MX2008005151A - Method and system for managing interventional pulmonology - Google Patents

Abstract

The invention provides a method and system for assessing an interventional pulmonology procedure. A plurality of sound transducers are fixed on a surface of the individual over an individual's respiratory tract that generate signals indicative of pressure waves at the transducers. A processor receives the signals and generates from the signals an image indicative of airflow in at least a portion of the respiratory tract before the interventional pulmonology procedure is carried out. A second image indicative of airflow in at least a portion of the respiratory tract is then generated from the signals after the interventional procedure has been carried out. display the first and second sequences of images simultaneously on a display device. The first and second images are then displayed on a display.

Description

METHOD AND SYSTEM FOR MANAGING PULMONOLOGY OF INTERVENTION DESCRIPTION OF THE INVENTION The invention relates to medical devices and methods, and more particularly to those devices and methods to carry out an intervention procedure. Interventional pulmonology is a field of pulmonary medicine focused on the use of bronchoscopy, pleuroscopy and other techniques for the treatment of thoracic disorders such as tracheobronchial stenosis and pleural effusions associated with malignant tumors. Several techniques, such as rigid bronchoscopic recanalization, balloon dilation, laser bronchoscopy, cryotherapy, electrocautery, bronchial therapy, photodynamic therapy, valve placement and stenting are of therapeutic use for the management of airway stenosis. A careful pretreatment evaluation is necessary to identify the source of airway obstruction and to select the course of treatment. Pulmonary function test (PFT) techniques and thoracic imaging such as computed tomography (CT) have been used in the evaluation of a patient with a suspected obstruction of the central airways, although bronchoscopy is considered as the diagnostic gold standard. He follow-up includes evaluation of treatment success (ie recanalization / resection index, rate of repeated interventions), complications (ie, stent migration, perforation of the respiratory tract, fistula formation), evaluation of clinical symptoms (ie say, dyspnea relief) and clinical outcomes such as lung function test results. Body sounds are routinely used by doctors in the diagnosis of various disorders. A doctor may place a stethoscope on a person's chest or back and monitor the patient's breathing to detect adventitious (ie, abnormal or unexpected) lung sounds. The identification and classification of lung sounds adventitious often provides important information about lung abnormalities. U.S. Patent No. 6,887,208 to Kushnir et al. , provide a system and method for recording and analyzing sounds produced by the respiratory tract. The sounds of the respiratory tract are recorded in a plurality of places in the individual's chest and the recorded sounds are processed to produce an image of the respiratory tract. The method involves determining, from recorded signals, an average acoustic energy, in a plurality of places in the thorax during a time interval from i to t2.

The term "acoustic energy" in one place is used in this document to refer to the parameter indicative of, or approximately, the product of the pressure and velocity of propagation of the mass at that location. The image can be used to analyze the physiology of the respiratory tract and to detect pathological conditions. In addition, a time interval can be divided into a plurality of sub-intervals, and an average acoustic energy determined at a plurality of places in the thorax for two or more of the sub-intervals. An image for each of these sub-intervals can then be determined and displayed sequentially on a display monitor. This generates a film showing dynamic changes that occur in the acoustic energy in the respiratory tract in the time interval. In the following description and set of claims, two variables explicitly described, calculable or measurable are considered equivalent when two variables are proportional to each other. In this first aspect, the present invention provides a method for handling an intervention pulmonary procedure. As used herein, the term "interventional pulmonary procedure" refers to any interventional procedure that affects the flow of air in the tract. respiratory during breathing. Such procedures include, for example, balloon dilation, laser bronchoscopy, cryotherapy, electrocautery, bronchial therapy, photodynamic therapy, and stent placement and administration of medication in target areas in the lungs. According to the invention, microphones are placed on the surface of the body of an individual in a plurality of places in the thorax. One or more times before carrying out a pulmonary intervention procedure, signals indicative of sounds of the respiratory tract are recorded. The signals are analyzed to generate one or more images of the respiratory tract indicative of the air flow in the respiratory tract of the individual before the procedure is carried out. One or more times after the intervention procedure, signals indicative of sounds of the respiratory tract are recorded again. The signals are analyzed to generate one or more images of the respiratory tract indicative of the air flow in the individual's respiratory tract after the procedure has been carried out. The images obtained before and after the procedure are compared to determine if a change in air flow occurred as a result of the intervention. The system of the invention includes a plurality of N transducers (microphones) configured to join an essentially planar region R of the back or chest of a guy in the chest. The transducers are inserted in a matrix that allows them to easily adhere to the skin of the individual. Such a matrix can usually be in the form of a vest or clothing to facilitate the adhesion of the microphones to the skin in the thorax. As you can see, different matrices can be used to accommodate individuals of different sizes, ages, sexes, etc. The system of the invention further comprises a display device for simultaneously displaying at least one image obtained before the intervention procedure and at least one image obtained after the procedure to allow the user to compare the images and determine whether a change occurred in the the air flow in the respiratory tract after the procedure. In a preferred embodiment, a first time interval before a procedure is carried out and a recent time interval after the procedure is carried out are each divided into a plurality of sub-intervals, and an image is produces for each sub-interval. This generates a first sequence of images indicative of the airflow of the respiratory tract before the procedure, and a second sequence of images indicative of airflow after the procedure. When the images in a sequence are displayed sequentially on the display device, the sequence is visualized as a film of the air flow of the respiratory tract in the time interval. Therefore, in a more preferred embodiment, a film of the airflow of the respiratory tract is obtained before and after the intervention procedure, and two films are displayed simultaneously on the display device. The positions in the R region are indicated by two-dimensional position vectors x = (x1, x2) in a two-dimensional coordinated system defined in the planar region R. The i-th transducer, for i = the N, is fixed at a position x2 in the region R and generates a signal, indicated here by L? (xl f t) indicative of pressure waves in the body reaching x? . Any known method for generating respiratory tract images from P (x2, t) can be used according to the invention. In a preferred embodiment, the respiratory tract images are obtained as described in U.S. Patent No. 6,887,208 to Kushnir et al. This patent describes a system and method for calculating an average acoustic energy in the region of a plurality of places x in the region R in a time interval from i to t2 indicated in this document by t2), from the signals P (xl f t) and generating an image of the lungs from P (x, t?).

In one embodiment of the invention, an average acoustic energy in a time interval from ti to t2 is obtained at a position of one of the microphones using the algebraic expression n? (»,?, ft)« JP2 (*, f) dr (1) Where xi is the position of the microphone. In a more preferred embodiment, an average acoustic energy "\ * /" 'J "' 2 / in a time interval from ti to t2 is obtained in a plurality of xx positions of the microphones, for example, using Equation (1) ), and then calculating • * (>?, f2) in other places x by interpolation of -P (x <, ív1, í2) using any known interpolation method. In a more preferred embodiment, the interpolation is performed to obtain an average acoustic energy "x **?" * 2) at a position x = (x1, x2) on the surface R using the algebraic expression: P (x, í t?) = 2P (x "í?, F2) g (, x (, s) (2) / =? Where g (x, x ^ r s) is a satisfactory central module (3) ds is approximately equal to 1 and where xx - (x11, x12) is the position of the i-th microphone and s is an eligible parameter. For example, the central module can be used It will also be understood that the system according to the invention can be a properly programmed computer. In the same way, the invention contemplates a computer program that is readable by a computer to execute the method of the invention. The invention further contemplates a machine readable memory tangibly representing a program of instructions executable by the machine to execute the method of the invention. Therefore, in this first aspect, the present invention provides a system for evaluating an interventional pulmonary procedure comprising: (a) a plurality of N transducers, each transducer configured to be fixed on a surface of the the respiratory tract of the individual, the i-th transducer that is fixed at a place x ± y that generates a signal P (x, t) indicative of pressure waves at the place xx; for i = 1 to N; (b) and a processor configured to (i) receive the signals P (xlrt) (ii) generate a first sequence of one or more images indicative of airflow in at least a portion of the respiratory tract from the signals P (xx, t) in a first time interval from a first time t \ to a second time t2, where the time interval from ti to t2 occurs before the intervention pulmonary procedure is carried out; (iii) generating a second sequence of one or more images indicative of the air flow in at least a portion of the respiratory tract from the signals P (xl rt) in a second time interval from a third time t3 a a fourth time t4, where the time interval from t3 to t4 occurs after the intervention procedure has been carried out; (iv) displaying the first and second sequences of images simultaneously in a display device; (C) The display device simultaneously displays the sequences of respiratory tract images generated by the processor. In this second aspect, the invention provides A method for evaluating an intervention pulmonary procedure in an individual, comprising: (a) Obtaining a first sequence of one or more images indicative of air flow in at least a portion of the individual's respiratory tract before carrying out the procedure of pulmonary intervention, (b) Obtaining a second sequence of one or more images indicative of the air flow in at least a portion of the individual's respiratory tract after carrying out the intervention procedure; and (c) Compare the first and second image sequences to determine a change in airflow in the respiratory tract after the pulmonary intervention procedure.; wherein one or more images are obtained in a process, comprising: (i) attaching a plurality of N transducers, on the surface of the individual in the individual's respiratory tract, the i-th transducer being fixed at the point x; (ii) obtain a signal P (x, t) indicative of the pressure waves at the place x; for i = l to N; (iii) generate the image from obtained signals P (x, t). In its third aspect, the invention provides a computer program comprising code means of computer program to perform all steps of the method of the invention when the program is executed on a computer. In its fourth aspect, the invention provides a computer program comprising computer program code means for performing all steps of the method of the invention when the program is executed on a computer represented on a computer readable medium. BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and see how the practice may be carried out, a preferred embodiment will now be described, by way of only a non-limiting example, with reference to the accompanying drawings, in which: Figure 1 shows a system for managing intervention pulmonology according to an embodiment of the invention; Figure 2 shows a flow diagram for carrying out a method for managing intervention pulmonology according to an embodiment of the invention; Figure 3a shows an image of the respiratory tract of an individual in which a tumor obstructs the right main bronchus restricting the air flow in the right lung and Figure 3b shows an image of the respiratory tract of the same individual after the implementation of a stent in the right main bronchus; Figure 4a shows an image of the respiratory tract of an individual in which a tumor obstructs the right main bronchus restricting the air flow in the right lung and Figure 4b shows an image of the respiratory tract of the same individual after the laser resection of the right main bronchus; and Figure 5a shows an image of the respiratory tract of an individual in which a foreign body obstructs the left main bronchus restricting air flow in the left lung and Figure 5b shows an image of the respiratory tract of the same individual after removing the strange body. Figure 1 shows a system generally indicated by 100 for carrying out and evaluating a pulmonary intervention procedure according to one embodiment of the invention. A plurality of N sonic transducers 105, of which four are shown, are applied to the flat region of the skin of the chest or back of the individual 110. The transducers 105 can be applied to the subject by any means known in the art, for example , using adhesive, suction or tie strips. Each transducer 105 produces a voltage analogue signal 115 indicative of pressure waves reaching the transducer. The analog signals 115 are digitized by a multichannel analogue to the digital converter 120. The digital data signals 125 (x?, T) they represent the pressure wave at the xx place of the i-th transducer (i = l to N) at time t. The data signals 125 are inputs to a memory 130. The data input to the memory 130 is accessible by means of a processor 135 configured to process the data signals 125. The signals 125 can be removed by filtering noise that has frequencies outside the range of lung sounds, for example, vibrations due to the movement of the individual. Each signal 125 may also be subject to bandpass filter so that only the components in the signal in a range of interest are analyzed. An input device such as a computer or mouse keyboard 140 is used to input relevant information related to the examination, such as personal details of the individual 110. The input device 140 can also be used to input values of a first pair of times i and t2 where the time interval of ia t2 occurs before the intervention procedure has been carried out. The processor 135 performs an analysis of the signals P (x ±, t) from i to t2 to generate one or more images 137 indicative of air flow in the respiratory tract of the individual prior to the intervention procedure. In a preferred embodiment, the analysis involves determining an average acoustic energy P (x, tl, t2) in a time interval from i to t2 in at least one place x in the region R in a calculation involving at least one of the signals P (x ±, t). The input device 140 can also be used to input values in a second pair of times t3 and t4 where the time interval t3 to t4 occurs after the intervention procedure has been carried out. The processor 135 then performs an analysis of the signals P (xl f t) from t3 to t4 to generate one or more images 139 indicative of the air flow in the individual's respiratory tract after the intervention procedure has been carried out. The images 137 and 139 of the respiratory tract generated before and after the intervention procedure are simultaneously displayed on the display device 150, as a monitor screen. In a more preferred embodiment, the time intervals from i to t2 and from t3 to t are divided into a plurality of sub-intervals, and an image of the signals P (x ±, t) of each sub-interval is generated. This generates films of the airflow of the respiratory tract before and after the intervention procedure which are simultaneously displayed in the display device 150. Figure 2 shows a flow chart for managing a pulmonary intervention procedure according to an embodiment of the method of the invention. In step 200, the values of times i and t2 are input to the processor 135 using input devices 140 or 145 where the time interval of i and t2 occurs before the pulmonary intervention procedure is carried out. In step 205, the signals P (x, t) are obtained from N transducers placed at predetermined locations xx for i from 1 to N in a region R resting on the lungs in a time interval from a time ti to a time t2 . In step 210, an average acoustic energy is calculated while the individual is breathing in a plurality of places x in the region R for one or more sub-intervals of the time interval i to t2. In step 215 a first sequence of one or more images of the lungs is generated from average acoustic energies indicative of air flow in the individual's respiratory tract before carrying out the intervention procedure. In step 230 time values t3 and t enter the processor 135 using the input devices 140 or 145, where the time interval t3 to t4 occurs after the pulmonary intervention procedure has been carried out. In step 235, the signals P (xl t) are obtained from N transducers located at the locations xx for i from 1 to N in the R region. In step 240, an average acoustic energy for one or more sub-intervals is calculates in a plurality of places x in the R region for one or more interval sub-intervals of time t3 to t4. In step 245, a second sequence of lung images of average acoustic energies indicative of air flow in the individual's respiratory tract after the intervention procedure is generated. In step 250, the first and second images are displayed simultaneously in the display device 150. In step 255, the first and second images are compared and the effect of the intervention process is evaluated. EXAMPLES The system and method of the invention were used to perform a pulmonary intervention procedure. Figure 3a shows an image 300 of the right lung 302 and the left lung 304 of an individual indicative of air flow in the lungs obtained by a method described in US Patent 6,887,208 to Kushnir et al using equations (2), ( 3) and (4) mentioned above with s = 36. The 300 image was obtained in the meso-respiratory phase. A tumor obstructs the right main bronchus restricting the flow of air in the right lung 302. The air flow in the left lung 304 appears unobstructed. Figure 3b shows an image 306 of lungs 302 and 304 of the same individual in the meso-respiratory phase obtained by the same method after placement of a stent in the right main bronchus. The Comparison of the image 300 of Figure 3a with the image 306 of Figure 3b shows that after the implementation of the stent, the airflow in the right lung 302 was significantly increased. Figure 4 shows an image 400 of the left lung 402 and the right lung 404 of an individual indicative of air flow in the lungs obtained by the method described in US Patent 6,887,208 to Kushnir et al using equations (2), (4) ) and (4) mentioned above with s = 36. The 400 image was obtained in the meso-respiratory phase. A tumor obstructs the right main bronchus by restricting the flow of air in the right lung. The airflow in the left lung 404 appears unobstructed. Figure 4b shows an image 406 of lungs 402 and 404 of the same individual in the meso-respiratory phase obtained by the same method after laser resection of the right main bronchus. The comparison of the image 400 of Figure 4a with the image 406 of Figure 4b shows that after the laser resection, the air flow in the right lung 402 increased significantly. Figure 5 shows an image 500 of the left lung 502 and the right lung 504 of an individual indicative of air flow in the lungs obtained by the method described in US Pat. No. 6,887,208 to Kushnir et al using the equations (2), (5) and (4) mentioned above with s = 36. The 500 image was obtained in the meso-respiratory phase. A foreign body obstructs the left main bronchus restricting the flow of air in the left lung. The air flow in the right lung 504 appears unobstructed. Figure 5b shows an image 506 of lungs 502 and 504 of the same individual in the meso-respiratory phase obtained by the same method after removing the foreign body from the left main bronchus. The comparison of the image 500 of Figure 5a with the image 506 of Figure 5b shows that after removing the foreign body, the air flow in the left lung 502 increased significantly.

Claims (18)

1. CLAIMS 1. A system for evaluating an intervention pulmonary procedure characterized in that it comprises: (a) a plurality of N transducers, each transducer configured to be fixed on a surface of the individual in a respiratory tract of the individual, the i-th transducer that it is fixed at a place x2 and that generates a signal P (x, t) indicative of pressure waves at the place xx; for i = l to N; (b) and a processor configured to (i) receive the signals P (xrt) (ii) generate a first sequence of one or more images indicative of air flow in at least a portion of the respiratory tract of the P signals (xl) ft) in a first time interval from a first time ti to a second time t2, wherein the time interval of ia t2 occurs before the intervention pulmonology procedure is carried out; (iii) generating a second sequence of one or more images indicative of air flow in at least a portion of the respiratory tract of the signals P (x, t) in a second time interval from a third time t3 to a fourth time t, where the time interval from t3 to t4 occurs before the intervention procedure has been carried out; (iv) displaying the first and second sequences of images simultaneously in a display device; (c) the display device simultaneously displays the sequences of respiratory tract images generated by the processor.
2. 2. The system in accordance with the claim 1 characterized in that the processor is configured to generate one or more images in an algorithm that involves the calculation of an average acoustic energy P. (. x > t? > ti in a plurality of positions x in one or more sub-ranges that are calculated in an algorithm involving at least one of the signals.
3. 3. The system in accordance with the claim 2 characterized in that the average acoustic energy p in a sub-time interval from tkl to tk? it is determined in one place Xj. of a transducer using the algebraic expression:
4. 4. The system in accordance with the claim 2 or 3 characterized in that the function P is determined in one or more places x in an algorithm comprising: (a) determining an average acoustic energy in a sub-interval of time from t to tk2 in a plurality of places x? of transducers; Y (b) determine an average acoustic energy in at least one place x by interpolation of determined.
5. 5. The system according to claim 4, characterized in that an average acoustic energy it is determined in a time interval from tjti to tk2 in a plurality of places x of transducers using the algebraic expression:
6. 6. The system according to claim 4 or 5 characterized in that the average acoustic energy is determined in at least one place x by interpolation of P xl, tk tk) determined using the algebraic expression: where g (x xl f s) is a satisfactory central module! -_ dS 6 ds (3) Y] g (x, X?, Cr) is approximately equal to l. (4) (-1
7. 7. The system according to one or more of the preceding claims, characterized in that at least one of the first sequence of images and the second sequence of images is a film indicative of the air flow in at least a portion of the respiratory tract.
8. 8. A method for evaluating an intervention pulmonary procedure in an individual, characterized in that it comprises: (a) Obtaining a first sequence of one or more images indicative of air flow in at least a portion of the individual's respiratory tract prior to carry out the procedure of pulmonology intervention, (b) Obtain a second sequence of one or more images indicative of air flow in at least a portion of the respiratory tract of the individual after carrying out the procedure of intervention; and (c) Comparing the first and second sequence of images to determine a change in airflow of the respiratory tract after the procedure of pulmonary intervention; wherein one or more images are obtained in a process comprising: (i) attaching a plurality of N transducers, on a surface of the individual in the respiratory tract of the individual, the i-th transducer which is fixed at a location x; (ii) obtain a signal P (x, t) indicative of pressure waves at the place x ?; for i = l to N; (iii) generate the image of the obtained signals P (??, t).
9. 9. The method of compliance with the claim 8, further characterized in that it comprises calculating an average acoustic energy P (x, f?, Í2) in a plurality of positions x in a time interval from a first time ti to a second time fc2, p is determined in an algorithm involving at least one of the signals P (x ±, t), and that generates an image of the respiratory tract based on the
10. . 10. The method of compliance with the claim 9, characterized in that the average acoustic energy p in a time interval from i to t2 is determined in a place x of a transducer using the algebraic expression:
11. 11. The method in accordance with the claim 9, characterized in that the function P is determined in one or more places x in an algorithm, comprising: (c) determining an average acoustic energy in a time interval from i to t2 in a plurality of places x of transducers; and (d) determine an average acoustic energy in p? r j_0 minus one place x by interpolation of P (x "t?, t2). determined./*
12. 12. The method in accordance with the claim 11, characterized in that an average acoustic energy P (x, t?, T2) is determined in a time interval from ti to t2 in a plurality of places xx of transducers using the algebraic expression:
13. 13. The method according to claim 12, characterized in that an average acoustic energy is determined in at least one place x by interpolation of P (x¡> t?, T2) determined using the algebraic expression: where g (x, xx, s) is a satisfactory central module 2 * = - ^ - (3) * ds N ^ .¿ • (XJ JJG) is approximately equal to 1 (4! W
14. 14. The method according to claim 13, characterized in that q (x, v1, o) is the central module
15. 15. The method according to any of claims 8 to 14, characterized in that at least one of the first sequence of images and the second sequence of images is a film that is indicative of the air flow in at least a portion of the respiratory tract . The method according to any of claims 8 to 15, further characterized in that it comprises displaying the first and second image sequences simultaneously in a display device. 17. The computer program characterized in that it comprises computer program code means for performing all steps according to any of claims 8 to 16 when the program is executed on a computer. 18. The computer program according to claim 17, characterized in that it is represented on a computer readable medium.