for the coils and to generate, using the electrical power from the bus, driving signals to drive the coils to produce magnetic fields at the respective driving frequencies. The apparatus also includes a console, which is configured to receive and process sensor signals from a magnetic sensor fixed to the object, in response to the magnetic fields in the body cavity, in order to compute position coordinates of the object.

Abstract: A method is described for estimating skin thickness over an implanted magnet. A plane is defined that is perpendicular to the skin of a patient over an implanted magnet and characterized by x- and y-axis coordinates. The magnetic field strength of the implanted magnet is measured using an array of magnetic sensors on the skin of the patient. From the measured magnetic field strength, at least one x-axis coordinate in the plane is determined for at least one y-axis zero position on the array where a y-axis component of the measured magnetic field strength is zero. From that, a y-axis coordinate of the at least one y-axis zero is calculated as a function of the at least one x-axis coordinate, such that the y-axis coordinate represents thickness of the skin over the implanted magnet.

Abstract: A apparatus includes an acquisition unit to acquire magnetic resonance data in every data group, a unit to control the acquisition unit to collect the data for one or a plurality of data groups during a collection period which is set based on a starting time phase of a cardiac cycle of the subject, a unit to determine the data among the data acquired by the acquisition unit as ineffective data if at least a part of it is related to a data group acquired during an ineffective period, and as effective data if all of it is related to a data group acquired during a period other than the ineffective period, the ineffective period being set based on an ending time point of the cardiac cycle in which the data is acquired, and a unit to reconstruct an image regarding the subject by using the effective data.

Abstract: The present invention relates to an apparatus and a method for influencing and/or detecting magnetic particles in a field of view.

Abstract: Method and device for the automatic identification of phase-locked high-frequency oscillations (PLHFO) to localize epileptogenic brain for neurosurgical intervention, including filtering brain signals into low frequency and high frequency oscillation (HFO) data streams. Applying ICA to the HFO data stream, transforming the data streams to produce an HFO instantaneous amplitude (HFOIA) and a low-frequency instantaneous phase (LFIP) data stream. Transforming the normalized HFOIA to produce an instantaneous phase of the normalized HFOIA. Determining a continuous or discrete PLHFO calculation that measures cross frequency coupling between the instantaneous phase of the low frequency data stream, and the instantaneous amplitude of the HFO data stream based at least in part on LFIP, raw or normalized HFOIA, and may include the instantaneous phase of normalized or raw HFOIA.

Abstract: A method of making a sensor includes depositing a layer of hydrogel over a substrate, the hydrogel configured to change thickness or volume in response to a selected condition and including a plurality of magnetic particles disposed in the hydrogel so that a magnetic property of the hydrogel changes with changes of thickness or volume of the hydrogel. The hydrogel is sacrificed in selected region(s) of the layer so that the hydrogel outside the selected region(s) forms a plurality of spaced-apart islands of the hydrogel. The islands of the hydrogel are enclosed in an enclosure at least partly permeable to a selected fluid. A sensor for detecting a condition includes the substrate, islands, and a device coil arranged with respect to the hydrogel so that changes in the magnetic property modulate an electrical property of the sensor. A system includes the substrate, islands, and a magnetic-field detector.

Abstract: Systems and methods for evaluating prospective treatments for progressive brain disorders like Alzheimer's disease and the progressive effects of aging involve the use of an imaging device communicatively coupled to a computing device. The imaging device may takes a plurality of brain imaging measurements from each of a plurality of human subjects who are divided into a treated group and an untreated group based on various subject data including whether the subjects carry certain alleles of genes known to increase the risk of developing the brain disorder at issue. The computing device receives the brain imaging measurements from the imaging device and applies an advanced processing method that permits enhanced computational efficiency when calculating rates of change for the two groups and determining whether any calculated difference between the rates is statistically significant.

Abstract: It is an object of the present invention to provide a motor function analyzing apparatus which simplifies a calibration measurement necessary before measuring a finger tapping motion, and which is capable of evaluating a motor function highly precisely. The present invention provides a motor function analyzing apparatus which simplifies a calibration measurement necessary before measuring a finger tapping motion, and which is capable of evaluating a motor function highly precisely by using a calibration point unique to each apparatus and a calibration point unique to each subject.

Abstract: A method, including inserting a probe into a cavity in a subject's body and receiving, from a force sensor in the probe, first readings indicative of a first change in measured contact forces between the probe and the cavity by less than a predetermined limit over at least a predetermined interval of time. The method continues by receiving second readings from the force sensor when the second readings have changed by more than a predetermined force threshold or location coordinates of the probe have changed by at least a predetermined location change threshold. The method continues by receiving third readings indicative of a second change in the measured contact forces between the probe and the cavity by less than the predetermined limit over at least the predetermined interval of time. The method concludes by calibrating a zero-force point for the force sensor according to the third readings.

Abstract: The present invention relates to an arrangement and a method for influencing and/or detecting magnetic particles in a region of action, in particular for monitoring of intra-cerebral or intra-cranial bleeding using Magnetic Particle Imaging (MPI). A common coupling unit per coil of a coil array is provided for coupling all signals for generating the magnetic fields to the set of common coils. Further, the same coils are used for acquiring detection signals. In this way a small scanner can be built that can be left permanently or can be provided periodically to the patient, in particular for bleeding monitoring.

Abstract: Devices, systems and methods for using those devices and systems are disclosed to facilitate mapping and navigation during a minimally invasive surgical procedure. These devices, systems and methods include implantable magnetic devices and sensing devices that facilitate locating the implantable magnetic devices such that a surgeon can accurately locate and place devices at particular points of interest during a medical procedure.

Abstract: A method for displaying a position of a medical device, such as a catheter, during insertion thereof into a patient. In one example embodiment, the method includes obtaining a first set of detected position data relating to a location marker, such as a permanent magnet, then determining a possible first position thereof. A first confidence level relating to a match between the first set of detected position data and a first set of predicted position data is assigned. A determination is made whether the first confidence level meets or exceeds a first threshold. If the first confidence level meets or exceeds the first threshold, a determination is then made whether the first position of the location marker is within a first detection zone. If the first position of the location marker is within the first detection zone, the first position of the location marker is displayed.

Abstract: A method, including capturing, from an imaging system, a three-dimensional (3D) image of a body cavity, and using the captured 3D image to construct a simulated surface of the body cavity. A probe having a location sensor is inserted into the body cavity, and in response to multiple location measurements received from the location sensor, multiple positions are mapped within respective regions of the body cavity so as to generate respective mapped regions of the simulated surface. Based on the simulated surface and the respective mapped regions, one or more unmapped regions of the simulated surface are delineated, and the simulated surface of the body cavity is configured to indicate the delineated unmapped regions.

Abstract: An inductive sensing system is adapted for noninvasive measurement of blood flow through a blood vessel. A resonant sensor is disposed in proximity to the blood vessel, and includes a coil resonator that generates a magnetic field within a sensing area that includes the blood vessel. The resonator changes resonance state based on changes in a flow of blood hemoglobin through the sensing area. The IDC unit establishes an IDC control loop, including the resonator as a loop filter, that provides feedback resonance control of the resonator to maintain a resonant frequency state (steady state oscillation) representative of blood hemoglobin flow through the sensing area. A feedback resonance control signal provides sensor data corresponding to the resonant frequency state as representative of blood flow through the sensing area. In one embodiment, the IDC control loop is implemented as a negative impedance control loop, controlling negative impedance to counterbalance resonant impedance.

Abstract: An integrated system for facilitating local treatment in an organ and capable of universally interfacing with other devices and systems is provided. The integrated system comprises an imaging system interface module configured to functionally associate with an imaging system capable of presenting to a user, through a user-interface device, parameters indicating a mode of operation of the imaging system. The imaging system interface module is configured to receive at least one of the parameters, to interpret such parameter and to allow the integrated system to assume a mode of operation according the parameter. The integrated system further comprises a treatment tool interface module, configured to receive and detect a treatment event signal from a portable treatment tool. The treatment event signal indicates a treatment event, thereby allowing establishing a time of the treatment event and thereby establishing a locality of a treatment provided to the organ by the portable treatment tool.

Abstract: In a system (2) having a balloon catheter (1) with a balloon (7) and an elongated catheter (3), a planimetry measuring system (19) in the balloon, and a linear distance measuring element (23) slideable along the elongated catheter from a proximal end (4) thereof to the datum location (8) when the balloon catheter has been inserted through the arterial system with the balloon located in the valve orifice (17), a plurality of secondary optically detectable elements (30) are equi-spaced longitudinally along the catheter and an optical encoder (32) in the linear distance measuring element counts the detectable elements as the linear distance measuring element is moved from a reset position to the datum location. A signal processor (20) reads signals from the linear distance measuring element and from the planimetry measuring system for determining the distance of the valve orifice of the aortic valve (9) from the datum location.

Abstract: The disclosure relates to a method for reconstructing the source of an electromagnetic field. Firstly, a measurement space separate from the source is selected so that the measurement space is connected to the source via a magnetically homogeneous spatial region. Measured values of the electromagnetic field emitted by the source are recorded on the surface of the measurement space so that the electromagnetic field in the measurement space can be uniquely determined in the context of an error bound determined by the discreteness of the measured values. A mathematical model of the electromagnetic source is developed which has a multiplicity of unknowns, and a system of equations is set up that relates the unknowns of the model to the measured values. The system of equations is solved in order to determine the characteristics of the electromagnetic source. The disclosure also relates to an arrangement for carrying out the method.

Abstract: A magnetocardiography arrangement for producing stress magnetocardiograms that comprises a magnetocardiograph (1) and a stress unit (2) consisting of non-magnetic components. The magnetocardiograph (1) and the stress unit (2) are arranged in a shielded chamber (4) for shielding against external magnetic fields, and the stress unit (2) is or includes a bicycle ergometer braked by means of pressurised gas or a pressurised gas mixture from a source (6) for the pressurised gas or the pressurised gas mixture arranged outside the shielded chamber (4).

Abstract: In general, in one aspect, the invention features a method that includes using an optical coherence tomography system to acquire a plurality of frames of a sample where each frame includes optical information about the composition of the sample through a section of the sample. The method further includes averaging over two or more of the frames to provide an image of the section of the sample where successive frames of the two or more frames are acquired with a time lapse of 0.05-0.7 seconds. Embodiments of the method may have unique advantages for endoscopic subcellular imaging. For example, they can enable subcellular imaging with low-NA optics (e.g., NA=0.25 or less) while providing morphological imaging of the underlying tissue up to 0.6 mm without focal tracking.

Abstract: A magnetic sensor includes a plurality of assemblies combined. Each assembly includes a plurality of tunnel magnetoresistive elements, a capacitor and a fixed resistor. The tunnel magnetoresistive dements are (i) disposed in such a way that fixed magnetization directions of fixed magnetic layers are substantially identical and changeable magnetization directions of free magnetic layers with no magnetic field applied are substantially identical and (ii) connected to each other in series-parallel. The capacitor is connected in parallel to the tunnel magnetoresistive elements. The fixed resistor is connected in series to the tunnel magnetoresistive elements and to the capacitor. The assemblies are (i) disposed in such a way that the fixed magnetization directions of the fixed magnetic layers of the assemblies have a relative angle of more than 90 degrees and (ii) connected to each other in series and/or in parallel.

Abstract: A system includes an adjustable implant configured for implantation internally within a subject and includes a permanent magnet configured for rotation about an axis of rotation, the permanent magnet operatively coupled to a drive transmission configured to alter a dimension of the adjustable implant. The system includes an external adjustment device configured for placement on or adjacent to the skin of the subject having at least one magnet configured for rotation, the external adjustment device further comprising a motor configured to rotate the at least one magnet and an encoder. Rotation of the at least one magnet of the external adjustment device effectuates rotational movement of the permanent magnet of the adjustable implant and alters the dimension of the adjustable implant. Drive control circuitry is configured to receive an input signal from the encoder.

Abstract: The present invention relates to a multimodal fiducial marker (10) for registration of multimodal data, comprising a first portion (12) comprising magnetic material visible in MPI data obtained by a magnetic particle imaging method and a second portion (14) comprising a second material visible in image data obtained by another imaging method, which image data shall be registered with said MPI data. Further, the present invention relates to a marker arrangement (20).

Abstract: Invention is related to cardiology and intended for diagnosis of ischemic myocardial injuries. Magnetocardiographic examination is executed, current density vectors maps are reconstructed during ST-T interval and 4 sub-intervals of QRS complex, quantitative diagnostic indicators are calculated. Characterized in that, for said time intervals total length of all vectors (total current), autocorrelation coefficient of the instant map and its correlation with map onto the T wave peak are derived, several quantitative indicators for these curves are calculated (area under the curve, time intervals, their ratio, etc.) and ranges of their values are divided onto 3 intervals. As a result, absence/presence of ventricles injuries is diagnosed according to the rule—injury is absent (presence minor, significant), if certain quantitative indicator is ranged in one of 3 said intervals or if score of points for separate quantitative indicators is less than or equal to 7 (8-16, 17 and more).

Abstract: Stimulated emissions due to nuclear quadropole resonance are detected utilizing a terminated balanced transmission line and a directional coupler for the detection of explosives, contraband, narcotics and the like that exist between the transmission lines, in which a swept frequency continuous wave generator is utilized to scan between 100 KHz and 10 MHz.

Abstract: A method of providing medical imaging guidance information for use in operating a medical imaging apparatus detects motion of an examinee placed on a support table positioned for imaging by a medical imaging device. The method compares a level of the detected motion with a predetermined threshold value and adaptively selects and provides guidance information enabling reducing impairment of image quality due to examinee physical motion, in response to the comparison.

Abstract: Techniques, devices and systems are disclosed for magnetoencephalography (MEG) source imaging. In one aspect, a method includes selecting signal data associated with one or more frequency bands from a spectrum of the signal data in the frequency domain, in which the signal data represents magnetic signals emitted by a brain of a subject and detected by a plurality of sensors outside the brain, defining locations of sources within the brain that generate the magnetic signals, in which the number of locations of the sources is selected to be greater than the number of sensors, and generating a source value of signal power based on the selected signal data corresponding to a respective location of the locations at the one or more frequencies.

Abstract: An imaging system is provided with an ultrasound catheter and a controller coupled to the ultrasound catheter. The catheter includes a localizer sensor configured to generate positional information for the ultrasound catheter, and an imaging ultrasound sensor having a restricted field of view. The controller co-registers images from the imaging ultrasound sensor with positional information from the localizer sensor.

Abstract: In order to increase the accuracy and speed of catheter reconstruction in surgical procedures such as an HDR prostate implant procedure, an automatic tracking system is provided preferably using an electromagnetic tracking device. The system uses a transmitter with a sensor used for catheter position. Due to substantial interference in the electromagnetic field from the surgical table, implant stepper/stabilizer etc, a calibration algorithm using a scattered data interpolation scheme is implemented to correct tracking location errors. The invention includes methods and systems used to carry out the methods.

Abstract: The use of machine learning for pattern recognition in magnetocardiography (MCG) that measures magnetic fields emitted by the electrophysiological activity of the heart is disclosed herein. Direct kernel methods are used to separate abnormal MCG heart patterns from normal ones. For unsupervised learning, Direct Kernel based Self-Organizing Maps are introduced. For supervised learning Direct Kernel Partial Least Squares and (Direct) Kernel Ridge Regression are used. These results are then compared with classical Support Vector Machines and Kernel Partial Least Squares. The hyper-parameters for these methods are tuned on a validation subset of the training data before testing. Also investigated is the most effective pre-processing, using local, vertical, horizontal and two-dimensional (global) Mahanalobis scaling, wavelet transforms, and variable selection by filtering.

Abstract: A system and method for guiding a catheter or other medical device to a desired target destination within the vasculature of a patient via bioimpedance measurements is disclosed. The target destination in one embodiment includes placement of the catheter such that a distal tip thereof is disposed proximate the heart, e.g., the junction of the right atrium and superior vena cava. In one embodiment the method for guiding the catheter comprises introducing the catheter into a vessel of the patient, the catheter defining a lumen through which fluids can be infused into the vasculature of the patient. The catheter is advanced toward a target destination within the vasculature. A first impedance value based on intravascular detection of at least one electrical property related to a first tissue surface of the vessel is calculated to enable determination of the proximity of a distal end of the catheter to the target destination.

Abstract: Provided are an ultra-low-field nuclear magnetic resonance device and an ultra-low-field nuclear magnetic resonance measuring method. The method includes applying a first measurement bias magnetic field corresponding to an excitation frequency of a coherent biomagnetic field generated in association with the electrophysiological activity of human body organs, applying a second measurement bias magnetic field having the same direction as the first measurement bias magnetic field and having a different magnitude than the first measurement bias magnetic field, and measuring a magnetic resonance signal generated in the human body by using magnetic field measuring means.

Abstract: A system and method for providing magnetic based navigation in dental implant surgery is disclosed. According to one embodiment, a surgical navigation system comprises a custom piece that is made to fit in a patient's anatomy and comprises a first magnetic component. The surgical navigation system further comprises an instrument assembly comprising a drill bit and a second magnetic component. A processing unit receives and displays a first position and orientation data from the first magnetic component with respect to a second position and orientation data from the second magnetic component to track the movement of the first magnetic component with respect to the second magnetic component.

Abstract: A system and method for measuring a magnetocardiogram (MCG) in order to measure a weak magnetic field generated from the heart of a small animal such as a laboratory rat are provided. The system includes a case, a SQUID sensor located and fixed inside the case to detect magnetism, a platform arranged near the SQUID sensor inside the case, the small animal being placed on the platform, a linear station to which the platform is fixed to move a location of the platform, and a control unit configured to control operations of the SQUID sensor and the linear station and measure the MCG of the small animal using intensities of the magnetism detected by the SQUID sensor.

Abstract: A pulmonary ventilation system comprising means for storing an empirical relationship that is designed and adapted to determine at least one pulmonary ventilation parameter as a function of a plurality of measured anatomical distances and volume-motion coefficients, means for acquiring the anatomical distances, means for determining the plurality of motion coefficients, and processing means for determining the ventilation parameter based on the acquired anatomical distances and determined plurality of volume-motion coefficients. In one embodiment, the system further includes means for acquiring base-line ventilation characteristics and means for correlating the base-line ventilation characteristics to the ventilation parameter determined with the empirical relationship.

Abstract: The present invention can provide a method of determining the presence, location, quantity, or a combination thereof, of a biological substance, comprising: (a) exposing a sample to a plurality of targeted nanoparticles, where each targeted nanoparticle comprises a paramagnetic nanoparticle conjugated with one or more targeting agents that preferentially bind with the biological substance, under conditions that facilitate binding of the targeting agent to at least one of the one or more biological substances; (b) subjecting the sample to a magnetic field of sufficient strength to induce magnetization of the nanoparticles; (c) measuring a magnetic field of the sample after decreasing the magnetic field applied in step b below a threshold; (d) determining the presence, location, quantity, or a combination thereof, of the one or more biologic substances from the magnetic field measured in step (c).

Abstract: An arrangement and a corresponding method for influencing and/or detecting magnetic particles in a region of action include storing required reactive energy in a tank circuit, which is preferably operating at the center frequency of a magnetic particle imaging (MPI) drive field. Reactive elements, such as capacitors and/or inductors, couple one or more tank circuits to the drive field resonator. The coupling strength maybe varied by switching additional reactive elements into and out of the coupling unit to vary the strength of coupling.

Abstract: An object information acquiring apparatus is used, which includes: a receiver configured to receive a photoacoustic wave generated from an object irradiated with light and output a time-series electric signal; and a processor configured to acquire characteristic information relating to an inside of the object by using the time-series electric signal, wherein the light is emitted at a plurality of timings, the receiver receives the photoacoustic wave at the plurality of timings, and the processor determines a projection position coordinate on which the time-series electric signal is projected on the basis of an amount of displacement of the inside of the object among the plurality of timings, for each of a plurality of time-series electric signals corresponding to the plurality of timings, and acquires the characteristic information.

Abstract: A method and medical system for providing needle guidance. The method and system includes acquiring ultrasound data while manipulating a needle and tracking the needle tip while manipulating the needle. The method and system includes displaying a first live image including at least a portion of the needle in a first viewing pane and displaying a second live image including the needle tip in a second viewing pane at the same time as the first live image. The second live image includes a portion of the first live image at a greater level of zoom than the first live image.

Abstract: A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

Abstract: A medical imaging system is provided. The medical imaging system comprises a movable acquisition device, a processing unit and a display, wherein the display is fixed to the movable acquisition device.

Abstract: A magnetic particle imaging apparatus includes magnets [106,107] that produce a gradient magnetic field having a field free region (FFR), excitation field electromagnets [102,114] that produce a radiofrequency magnetic field within the field free region, high-Q receiving coils [112] that detect a response of magnetic particles in the field free region to the excitation field. Field translation electromagnets create a homogeneous magnetic field displacing the field-free region through the field of view (FOV) allowing the imaging region to be scanned to optimize scan time, scanning power, amplifier heating, SAR, dB/dt, and/or slew rate. Efficient multi-resolution scanning techniques are also provided. Intermodulated low and radio-frequency excitation signals are processed to produce an image of a distribution of the magnetic nanoparticles within the imaging region. A single composite image is computed using deconvolution of multiple signals at different harmonics.

Abstract: A surgical locator circuit identifies a surgical target such as a kidney stone by disposing an emitter such as a magnetic source behind or adjacent the surgical target, and employing the circuit to identify an axis to the emitter, thus defining an axis or path to the surgical target. An array of sensors arranged in an equidistant, coplanar arrangement each senses a signal indicative of a distance to the emitter. A magneto resistor sensor generates a variable resistance is responsive to the distance to a magnetic coil emitting a magnetic field. An equal signal from each of the coplanar sensors indicates positioning on an axis passing through a point central to the sensors and orthogonal to the plane. A fixed element and signal conditioner augments and normalizes the signal received from each of the sensors to accommodate subtle differences in magneto resistive response among the plurality of sensors.

Abstract: Embodiments of the invention provide a guided surgical tool assembly with a guide tube including a sensor, a surgical instrument including a detectable feature moveable within the guide tube, and the sensor capable of detecting the detectable feature when the surgical instrument is inserted in the guide tube. Some embodiments include a sensor pad, a guide stop coupled to the surgical instrument, a plunger mechanism including a compressible spring mechanism coupled to the guide tube, and a wiper capable of being sensed by the sensor pad. Some embodiments include a guided surgical tool assembly system comprising a tool sensor system including a processor and at least one data input/output interface. Some embodiments include a medical robot system with a guided surgical tool assembly and including a robot coupled to an effectuator element configured for controlled movement and positioning along one or more of an x-axis, a y-axis, and a z-axis.

Abstract: A medical system for locating a catheter distal tip within a body using a plurality electrical position sensors and a magnetic position sensor in conjunction with an acceleration sensor or rotational encoder. The system locates the catheter by using signals from the acceleration sensor or rotational encoder and magnetic sensors to compensate for positioning errors associated with electric positioning sensors.