Autonomous system for the examination of blood vessels

Abstract

An autonomous system for the examination of blood vessels provides a digital probe (102) suitable for being placed on a patient (101) undergoing the examination and which provides images of the internal part of the body of the patient (101), a movement apparatus (100) to which the digital probe (102) is connected, a command, processing and control unit (104) connected to the movement apparatus (100) and to the digital probe (102), essentially formed by a processor which processes digital signals, by a memory in which digital data relating to the blood vessel to be examined are stored, and by a controller which moves the movement apparatus (100) and controls its movement, a monitor (103) connected to the probe (102) and to the processor for displaying the images; the memory contains a segmentation algorithm implemented through an artificial neural network, trained on a large series of acquired sample digital images relating to the area of the blood vessel of a high number of individuals, in which the processor of the command, processing and control unit (104) processes the digital image acquired by the probe (102) by applying the segmentation algorithm, moves the movement apparatus (100) until the blood vessel under examination is identified, and calculates the dimensions of the cross section of the blood vessel. The system can be managed by non-specialized personnel.

Description

Autonomous system for the examination of blood vesselsBackground of the invention

[0001] The present invention relates to an autonomous system that allows the examination of blood vessels in general and that can be used particularly but not exclusively to detect parameters of the abdominal aorta.State of the art

[0002] The abdominal aorta is the main blood vessel of the human body and runs through the abdominal cavity, in the direction of the lower limbs from the diaphragm to the fourth lumbar vertebra.

[0003] The function of the abdominal aorta is to supply oxygenated blood to the abdominal and pelvic tissues and organs and to the lower limbs.

[0004] Diseases of the abdominal aorta can lead to a dilation of this blood vessel. When the dilation of the abdominal aorta exceeds a certain value, it is called an aneurism and leads to a weakening of the aortic wall, which significantly increases the risk of rupture of the aorta.

[0005] In the event of aortic rupture, the mortality rate is very high and can vary between 70% and 90%.

[0006] Abdominal aortic aneurysm is an asymptomatic pathology and therefore the only tool currently available to prevent potentially fatal outcomes consists of screening campaigns dedicated above all to the subjects most at risk such as genetically predisposed subjects, subjects over 65 years of age, smokers, hypertensives, dyslipidemics, etc.

[0007] Current technology for abdominal aorta screening involves using an ultrasound scanner operated by a specialist physician, such as a vascular surgeon, a radiologist, an angiologist, or a cardiologist, who examines the images provided by the ultrasound scanner and provides a diagnosis.

[0008] In countries where there is a shortage of these qualified medical personnel, this causes a dramatic lengthening of the waiting lists for the aforesaid abdominal aortic screening.

[0009] Alternative diagnostic techniques to ultrasound can be computed axial tomography and magnetic resonance imaging.

[0010] However, these alternative diagnostic techniques require bulkier and more expensive apparatuses and may require additional personnel for their management such astechnicians and transporters.

[0011] Furthermore, in the case of computed axial tomography the patient is exposed to ionizing radiation, requiring limited use of this diagnostic technique in a protected environment.Object of the invention

[0012] The object of the present invention is to propose an autonomous system for the examination of blood vessels that allows to solve the problems seen above.Brief description of the invention

[0013] This object is achieved by an autonomous system for the examination of blood vessels in accordance with the first claim.Brief description of the drawings

[0014] To better understand the invention, a non-limiting exemplary embodiment thereof is described below, illustrated in the annexed drawings in which:

[0015] FIG. l shows schematically an autonomous system for the examination of blood vessels according to the invention;

[0016] FIG.2 is a block diagram of a component of the system of FIG.l;

[0017] FIG.3 is a flow chart that graphically represents the way the system of FIG.l works;

[0018] FIG.4 shows an image processed by the component of FIG.2.Detailed description of the invention

[0019] The autonomous system illustrated in FIG.l is intended to perform ultrasound screening of the abdominal aorta by measuring the diameter thereof and thus providing an early diagnosis of aortic aneurysm.

[0020] The system provides an anthropomorphic robot 100 suitable for being positioned on a patient 101 who must undergo ultrasound screening of the abdominal aorta.

[0021] The anthropomorphic robot 100 is a collaborative 7-axis force-controlled robot which recalls the human arm in shape and articulation possibilities. On each axis there is a torque sensor which gives the robot significant sensitivity.

[0022] The anthropomorphic system 100 allows to exert on a patient a variable pressure which varies according to the static and dynamic needs during the screening and according to the diagnostic needs, as will be seen later.

[0023] The system also includes a digital ultrasound probe 102 which is connected toone end of the anthropomorphic robot 100.

[0024] Lastly, the system includes a monitor 103 with keyboard and a command, processing and control unit 104 which are connected to each other.

[0025] The monitor 103 and the unit 104 are connected to both the anthropomorphic robot 100 and the ultrasound probe 102.

[0026] As illustrated inFIG.2, the unit 104 is essentially made up of a processor P which processes digital signals, by a memory M in which digital data relating to the ultrasound screening of the abdominal aorta are stored, and a controller C which moves the anthropomorphic robot 100 and controls the movement thereof.

[0027] The memory M contains a segmentation algorithm implemented through an artificial neural network, trained on a large series of acquired sample digital images, relating to the blood vessel area, coming from a high number of individuals.

[0028] In particular, the following procedure is followed to create this digital representation.

[0029] Specialized operators (medical personnel) perform an acquisition of ultrasound images of the abdominal aorta area of volunteer patients who have different physical characteristics (height, weight, etc.) from each other.

[0030] The specialized operators identify the main anatomical structures of reference for each image, and particularly the abdominal aorta, with regard to position and shape.

[0031] The images thus classified are used to train the artificial neural network that implements the segmentation algorithm.

[0032] The procedure followed by the autonomous system described above, once activated, to perform ultrasound screening of the aorta is shown in the flow chart of FIG. 3.

[0033] This procedure is disclosed below with reference to the letters indicated in the flow chart.

[0034] I - The probe 102 is manually positioned in the abdominal area of the patient 101 in contact therewith so as to send ultrasound images to the monitor 103 and to the command, processing and control unit 104. The unit 104, through its processor P, processes the digital image acquired by the probe 102 by applying the segmentation algorithm.

[0035] SI - The unit 104 activates the robot 100 and then the probe 102 according to a sequence of wide-ranging movements so that the probe 102 exerts a predetermined low pressure on the patient so as not to create problems for the patient during movement of theprobe 102. The movement of the robot 100 continues until the abdominal area of interest for the diagnosis is recognized via the segmentation algorithm.

[0036] F - Once the abdominal area of interest has been identified, the probe 102 is stopped in the area of interest and the pressure of the probe 102 on the patient is increased to better focus on the identified area.

[0037] El - The unit 104 detects whether the abdominal aorta is present in the ultrasound image.

[0038] Cl - If the abdominal aorta is not identified, the search is returned to point SI and continued.

[0039] C2 - If the abdominal aorta is identified, the search is continued.

[0040] S2 - The unit 104 operates the robot 100 according to a sequence of short-range movements, decreasing the pressure exerted on the patient by the probe 102 in the step F until the low pressure exerted in the step SI. These short-range movements allow for a refinement of the search and are calculated in real time on the basis of the patient’s anatomy identified by the segmentation algorithm.

[0041] F - Once the abdominal area of interest has been identified, the unit 104 stops the probe 102 in the area of interest and the pressure of the probe 102 on the patient is increased, as in the previous step F, to bring the area identified into better focus.

[0042] E2 - The unit 104 detects whether the abdominal aorta is present in the ultrasound image within a predetermined margin of error.

[0043] Cl - If the abdominal aorta is not identified, the search is returned to point SI and continued.

[0044] C3 - If the abdominal aorta is not identified within the predetermined margin of error, the search is returned to point S2 and continues until the abdominal aorta is identified within the predetermined margin of error.

[0045] CO - The unit 104 has identified the abdominal aorta within the predetermined margin of error and has reached the end of the search.

[0046] O - End of the search.

[0047] The digital image obtained by the unit 104 is illustrated for example in FIG.4.

[0048] The identified abdominal aorta, displayed in cross section, is represented by a circle, indicated in FIG.4 by an arrow, which identifies in a simplified manner the abdominal aorta. Alternatively, the abdominal aorta can be represented by an ellipse or by anothergeometric figure.

[0049] At this point, the unit 104 moves the probe 102 until it centres the abdominal aorta in the monitor 103 so as to optimize the display thereof.

[0050] This centering of the abdominal aorta and therefore of the probe 102 is very useful for possibly guiding the robot 100 to examine further sections of the abdominal aorta in addition to the one under examination.

[0051] Lastly, once a good-quality image has been obtained, the unit 104 calculates the diameter of the abdominal aorta using the minimum included circle method, i.e. the minimum circle that includes all the pixels relating to the abdominal aorta. This calculation is repeated by taking the probe to a series of points close to the centering position until the difference in measurement is below a certain threshold so as to maximize the reliability of the measured data.

[0052] At this point, the diameter of the abdominal aorta has been determined within a predetermined margin of error.

[0053] For the movement of the robot 100, the unit 104 uses the method of artificial potentials, creating a set of artificial attractive and repulsive forces which guide the motion of the robot.

[0054] The sample digital images acquired may also refer to a sequence of images from an ultrasound video which shows the dynamic situation of the abdominal aorta, in particular the dilation and contraction thereof. In this case, the system will allow to determine not only the diameter of the abdominal aorta but also the morphological changes of the aorta itself.

[0055] The proposed system can be applied in the clinical setting for ultrasound screening operations of abdominal aortic aneurysm, with telemedicine and / or proximity medicine modalities.

[0056] The main advantage of the robotic system described and illustrated is that it can also be supervised by non-qualified personnel and no longer requires the presence of a physician, thus lightening the workload of specialist personnel who could then dedicate themselves to more urgent tasks. This is particularly important in areas with a shortage of medical personnel, significantly reducing the waiting time for ultrasound screening for abdominal aortic aneurysm. Specialist physicians are focused only on patients actually affected by the aforesaid pathology in order to deepen the diagnosis, administer correct therapy, and in most serious cases urgently operate on the patient before the rupture of thearterial wall, very often fatal.

[0057] The robotic system disclosed and illustrated also has the advantage of reducing human errors. In fact, carrying out ultrasound examinations, due to their nature, requires not ordinary manual skills which operators in the sector acquire only over time and with experience in the field.

[0058] It should be noted that the processing of the image acquired by means of a segmentation algorithm allows for rapid and precise automatic identification of the abdominal aorta, with a procedure similar to that is identical to that of a specialist physician who manually moves the ultrasound probe, examines the images provided by the ultrasound probe and provides a diagnosis.

[0059] The robotic system described and illustrated also has the advantage of being made up of commercially available components and of requiring only specific programming of the command, processing and control processing unit 104.

[0060] A further advantage is that this robotic system can be easily assembled, disassembled and transported, and therefore, once installed in one place, can be uninstalled and installed in another place.

[0061] All the aforesaid features of this robotic system make it usable in areas of geographical disadvantage such as islands or mountain regions, where it is difficult for patients to get to specialized hospitals. In this case, it is simple to temporarily install the robotic system in a disadvantaged area and proceed with screening by non-specialized personnel of patients who live in that area and who are required to make only a minimal movement. Once the patient screening is completed, the robotic system is disassembled and transported to another disadvantaged area for a further screening.

[0062] The robotic system disclosed and illustrated can be used in general for the examination of blood vessels, in a manner similar to that seen for the abdominal aorta.

[0063] The robotic system described and illustrated can be used to detect a thrombus in a venous vessel. In this case, the unit 104, once identified the venous vessel, activates the robot 100 and therefore the probe 102 to exert on a patient a predetermined pressure capable of causing the collapse of the venous vessel. Depending on whether or not the venous vessel has collapsed as detected in the ultrasound image, the unit 104 determines the absence or presence of the thrombus in the venous vessel.

[0064] For the dynamic analysis, the robotic system described and illustrated may alsoinclude a device for monitoring the heartbeat, such as an electrocardiograph or a heart rate monitor connected to the unit 104. In this way, the analysis of the vessel is synchronized with cardiac activity to detect parameters such as the elasticity of the vessel or to measure the dimensions, flow and pressure of the vessel with greater accuracy. Above all, it becomes possible to normalize the time variable to the heart rate of the individual under investigation.

[0065] The ultrasound probe may be so programmable so that the unit 104 can vary the parameters of the probe (zoom, frequency, contrast, greys, etc) depending on the characteristics of the patient and on the situation during the examination (force exerted by the ultrasound probe, shadow areas, movements of the patient, etc).

[0066] At present, the use an ultrasound device in this autonomous system for the examination of blood vessels appears to be the best solution. However, the use of other types of diagnostic imaging devices cannot be excluded now and in the future.

[0067] Instead of the anthropomorphic robot, any movement apparatus performing the same function can be used.

Claims

CLAIMS1. Autonomous system for the examination of blood vessels comprising a digital probe (102) suitable for being placed on a patient (101) undergoing the examination and which provides images of the internal part of the body of the patient (101), a movement apparatus (100) to which said digital probe (102) is connected, a command, processing and control unit (104) connected to said movement apparatus (100) and to said digital probe (102), essentially formed by a processor (P) which processes digital signals, by a memory (M) in which digital data relating to the blood vessel to be examined are stored, and a controller (C) which moves said movement apparatus (100) and controls its movement, a monitor (103) connected to said digital probe (102) and to said processor (P) for the display of images, wherein said memory (M) contains a segmentation algorithm implemented by an artificial neural network, trained on a large series of acquired sample digital images relating to the area of the blood vessel, coming from a high number of individuals, wherein said processor (P) of said command, processing and control unit (104) processes the digital image acquired by said probe (102) applying said segmentation algorithm, moves said movement apparatus (100) until the blood vessel under examination is identified and calculates dimensions of the crosssection of said blood vessel.

2. Autonomous system for the examination of blood vessels according to claim 1, wherein to calculate the transverse dimensions of said blood vessel said processor (P) approximates said cross-section to a circle and calculates the diameter of said circle.

3. Autonomous system for the examination of blood vessels according to claim 2, wherein before calculating the diameter of said blood vessel said processor (P) centers said circle in the detected image.

4. Autonomous system for the examination of blood vessels according to any of the preceding claims, wherein said processor (P) commands said movement apparatus (100) to exert a minimum pressure on the patient in a dynamic phase of said movement apparatus (100) in which the search for the blood vessel takes place and a pressure higher than said minimum pressure in a static phase of said movement apparatus (100) once the blood vessel has been identified.

5. Autonomous system for the examination of blood vessels according to any of the preceding claims, wherein said processor (P) uses the method of artificial potentials for moving said movement apparatus (100).

6. Autonomous system for the examination of blood vessels according to claim 2 or 3, wherein said command, processing and control unit (104) calculates the diameter of the blood vessel with the method of the minimum included circle, i.e. the minimum circle that includes all the pixels relating to the blood vessel under examination.

7. Autonomous system for the examination of blood vessels according to any of the preceding claims, wherein said digital probe (102) is a digital ultrasound probe.

8. Autonomous system for the examination of blood vessels according to any of the preceding claims, wherein said movement apparatus (100) is an anthropomorphic robot.

9. Autonomous system for the examination of blood vessels according to any of the preceding claims, intended for screening the abdominal aorta, for the early diagnosis of abdominal aortic aneurysm.

10. Autonomous system for the examination of blood vessels according to any of the preceding claims, intended for detecting a thrombus in a venous vessel, wherein said command, processing and control unit (104), once the venous vessel has been identified, activates said movement apparatus (100) and therefore said digital probe (102) to exert on a patient a predetermined pressure capable of causing the collapse of the venous vessel, depending on whether or not the venous vessel has collapsed as detected in the ultrasound image said unit (104) determining the absence or presence of the thrombus in the venous vessel.

11. Autonomous system for the examination of blood vessels according to any of the preceding claims, also comprising a heart rate monitoring apparatus connected to said command, processing and control unit (104) to synchronize the analysis of the vessel with cardiac activity in order to detect parameters and measurements relating to the blood vessel.

12. Autonomous system for the examination of blood vessels according to any of the preceding claims, wherein said digital probe (102) is programmable, said command, processing and control unit (104) varying the parameters of the digital probe (102) depending on the characteristics of the patient and of the situation during the examination.

Images