US-12622589-B2 - Method and examination apparatus for medical examination of an animal

US12622589B2US 12622589 B2US12622589 B2US 12622589B2US-12622589-B2

Abstract

A method for medical examination, in particular determination of the blood pressure of an animal that preferably has a paw and is in particular an animal of the subfamily of the Felinae. In the method, a curve comprising information about the arterial blood flow of the animal, in particular a photoplethysmogram, is recorded, and the curve is cut into several curve sections in such a way that each curve section corresponds to a heartbeat. According to another independent aspect, a sensor or a subset of sensors is selected from several sensors of the same kind to perform the examination.

Inventors

Urs Anliker
Tanja Margrit ZIMMERING
Stefan Bauer
Marco BURGENER
Christian Kauth
Jeannine FLETH-JAMES
Reinhard FORBERGER
Silke HAAG-DIERGARTEN
Dagmar POLOTZEK
Daniela Katharina RAHMEL

Assignees

BOEHRINGER INGELHEIM VETMEDICA GMBH

Dates

Publication Date: 20260512
Application Date: 20201015
Priority Date: 20191017

Claims (20)

1 . A method for blood pressure determination of an animal, comprising: using a sensor device having a plurality of sensors which form a sensing region for measuring arterial blood flow and transmitting readings of the sensors to a recording device, said plurality of sensors being located in an area larger than that which would be contacted by the animal during said determination and wherein a specific partial region of the sensing region is selected for medical examination, recording a curve comprising information about an arterial blood flow of the animal with the recording device, and automatically cutting the curve into several curve sections in such a way that each curve section corresponds to a heartbeat, the curve sections being produced using different sensors of said plurality of sensors; recording and using curve sections of curves recorded simultaneously with the different sensors for evaluation in a manner compensating for motion artifacts or errors caused by a movement of the animal during measurement or recording, and determining the blood pressure from readings of the curve sections using a resampling method in which statistical properties of sample statistics are determined based on a repeated drawing of subsamples from an initial sample, wherein the initial sample comprises the plurality of the curve sections and the subsamples are automatically created by selecting curve sections from the initial sample.
2 . A method for blood pressure determination of an animal, comprising: using a sensor device having a plurality of sensors which form a sensing region for measuring arterial blood flow and transmitting readings of the sensors to a recording device, said plurality of sensors being located in an area larger than that which would be contacted by the animal during said determination and wherein a specific partial region of the sensing region is selected for medical examination, recording a curve comprising information about an arterial blood flow of the animal with the recording device, and automatically cutting the curve into several curve sections in such a way that each curve section corresponds to a heartbeat; determining the blood pressure from the curve sections using a resampling method in which statistical properties of sample statistics are determined on the basis of a repeated drawing of subsamples from an initial sample, wherein the initial sample comprises a plurality of the curve sections and the subsamples are automatically created from selected curve sections from the initial sample.
3 . The method according to claim 2 , further comprising carrying out an averaging on the basis of the several curve sections for evaluation of the information.
4 . The method according to claim 2 , wherein a subset of the curve sections is selected for evaluation.
5 . The method according to claim 2 , wherein a length of the curve sections is determined on the basis of an average heart rate.
6 . The method according to claim 2 , wherein the resampling method is a bootstrap method.
7 . The method according to claim 2 , wherein a curve feature is determined from at least one of (a) the curve sections or (b) subsamples, wherein at least one of (a) a curve feature is determined for each subsample or (b) a mean value is determined from several curve features.
8 . The method according to claim 7 , wherein a measure of dispersion of the curve feature is determined, wherein several curves are recorded and one of the curves is selected for further evaluation on the basis of the measure of dispersion.
9 . The method according to claim 7 , wherein the blood pressure is determined by means of a correlation function based on the curve feature.
10 . The method according to claim 2 , wherein a cardiogram is recorded simultaneously with the curve, wherein cutting of the curve into curve sections is performed by means of information from the cardiogram, wherein R peaks of QRS complexes of the cardiogram are used to determine times of heartbeats, wherein the curve is cut into curve sections at the times determined by means of the QRS complexes, wherein at least one of (a) a Pan-Tompkins plot of the cardiogram or (b) an adaptive threshold value are used for determining the R peaks or their positions, wherein the positions of the R peaks determined by means of the Pan-Tompkins plot are subsequently corrected.
11 . The method according to claim 2 , wherein a cardiogram is recorded simultaneously with the curve, wherein the cardiogram is automatically checked for usefulness, wherein, if the cardiogram is not useful, the cardiogram and the curve are discarded and a new cardiogram and a new curve are recorded.
12 . The method according to claim 2 , wherein the curve is at least one of (a) automatically or (b) repeatedly checked for usefulness, wherein, if the curve is not useful, the curve or individual curve sections are discarded and a new curve is recorded.
13 . The method according to claim 2 , wherein a diastolic blood pressure is determined.
14 . The method for medical examination of an animal according to claim 1 , wherein an arterial blood flow of the animal is optically examined by carrying out a photoplethysmography with said sensor device, wherein the sensor device comprises one or more emitters of the same kind for emitting electromagnetic radiation and several detectors of the same kind for detecting the radiation emitted by the emitter, so that the emitter/emitters and detectors form several sensors of the same kind.
15 . The method according to claim 14 , wherein the sensors each have a sensor region, the sensor regions of the sensors each being located at different locations and together forming said sensing region, so that with each sensor a different partial region of the sensing region is sensed.
16 . The method according to claim 14 , wherein the animal is one having paws, and wherein a location of a paw within the sensor region of the sensor is checked, wherein the check comprises analyzing a signal measured with the sensor.
17 . The method according to claim 14 , wherein the animal is one having paws, and wherein a position of a paw of the animal is determined relative to the sensor device or the sensors.
18 . The method according to claim 17 , wherein the determined position of the paw is stored and during a recording of at least one curve comprising information about the arterial blood flow with the selected sensor/sensors, it is at least one of (a) automatically, (b) continuously or (c) regularly checked whether the position of the paw has been changed.
19 . The method according to claim 18 , wherein a new or repeated position determination of sensors takes place when it has been determined that the position of the paw has been changed.
20 . The method according to claim 14 , wherein several curves comprising information about an arterial blood flow are recorded with the sensors, wherein at least one of the curves is selected for evaluation, wherein a quality of the recorded curves is determined by means of a statistical analysis and the curve with the highest quality is selected for evaluation.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method for medical examination of an animal as well as an examination apparatus, a computer program and a computer-readable storage medium. Generally, it is an aim of the present invention to enable or simplify a noninvasive blood pressure measurement in pets such as cats or dogs. In humans, an inflatable cuff, which is placed around the arm, is often used for non-invasive blood pressure measurement. However, measuring blood pressure with a cuff is not unproblematic for dogs and in particular for cats, because these animals are not used to such examinations and in particular for cats it can thus be difficult to put on a cuff. On the other hand, the application of a cuff is also associated with stress for the animal, which should be avoided if possible, as the stress can falsify the result of the measurement. However, the present invention is not limited to the application to pets such as cats or dogs, but can in principle be used for any kind of animal, in particular humans as well. Furthermore, the present invention is not limited to a blood pressure measurement, but is generally designed or suitable for medical examination, in particular an optical, non-invasive and/or percutaneous examination, particularly preferably photoplethysmography and/or pulse oximetry. Description of Related Art In addition to a blood pressure measurement using a cuff, other methods for non-invasive determination of blood pressure are already known in the prior art. International Patent Application Publication WO 85/03211 A1 relates to a method for determining the arterial blood pressure, in which heartbeats are measured by means of an electrocardiography and an arterial blood flow is measured by means of a photoplethysmography. The blood pressure is then determined from the time interval between a heartbeat and a pulse wave in the arteries triggered thereby and measured by the photoplethysmography. This is done by taking advantage of the fact that the blood pressure is correlated with the time span between the heartbeat and the resulting pulse wave in the arteries triggered thereby. The time between a heartbeat and the resulting pulse wave in the arteries is also called pulse transit time. International Patent Application Publication WO 89/08424 A1 and corresponding U.S. Pat. No. 5,237,997 relate to a method for the continuous measurement of blood pressure in humans. To determine one of the three blood pressure quantity (systolic, diastolic or mean blood pressure), the pulse transit time is measured continuously, making use of a proband-specific calibration curve which indicates the pulse transit time as a function of the blood pressure quantity used. To measure the pulse transit time, an ECG is recorded by means of two electrodes placed over the patient's heart and a sensor is attached to the earlobe with an ear clip. A small light source of the sensor shines through the earlobe and the transmission of the earlobe, which varies proportionally with the blood pressure, is measured by a photodiode. The temporal transmission curve shows the arrival of the pulse wave at the earlobe relative to the systole registered by the ECG signal. Thus, the pulse transit time is determined for the distance between the heart and the earlobe. SUMMARY OF THE INVENTION It is an object of the present invention to provide a solution by which a reliable, accurate, fast and/or non-invasive, in particular cuff-free, medical examination, in particular blood pressure measurement, of animals such as dogs or cats is made possible and the examination or measurement is made as pleasant as possible for the animal. The above object is solved by a method, an examination apparatus, a computer program and a computer-readable storage medium as described herein. In particular, the present invention relates to a method for the medical examination of an animal. In particular, a blood pressure of the animal is determined with the method. The determined blood pressure can in particular be a diastolic blood pressure. Furthermore, the method is preferably configured and/or suitable for the examination of animals having a paw, preferably animals from the superfamily of the Feloidea (cat-like) or Canoidea (dog-like), in particular animals from the family of the Felidae (cats) or Canidae (dogs), particularly preferably animals from the subfamily of the Felinae (small cats) or the tribe of the Canini (true dogs), in this tribe particularly animals of the genus Canis (wolf-like and jackal-like), particularly preferably domestic cats or domestic dogs. In principle, however, the method is suitable for the medical examination, in particular blood pressure determination, of any animals, in particular humans. In the method according to the invention, an arterial blood flow of the animal is optically examined, preferably with a sensor device. Particularly preferably, a photoplethysmography is perfor