An acoustic imaging system for use within a heart has a catheter, an ultrasound device incorporated into the catheter, and an electrode mounted on the catheter. The ultrasound device directs ultrasonic signals toward an internal structure in the heart to create an ultrasonic image, and the electrode is arranged for electrical contact with the internal structure. A chemical ablation device mounted on the catheter ablates at least a portion of the internal structure by delivery of fluid to the internal structure. The ablation device includes a material that vibrates in response to electrical excitation, the ablation being at least assisted by vibration of the material. The ablation device may alternatively be a transducer incorporated into the catheter, arranged to convert electrical signals into radiation and to direct the radiation toward the internal structure. The electrode may be a sonolucent structure incorporated into the catheter, through which the ultrasound device is arranged to direct signals. An acoustic marker mounted on the catheter emits a sonic wave when electrically excited. A central processing unit creates a graphical representation of the internal structure, and super-imposes items of data onto the graphical representation at locations that represent the respective plurality of locations within the internal structure corresponding to the plurality of items of data. A display system displays the graphical representation onto which the plurality of items of data are super-imposed.

Catheters for imaging, sensing electrical potentials and ablating tissue

A method and apparatus for defining the location of a medical instrument relative to features of a medical workspace including a patient's body region are described. Pairs of two-dimensional images are obtained, preferably by means of two video cameras making images of the workspace along different sightlines which intersect. A fiducial structure is positioned in the workspace for defining a three dimensional coordinate framework, and a calibration image pair is made. The calibration image pair comprises two 2D projections from different locations of the fiducial structure. After the calibration image pair is made, the fiducial structure is removed. A standard projection algorithm is used to reconstruct the 3D framework of the fiducial structure from the calibration image pair. Appropriate image pairs can then be used to locate and track any other feature such as a medical instrument, in the workspace, so long as the cameras remain fixed in their positions relative to the workspace. The computations are desirably performed with a computer workstation including computer graphics capability, image processing capability, and providing a real-time display of the workspace as imaged by the video cameras. Also, the 3D framework of the workspace can be aligned with the 3D framework of any selected volume scan, such as MRI, CT, or PET, so that the instrument can be localized and guided to a chosen feature. No guidance arc or other apparatus need be affixed to the patient to accomplish the tracking and guiding operations.

Apparatus and method for photogrammetric surgical localization

Apparatus and methods are disclosed for use within an image-guided surgical navigation system for facilitating the combined positioning and orientation of multiple surgical implements. A tool guide having multiple cannulas is tracked by a surgical navigation system in real time. Position data of the tool guide is registered and combined with pre-acquired images by the navigation computer. Concurrent graphical representations of the plurality of cannulas are superimposed over the images and displayed. The display allows the surgeon to place the tool guide into the patient's body and position and orient the plurality of cannulas which are then used to place each of the implements.

Multiple cannula image guided tool for image guided procedures

A method and apparatus for determining, calculating, and/or viewing a trajectory. The trajectory can be displayed on a display relative to image data of a patient. A user can use the system to determine relationships between two or more trajectories that have been determined. The relationships can be within two dimensional, three-dimensional, or four dimensional space. The relationships can include distance, angle, etc. The relationships can also be determined between real time trajectories and stored trajectories, or combinations thereof.

Trajectory storage apparatus and method for surgical navigation systems

An X-ray computed tomography apparatus includes an X-ray source (101) which generates X-rays, a high voltage generating unit (104) which generates a high voltage to be applied to the X-ray source, an X-ray detector (102) which detects X-rays transmitted through a subject to be examined to generate projection data, a storage unit (203) which stores the projection data in association with electrocardiographic data of the subject, a setting unit (207) which sets a specific cardiac phase in accordance with an operator's instruction, a reconstruction unit (206) which reconstructs a tomogram on the basis of a plurality of projection data sets acquired in a plurality of specific periods centered on the specific cardiac phase throughout a plurality of cardiac cycles, a period extending unit (207) which extends the specific period on the basis of a heart rate fluctuation range of the subject, and a control unit (212) which controls the high voltage generating unit to generate a relatively high dose of X-rays in the extended specific period and generate a relatively low dose of X-rays in a period other than the extended specific period.

X-Ray computed tomography apparatus

An X-ray imaging apparatus comprises an X-ray emission unit for emitting X-rays onto a human body under examination, an X-ray emission control unit for outputting an X-ray emission signal to direct the X-ray emission unit to emit X-rays, a flat panel X-ray detector having a two-dimensional array of detector elements in rows (lines) and columns, each of the detector elements converting incident X-rays passed through the human body under examination into an electric charge signal and storing it, a resetting unit for placing each line of the detector elements in the readout state in sequence, thereby discharging electric charge stored on each of the detector elements, a storage unit for placing all the lines of the detector elements in the readout state to thereby allow each of the detector elements to store an electric charge signal, and a readout unit for placing each line of the detector elements in the readout state in sequence to thereby read an electric charge signal from each of the detector elements.

X-ray imaging apparatus using X-ray planar detector

A diagnostic apparatus for diagnosing the circulatory system of a patient, including an X-ray diagnostic system and an ultrasonic diagnostic system. The ultrasonic diagnostic system has an ultrasonic catheter for insertion into the circulatory systems of the patient and for scanning a circulatory organ with an ultrasonic wave to thereby an ultrasonic tomogram. A roadmap image is obtained prior to the ultrasonic diagnosis. When the ultrasonic catheter is inserted into the circulatory system of the patient, the X-ray diagnosis is performed to obtain a live image of the circulatory system which includes a picture of the catheter and is displayed overlapped on the roadmap image. The ultrasonic catheter is inserted into the circulatory system of the patient while the location of the catheter is monitored from the overlapped display of the live image and the roadmap image.

Diagnostic apparatus for circulatory systems

Flat-panel detector (FPD) is the driving force for realizing the next generation of x-ray systems. The purpose of this study was to develop a selenium-based FPD for both radiography and fluoroscopy. The detector uses amorphous selenium (a-Se) and a thin-film transistor (TFT) array. The simple construction of the a-Se layer permits real-time readout. The unique response characteristics of the FPD, which can be saturated over permitted x-ray doses, are provided by the TFT structure. Our prototype FPD was designed to acquire images at 30 frames per second (fps). A high modulation transfer factor was obtained: 0.63 at 2.0 Lp/mm. Sequential fluoroscopic images were acquired at up to 30 fps. The linear characteristics of the detector covered the commonly employed range of clinical exposure dose. Less than 1.5% image lag was measured at 30 fps.

Development of a selenium-based flat-panel detector for real-time radiography and fluoroscopy

Pixel data in a region of a flat panel detector is obtained and displayed. For example, pixel data in a region irradiated with X-ray is obtained and displayed. The region to be irradiated with-the X-ray is estimated according to a degree of opening of an X-ray beam limiting device and a distance between the X-ray beam limiting device and the flat panel detector. Further, it can be determined from pixel data value of the flat panel detector also. A region of a patient can be also determined from the pixel data. Thus, an image corresponding to the entire flat panel detector, an image corresponding to an X-ray irradiation region and an image corresponding to a patient region can be displayed. A resolution for obtaining the pixel data is changed corresponding to the size of a region in the flat panel detector whose pixel data should be obtained and a processing resolution of an image processing means at post step. Particularly in an X-ray diagnostic apparatus of bi-plane structure, an observation region can be traced flexibly.

X-ray diagnostic apparatus using an X-ray flat panel detector and method for controlling the X-ray diagnostic apparatus

PURPOSE: To heighten the rate at which images are collected without causing deterioration of the dynamic range of signals by providing an A/D converter to each line of a first signal processing portion for spliting into plural lines a signal from an image pickup means, and providing a second signal processing portion for synthesizing and outputting signals from the A/D converter. CONSTITUTION: An X-ray image pickup device 1 consists of image converting means I.I.2, a solid photographing element 3 for converting optical images into electric signals, a first signal processing portion 4 for splitting each signal into plural lines, and a second signal processing portion 5 for synthesizing signals and outputting them on one line as a signal of an image on one screen. Signals are each split into two lines by the signal processing portion 4 and subjected to A/D conversion on each line at different sampling timing and are therefore subjected to parallel processing shared by A/D converters 12a, 12b. The speed at which each A/D converter 12a, 12b processes signals is the same as in conventional ways but the sampling frequency of the whole signals is half the frequency of input signals to the first signal processing portion 4 and the rate of image collection is made as high as twice its conventional maximum value. COPYRIGHT: (C)1992,JPO&Japio

Akira Tsukamoto

Papers

X-ray imaging apparatus using X-ray planar detector

Diagnostic apparatus for circulatory systems

Development of a selenium-based flat-panel detector for real-time radiography and fluoroscopy

X-ray diagnostic apparatus using an X-ray flat panel detector and method for controlling the X-ray diagnostic apparatus

X-ray image pickup device