Method and an apparatus for recording bladder volume

Abstract

The invention relates to a method and an apparatus for recording volume in humans or animals. The method is non-invasive, and two or more phased-array ultrasound transducers are used for the recording of the volume of the bladder, which, in a bell or a waistband of a pair of trousers, are positioned on the same circle, whose centre is disposed above the bladder whose volume is to be determined. The transducers are oriented in such a manner relative to the bladder to be measured that the ultrasound signals penetrate the surface of the bladder to some extent perpendicularly to it, thereby optimizing the signal/noise ratio. The apparatus, which forms part of the invention, contains no mechanically movable parts and is therefore sturdy, has a low noise level and may easily be powered by small batteries. The apparatus has a low weight and volume and may be used for long term monitoring of the volume of the bladder of ambulatory or sleeping individuals without appreciable discomfort. The apparatus may be used for giving an alarm when the recorded volume of a bladder exceeds a programmable maximum, which may e.g. be of benefit to individuals who suffer from urinary nocturnal incontinence.

1 . A method of recording the bladder volume in humans or animals, characterized in that the recording takes place on the basis of analysis of signals from two or more ultrasound transducers which are arranged in a portable fixture, such as a belt or a waistband of a pair of trousers, which is attached to the individual being measured, and in that each transducer, by signal sweep, images a plane in the body of the individual being measured, which in one dimension, runs radially from each individual transducer to the centre of a circle on which all the transducers are positioned.  
     
     
         2 . A method of recording the bladder volume according to  claim 1 , characterized in that the transducers used re fixed mechanically as phased-array units.  
     
     
         3 . A method of recording the bladder volume according to  claim 1  or  2 , characterized in that a central line passing through the centre of the circle perpendicularly to the circle face will extend through the mass centre of the bladder in the individual being measured.  
     
     
         4 . A method of recording the bladder volume according to  claim 3 , characterized in that the transducers are positioned such that lines of sight drawn perpendicularly out from the centre of the measuring face for each transducer will extend through the same point on the central line of the circle on which the transducers are positioned, in a direction toward the bladder which is to be measured.  
     
     
         5 . A method of recording the bladder volume according to one or more of claims  1 - 4 , characterized in that the signals from the ultrasound transducers are processed in an electronic circuit which is integrated in the fixture, and which calculates the volume of the bladder and is capable of emitting a signal if the volume exceeds a preselected maximum.  
     
     
         6 . An apparatus for recording the bladder volume in humans or animals, characterized in that the apparatus contains two or more mechanically fixed ultrasound transducers of the phased-array type, and in that each transducer, by signal sweep, images a plane in the body of the individual being measured, which, in one dimension, is described by a line extending through the transducer and the central line extending through the centre of a circle line on which the transducer is positioned, said transducers being arranged in a portable fixture, such as a belt or a waistband of a pair of trousers, which may be attached to the individual being measured, as well as a calculation unit which is capable of calculating the volume of the bladder on the basis of the signals from the ultrasound transducers.  
     
     
         7 . An apparatus for recording the bladder volume according to  claim 6 , characterized in that two transducers are positioned on a common circle line with a spacing of 90 degrees.  
     
     
         8 . An apparatus for recording the bladder volume according to  claim 6 , characterized in that three or more transducers are positioned equidistantly on a common circle line.  
     
     
         9 . An apparatus for recording the bladder volume according to  claim 6 ,  7  or  8 , characterized in that the transducers are positioned on a common circle line in such a manner that lines of sight pointing perpendicularly out from the centre of the active surface of each transducer in a direction toward the object to be measured, will extend through the same point on the central line extending through the centre of the circle on which all the transducers are positioned.  
     
     
         10 . An apparatus for recording the bladder volume according to one or more of claims  6 - 9 , characterized in that the fixture has integrated therein electronic circuits which are used for controlling the transducers as well as processing the signals from the transducers, which electronic circuits may be connected to an input medium, such as a keyboard, and an output medium, such as a sound generator or vibrator.  
     
     
         11 . An apparatus for recording the bladder volume according to one or more of claims  6 - 10 , characterized in that the belt has integrated therein electronic circuits which are capable of wirelessly communicating with external units, such as computers or mobile telephones.  
     
     
         12 . An apparatus for recording the bladder volume according to one or more of claims  6 - 11 , characterized in that the apparatus is powered from batteries which are integrated in the fixture, and which may be rechargeable.