INVOLUNTARY CONTRACTION INDUCED PRESSURE AS A MEDICAL DIAGNOSTIC TOOL USING INVOLUNTARY REFLEX COUGH TEST
A system and method allows diagnosis of a patient for physiological abnormality such as a neurological deficiency. An involuntary reflex cough event is induced within the patient that activates the nucleus ambiguus and medial motor cell column of the patient and stimulates involuntary cough activated paraspinal muscles in the pelvis of the patient. An electromyogram (EMG) is obtained from the involuntary cough activated paraspinal muscles while inducing involuntary reflex cough and determining its duration. The intra-abdominal pressure (IAP) is determined and the IAP is correlated with the EMG duration of the involuntary cough event within a processing device to diagnose a physiological abnormality such as a neurological deficiency within the patient.
This application is a continuation-in-part application of prior filed U.S. application Ser. No. 11/608,316 filed Dec. 8, 2006, which claims priority to U.S. provisional application Ser. No. 60/748,892 filed Dec. 9, 2005 which are both incorporated herein by reference in their entirety. This application also claims priority to prior filed U.S. provisional application Ser. No. 61/139,649 filed Dec. 22, 2008 and prior filed U.S. provisional application Ser. No. 61/244,167 filed Sep. 21, 2009, which are both incorporated herein by reference in their entirety.FIELD OF THE INVENTION
This invention relates to medical diagnostic tests and, more specifically, to a diagnostic test for evaluating a neurological deficiency in a patient.BACKGROUND OF THE INVENTION
People may experience many different types of neurological deficiencies. One common type, for example, is the iatrogenic neurological deficiency caused by general anesthesia. Another example includes urinary incontinence, where a patient loses either complete or partial bladder control due to nerve damage of some sort. Still another example, may be the stroke victim who has lost muscle strength and tone along one side of the body, consequently being unable to contract at least half the muscles which help produce a cough forceful enough to properly clear the respiratory airways.
For example, a patient experiencing urinary incontinence must be properly diagnosed to identify the specific type of incontinence from which the patient suffers. The treatments may be different, depending on the type of incontinence. Therefore, proper diagnosis becomes important at least for that reason.
Stress incontinence is a condition believed to result primarily in older women due to loss of extrinsic support for the pelvic organs and for the neck of the bladder. The tissues of the pelvis and of the distal urethra contain estrogen and progesterone receptors. Following menopause and decrease of the hormones, the tissues of the urethra may lose resiliency and become somewhat flaccid. Under those conditions, any increase in intra-abdominal pressure causes urine in the bladder to be pushed outwardly as resistance in the urethra is overcome, resulting in, leakage of urine. This condition is known as stress incontinence and occurs in the absence of contractions by the detrusor muscle of the bladder. Stress incontinence may be responsive to treatment with exogenous estrogens, although this is not an effective treatment for all patients, particularly depending on age. Alternative treatments may include pelvic muscle exercises and a-adrenergic agents, such as phenylpropanolamine, which act on the a-adrenergic receptors along the urethra and increase urethral tone.
The most common cause of urinary incontinence, however, is detrusor hyperreflexia, or hyperactivity of the detrusor muscle. This type of incontinence is believed to result from lack of inhibition of the detrusor muscle due to a decreased detrusor reflex in the brain stem. Nevertheless, in most affected elderly there appears to be no underlying neurological defect. In this condition, treatment may include antispasmodic agents, which tend to relax the wall of the bladder.
A typical test employed to distinguish these two types of urinary incontinence is one which increases intra-abdominal pressure so as to, in turn, put pressure on the bladder. The Valsalva maneuver is one such test. This procedure is named after Antonio M. Valsalva, an Italian anatomist of the late seventeenth and early eighteenth centuries. In this technique, the patient generates a muscular contraction of the chest, abdomen and diaphragm in a forced expiration against a closed glottis. This increases pressure within the thoracic cavity and also in the abdominal cavity. The Valsalva maneuver also refers to raising the pressure in the nasopharynx by a forced expiration with the mouth closed and the nostrils pinched, for example, to clear the patency of the Eustachian tubes. Other testing techniques involve having the patient jump up and down to jostle the bladder, or bend down so as to compress the abdomen. Yet another method involves having the patient generate one or more strong voluntary coughs.
It is known, however, that some patients are unable to perform these physical acts. For example, a patient may not be able to jump, or to bend, or to generate a strong voluntary cough. Additionally, there are some patients who will not be correctly diagnosed on the basis of the cough test, perhaps because their coughs are insufficiently strong. Accordingly, there is a need for alternative or supplementary tests that will aid in diagnosing urinary stress incontinence and neurological deficiency.
As noted above, however, other clinical diagnostic tests also rely on the patient's ability to generate a forceful volitional abdominal contraction or Valsalva maneuver as an identifier of normal neurological and/or muscular function. Many patients, however, are unable to produce a forceful voluntary abdominal contraction or voluntary Valsalva maneuver and the associated diagnosis may be hampered or missed altogether.
A rather complete discussion of methods of evaluating urinary incontinence is found in a February 2006 article by JL Martin et al. entitled, “Systematic Review and Evaluation of Methods of Assessing Urinary Incontinence (hereinafter referred to as Systematic review).”
One of the problems associated with the prior art techniques is that some patient's are unable or are unwilling to perform the physical acts to the extent needed. For example, a patient may not be able to jump, or to bend, or to generate a strong voluntary cough. For some patient's they maybe able to perform these acts, but be unwilling to do so because, in the use of stress incontinence, an involuntary release of urine maybe embarrassing or contrary to what is considered proper in society.SUMMARY OF THE INVENTION
Various aspects of the invention are directed toward apparatus and techniques for evaluating neurological deficiency, such as iatrogenic neurological deficiency caused by general anesthesia, urinary incontinence (full or partial) caused by nerve damage, or loss of muscular control caused by stroke using an involuntary reflex cough test.
A system and method allows diagnosis of a patient for physiological abnormality such as a neurological deficiency. An involuntary reflex cough event is induced within the patient that activates the nucleus ambiguus and medial motor cell column of the patient and stimulates involuntary cough activated paraspinal muscles in the pelvis of the patient. An electromyogram (EMG) is obtained from the involuntary cough activated paraspinal muscles while inducing the involuntary reflex cough and determining its duration. The intra-abdominal pressure (IAP) is determined and the IAP is correlated with the EMG and duration of the involuntary cough event within a processing device to diagnose a physiological abnormality such as a neurological deficiency within the patient.
EMG signals are obtained in one aspect from the L5/S1 paraspinal muscles. The bladder is filled with a fluid to a predetermined level before inducing the involuntary reflex cough event and a determination is made if urine leakage occurs during the involuntary reflex cough event. The IAP obtained from the involuntary reflex cough test is compared to the IAP of a normal nuerological range to determine if the patient is outside the normal range, indicative that the patient has a neuropathological deficiency. Based upon this information it is possible to determine abnormal airway in the patient based on the deviation from a normal airway value.
In yet another aspect it is possible to determine the peak IAP and correlate it with the IAP and duration of the involuntary reflex cough event. The average IAP is determined and correlated with the peak IAP and duration of the involuntary reflex cough event in a non-limiting aspect. An area under the curve corresponding to IAP samples is obtained during the involuntary reflex cough event and correlated with the IAP and duration of the involuntary reflex cough event. In yet another aspect the bladder functionality and airway protection capability are diagnosed simultaneously.
In yet another aspect a urine leakage time is determined and this time is correlated with the IAP and duration of the involuntary reflex cough event to determine a pathophysiological problem. This information is used in one aspect for diagnosing intrinsic sphincter deficiency based on the urine leakage time. In another aspect a determination is made if a lower esophageal sphincter (LES) exists.
A system and device for diagnosing the patient is also set forth. The device includes a housing configured for handheld use and at least one interface carried by the housing and configured to receive electromyogram (EMG) data from at least one sensor located at the paraspinal muscles in the pelvis of the patient that had been activated by an involuntary reflex cough event, which activates the nucleus ambiguus and medial motor cell column of the patient. At least one interface is configured to receive data relating intra-abdominal pressure (IAP) obtained during the involuntary reflex cough test. A processor is carried by the housing and configured to receive the EMG and IAP and correlate the IAP with duration of the involuntary reflex cough event to diagnose a physiological deficiency.
In another aspect a catheter is disclosed and includes a catheter body having an outer surface and dimensioned for insertion within a urethra and into a bladder. This catheter has a first lumen configured to monitor bladder activity and a second lumen configured to fill the bladder with fluid. At least one indicator is positioned along the surface of the catheter that is configured to change color when exposed in combination to two separate urine characteristics to indicate urine leakage. The two separate urine characteristics in one non-limiting aspect comprise a temperature of a predetermined value and a presence of urea. The at least one indicator is responsive to fluid that is a temperature above about 30 degrees Celsius. The catheter body in one non-limiting aspect includes a distal end and sensor positioned thereat.
Other objects, features and advantages of the present invention will become apparent from the detailed description of the invention which follows, when considered in light of the accompanying drawings in which:
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
In one aspect there is provided a clinical test which depends neither on the patient's ability to generate a forceful volitional abdominal contraction or Valsalva maneuver nor on personal observation by the physician to make the diagnosis. The method includes positioning a pressure transducer in a patient being evaluated and inducing the involuntary reflex cough test as described below.
Pressures are obtained such as by a transducer during the involuntary reflex cough test. Placement of any transducer in the body of the patient will depend on the specific neurological deficit being evaluated. The transducer may be placed in the bladder or intra-rectally, for example. The agent effective for inducing an involuntary reflex cough test may be any one of several known to the skilled, for example, tartaric acid, capsaicin, citric acid, saline, distilled water, powders of various types, and others.
Because the reflex cough test is involuntary, any uncertainty as to the degree of patient cooperation is eliminated. Further, since patient cooperation in producing the involuntary reflex cough test is not needed, the test may be applied to patients who may be under sedation, for example, a patient who may have had a spinal anesthetic. Similarly, a patient who has had a stroke and who has lost volitional muscle control on one side of the body will still be able to produce the involuntary reflex cough test, albeit having a lower expiratory pressure.
The pressure produced by the involuntary reflex cough test can be sensed by a pressure transducer placed in the patient's body such as in the bladder and provides a quantitative, non-subjective measure by which the patient's condition may be determined. A population of healthy, non-smoking, normal individuals are expected to produce a range of pressures displaying the typical bell-shaped curve through the use of the involuntary reflex cough test. A normal curve or range is for males and a slightly different normal curve or range is for females.
Comparing the involuntary contraction-induced pressure using the involuntary reflex cough test generated by a patient to the normal distribution, it is possible to classify the patient to be either within the normal range or outside the normal range and this could be done with a large degree of certainty based on objectively measured pressures, rather than more subjectively based on skilled observation.
The presently described diagnostic test could be used to quantify loss of function or, conversely, return of function following a loss. For example, in a stroke patient, measurement of the involuntary contraction-induced pressure through the involuntary reflex cough test could be used to monitor the return of muscle tonicity and control during recovery. Expiratory pressure readings would be indicative of whether the patient has sufficient ability to clear the airway and, consequently, whether the patient is recovering or whether the patient requires continued ventilatory assistance.
In another example, the involuntary reflex cough test could be applied to a patient undergoing surgery for strengthening the support of the neck of the bladder so as to correct urinary incontinence. The patient would most likely have received a spinal anesthetic but may not be easily able to produce a voluntary cough while on the operating table so as to test the effectiveness of the repair. The patient could be administered the cough-inducing inhalant while the intrarectal pressure is monitored. The pressure reading would indicate whether a normal pressure was reached during the cough and the surgeon could monitor whether there was bladder leakage during the cough. Leakage occurring during an induced cough generating normal pressure would definitely indicate that the repair has not been effective. The surgeon would then have the opportunity of realigning the repair in order to make it effective, this with the patient still on the surgical table.
The patient is then asked to voluntarily cough (120) and the results of the voluntary cough are recorded (130) by recording the variations in pressure as a function of time and by recording whether or not the cough induced involuntary expulsion of urine. See item 130.
Then, a reflex cough test is performed (140) and the results are recorded in a manner substantially similar to step 130. Details of the involuntary reflex cough tests (iRCT) are discussed more in conjunction with
There now follows a description relative to
Interface 518 receives signals from pressure transducers connected to catheters, such as catheters inserted through the urethra and/or rectum and other signals, for example, EMG (electromyogram) signals such as taken from the paraspinal muscles as explained in greater detail below. EMG signals can be processed alone without catheter pressure signals.
Computer system 500 may be coupled via bus 502 to a display 512, such as a cathode ray tube (CRT), for displaying information to a computer user. An input device 514, including alphanumeric and other keys, is coupled to bus 502 for communicating information and command selections to processor 504. Another type of user input device is cursor control 516, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 104 and for controlling cursor movement on display 512. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane.
Computer system 500 operates in response to processor 504 executing one or more sequences of one or more instructions contained in main memory 506. Such instructions may be read into main memory 506 from another computer-readable medium, such as storage device 510. Execution of the sequences of instructions contained in main memory 506 causes processor 504 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.
The term “computer-readable medium” as used herein refers to any medium that participates in providing instructions to processor 504 for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical or magnetic disks, such as storage device 510. Volatile media includes dynamic memory, such as main memory 506. Transmission media includes coaxial cables, copper wire and fiber optics, including the wires that comprise bus 502. Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications.
Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punchcards, papertape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read.
Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor 504 for execution. For example, the instructions may initially be carried on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system 500 can receive the data on the telephone line and use an infra-red transmitter to convert the data to an infra-red signal. An infra-red detector can receive the data carried in the infra-red signal and appropriate circuitry can place the data on bus 502. Bus 502 carries the data to main memory 506, from which processor 504 retrieves and executes the instructions. The instructions received by main memory 506 may optionally be stored on storage device 510 either before or after execution by processor 504.
After receipt of the starts signal, the processing unit stores the samples and displays the plot of the pressure sample values (620).
Upon completion of the cough sequence, software is programmed to calculate the area under the curve of a plot of the sample values (630). The areas under the curve (AUC) values are calculated by the numerical integration of intravesical pressure over time with either Simpson's ⅜-rule or Bode (or Boole's) rule. Both Simpson's ⅜-rule and Bode (or Boole's) rule are methods of numerical integration that yield more accurate results for AUC than the trapezoidal method.
Simpson's ⅜ rule:
Bode's (Boole's) rule:
All AUC values were calculated using Bode's (Boole's) rule, except for that of Patient #1, which was calculated with Simpson's ⅜-rule. Bode's (Boole's) method was not very adept at handling as few data points (3).
The process may selectively display the calculated area under the curve to the user either with or separately from display of the plot of the sample values (640).
Optionally, one may output the raw and calculated data for use outside of the processing device (650). This can be done utilizing interface 518.
The testing that produced the results shown in
Objective: The objective of this study were to:
1) Evaluate the effectiveness of the reflex cough test (RCT) versus voluntary cough in confirming stress urinary incontinence in female subjects with a history of mild urinary incontinence as determined by the Incontinence Quality of Life Instrument (I-QOL); and
2) Correlate, if indicated, intravesicular pressure measurements with urinary leakage after RCT.
Materials and Methods: Voluntary and involuntary (RCT) cough provocation maneuvers were performed during urodynamic testing in 6 women. Four women had a history of mild stress urinary incontinence and two were normal controls. The order of the cough provocation procedures was randomized.
Prior to urodynamic assessment, subjects were instructed to empty the bladder (confirmed via ultrasound). Using sterile technique, calibrated bladder and rectal catheters were placed and continuous dual-channel pressure recording was performed and the subject's bladder was filled slowly with sterile water until 200 mL had been delivered.
Cough Leak Point Pressure (CLPP) was assessed with a bladder volume of 200 mL. Leakage was determined by visual inspection of the perineum by the Investigator during the coughs, and electronically marked on the printout. If the subject did not leak with either cough maneuver in the semi-recumbent position, the standing position was used. Urodynamic testing was completed with filling to capacity to observe for detrusor instability.
After instruction, subjects performed a maximal forceful voluntary cough (VC) and an involuntary cough. The involuntary cough was elicited by stimulating the laryngeal cough reflex by performing the RCT with the patient's nose held closed. The RCT involves inhaling a concentration of 20% L-(+)-tartaric acid dissolved in normal, sterile saline (Nephron Pharmaceuticals, Orlando, Fla.) delivered via jet nebulizer.
An independent reviewer used the continuous pressure recording of each subject to determine peak pressures, measure duration of the cough events, count the number of pressure spikes, and derive area under the curve (AUC) numbers.
Results: Peak pressures were similar when comparing voluntary cough with the RCT (
RCT provides considerable “stress” in subjects with stress urinary incontinence is a useful involuntary maneuver in eliciting leakage in subjects with this condition. No other involuntary maneuver has been studied in evaluating this condition. RCT is more efficient in provoking leakage in subjects with stress urinary incontinence than voluntary cough.
There now follows greater details of the involuntary reflex cough used not only for accessing stress urinary incontinence, but also for use as a medical diagnostic tool in accordance with non-limiting examples.
There now follows a general description of physiology for the involuntary reflex cough test (iRCT), which activates the Nucleus Ambiguus. The iRCT selectively activates the Medial Motor Cell Column (MMCC) of the spinal cord rather than the (Lateral) LMCC to fire muscles embryologically predetermined to be involuntary cough activated muscles in the pelvis. In the past, urologists did not selectively activate MMCC without overtly activating the LMCC. Magnetic stimulation or electrical spinal cord stimulation activate both cell columns and thus it is not possible to sort out pathology with these. Magnetic stimulation or other approaches from CNS activation set off both columns.
The pelvic muscles that typically are activated with MMCC cough activation include the lumbar-sacral L5/S1 paraspinal axial musculature, which facilitates inpatient continence screening. An example is through MMCC iRCT muscle activation, obtaining L5/S1 paraspinal firing but not L5/S1 lateral gastrocnemius activation because the gastroc muscles are limb muscles activated primarily through the LMCC.
The L-S paraspinals are easier to access with a large pad placed above the sacrum on the midline that contains active, reference and ground combined. It is not important to determine lateralization of the activity like needle EMG for radiculopathy, but only if activation occurs reflexively where the onset latency is under the pressure activation of the abdomen such as the Levator Ani. This is a poor muscle for these purposes because people train it to activate and set their pelvis if the person senses any intra-abdominal pressure elevation. Also, it is difficult to get pads to stick to that area with hair, perspiration, fungal infections or bowel/bladder incontinence present, and other factors.
Some examples have been developed and studied, including a normal CNS patient with Lumax bladder and bowel catheters and pads at L5/S1 paraspinals and a separate EMG machine and electrodes at the pelvic floor in a standard 3:00 and 9:00 o'clock set-up to demonstrate simultaneous involuntary activation with iRCT. This sets off the pelvic floor muscles. Thus, normal airway protection data is obtained and normal CNS data to L1 (where spinal cord ends). The set-up includes a complete T12 that cannot void and needs intermittent catheterization with the same set up, thus demonstrating data for normal airway but no L5/S1 EMG activation by MMCC with all the other data necessary to prove an unsafe bladder by the algorithm. A quadriplegic can demonstrate abnormal airway protection and abnormal EMG activation at both paraspinal and pelvic floor muscles with unsafe bladder measurements that follow the algorithm.
It should be understood that iRCT is an involuntary maneuver that activates embryologically predetermined muscles for airway protection and continence that travel primarily through the MMCC in the spinal cord. Different varieties of lesions are captured and determined with summated interval data approach for general screening purposes.
There now follows an initial study of the iRCT test results relative to SUI and followed by detailed examples showing support for iRCT to determine SUI and for neurophysiological analysis and showing progressive understanding of the advantageous use of the iRCT.
It is known that the laryngeal cough reflex (LCR) is a strong brainstem-mediated reflex that protects the upper airway by preventing aspiration, or the entrance of secretions, food, and/or fluid into the airway below the level of the true vocal cords (rima glottidis), through elicitation of an involuntary cough. The LCR is activated through the stimulation of cough receptors in the vestibule of the larynx. One way this is achieved is through the inhalation of chemostimulants, such as tartaric acid. Studies have shown that if the LCR is intact, the subject will involuntarily cough (normal LCR) upon inhaling a solution containing TA.
In one non-limiting example, the iRCT involves the inhalation of a nebulized 20% normal saline solution of L-TA (Tartaric Acid). Subjects are asked to perform 1 to 3 effective, full inhalations (about 15-20 second exposure by mouth for tidal breathing wearing a nose clip) from a standard jet nebulizer with at least 50 psi from an oxygen wall unit or tank that produces an average droplet diameter of 1 to 2 microns or less. The nebulizer output is 0.58 mL/min. The initiation of an involuntary cough reflex after any one of the inhalations is the end point of the procedure.
Nebulized TA is a chemical tussive that stimulates irritant receptors in the mucosa of the laryngeal aditus. Mild irritation of these receptors results in nerve impulses being conveyed by the internal branch of the superior laryngeal nerve (ibSLN) to bulbar centers of the brainstem. This nerve constitutes the afferent sensory component of the LCR arc. The efferent component of the LCR is mediated through the vagus, phrenic, intercostals and thoracoabdominal nerves.
Inhaled TA is selective in stimulating rapidly adapting (“irritant”) receptors (RARs), in the supraglottic region. In humans, bilateral anesthesia of the ibSLN abolishes TA-induced cough and permits tidal breathing of the nebulized vapor without coughing, supporting the idea that the RARs are responsible for TA-induced cough.
The physiological response from inhalation of TA in a normal subject is abrupt, forceful coughing of short duration. Using a 20% solution of inhaled nebulized TA is a safe, reliable way to assess the sensation in the supraglottic laryngeal region and subsequently the neurologic circuitry of the LCR. In addition, the ability of the iRCT to predict the integrity of the protective LCR in subjects with stroke has been studied.
A 20% solution of TA as an aerosol causes cough by stimulating sensory nerves in and under the laryngeal epithelium. These nerves have been identified histologically, and the reflexes they cause have been identified. The sensory nerves can be stimulated by both non-isosmolar and acid solutions. Tartaric acid may act in both ways, but the balance between them is uncertain.
The nerves are stimulated by the opening of membrane channels in the nerve terminals. More than 20 categories of channels have now been identified, the opening of which will allow calcium flow into the nerve (and also sodium, with exit of potassium), with the result that an action potential is set up, which travels to the brainstem in the central nervous system (CNS), and reflexively induces cough.
Several different types of sensory nerve ending in the larynx have been identified that may mediate cough and other defensive reflexes. They have been extensively studied, mainly in experimental animals by recording the action potentials in their nerve fibers. The probable candidates for cough are the RARs or ‘irritant’ receptors. These are highly sensitive to mechanical stimuli, to hyperosmolar solutions, and to acids.
Once stimulated, the sensory nerves will induce a variety of defensive reflexes which protect the lungs from invasion of harmful material. These include cough (an inspiration, followed by a forced expiration against a closed glottis, followed by opening of the glottis with an expiratory blast); the laryngeal cough expiratory reflex (LCER, a powerful expiratory effort with the glottis open); and the glottal closure reflex. In some instances a reflex apnea can be produced. The balance of these reflexes may depend on the nature and the strength of the stimulus. In the case of TA, the LCER seems to be dominant, possibly followed by glottal closure, and the pathophysiological advantage of this response in preventing aspiration is obvious.
There is clinical experience in subjects with stress urinary incontinence. A pilot study was initially designed as a single-center, single-blind study to evaluate the effectiveness of the iRCT in inducing an involuntary cough that would confirm urinary leakage in female subjects with a history of mild SUI. Up to 3 inhalations of a 20% sterile, aqueous solution of TA delivered via an ultrasonic jet nebulizer with oxygen at 50 psi to deliver droplets of ≦1 μm were administered to yield a reflex cough. The primary endpoint was the observation of urinary incontinence in subjects with a history of mild SUI during iRCT and a lack of urinary incontinence in normal subjects. Secondary endpoints were documentation of bladder and abdominal pressures and tolerability of iRCT.
The initial enrollment was 6 women (18-75 years of age), including 4 women with a history of mild SUI as determined by the Incontinence Quality of Life Instrument (IQOL) and 2 healthy controls with no history of SUI. However, the protocol was amended to increase total enrollment from 6 to 9 subjects (7 with SUI and 2 healthy controls).
The study protocol assessed the two cough provocation maneuvers (voluntary cough test and iRCT) for each subject. The order of the cough provocation was randomized but each subject completed both tests. The protocol was subsequently amended to remove blinding and randomization from the study and all subsequently enrolled subjects underwent VCT followed by iRCT followed by a second VCT. Subjects underwent the provocation maneuvers within 30 days of screening and then had two follow-up visits: the first 1 to 5 days after treatment; the second 5 to 7 days after treatment.
Urodynamic evaluation was done during each cough maneuver. The parameters determined during this evaluation included maximal urethral pressure (MUP), maximal abdominal pressure (MAPP), maximal detrussor pressure (MDPP), maximal abdominal leak point pressure (MALPP), maximal detrussor leak point pressure (MDLPP), and CLPP.
A total of 9 subjects were evaluated, 2 without SUI and 7 with a history of mild SUI. All subjects enrolled in this study were white and not of Hispanic or Latino background. Subject age ranged from 31 to 71 years. The mean subject age was 48.4 years: 51.0 years for healthy controls and 47.7 years for subjects with SUI. Two (22%) subjects were smokers: 1 (50%) healthy control and 1 (14%) subject with SUI. The remaining 7 (78%) subjects were non-smokers.
Individual subject responses to the cough provocation tests are summarized in Table 1. The two control subjects (#2 and #3) did not leak with either VCT or iRCT. Of the remaining 7 subjects with mild SUI, only 2 subjects (#8 and #4) did not produce leak with either VCT or iRCT. Two other subjects (#5 and #6) produced leak with both VCT and iRCT. The remaining 3 subjects (#1, #7, and #9) did not produce leakage with VCT but did with the iRCT.
The performance of the cough provocation procedures is presented in Table 2. Sensitivity of the cough provocation maneuvers was 71.4% during iRCT and 28.6% during VCT. Specificity was 100% during iRCT and VCT. The positive predictive value (PPV) was 100% for iRCT and VCT; the negative predictive value (NPV) was 50% for iRCT and 28.6% for voluntary cough.
The evaluable population was defined as all subjects who met study entry criteria and completed all cough maneuvers.
For subjects enrolled after Protocol Amendment 1, data from the first voluntary cough was used.
The urodynamic parameters were summarized and there was a trend for increased mean abdominal pressure (cm H2O) and mean detrussor pressure when the subjects were administered the iRCT compared with the VCT. The CLPP was not consistently higher after iRCT compared with after VCT.
The trend for an increase in abdominal and intravesicular pressures after the iRCT compared with the VCT in those subjects who experienced leakage suggests that the iRCT causes significant stress on the sphincter, resulting in urinary leakage.
Analysis compared a digitized area under the pressure curve (AUC) after the iRCT, and after VCT was also conducted. Digitization of the pressure-time curve from the recordings allowed quantification of the stress generated during the cough procedures. Using the average intravesicular pressure (Pves) values, AUC values were calculated by the numerical integration of Pves over time with either Simpson's ⅜-rule or Bode (or Boole's) rule. There was a trend for higher peak Pves and greater AUCs in subjects after iRCT compared with VCT. The results show that the iRCT provides a larger and more robust stress than VCT. The relatively increased value of AUC measurements with iRCT are a good numerical representation of the magnitude of stress placed on the urethral sphincter and offers an explanation for the increased number of subjects with mild SUI that leaked with iRCT when compared to VCT.
These results, combined with the urinary leakage observed after the iRCT, show that the iRCT has clinical utility in producing a standardized cough that allows for a definitive diagnosis of SUI as later explained in greater detail with further results.
No AE's occurred during this study and no clinically significant laboratory abnormalities were noted. No subjects discontinued from the study for any reason. The iRCT procedure was safe and tolerable to the subjects in this study.
In summary, three out of five women (60%) with SUI experienced urinary leakage only after the iRCT while two of the SUI subjects (40%) experienced urinary leakage after both the iRCT and VCT. Neither of the two healthy control subjects experienced urinary leakage after either the iRCT or VCT. Based on these initial results, the iRCT is more specific and sensitive than the VCT, indicating that iRCT is advantageous in the diagnosis of SUI.
There now follows an analysis and test results in greater detail that explain the advantageous use of the involuntary reflex cough test (iRCT) for investigating and diagnosing not only SUI but also physiological abnormalities such as neurologic deficiencies. It should be understood that there are differences between normal and neurological patients.
As noted before, there are ranges and boundaries with parameters that are now used to establish a normal neurological range. Some of the graphs representative of urodynamic testing as explained below show a delay between the EMG muscle activity and actual occurrence of a leak. In one non-limiting example, it is no more than a few milliseconds (six) in some examples between when the patient coughs and the leak occurs. The EMG corresponds to the electromyogram test and detects muscle electrical activity. It can be displayed visually on an oscilloscope and detected with signal peaks in a non-limiting example.
It is possible to conduct a Nerve Conduction Velocity (NCV) test as verification, and if there is a large delay, for example, six milliseconds, in one aspect, it could correspond to a neuropathological problem. In accordance with a non-limiting example, the involuntary reflex cough test (iRCT) is useful as a medical diagnostic tool and permits analysis of neuropathological problems. The involuntary reflex cough test also is used for analyzing stress urinary incontinence. A data processing methodology based on urodynamic testing and useful with the handheld device as described above is later set forth. A methodology for stress urinary incontinence analysis using the handheld device for example, is explained relative to the flowcharts of
The EMG from the parineal muscles respond almost simultaneously to the onset of the voluntary cough because the patient does not want to leak. With the involuntary reflex cough test, on the other hand, the fast fibers that are set off reach the abdominal muscles quickly, such as in 17 milliseconds as an example. the patient is not able to set their pelvis. In some of the graphs reflecting urodynamic testing as will be described, it is evident that the onset of the EMG activity does not happen at the same time the pressure rises. Some people that have neuropathy, for example, spinal stenosis or nerve injury (even if it is mild), have a situation that prevents the reflexes from closing before the pressure has changed to push on the bladder. It is not possible to obtain this diagnostic tool methodology unless the involuntary cough reflex test is accomplished. When the involuntary reflex cough test is accomplished, it is possible to demonstrate a latency delay and show that the pathophysiology is a neuropathic problem rather than a structural problem. It is possible to separate the pathophysiology using the involuntary reflex cough test and methodology as described.
In one example, a female patient could have a weak spinal cord and her physiology is normal. This patient may not leak during the test, but the patient cannot protect her airway. Thus, using the methodology apparatus and system associated with the involuntary reflex cough test, in accordance with non-limiting examples, it is possible not only to diagnose an unprotected airway, but also to diagnose normal bladder physiology, including the neurophysiology to the patient's sphincter closure process. This is advantageous because it is then possible to determine when someone cannot protect their airway, even though they may have a normal bladder. Conversely, there are patients with a normal airway, but cannot control their bladder. This process and system as described is able to make that diagnosis and thus the involuntary reflex cough test is an advantageous medical diagnostic tool. For example, it is possible to have a patient with a poorly functioning bladder and normal airway and use of the test allows a doctor to find lower urinary tract symptoms and neuropathology. It becomes possible to diagnose a level of lesion in a patient with a full comprehensive neurologic examination using the involuntary reflex cough test, methodology and apparatus as described.
As will be described in detail later, the various components such as the nebulizer, one or more catheters, any pads for the paraspinal muscles when EMG is used, and drug as part of the nebulizer are inserted in a kit for use at the clinic, hospital or setting. Those components can be discarded after use. The handheld device, of course, will be used again. Use of the kit provides a clinician, doctor or other medical professional the readily available diagnostic tool to determine if a patient has a questionable airway and determine bladder physiology at the same time, all with the use of the one kit.
The EMG component of the waveform is typically important for analysis as explained. Two catheters are used in some analysis, one for the rectum and one for bladder. In another example one catheter is used. In yet another example no catheter is used. EMG is taken from the paraspinals. In examples, the intravesicular pressure is important in combination with EMG taken at paraspinals. The EMG is correlated with pressure (e.g., intravesicular pressure) and a delay component. In the preferred method, the EMG is taken from the paraspinal muscles to obtain a clean signal where EMG sensors are placed on the back at the spine. In conjunction with the clean EMG signal obtained from the paraspinal muscles, it is possible to obtain the representation of where the involuntary cough event “take-off” starts and where it ends. The handheld device includes a processing device such as a microprocessor and appropriate software that correlates the data. It is possible to obtain a diagnosis for the level of lesion in a patient, while also obtaining a full comprehensive neurophysiological examination as noted before. Data is obtained from the involuntary reflex cough test and from the EMG. In one aspect depending on the type of desired analysis, a catheter is used in a non-limiting example to obtain the intravesicular pressure (PVES).
Referring now to the graphs for the urodynamic testing shown in
It should be understood that a Foley catheter could block the urethra. A smaller catheter is preferred to measure such as described relative to the catheter of
A kit that is marketed for the iRCT diagnostic tool could include the nebulizer and its drug as TA in one example and one or more pads for the electrodes at the paraspinal and use with EMG. The pad may only be necessary for stress incontinence determinations. A catheter is included in another kit example for use in measuring airway and intra-abdominal pressure. In one non-limiting example, a pad can be placed on a catheter to determine urine leakage and aid in determining stress incontinence. Pressure data is sent to the handheld device in some examples. Obtaining any EMG values from the paraspinal in conjunction with the urology analysis is advantageous. It is possible in one example to measure pressure from a bladder catheter and determine at the same time EMG signals using the EMG electrodes at the L5/S1 in conjunction with the measured involuntary reflex cough test and urology catheter sensing. This is advantageous compared to placing electrodes at the perineal muscles on each side of the sphincter. The graphs in
It has been found that EMG signals obtained from the perineal muscles have EMG activity from the non-involuntary muscles, i.e., the voluntary muscles blacking out and making analysis difficult because of the signal interference. When the electrodes are placed at the back at the L5/S1 junction, on the other hand, there is nothing else but the paraspinal muscles. It is bone below on each side at the L5/S1 junction. The electrical impulses can be obtained that determine the number of cough impulses coming down through the patient. This is accomplished even if a person has much adipose. The electrode pad used at the L5/S1 junction, in one non-limiting example, typically has an active reference and ground. A pad holds this active reference and ground and the leads as the active reference and ground are plugged into the handheld device (or wireless sensing device in another example) and transmit data to the processor. At least one catheter is also plugged into the handheld device (or wireless sensing device) and measures bladder pressures. A rectal catheter can also be used in some examples. The processor receives EMG signals and determines when the cough event is over.
The involuntary coughs are not hidden by interference when measured from the lower back at the paraspinals as described. This allows a clinician to determine coughs from the bladder when the EMG located at the L5/S1. In one aspect, the area under curve and the average pressure is determined for the cough event corresponding to the involuntary reflex cough test. When this involuntary component of the cough ends, in one example, it becomes silent EMG activity for a period of time. The pressures are at baseline for a period of time, which corresponds in one example to an inhalation. The involuntary component is over.
Sometimes with the involuntary reflex cough test, the cough occurs six times without breathing, but when the patient stops to breathe, the event is over. Using the programming applied with the processor in the handheld device, it is possible to calculate the variables inside the wave as to the involuntary cough and determine airway protection capability. Thus, it is possible to determine and measure cough by defining through appropriate data processing the involuntary cough event compared to the whole cough epoch. For example, a patient could cough ten times, but only the first four are part of the involuntary cough event. The coughs after that event are not part of the epoch.
The graphs for urologic testing in
As will be explained, the programming includes algorithm branches resulting in a conclusion of unsafe bladder based on the data analysis. It is possible to calculate from the waveforms information necessary for assessing airway protection ability. It should be understood that taking the EMG from the L5/S1 is also a better situation for the doctor or clinician, and the patient, since it is more acceptable in a hospital, outpatient or inpatient setting. The doctor or clinician does not have to bend down or stoop and look near the crotch area and place pads since the EMG can now be taken from the paraspinals. Also, the placement of pads and electrodes at the paraspinals is advantageous when patients are standing. If pads are placed at the perineal area, sweat and other problems could cause those pads to become loose and good signals may not be obtained. Also, it should be understood that the perineal muscles do not fire involuntarily. The sphincter may fire involuntarily, but that would create more noise as noted before. Electrodes are not placed at the vagina, but are placed at the paraspinal area instead.
This information obtained from iRct and the EMG taken at the paraspinals allows the doctor or clinician to obtain data leading directly to a diagnosis. For example, some patients that have urinary stress incontinence may have a normal airway in this analysis. It has been found by experimentation that the normal airway is about 50 centimeters water average intra-abdominal pressure. It should be understood that the vesicular pressure (bladder pressure) can track intra-abdominal pressure and terms are often similar and used together. “Bladder” or intravesicular pressure is often used to determine and equate with intra-abdominal pressure. The two are sometimes used interchangeably. Stress urinary incontinence and/or bladder physiology can be diagnosed. The system and method as described leads directly to diagnosis. Fifty centimeters average intra-abdominal pressure over time has been found to correspond to an involuntary reflex cough test normal airway. Thus, the standard deviations or other percentages from that value are used in one non-limiting example to determine an abnormal airway. In a conducted study, the actual value is determined to be about 50.6 centimeters water as compared to voluntary cough values of about 48 centimeters of water. In an outpatient setting, it is possible to have the nebulizer (and drug) and only a pad and test SUI. In hospitalized patients or inpatient settings, this combination is used to measure airway and bladder physiology and the test combination includes a catheter.
It should be understood that the involuntary cough reflex test (iRCT) gives a higher pressure average than obtained using a voluntary cough test. The involuntary cough reflex test is thus a valuable medical diagnostic tool. In one example, four variables are significant in this analysis. These variables include: (1) duration of the event; (2) average intra-abdominal pressure of the event; (3) peak intra-abdominal pressure (max) of the event; and (4) area under the curve. Using these four variables, it is possible to process the received data and obtain a specific diagnosis that could not otherwise be obtained without the use of the involuntary reflex cough test. Individual deficits in a specific variable or combination of variables are used to characterize specific diseases and problems and useful as a medical diagnostic tool.
Some specific examples obtained through experimentation follow. For example,
An analysis of the results in the tables of
The study did not have complete uniformity among sites. One site did not mark the leaks live during the event only if there was any leak at all with one mark at the end outside the event. This site was not included in the OtL Data Tables. Another nine sites marked the events the same, during the event when leakage was seen. These are relatively accurate and come only from pushing the button and cannot be marked as a leak (L) retrospectively by the sites. The number of times the button is pushed represents the individual urine leaks seen by the observer and may vary among sites, but gives added information separating voluntary cough test and involuntary reflex cough test regarding the severity of SUI. The line and pressure take off are live and if the marks are during the event they are reasonably accurate with time lapse error from manually pushing the button. This can be repeated in a small group with automatic sensors that would mark leakage more precisely. Regardless, the evidence on the graphs shows significant differences in SUI between the voluntary cough test and involuntary reflex cough test (iRCT) for severity and mechanisms of action (MOA).
This is an example of why regardless if a person leaks on both voluntary cough and iRCT, it is not possible always to determine MOA or severity of SUI with voluntary cough. It is evidence of one reason overall improvement in patient outcomes and quality of life have not significantly improved despite incontinence care, especially at the general practice (GP) level. Thus, iRCT is a screening health tool useful by the GP for early identification when conservative treatment could proactively help. IRCT is also a diagnostic tool useful by the urologists to assess severity, MOA and possibly intra-operatively and assist with sling or TVT tensioning.
This same approach may work in other sphincter deficiency situations such as Lower Esophageal Sphincter (LES) and reflux. It is possible reflux laryngitis is initiated by an involuntary event, which combined with insufficiency of the closure system, leads to acid reflux which with laryngeal acid receptor activation continue the involuntary event activation and further unopposed reflux of acid. Visualization with contrast may show significant reflux differences between voluntary cough, with inhalation tonic closure reinforcement, and iRCT activated intra-abdominal pressure onset to reflux differences.
Further description concerning the involuntary reflex cough test as a diagnostic tool is now set forth. This is important not only for lower esophageal sphincter, but also for the urinary sphincter function analysis. The analysis as the chi-squared test can be accomplished by a statistician. This OtL data outcome for the voluntary cough test versus the involuntary reflex cough test is in conjunction with lunch inflation with tonic urethral and lower esophageal sphincters closure principle. This is an advantageous finding and is conclusive of why the involuntary reflex cough test is an appropriate involuntary diagnostic maneuver as a health screen tool to improve outcomes, quality of life and decrease neurological, urological and gastroenterological pathophysiology disease by improved diagnostic and measurable capabilities.
Records of patients were checked in this process. Patients were located who had a leak with either voluntary cough or iRCT or both, and who had a clear indication of the timing of the leak. Each leak was labeled either as ‘early’ when it occurred during or immediately after the first expiratory phase of voluntary cough or iRCT, and as ‘late’ when it occurred during or after the second expiratory phase of voluntary cough or iRCT.
The hypothesis was that if early leak occurred more frequently with iRCT than with voluntary cough, this might be due to the leak-inhibiting mechanism in the inspiratory phase of voluntary cough, and could be a factor in explaining why time to leak (OtL) was greater with voluntary cough than with iRCT.
Records from 123 patients were analyzed. All leaked with voluntary cough or iRCT or both. Records were rejected when the leak time was not clearly identified. The distinction between early and late leak was occasionally difficult, and a ‘balanced judgment’ was made. Elimination of these rather uncertain timings do not change the general pattern of the analysis.Summary Analysis:
1) 8 pts leaked early with both VC and iRCT;
2) 20 pts leaked early with iRCT and late with VC;
3) 5 pts leaked early with VC and late with iRCT;
4) 14 pts leaked early with iRCT and not at all with VC.
5) 0 pts leaked early with VC and not at all with iRCT 123 pts leaked. 42 pts leaked early with iRCT. 13 leaked early with VC.
Detailed Analysis: Patients Who Leaked with Both VC and iRCT and Had Late Leak Times for Both:
612-2, 567-1, 605-1, 701-1, 519-1, 520-1, 522-1, 518-1, 539-1, 543-1, 551-1, 553-1, 562-1, 208-1, 303-1, 311-1, 315-1, 509-1, 511-1, 513-1, 1202-2, 1207-1, 1112-1, 823-1, 927-1, 812-1, 917-1, 1202-1, 716-1, 711-2, 1045-1, 1027-1
Patients Who Leaked with Both VC and iRCT and Had Early Leak Times for Both: 569-1, 616-1, 1114-1, 802-1, 1035-1, 554-1, 1014-1, 1038-1N=8
Patients Who Leaked with Both VC and iRCT and Had Late Leak Times for VC and Early Leak Times for iRCT:
568-1, 516-1, 544-1, 548-1, 555-1, 556-1, 560,1, 565-1, 313-1, 1017.1, 1011-1, 1025-1, 314-1, 1204-1, 1205-1, 1117-1, 1108-1, 805-1, 809-1, 1038-1
Patients Who Leaked with Both VC and iRCT and Had Early Leak Times for VC and Late Leak Times for iRCT:
1104-1, 1206-1, 934-1, 1001-2, 707-2
Patients Who Did not Leak with VC and Had Early Leak Times with iRCT:
540-1, 564-1, 567-1, 1203-2, 1102-1, 1106-1, 926-1, 921-1, 1021-1, 1043-1, 1029-1, 1019-1, 1012-1, 713-1
Patients Who Did not Leak with VC and Had Late Leak Times with iRCT:
549-1, 559-1, 517-2, 606-1, 531-1, 535-1, 536-1, 537-1, 547-1, 550-1, 552-1, 561-1, 510-1, 1208-1, 1119-1, 1120-1, 1107-1, 1111-1, 930-1, 823-1, 804-1, 702-1, 1003-1, 712-1, 717-1, 718-1, 719-1, 708-1, 701-1, 1040-1, 1041-1, 1046-1, 1036-1, 1015-1, 1008-1, 1009-1, 1006-1, 1048-2
Patients Who Did not Leak with iRCT but Who Had Late Leak Times with VC: 611-2, 530-1, 310-1, 505-1, 820-1N=5
Patients Who Did not Leak with iRCT but Who Had Early Leak Times with VC:N=0 Summary:
1) 123 pts were assessed. They all leaked with either VC or iRCT or both. Thus potentially there could be 246 leaks. In fact there were 189 since some pts did not leak on both tests.
2) 118 pts leaked with iRCT (96%); 71 leaked with VC (58%); 66 (54%) leaked with both.
3) 66 pts leaked with both VC and iRCT. 28 of them (42%) had early leak times for iRCT. 13 (20%) had early leak times for VC. (8, 12%, had both.) 33 pts (50%) had only late leak times.
4) 52 pts leaked only with iRCT; 14 (27%) had early leak times.
5) 5 pts leaked only with VC; none (0%) had an early leak.
As noted before, voluntary cough (VC) and the laryngeal expiratory reflex (LER) as elicited by an involuntary reflex cough test (iRCT), using a nebulized 20% tartaric acid solution, have distinctly different neurophysiological mechanisms. Voluntary cough is classically defined as an event that starts with an inspiration that leads to lung inflation. As the lungs inflate during inspiration, there is a corresponding increase in the tonicity of both the urethral sphincter (US) and lower esophageal sphincter (LES) (as shown in
There is increased tonicity of the US and LES with lung inflation. Increased sphincter tonicity is a patterned motor event, which facilitates US and LES closure during increases in intra-abdominal pressure (IAP) that commonly occurs following lung inflation, i.e., the inspiratory phase of voluntary cough. The LER does not have a significant lung inflation phase prior to the series of expiratory coughs. As such, increased IAP can cause stress urinary incontinence (SUI) or gastroesophageal reflux (GER) to occur due to inadequate closure of these sphincters in subjects who have Intrinsic Sphincter Deficiency (ISD) (as shown in
There now follows a description of what occurs as part of as part of normal lung inflation with inhalation as it relates to sphincter increased tonicity and closure for both urethral (US) and lower esophageal sphincter (LES) before Voluntary Cough. The Hering-Breuer inflation reflex (H-B Reflex) cannot be activated with iRCT because lung inflation does not occur. Airway protection from a perceived stimulus that could be perceived as life threatening by the body short circuits all the reflexes that are connected to the H-B Reflex system by causing vocal cord closure in 14 msecs, and in about 20 msecs IAP elevation occurs without the additional sphincter tonicity closure that would occur reflexively with inhalation lung inflation.
The involuntary reflex cough test causes significant diaphragm elevation with iRCT that does not occur with voluntary cough because the H-B Reflex, in part, holds the diaphragm down with the closed LES, despite quite highly elevated intra-abdominal pressure. The diaphragm is not held down with the iRCT, the diaphragm elevation actually pulls the LES up with it causing partial gastric content reflux. The reflux causes a vicious cough/reflux cycle to occur that leads to insidious diseases like GERD, COPD, laryngitis, Barret's Esophagitis, heartburn and similr problems. The same involuntary maneuver using the involuntary reflex cough test will diagnose SUI by blocking the inhalation tonicity that would possibly come from lung inflation via H-B Reflex.
The Hering-Breuer inflation reflex is a reflex triggered to prevent overinflation of the lungs. Pulmonary stretch receptors present in the smooth muscle of the airways respond to excessive stretching of the lung during large inspirations. Once activated, they send action potentials through large myelinated fibers of the paired vagus nerves to the inspiratory area in the medulla and apneustic area of the pons. In response, the inspiratory area is inhibited directly and the apneustic area is inhibited from activating the inspiratory area. This inhibits inspiration, allowing expiration to occur.
Josef Breuer and Ewald Hering reported in 1868 that a maintained distention of the lungs of anesthetized animals decreased the frequency of the inspiratory effort or caused a transient apnea. The stimulus was therefore pulmonary inflation.
The neural circuit that controls the Hering-Breuer inflation reflex involves several regions of the central nervous system, and both sensory and motor components of the vagus nerve. Increased sensory activity of the pulmonary-stretch lung afferents (via the vagus nerve) results in inhibition of the central inspiratory drive and thus inhibition of inspiration and initiation of expiration. The lung afferents also send inhibitory projections to the cardiac vagal motor neurones (CVM) in the nucleus ambiguus (NA) and dorsal motor vagal nucleus (DMVN). The CVMs, which send motor fibers to the heart via the vagus nerve, are responsible for tonic inhibitory control of heart rate. Thus, an increase in pulmonary stretch receptor activity leads to inhibition of the CVMs and an elevation of heart rate (tachycardia). This is a normal occurrence in healthy individuals and is known as sinus arrhythmia.
Early physiologists believed the reflex, played a major role in establishing the rate and depth of breathing in humans. While this may be true for most animals, it is not the case for most adult humans at rest. However, the reflex may determine breathing rate and depth in newborns and in adult humans when tidal volume is more than 1 L, as when exercising.
The Hering-Breuer deflation reflex serves to shorten exhalation when the lung is deflated. It is initiated either by stimulation of stretch receptors or stimulation of propriocetors activated by lung deflation. Like the inflation reflex, impulses from these receptors travel afferently via the vagus. Unlike the inflation reflex, the afferents terminate on inspiratory centers rather than the pontine apneustic center. These reflexes appear to play a more minor role in humans than in non-human mammals.
The discrepancy between the voluntary cough and iRCT in demonstrating SUI is due to the facilitatory effect of increased tonicity associated with lung inflation in voluntary cough. The voluntary cough in
The laryngeal expiratory reflex (LER) is normally triggered when food, fluid or secretions enter the larynx during swallowing or inspiration. Reflex cough can be triggered by aspiration of food or fluid during inspiration acid reflux stimulation of laryngeal receptors or post-nasal drip into the larynx, laryngeal inflammation or infection. Although the studies on gastroesophageal reflux (GER) claim that cough is a result of gastric acid reflux, it is believed that involuntary cough is the direct cause of GER and this may lead to a previously unrecognized cycle where cough causes reflux that produces the cough associated with GER. This infers that instead of treating the cough, steps should be clinically taken to reduce the reflux. SUI is primarily caused by cough. The type of cough that causes SUI is an involuntary cough and not voluntary cough, thus, by decreasing stimuli exposure, i.e., reflux that can trigger involuntary cough, SUI could be reduced. The more comprehensive clinical approach using the involuntary maneuver, i.e., iRCT, will improve the identification of both SUI and GER when they can still be effectively and conservatively treated before the development of significant comorbidities.
Intrinsic sphincter deficiency (ISD) may be clinically present as SUI and GER. The iRCT is clinically useful in improved evaluation of LES function and a more realistic assessment of SUI.
There now follows a description of a method that can be used for processing urodynamic data obtained during the iRCT and processed in the handheld device in accordance with non-limiting examples.
The process starts (1000) with the involuntary reflex cough test and proceeds from this test. One activity that may be pre-involuntary reflex cough test is an ultrasound to determine the starting bladder volume. It should be understood that
As shown in
If the post-void residual is greater than 50 ml, then a determination is made if the detrusor pressure is normal (1022). If yes, this could signify atonic bladder, detrusor hypotonia, or bladder outlet obstruction (BOO) (1024). Urecholine can be considered and possible post-void residual (PVR) intermittent catheterization procedure (ICP) in which the catheter is placed in the patient to drain the bladder (1026).
If the detrusor pressure was not normal, then a determination is made whether the detrusor pressure was increased (1028). If yes, this could signify an upper motor neuron bladder, stress or mixed urinary incontinence, overflow urinary incontinence, possible urinary tract infection, possible bladder outlet obstruction, and possible dyssynergia (1030). This can be followed by a urology evaluation and PVR/ICP corresponding to a post-void residual and intermittent catheterization procedure (1032). The possible dyssynergia (1030) corresponds to bladder sphincter dyssynergia also termed detrusor sphincter dyssynergia (DSD) in some non-limiting examples as a neurological condition with a contraction of the bladder musculature as not coordinated with the relaxation of the sphincter. In some of these instances, instead of the urethra completely relaxing during voiding, it may dyssynergically contract causing the flow to be interrupted and the detrusor pressure to rise. On cystography, there is typically an irregular appearance of a bladder outline because of musculature contraction against the unrelaxed bladder sphincter. Usually individuals with this type of condition may have daytime and night-time wetting and a history of urinary tract infections (UTI).
If the detrusor pressure is not increased, then recatheterization can occur if the detrusor pressure is less than zero and a rectal catheter can be moved or reinserted greater or equal to about 15 centimeters and retested in this non-limiting example (1034).
In one of these outcomes, the atonic bladder typically corresponds to a large dilated urinary bladder that does not empty, usually because of the disturbance of innervation or chronic obstruction. This could require a primary caregiver or other medical professional to consider urecholine if there is no urinary tract infection (UTI) or BOO (such as in 1026). A possible PVR ICP could be considered. Urecholine, of course, is also termed bethanechol as a parasympathetomimetic choline ester that stimulates the muscarinic receptors with further selectivity for M3 receptors without any effect on nicotinic receptors.
Diptropan as a generic oxybutynin is typically used to reduce muscle spasms of the bladder and urinary tract and treat symptoms of the overactive bladder causing frequent or urgent urination, incontinence as urine leakage and increased night-time urination.
If in these steps the post-void residual is greater than 50 ml, a determination is made if the detrusor pressure is normal (1056). If yes, this could be a sign of atonic bladder, detrusor hypotonia, stress urinary incontinence or overflow urinary incontinence (1058). Again, urinary tract infection is ruled out and a possible PVR/ICP with a time void and possible urecholine (1060).
If the detrusor pressure was not normal, a determination is made if the detrusor pressure was increased (1062), and if yes, this could signify upper motor neuron bladder, stress or mixed urinary incontinence, overflow urinary incontinence, or possible dyssynergia (1064). The outcome is a PVR/ICP, the rule-out of UTI, possible diptropan, and possible urological evaluation (1066). If the detrusor pressure was not increased and is less than zero, an outcome is to move or reinsert the rectal catheter, greater than or equal to about 15 centimeters and retest in a non-limiting example (1068).
If the voiding and detrusor pressure is greater than 60, then a determination is made whether the pad leaked (1086). If yes, this can correspond to bladder outlet obstruction and overflow incontinence (1088). Possible considerations can be the ICP, a Foley catheter, a urology evaluation. UTI is ruled out or prostate (PSA). The clinician also rules out bladder outlet obstruction, i.e., BPH or pelvic organ prolapse (10%). If there is no pad leak, this could possibly correspond to bladder outlet obstruction (1092) and the same outcome processing occurs (1090).
If the initial PVR was not greater than 100 ml, a determination is made if the detrusor pressure was greater than 30 centimeters of water at rest (1094). If yes, this can correspond to detrusor instability, urge incontinence and mixed incontinence (1096). UTI is ruled out and possible Ditropan or Detrol is considered if there is no UTI. A stress urinary incontinence evaluation in urology is considered at this time (1098). If the detrusor pressure was not greater than 30 centimeters of water, then a determination is made whether the pad leaked (1100), and if yes, this step corresponds to stress urinary incontinence (1102) and a time void or urology evaluation considered (1104). If there is no pad leakage, then a normal study is considered (1106).
If the detrusor pressure was greater than 60 ml at voiding, a determination is made if there is a pad leak (1130) and if yes, this can correspond to overflow incontinence and possible SUI (1132). The outcome can be PVR/ICP, the rule out of UTI, and urecholine if no UTI (1134). If there is no pad leakage, this can correspond to atonic bladder followed by hypotonic bladder consideration (1136). The outcome is as before (1134).
If the PVR was not greater than 100 ml (1112), a determination is made if the detrusor pressure is greater than 15 centimeters of water at resting (1138) and if yes, this can correspond to detrusor instability, urge incontinence and mixed incontinence (1140). UTI is ruled out. Ditropan or detrol is considered if there is no UTI. An SUI evaluation for urology is considered. Males can consider normal pressure hydrocephalus (NPH) (1142).
If the detrusor pressure was not greater than 15 centimeters of water at resting (1138), a determination is made whether there was a pad leak (1144) and if yes, this can correspond to SUI (1146) and the outcome can be a time void and urology evaluation with the time void indicating how much time it takes to void (1148). If not, then a normal study occurs (1150).
As shown by the different considerations and outcomes in
It should be understood that the improved catheter as described below
These examples show use of the pressure sensor as a TDOC-4030 pressure sensor and a catheter as a TDOC-7F (7 French) catheter. The catheter as described below relative to
Different processors 1204 as a single board computer can be used in a non-limiting example. The described Rabbit microprocessor is a low-power, single-board computer and is especially operable with portable handheld, battery-powered, remote monitoring systems. It includes built-in analog and digital input/output and typically consumes less than 20 milliamperes when operational and less than 100 microamps in a power-save mode. In this non-limiting example, it includes flash memory and SRAM and various inputs/outputs and in one non-limiting example eight analog/digital converter inputs with programmable gain and six serial ports. It has pulse width modulation (PWM) outputs. It can be programmed using C software in a non-limiting example.
It should be understood that the display unit 1208 as illustrated in
The catheter 1300 is used to evaluate bladder pressures at rest, empty or with urine, filling with fluid during voiding. It is used to evaluate for urinary incontinence by detecting a minimal amount of urine loss during voluntary and involuntary maneuvers of the type as described before. The stylet sensor in one non-limiting example is used alone for pressure monitoring while presenting the least amount of disruption/distortion of the urethra and urinary sphincters. The stylet in another non-limiting example is packaged separately and inserted into an existing Foley catheter to measure pressure and function in one non-limiting example.
In one non-limiting example, the catheter is a dual lumen six French catheter of about 50 centimeters and includes the sensor 1308 and fill port at the second lumen 1304. It is inserted in a non-limiting example about 10 centimeters for a female bladder and 15 centimeters for a male bladder. The location of color change indicators 1310 for a female could be about 11-14 centimeters, and for a male, about 16-19 centimeters. In one non-limiting example, the urine pH range is about 4.6 to about B.
It should be understood that the catheter is preferably a smaller diameter catheter and includes those down to 3 (three) and 4 (four) French. The smallest catheter possible is used as a urethra catheter and somewhat smaller than a standard ten (10) French cathether. It has been found that some patients have a tendency to leak with the larger catheter in place because of the size of the catheter or they become obstructed with that catheter in place. Smaller urinary bladder catheters are typically about 6 (six) French and used for neonatal infants. There are some PICC catheters (Peripherally Inserted Central Catheters) that are three (3) and four (4) French. These smaller catheters should be double lumen in this example. This system is not limited in size, but the smaller is advantageous.
The double lumen catheter, in accordance with a non-limiting example as described, has the first lumen 1302 for a sensor probe 1308 and a second lumen 1304 for the filling with liquid. The sensor probe is a “T-doc” as used with an air-charged catheter for pressure sensing and air-charged pressure recording in one non-limiting example. It should be understood that this catheter can be used with or without filling the bladder, and advantageously used in urodynamic testing. The doctor, nurse or clinician does not have to personally bend down and view the urethra area to determine if there is leakage, which is an advantage in a clinical test. Different types of indicators 1310 as chemical indicators can be used.
In another non-limiting example such as shown in
Different types of pads or substrates could be used in combination with the support ring 1320 and moveable along the catheter. This combination catheter and the urine indicating sensor, in one example, are specific for use to determine an instance of stress urinary incontinence. It is possible, however, to add a balloon to this catheter similar to a Foley catheter such that the catheter remains in place. Two catheters are thus possible. For example, a specific catheter and urine indicator are used for stress urinary incontinence. It is also possible to add a balloon with the larger 14, 16, 18 or 20 French catheters as a larger size. A sensing system is included in this example. Added to this catheter is a channel for urine drainage, the sensor, and an indwelling balloon to keep it in place. The catheter, in one example, is used to determine whether the patient can protect their airway in conjunction with the involuntary reflex cough test (iRCT).
The cloth or pad 1322 is attached to the support ring 1320 and includes on the pad a regent that is permanently attached. It can be a single use catheter for stress urinary incontinence (SUI) testing. It is included within the test kit to be described in one example and includes the nebulizer (and the drug) for involuntary reflex cough testing as described before.
In one example, it is possible to have a catheter of about three (3), four (4), or five (5) or somewhat larger French that thread inside a regular Foley catheter with pressure measurement capability. The catheter that goes inside the urethra, such as a seven (7) French catheter, can go inside a Foley catheter. In one example, the balloon is part of the smaller catheter and measures or tests for airway protection in the technique as described before.
An enzymatic moisture detector can be used. Initially, any indicators or pad and ring could be covered before catheter use. When needed, the catheter is uncovered and moved into the proper position against the meatus. A first catheter is used with stress urinary incontinence and testing. Another catheter as a second or larger diameter catheter is balloon specific for reflex cough testing to measure intra-abdominal pressure in determination of airway protection.
In an example, temperature is used with the sensor and changes the sensor as an indicator. It is possible to use the presence of urea for sensing urine. One problem is in bladder testing. The bladder is often filled with saline water or other fluid that is not urine. If the indicator is specific to ammonia or urea, then it would not indicate adequately. Temperature is one advantageous solution and a material that is sensitive to temperature change of about 90 degrees is adequate. The fluid is inserted into the bladder and becomes warmer than room temperature. If there is leakage, it changes the color of the catheter even without the presence of urea.
The tip of the catheter can be placed into the urethra and the outside of the catheter includes the indicator. It changes color if there is leakage whether there is urine inside the bladder or just fill. It could change the color of liquid after it leaks. This could be an assurance against false positives such as would occur with perspiration from the doctor's or nurse's hands. If there is a second testing such as in surgery (and the patient hopefully fixed), a different color could be used. In SUI testing, the liquid is placed in the bladder in one example, but would come out a different color when it reacts with the sensor on the bladder near the meatus. This assures that one is viewing a leakage and not a false positive.
There is a possibility for measuring airway using the port in combination. The catheter can be small enough to go into a side port of a Foley catheter similar to a guide wire. Thus it is possible to take the catheter out if it is obstructing in some way and leave a guide wire. It is possible to remove the catheter and still have a guide wire or small catheter that has a sensor probe on the end. Instead of having a dual channel and having a tube inside a tube that you could do a fill around, it is possible to remove the outside tube that is blocking the urethra. It should be understood that the catheter (depending on size and pathophysiology of a patient) can either block the urethra or hold the urethra open, causing additional leakage. Specific catheter designs as described alleviate these problems. With the larger catheters, the larger catheter size is used to fill and is taken out. The inside tube (catheter) stays. A smaller four (4) French catheter has a dual channel, one for the pressure sensor and the other to fill 1200 millimeters an hour and is adequate to cover different possibilities.
Any catheter could include a wireless sensing device 1530 that is included in the kit in case wireless technology is used. Although a wireless sensing device could be separately connected to the catheter after the kit is opened, in one aspect, it is possible to include the wireless sensing device connected to any appropriate catheter such that the kit is open, the nebulizer removed, any pad and the catheter with wireless sensing device. The handheld device can be a separate device and the catheter used and wireless signals sent to the handheld device. After analysis and testing on a patient, the kit components such as the catheter and wireless sensing device, pads and nebulizer could be disposed of in the proper manner. It is possible that the EMG pads could connect into the wireless sensing device such that wireless signals are transmitted to the handheld device that includes the pressure readings and the EMG signals. Thus, the kit or system when removed would include the pressure sensing device with the attached leads and EMG pad and catheter that may be integrated together or separately removed and then connected to each other.
This application is related to copending patent application entitled, “TECHNIQUES FOR EVALUATING STRESS URINARY INCONTINENCE (SUI) USING INVOLUNTARY REFLEX COUGH TEST” which is filed on the same date and by the same assignee, the disclosure which is hereby incorporated by reference in its entirety.
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.
25. A catheter, comprising:
- a catheter body having an outer surface and dimensioned for insertion within a urethra and into a bladder and having a first lumen configured to monitor bladder activity and a second lumen configured to fill the bladder with fluid; and
- at least one indicator positioned along the surface of the catheter that is configured to change color when exposed in combination to two separate urine characteristics to indicate urine leakage.
26. The catheter according to claim 25 wherein said two separate urine characteristics comprise a temperature of fluid above a predetermined value and a presence of urea.
27. The catheter according to claim 25 wherein said at least one indicator is responsive to fluid that is a temperature above about 30 degrees Celsius.
28. The catheter according to claim 25 wherein said catheter body includes a distal end and a sensor positioned thereat.
39. The catheter according to claim 25, wherein said catheter includes a distal end and said at least one indicator is positioned from 11 to 14 centimeters from the distal end along the surface for female use and from 16 to 19 centimeters from the distal end for male use.
40. The catheter according to claim 25, and further comprising a sensor extending through the first lumen configured to monitor pressure.
41. The catheter according to claim 40, wherein said sensor comprises a stylet sensor.
42. The catheter according to claim 40, wherein said sensor comprises an air-charged sensor.
43. The catheter according to claim 42, wherein said air-charged sensor comprises a T-doc sensor.
44. The catheter according to claim 25, wherein one of said two separate urine characteristics comprises pH.
45. The catheter according to claim 25, wherein said at least one indicator is sensitive to pH ranging from 4.6 to 8.0 to change color.
46. The catheter according to claim 25, wherein said catheter body is three to ten French diameter.
47. A catheter, comprising:
- a catheter body having an outer surface and dimensioned for insertion within a urethra and into a bladder; and
- a support member supported on the outer surface of the catheter body and movable therewith into a desired position for leakage testing when the catheter body is inserted within a urethra and into the bladder, said support member carrying a urine leakage indicator that detects urine leakage.
48. The catheter according to claim 47, wherein said support member comprises a support ring supported by the catheter body and slidably movable on the outer surface of the catheter body.
49. The catheter according to claim 47, wherein said urine leakage indicator comprises a moisture indicating dye to indicate urine leakage.
50. The catheter according to claim 47, wherein said urine leakage indicator comprises an enzymatic moisture detector.
51. The catheter according to claim 47, wherein said urine leakage indicator is configured to change color when exposed in combination to two separate urine characteristics to indicate urine leakage.
52. The catheter according to claim 51, wherein said two separate urine characteristics comprise a temperature of fluid above a predetermined value and a presence of urea.
53. The catheter according to claim 47, wherein said urine leakage indicator is responsive to fluid that is a temperature above about 30 degrees Celsius.
54. The catheter according to claim 47, wherein said catheter body includes a distal end and a sensor positioned thereat.
55. The catheter according to claim 47, wherein said catheter includes a distal end and said urine leakage indicator is positioned from 11 to 14 centimeters from the distal end along the surface for female use and from 16 to 19 centimeters from the distal end for male use.
56. The catheter according to claim 47, and further comprising a first lumen and a sensor extending through the first lumen configured to monitor bladder pressure.
57. The catheter according to claim 56, wherein said sensor comprises a stylet sensor.
58. The catheter according to claim 56, wherein said sensor comprises an air-charged sensor.
59. The catheter according to claim 58, wherein said air-charged sensor comprises a T-doc sensor.
60. The catheter according to claim 47, wherein said urine leakage indicator is sensitive to pH ranging from 4.6 to 8.0 to change color.
61. The catheter according to claim 47, wherein said catheter body is three to ten French diameter.
62. The catheter according to claim 47, further comprising a first lumen configured to monitor bladder activity and a second lumen configured to fill the bladder with fluid.
63. The catheter according to claim 47, wherein said support member comprises a color changing urinary pad and a medial section having a hole therein through which the catheter body is received.
Filed: Jul 16, 2013
Publication Date: Nov 14, 2013
Inventors: W. Robert ADDINGTON (Melbourne Beach, FL), Stuart P. MILLER (Indialantic, FL), Robert E. Stephens (Parkville, MO), Michael M. PHELIPA (Melbourne, FL), Mary W. BRIGANTI (Melbourne, FL)
Application Number: 13/943,163
International Classification: A61B 5/20 (20060101); A61B 5/145 (20060101); A61B 5/01 (20060101);