Patient monitor

• US 10,154,803 B2
• Filed: 04/16/2015
• Issued: 12/18/2018
• Est. Priority Date: 09/05/2006
• Status: Active Grant

• Current Assignee: Vision RT Limited
• Original Assignee: Vision RT Limited
• Inventors: Meir, Ivan Daniel, Smith, Norman Ronald, Ruto, Anthony Christopher
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US14/688,853
• Publication Number:
  US 20150216450A1
• Time in Patent Office: 1,342 Days
• Field of Search: 600529, 600533-536, 600538, 600547
• CPC Class Codes: A61B 2576/02 specially adapted for a particular organ or body part
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61N 2005/1059 using cameras imaging the patient
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1064 for adjusting radiation treatment in response to monitoring
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/10076 4D tomography; Time-sequential 3D tomography
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/30096 Tumor; Lesion
• CPC Class Codes: G06T 7/593 from stereo images

Abstract

A patient monitor is disclosed for detecting patient movement or abnormal breathing. Images of a patient are obtained by a stereoscopic camera. These images are then processed by a 3D position determination module which determines measurements indicative of positions of at least part of a patient. The obtained measurements are then passed to a model generation module which generates a breathing model of the variation in position of the at least part of a patient during a breathing cycle. Subsequently abnormal breathing or patient movement can be detected by processing further images obtained by the stereoscopic camera to determine more measurements indicative of positions of at least part of a patient. These measurements are then compared with a stored breathing model by a comparison module. If abnormal breathing or patient movement is detected the comparison module sends a signal to a treatment apparatus to interrupt treatment until normal breathing resumes or alternatively to a mechanical couch to reposition the patient to account for the detected movement.

Claims

1. A radio therapy device, comprising:

a treatment apparatus for applying radiation to a patient, and

a patient monitor, the patient monitor including;

a 3D position determination module operable to determine measurements indicative of positions of at least part of a patient undergoing radiotherapy;

a clock module operable to associate measurements indicative of positions of at least part of a patient determined by the 3D position determination module with timing data;

a model generation module operable to (1) use obtained position and timing data for a plurality of breathing cycles obtained from the 3D position determination module and clock module to generate a component analysis model of the variation in position of at least part of a patient during the plurality of breathing cycles, and (2) model a representation of further position and timing data obtained from the 3D position determination module and clock module during a subsequent period of breathing using the component analysis model; and

a comparison module operable to calculate a Mahalanobis distance between the modeled representation of the further position and timing data and a mean representation of the generated component analysis model, and compare the calculated Mahalanobis distance with a threshold value, and halt the application of radiation if the comparison between the calculated Mahalanobis distance and the threshold value indicated the breathing cycle is abnormal.

2. The radio therapy device of claim 1, further comprising:

a phase detection module operable to process measurements indicative of positions of at least part of a patient obtained by the 3D position determination module and associate measurements with different breathing cycles, wherein the model generation module is operable to generate a component analysis model of the variation in position of the at least part of a patient during a breathing cycle using measurements determined by the 3D position determination module associated with different breathing cycles by the phase detection module.

3. The radio therapy device of claim 1, further comprising:

a stereoscopic camera operable to obtain images of a patient to be monitored, wherein the 3D position determination module is operable to process images obtained by the stereoscopic camera to determine measurements indicative of positions of at least part of a patient being monitored.