Device and method for monitoring bladder volume of a subject

Abstract

The present invention provides a device and a method for monitoring the bladder volume of a subject. A device for monitoring the bladder volume of a subject comprises a sensor to be attached to a region on the exterior surface of the abdomen of the subject, the region corresponding to the bladder of the subject, the sensor being configured to obtain a sensor signal indicating the bladder volume of the subject; a controlling unit configured to generate a control action signal if it determines, based on the sensor signal, that the change of the bladder volume of the subject exceeds a predetermined amount; an ultrasound probe to be attached to the subject and configured to emit, in response to the control signal, an ultrasonic signal toward the bladder of the subject and receive echo signals from the bladder of the subject; a deriving unit configured to derive the bladder volume of the subject from the received echo signals. According to the device, long-time monitoring of the bladder volume of the subject may be achieved.

1 . A device, comprising:
 a sensor configured to obtain a sensor signal indicative of a subject's bladder volume;   an ultrasound probe configured to contact the subject, emit an ultrasonic signal, and receive echo signals;   a controlling unit configured to (1) determine, based on the sensor signal, if a change in the subject's bladder volume exceeds a predetermined amount; and (2) if the change of the bladder volume of the subject exceeds the predetermined amount, control the ultrasound probe to emit the ultrasonic signal toward the subject's bladder and receive echo signals from the subject's bladder; and   a deriving unit configured to determine the subject's bladder volume from the received echo signals from the subject's bladder.   
     
     
         2 . The device of  claim 1 , wherein the device further comprises an alarm, and wherein the controlling unit is further configured to (1) determine whether the derived bladder volume of the subject reaches a predefined threshold and (2) control the alarm to alert a user that the derived bladder volume reached the predefined threshold if the controlling unit determines that the derived bladder volume of the subject reaches the predefined threshold. 
     
     
         3 . The device of  claim 1 , wherein the device further comprises a low-pass filtering unit configured to apply low-pass filtering to the sensor signal, wherein the controlling unit is configured to determine, based on the sensor signal, if the change the subject's bladder volume exceeds the predetermined amount by determining based on the low-pass filtered sensor signal whether a change of the subject's bladder volume exceeds the predetermined amount. 
     
     
         4 . The device of  claim 1 , further comprising one or more additional sensors configured to attach to an exterior surface of the subject's abdomen and to obtain one or more additional sensor signals 
     
     
         5 . The device of  claim 4 , wherein the controlling unit is configured to determine if the change in the subject's bladder volume exceeds the predetermined amount based on the sensor signal and the one or more additional sensor signals. 
     
     
         6 . The device of  claim 1 , further comprising a movement detecting unit configured to obtain movement data of the subject. 
     
     
         7 . The device of  claim 6 , wherein the controlling unit is further configured to (1) determine whether a variation rate of the movement data of the subject is less than a predetermined value, and (2) if the variation rate of the movement data of the subject is less than the predetermined value, to control the ultrasound probe to emit the ultrasonic signal towards the subject's bladder and receive the echo signals from the subject's bladder. 
     
     
         8 . The device of  claim 2 , further comprising a receiving unit for receiving a parameter value indicating the predefined threshold, wherein the controlling unit is configured to generate the predefined threshold based on the parameter value. 
     
     
         9 . The device of  claim 1 , wherein the ultrasound probe comprises an ultrasound transducer comprising two sets of ultrasound transducer elements configured in a cross shape or T shape, each set comprising one or more ultrasound transducer elements. 
     
     
         10 . The device of  claim 1 , wherein the sensor comprises a pressure sensor. 
     
     
         11 . The device of  claim 1 , wherein the sensor comprises a piezoelectric sensor configured to obtain a pressure signal indicative of internal pressure from the subject's bladder, and the sensor signal comprises the pressure signal. 
     
     
         12 . The device of  claim 1 , wherein the sensor comprises a linear displacement sensor configured to obtain a perimeter signal indicative of a perimeter of the subject's bladder, and the sensor signal comprises the perimeter signal. 
     
     
         13 . A device comprising one or more processors and instructions stored thereon, which when executed, cause the one or more processors to implement the following steps:
 (a) obtain a sensor signal indicating a subject's bladder volume by means of a sensor contacting an exterior surface of the subject's abdomen;   (b) determine, based on the sensor signal, whether a change in the subject's bladder volume exceeds a predetermined amount based on the sensor signal;   (c) if the change of the bladder volume of the subject exceeds a predetermined amount, then cause an ultrasound probe to emit an ultrasonic signal toward the subject's bladder and receive echo signals from the subject's bladder;   (d) determine the subject's bladder volume of the subject from the received echo signals; and   (e) determine whether the bladder volume of the subject reaches a predefined threshold;   
     
     
         14 . The device of  claim 13 , the steps further including: if it is determined that the bladder volume of the subject does not reach the predefined threshold in the step (e), then repeat steps (a)-(e). 
     
     
         15 . The device of  claim 13 , the steps further including: alert a user if the derived bladder volume of the subject reaches the predefined threshold in the step (e).