Devices and methods for sensing bladder fullness

Abstract

A bladder fullness monitoring system includes a controller and an active optical sensor that is affixed to a patient's bladder. The sensor emits light onto the bladder and further detects light reflected from the bladder, in order to generate an output signal that indicates an amount of emitted light was reflected back to the detector. The controller is coupled to the optical sensor to receive and interpret the output signals, e.g., to determine when the bladder is full. The controller may be operatively coupled to a urinary control apparatus which uses the output signals to trigger urination in patients who have lost the ability to voluntarily urinate. Embodiments are particularly useful for monitoring bladder fullness in patients who have lost bladder sensation and/or the ability to voluntary urinate and rely on a urinary control apparatus in order to urinate.

What is claimed is: 
     
         1 . A system for determining a concentration of chromophores in bladder fluid of a bladder of a patient, comprising:
 a sensor device fixedly positionable on an external wall of the bladder without piercing an internal wall of the bladder, the sensor device including a light emitter and a detector, wherein the sensor device is configured to
 emit light from the sensor device at a first wavelength range onto the patient's bladder wall; 
 detect by means of the sensor device, light scattered by fluid of the bladder for the first wavelength range; 
 emit light from the sensor device at a second wavelength range onto the patient's bladder wall; 
 detect by means of the sensor device, light scattered by fluid of the bladder for the second wavelength range; and 
   a controller operatively coupled to the sensor device, the controller including logic to
 determine a ratio of a first concentration of chromophores related to the first wavelength range to a second concentration of chromophores related to the second wavelength range; and 
 monitor the ratio for changes in the first concentration relative to the second concentration. 
   
     
     
         2 . The system of  claim 1 , wherein the controller further comprises logic to detect a color change in urine collected by the bladder. 
     
     
         3 . The system of  claim 1 , wherein the first wavelength range is ultraviolet light, and the second wavelength range is in the 532-585 nm range. 
     
     
         4 . The system of  claim 1 , wherein the first concentration is protein and bacteria present in the bladder, and the second concentration is hemoglobin present in the bladder. 
     
     
         5 . The system of  claim 1 , wherein the controller is configured to utilize the Beer-Lambert Law to solve for the first concentration and the second concentration. 
     
     
         6 . The system of  claim 1 , wherein the sensor device is further configured to:
 emit light from the sensor device at a third wavelength range onto the patient's bladder wall;   detect by means of the sensor device, light scattered by fluid of the bladder for the third wavelength range; and   wherein the controller further comprises logic to:   determine a control or baseline concentration of chromophores related to the third wavelength range.   
     
     
         7 . The system of  claim 6 , wherein the controller further comprises logic to measure the relative concentrations of protein/bacteria and hemoglobin against the control or baseline concentration. 
     
     
         8 . The system of  claim 6 , wherein the third wavelength range is the near infrared region. 
     
     
         9 . The system of  claim 1 , wherein the sensor device includes at least one pair of suture openings, the at least one pair of suture openings configured to affix the sensor device to the external wall of the bladder without piercing an internal wall of the bladder. 
     
     
         10 . The system of  claim 1 , wherein the controller is integrated with a urinary control apparatus. 
     
     
         11 . The system of  claim 1 , wherein the controller is separate from a urinary control apparatus. 
     
     
         12 . The system of  claim 1 , wherein a spacing between the light emitter and the detector is in a range from about 8.2 to 10.4 mm. 
     
     
         13 . A method for determining a concentration of chromophores in bladder fluid of a bladder of a patient, the method comprising:
 positioning a sensor on an external wall of the bladder, the sensor including a light source and detector;   emitting light from the sensor at a first wavelength range onto the patient's bladder wall;   detecting by means of the sensor, light scattered by fluid of the bladder for the first wavelength range;   emitting light from the sensor at a second wavelength range onto the patients bladder wall;   detecting by means of the sensor, light scattered by fluid of the bladder for the second wavelength range;   determining a ratio of a first concentration of chromophores related to the first wavelength range to a second concentration of chromophores related to the second wavelength range; and   monitoring, by means of a controller, the ratio for changes in the first concentration relative to the second concentration.   
     
     
         14 . The method of  claim 13 , further comprising detecting a color change in urine collected by the bladder. 
     
     
         15 . The method of  claim 13 , wherein the first wavelength range is ultraviolet light, and the second wavelength range is in the 532-585 nm range. 
     
     
         16 . The method of  claim 13 , wherein the first concentration is protein and bacteria present in the bladder, and the second concentration is hemoglobin present in the bladder. 
     
     
         17 . The method of  claim 13 , further comprising utilizing the Beer-Lambert Law to solve for the first concentration and the second concentration. 
     
     
         18 . The method of  claim 13 , further comprising:
 emitting light from the sensor at a third wavelength range onto the patient's bladder wall;   detecting by means of the sensor, light scattered by fluid of the bladder for the third wavelength range; and   determining, by the controller, a control or baseline concentration of chromophores related to the third wavelength range.   
     
     
         19 . The method of  claim 18 , further comprising measuring, by the controller, the relative concentrations of protein/bacteria and hemoglobin against the control or baseline concentration. 
     
     
         20 . The method of  claim 18 , wherein the third wavelength range is the near infrared region.