The urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. If any constrictions or obstructions are formed in the urethra, the flow in urethra is reduced. Prostatic hyperplasia, which affects a significant proportion of male population, particularly at advanced stages of life, is one such condition.
According to one estimate (http://www.ennovations.co.uk/urine-flow-meter), Prostate disorders affect approximately 50% of the male population over 40 years old. Furthermore, around 24,700 men are diagnosed with prostate cancer each year in the UK. A regular urine flow test becomes a valuable tool in such instances to spot early signs of abnormalities.
There is currently a problem in timely and accurate diagnosis of the urodynamic obstruction. First small reductions in the urine flow often go unnoticed by patients. Second, due to variation in the patient awareness, reliance on patient awareness often produces distorted picture depending on the patient norm. In general, an urination peak flow rate of greater than around 15 ml/sec is considered normal for a man. A peak flow of less than 10 ml/sec has an 80% chance of being associated with urodynamic obstruction.
Current Devices for measuring the rate of flow of urine are cumbersome and require cleaning and maintenance. The hygiene awareness among patients and health workers is rising and the manual operations involving handling of urine containing vessels and equipment are considered unhygienic or undesirable according to modern hygiene norms.
Urine flow meters are used regularly to get urine flow rate, average urine flow rate, Peak urine flow rate & graph representing urine flow against time.
Three types of urine flow meters are widely available. These are:
1 Rotating disk method
2 Gravimetric or Weight type
3 Capacitance type
The present general arrangement for gravimetric or capacitance type urine flow meters is shown in FIG. 1 or FIG. 2. The patient is made to pass urine in funnel while standing (FIG. 1) or by sitting on commode type chair (FIG. 2). The patient urinates in a funnel and the urine is collected in a beaker which is taken away, emptied and rinsed clean. Also, because of the way the beakers are positioned in the currently available urine flow meters, the beakers are easily tilted spilling the urine on the floor, and more importantly on the sensors. The present urine flow meters are thus not very easy and hygienic to use, having the main disadvantage that the urine container has to be emptied & cleaned, by, either the patient or the attain dent.
There is a further problem with the present urine flow meters. The typical patient psychology is such that the urine flow of a patient possibly gets affected if the patient knows he is undergoing a specific test. It widely acknowledged by health professionals that the patient should be in his natural regular position while passing the urine to get his correct urine flow characteristics. However, the existing urine flow meters do not always provide natural conditions or environment in which a patient would be encouraged to urinate naturally. The instances of patient manipulating urine flow to mask the actual flow rates are common. The sight of large and unsightly flow meters can thus have an adverse impact on the urine flow related diagnosis.
With regards the patent literature available on the subject of uroflow meters, we have found a large body of works that suggest that there is a great room for improvement in this field. It is evident from a study of the number of patent applications available on the topic that the current ways of measuring the urinary flow rate has several limitations and drawbacks. Some of these are discussed here.
U.S. Pat. No. 5,176,148 by Weist et al, in relation to the West German Patent Specification No. 30,07,855 states that: ‘A Uroflow measuring device of this class must also be able to be installed in the bathroom in the urological office, so that the urine can flow off directly. This permits only the use of a device which does not collect the urine. However, much greater importance is attached to accurate volume measurement in clinical urodynamic investigations. The urine is collected in a beaker at the measuring device. Furthermore, accurate representation of the flow curve as a function of time is very important for diagnosis. This is possible only when the flow is measured directly. When double differentiation is required for volume-based measurement to represent the increase in flow, the calculated result will be too inaccurate because of the effect of disturbances e.g., vibrations and wave movements of the liquid collected. Emptying of the collected liquid is too expensive in urological practice because of the great number of uroflow tests performed as a preliminary examination.’U.S. Pat. No. 6,750,773 by Higgins in relation to the waterless urinals, such as those disclosed in U.S. Pat. No. 6,053,197 and U.S. Pat. No. 6,425,411 states that: ‘ . . . such devices typically use a water trap in which a low density sealant layer covers a small amount of wastewater remaining in the urinal trap. Such urinals conventionally do not have a flush mechanism; therefore, some amount of wastewater will remain in the trap at all times. The sealant layer prevents odors from escaping from and through the wastewater. Any slow draining of wastewater from the trap or blocking within the trap or sufficient use of the urinal to cause the supply of sealant to be significantly diminished, will result in unpleasant odors. Therefore, it is important for such urinals to be cleaned and serviced regularly, and especially when draining slowly, and a need exists for determining when the conditions for cleaning and servicing pertain.’
Brohan in the U.S. Pat. No. 7,811,237 states that: ‘uroflowmeters that existed at the time of that application required that the user direct his/her urine stream into a device and, thus, today's uroflowmeters can be uncomfortable, messy, and difficult for the patient to use. Furthermore, the use of uroflowmeters in hospitals and doctor's offices poses a risk to medical personnel of contacting urine excrements. Additionally, collecting data using today's commercially available portable uroflowmeters is still unpractical, available only to a limited number of patients producing only limited number of measurements.’
For these reasons, a need exists for improved systems for and methods of assessing urinary flow rate, in order to provide mechanisms for measuring urinary flow rate that are portable, convenient, easy to use in a non-stressful and risk-free environment and able to be used for mass examinations.
There is therefore a need to provide urine flow meters that are easy to use, preferably hidden from the patient sight, and hygienic to operate.