THE-“I .“fi “’22” _.§WW§VI§~I,u-’ h .2 ’r.' ... p 0 C'.‘ ff" f4 .2: NS“ ;-. ‘2 " ~ w' ;' - ' Av’ -;.,_I'~.-3J{Y ' "o , . .f i '1 . .f' . “Q“, {v.fi“ S a £3 _ lit—.- ‘gtj’ 1 1 mike '2' 13”“. ’ . I. 3;)- d $4 3 9.93132” . P"; O”, -.'_l.-" '2 9" .3... .'-. wmmwau.‘ 155‘- ~' I “‘ 4"”‘w This is to certify that the thesis entitled A Computer Based Biofeedback Training System presented by Juan Carlos Esteva has been accepted towards fulfillment of the requirements for m degree in 5C1 ence Electrical Engineering ' 8 Systems Science Major professo .\ Date “1““ ‘1? ank 0-7 639 MS U is an Affirmative Action/Equal Opportunity Institution . MSU LIBRARIES .—._—. RETURNING MATERIALS: Place in book drop to remove this checkout from your record. FINES will be charged if book is returned after the date stamped below. © 1982 JUAN CARLOS ESTEVA All Rights Reserved G// 7wa A COMPUTER BASED BIOFEEDBACK TRAINING SYSTEM By Juan Carlos Esteva A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Electrical Engineering and Systems Science l982 ABSTRACT A COMPUTER BASED BIOFEEDBACK TRAINING SYSTEM BY Juan Carlos Esteva This thesis is concerned with the development and testing of an instrumentation system to be used as the basis of a biofeedback training technique in the treatment of fecal incontinence (encopresis). The system records, digitizes and processes human rectosphincteric responses,utilizing this information to create animated figures to be employed as the biofeedback visual pathWay. The rectosphincteric responses are detected by a pressure trans- ducer, passed through an amplifier, digitized, and finally displayed in a comprehensive form using a T.V. monitor. An APPLE 11 computer conducted the digital data processing necessary to display the animated figures, making use of high-resolution graphics. Truly, truly, I say to you, he who believes in me, the works that I do shall he do also; and greater works than these shall he do; because I go to the Father. --John l4:l2 ACKNOWLEDGEMENTS The author wishes to express his deep appreciation and gratitude to these people, for making this phase of his graduate work possible: To Richard C. Hallgren, Ph.D., his major advisor, for his encouragement, support, and friendship, and, especially, for his valuable assistance in the preparation of this thesis; To his family, Motek, Marita, and Gabo, for their understanding, encouragement, endless patience, and interest in his graduate work and academic education. iv TABLE OF CONTENTS Acknowledgements Table of Contents . List of Figures. List of Tables . I.v INTRODUCTION. -II. LITERATURE SURVEY . .l NNNNN N N .3 NNNNN N .3. 2.3. III. SYSTEM 3.l 3.2 .l. .l. .DOON —l l 2 BiOfeedback. Definition . Historical Background The Biofeedback Paradigm Clinical Applications Physiological Background Gross Anatomy of Anorectum. Mechanism of Continence. Pathophysiology of Defecation. Advances in Biofeedback/Conditioning for Encopresis Motility Recordings . Operant Conditioning (Biofeedback) . ORGANIZATION Characteristics of the System. Pressure Measurement Device Page iv 10 l5 l7 l7 19 24 24 24 vi Table of Contents, cont'd. 3.3 Data Acquisition . 3.4 Data Analysis and Graphics Generation . IV. EXPERIMENTAL PROTOCOL. .. . . . . V. RESULTS AND CONCLUSION Glossary of Medical Terms . Glossary of Engineering Terms. . Appendix A: Machine Language Subroutine to Transfer Data (READER). . . . . . . . Appendix B: APPLESOFT Basic to Calibrate (CALIBRATION) . . . . . . Appendix C: APPLESOFT Basic to Diagnose Initial Response (PRESSURE) . . . . . . . . Appendix D: APPLESOFT Basic Display Program (SQUARE). . . . . . . Appendix E: APPLESOFT Basic Display Program (COLORLINE). . . Appendix F: APPLESOFT Basic Display Program (GLASS). . .. . Appendix G: Machine Language to Show an Exact Representation (EXACT) . . . . . . . . . Appendix H: System Manager (HELLO) . . . . . . Bibliography . . . 29 36 52 56 59 61 65 66 67 68 69 7O 7l 77 78 Figure l0. ll. 12. l3. l4. l5. l6. l7. l8. LIST OF FIGURES Page. Closed-loop Biofeedback System . . . ............ 6 Muscles of the Anal Region (Perineum) ........... 9 Internal and External Sphincters .............. ll Diagram of Sagittal Section through Anal Canal and Lower Rectum To Demonstrate Factors Involved in Anal Continence l3 Schematic Diagram of Recording Technique .......... 20 Measurement Device for Internal and External Sphincters . . 2l Biofeedback System ..................... 25 Triple Lumen/Double Balloon ................ 27 Schematic Diagram of Recording Technique . ......... 28 Pressure Transducer . . . . ................ 32 High Sensitivity Amplifier ................. 34 High Speed A/D Converter Circuit Diagram .......... 35 Flow Chart for the Machine Language Program to Digitize Sphincteric Muscle Response (READER) ........... 37 Flow Chart for Applesoft Basic Program to Calibrate Input (CALIBRATION) ...................... 39 Flow Chart for Applesoft Basic Program to Diagnostic Initial Response (PRESSURE) ............... 40 Flow Chart for Applesoft Basic Program that Displays a Square (SQUARE) ..................... 4l Flow Chart for Applesoft Basic Program that Displays a Color Line (COLORLINE) .................. 42 Flow Chart for Applesoft Basic Program that Displays a Glass (GLASS) ...................... 43 vii viii List of Figures, cont'd. l9. 20. 21. 22. 23. 24. Shape Displayed by the Program SQUARE ............ Shape Displayed by the Program COLORLINE .......... Shape Displayed by the Program GLASS . . .......... Flow Chart for Machine Language Program with High speed and Accuracy (EXACT) ................... Shape Displayed by Program EXACT ........... Biofeedback Control System ................. Page 44 LIST OF TABLES Summary of Studies Using Biofeedback of Heart Rate . Approximate Transducer Response . Output Voltage of the Pressure Transducer Sphincteric Muscles Responses ........ ix Page 3O 31 3l Chapter I. INTRODUCTION In our rigidly toilet-trained society, fecal incontinence (encopresis) is a stigma of great magnitude. This condition of disorder- ed motility often imposes sharp limitations on geographic and social mobility on human patients. Presently the treatment of encopresis is generally of two types, one comprising a wide range of anti-obstipational measures, such as dieting, laxatives, enemas, and manual evacuation, and the other being psychiatric. Most authors who address the topic appear to consider simple psychological measures sufficient if the patient is willing to cooperate. I The application of psychotherapeutic techniques, like biofeedback, in the treatment and control of different bodily responses has been studies since l967 but it was not until T974 that biofeedback was applied in the treatment of fecal incontinence by Engel et al [1]. The Engel experiment showed that rectosphincteric responses can be brought under voluntary control in patients with chronic fecal incon- tinence, even when the problem was secondary to organic lesions. It was found, while searching the literature, that some other authors had done similar experiments. Cerulli treated fifty patients with severe cases of encopresis and achieved a good response to the biofeedback training. Ninety percent of his patients learned to have almost normal bowel movements. Wald uses the same technique but applied it to children with meningomyelocele and obtained a good clinical response with the dis- appearance of soiling or a greater than 75 percent improvement in the frequency of soiling. In general, the biofeedback technique used in these experiments was to provide the patient with a feedback signal in the form of poly- graph tracings that would allow him to perceive his previously unavail- able physiologic response. The work that preceded the writing of this document was intended to develop an instrumentation system that would record, digitize and process human rectosphincteric responses that will form the feedback pathway in the treatment of fecal incontinence. . The main body of this thesis deals with the description of the system and the experiment protocol developed. For those persons unfamiliar with either medical and engineering terms, a glossary of terms used in this thesis is provided. Chapter II. LITERATURE'SURVEY 2.1 Biofeedback 2.l.l Definition Biofeedback can be defined as the use of monitoring instruments to detect and amplify signals provided by some selected physiologic processes in order to make previously unavailable physiologic information accessible to the subject's consciousness. The subject is thus able to learn voluntary control over autonomically regulated body functions. 2.l.2 Historical Background Since the time of Plato a dichotomy has been maintain between ”reason” on the one hand and ”emotions" on the other. Associated with "reason" are the voluntary responses of the skeletal muscles, while ”emotions" are related to the presumably involuntary glandular and visceral responses. This conception has persisted, in one form or another, to the present time. Learning processes, which have been studied by psychologists and physiologists since the latter part of the nineteenth century, have been divided into two kinds: one is the classical or Pavlovian conditioning, and the other is the operant or instrumental conditioning. In classical conditioning (which is thought to be involuntary) a stimulus or signal is identified, such that when it is presented, it will elicit a reliable and consistent response from a subject. Such a signal is called an unconditioned stimulus (US), and the response it elicits is called an unconditioned response (UR). A second signal, one that neither elicits nor inhibits the UR, is then identified; it is termed the conditioned stimulus (CS). In a typical experiment, the CS is presented along with an innate US (such as food), which normally elicits a particular innate UR (such as salivation). After several such pairings, or associations, the CS can be seen to elicit the same UR as the US. The CR's are mediated by the autonomic nervous system (ANS), as well as by the somatic nervous system (SNS). Most human learning is not acquired through classical conditioning; it is acquired through operant conditioning. The analysis of operant conditioning begins with a response (R). The goal of operant condition- ing is to change the frequency and/or the probability of occurrence of R. Once the operant level, or base rate, of R is determined, the investigator then modified the situation so that whenever R occurs, it always will be followed by a consequence, or reinforcer, which is salient to the subject. If the reinforcer is positive (rewarding), the frequency and the probability of occurrence of R will increase; if the reinforcer is negative (punishment), the frequency and probability of occurrence of R will decrease. The possibilities of learning are limited in classical conditioning, as the US and UR must have a natural, direct relationship to begin with. In operant conditioning, on the other hand, the reinforcer strengthens any immediately preceding response. 5 These assumptions have coalesced into the point of view that operant conditioning is possible only for skeletal responses mediated by the central nervous system (CNS). Conversely, classical conditioning is the only procedure available for the "inferior" visceral, emotional, and presumably involuntary responses mediated by the ANS. Recently, an abundance of data (Barber et al [2], Kimmel [3]) perti- nent to these assumptions has appeared, all of which demonstrate that the traditional view concerning the ANS is fallacious. Kimmel (1967), in a review of recent research on this topic, concluded: ”The autonomically mediated responses can be changed by operant training procedures.f (Page 344) 2.l.3 The Biofeedback Paradigm The concept of biofeedback involves an organism placed in a closed feedback-loop where information concerning one or more of his bodily processes is continually made known to him. This system is illustrated in Figure l. When the organism possesses such information about a bodily process, he can learn to control the function. Thus, biofeedback techniques are based on the principle that certain responses are made when informational feedback is received by an organism. These responses are adjusted, corrected, and modified as feedback is con— tinually received until a determination is made that a final goal has been achieved. 2.l.4 Clinical Applications of Biofeeback Training Several studies have shown that the clinical application of biofeed- back training has profound implications for a variety of disorders. Empmzm xomnnwmmowm aoOFIGmmoFu ._ mczmwd Emumzm oweocopz<14 Emumxm 3:632k [ mmmcmzovomcou Lemmmooca chpcmo pcmscocw>cm Among the responses already studied are heart rate and heart rhythm [4,5,6]; blood pressure [3,5]; muscle spasm; vascular tone; skin tempera- ture and/or peripheral blood flow; and sweat gland activity. General references to these studies are given in the bibliography [2]. An example of such studies are those done by Blanchard et al [7], in which patients have been taught to modify heart rate (HR) through operant conditioning (or biofeedback training); Table l presents a summary. 2.2 Physiological Background 2.2.l Gross Anatomy of Anorectum The perineal region, or perineum, includes two parts, the anal and the urogenital regions. The former (Figure 2) includes the area between the tip of the coccyx and an approximately transverse line passing in front of the anal canal, between it and the urethra in the male and the vagina in the female. The roof of the anal region, separating it from the pelvis, is the pelvic diaphragm, formed by the levator ani and coccygeous muscles. I Rectum: The rectum varies in length from l2 to l5 centimeters. Its cephalad limit is indefinite, and its caudal border lies at the junction at which the mucous membrane of the rectum blends into the anal canal (anorectal line). The portion of the rectum which lies caudal to the perineal portion is supported by all the muscles of the anorectal region, namely the coccygeous, rectococcygeous, levator ani and external sphincter. Anus: The anus measures 2 to 4 centimeters in diameter when dis- tended. It is surrounded by the internal anal sphincter; and as the .mcov.nm uo unauu¢a .L-om be ac—xo_> o——:x ammo gauze-05¢ acaomcou a: ape; .xnau uc—uuogu .omoa an uuuo— .pouucou us ca vo:_-Lu muuun we ago—mama 15:» —osu:ou :L-u— so: 1&5“ —-u=u5_soa Acct—am. ~ vo>—ooog Ange“ oeou a —oacua-Loa v.v wagon uxo "voumouosa «co—«mom yuan conccoa .umooucn so am -azo nacho 1:0 causes: 1&2» —uu mauonaam pogucou c.5 .50 cocoa» was -zUuoE m—ocucou cop—ocuzou oucoso~m_a on u:n§.guaxu one: a pauses—Lonxu uoo .N mm ca guaocna< oceuom_ca .vuuo: muuouuu —-u.:._u ac. 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IlomQMolfl 28:2; 2338.. 35.: 205.5 “ltd—dd 8:83.. 2352 nu : u Laue no Loguo envy-5:: yo .9: poo—:.—u : .mua poucospco xu nu—amoz ucvccaucou mucosaogu m5 apex pcmm: mo xomncmwwowm mcwm: mowvzpm to >2m553m .F mFQmH Tuber ischiad Inferior Urogenital Anus ——* Levatori ani Gluteus Maximus ,/;(;//<;/l Coccyx Sphincter ani Externus Figure 2. Muscles of the Anal Region (Perineum) lO anal canal makes its exit through the pelvic diaphraghm, it is surrounded by the external anal sphincter (Figure 3). The internal anal sphincter is a circular muscle which is continuous with the inner, circular layer of smooth muscle of the anal region. In its normal, resting state the internal sphincter is strongly contracted. Since this sphincter is smooth muscle, it is autonomically innervated. Parasympathetic stimulation relaxes it, and sympathetic stimulation con- tracts it. Relaxation of the internal anal sphincter is a necessary condition for the occurrence of defecation.- The external anal sphincter surrounds the internal sphincter and extends beyond it to form the terminal musCle of the anal canal. In its normal, resting state the external sphincter is slightly contracted. It is innervated by the somatic nervous system. Relaxation of this sphinc- ter is necessary for defecation to occur, while its contracture is necessary to preserve continence. Stimulation of the nerves produces contraction, and inhibition produces relaxation. The internal anal sphincter is innervated by autonomic nerves, and the external sphincter is amenable to voluntary control. 2.2.2 Mechanisms of Continence Fecal continence refers to the ability to retain bowel contents until evacuation becomes convenient. This includes the recognition and differential control of the passage of solids, liquids, and gases. Thus, continence requires an intact nervous reflex arc and a functioning motor component capable of retaining material. Normally, defecation is under cortical control and can be suppressed at will; and conscious differential recognition can be made of the three physical states of the bowel contents. ll Sigmoid colon Rectum Recto-sigmoid junction Internal anal sphincter External anal sphincter Figure 3. Internal and External sphincters l2 Three basic mechanisms (Figure 4) are involved in the maintenance of continence: the sensory stimulation by intraluminal contents, reservoir action of the colon, and Sphincteric contractions. Recto- sphincteric reflexes play an important role in this regard. 2.2.2.l Reservoir Continence The rectum usually contains little or no material except shortly before defecation, at which time feces are propelled into the rectum. The rectum serves a twofold role in preserving continence. It acts as a compliant reservoir for intestinal contents, and also as the sensory receptor organ for rectosphincteric reflexes. Reservoir continence refers to plastic adaptation (compliance) of the colon and can be totally sufficient even in the absence of anal sphincters. This reservoir function plays a more important role in the prolonged reten- tion of feces than the sphincters, since the external sphincter fatigues after brief contraction (less than one minute). Rectal sensory receptors apparently increase in concentration in a caudad direction, since smaller volumes of distention are required to elicit sensation or to initiate rectosphincteric reflexes as distention progresses caudally. Evidence is conflicting as to whether these receptors are in rectal mucosa or the muscle wall. 2.2.2.2 Sphincter Continence Like the rectum, the anal sphincters subserve two functions in pre- serving continence. The constant tone of the anal sphincters (especially the internal sphincter) cloSes the anal orifice and may serve to impede the rectum in amounts insufficient to distend it. This is a reflex l3 Levator ani //,Puborectal1s sl1ng f, Internal anal sphincter 0 Anal valves ‘l , v ”UV ‘y External anal sphincter Sensory part of anal canal Ax1s of anal cagaborectalis’//€7 42:? Internal anal?”O WWW CK sphincter /’5 D Externalanalsgs sphincter G" Figure 4. Diagram of Sagittal Section through Anal Canal and Lower Rectum To Demonstrate Factors Involved in Anal Continence. [Arrows 1n outl1ne diagrams at right represent forces involved. (From Duth1e,20 )]. l4 phenomenon without a voluntary component. The internal sphincter appears primarily concerned with the control over flatus and liquid stool. The external sphincter, by its voluntary contraction when rectal fullness is sensed, or by reflex contraction when the rectum is dis- tended, may facilitate continence. The external sphincter reflexly develops increased tone under circumstances that threaten continence, as when intraabdominal (and intrarectal) pressure is increased during weight-lifting or coughing. Since the external sphincter fatigues with less than a minute of voluntary contraction and also reflexly contracts only briefly even with prolonged rectal distention, its role in main- taining continenceis.an emergency mechanism effective only briefly. This mechanism can be effective because feces, entering the rectum, stimulate a very transient rectal contraction lasting a few seconds. There is concomitant contraction of the external sphincter which outlasts the rectal contraction. The greater the rectal distention, the greater is the force of sphincter contraction, although the duration of sphincter contraction remains unchanged. Removing the rectum destroys this reflex, although the external sphincter and its motor supply remain intact, as demonstrated by normal voluntary contraction. In summary, the maintenance of continence is a complex and poorly understood phenomenon relying largely on reflex mechanisms and on the threatening stimulus. Rectal pressures, folds, and valves keep this area relatively free of intestinal contents. When material enters the rectum in amounts insufficient to distend it, continence is maintained by the "locking" effect or resistance of the tonically contracted internal sphincter. Increased intraabdominal pressure (produced by l5 coughing, straining, and lifting) does not expel the material, because it activates the flutter-valve mechanism that tends to keep the anal canal closed and thus avoids stimulation of anal mucosa and conscious awareness of threatening incontinence. When contents enter the rectum sufficiently to distend it, and intraluminal pressure increases, the internal sphincter relaxes momentarily; this permits stimulation of the sensitive anal mucosa, but simultaneous external sphincter contraction prevents soiling. The warning signals from the anal receptors allow voluntary contractions to act as a further retentive force, and this, with the compliant adaptation of the rectum, permits a reversal of the pressure differential to the normal resting state. The adaptation of the rectum to its new volume and the removal of anal sensory stimulation also afford relief from discomfort. 2.2.3 Pathophysiology of Defecation Most of our understanding of human disturbances in defecation derives from the perceptive observations of Hurst, whose balloon and radiographic studies of the pelvic colon and rectum clearly showed that the rectum could adapt in a plastic manner to increasing pressure or bolus size without triggering off a defecatory reflex. He distinguished between defecatory disturbances due to problems in the colon above the rectum and those due to rectal defects. As a general rule, patients with disturbances in defecation either have a rectal ampulla empty of feces--implicating the pelvic colon as the source of the difficulty--or chronically full of feces--focusing attention on the rectum itself as the cause of the trouble. Socially acceptable behavior requires that normal persons must often inhibit defecatory impulses as soon as they l6 occur; this inhibition is effected by voluntary contraction of the ex- ternal anal sphincter and by voluntary elevation of the pelvic floor. It is probable that the rectum adapts to the magnitude of the pressure increase which initiated the reflex, and it can be demonstrated that a large pressure increase will be necessary subsequently to cause the rectal sensors to fire off. Continuous inhibition of these reflexes over a period of months or years is probably a principle mechanism for the development of rectal constipation. Another disturbance is fecal incontinence or encopresis. As a rule, encopresis is defined in the literature as repeated, involuntary evacua- tion of feces in the clothes without there being any gross explanatory cause. Isolated mishaps are thus not included. A typical feature of this syndrome is that the child refuses to use a pot or toilet or that it repeatedly postpones the use of these facili- ties. Usually, the consistence of the feces is normal. In those cases in which the patient completely refuses to use the toilet, all the feces are passed into the clothes, usually daily and with the usual amount, consistence, and caliber; this mostly occurs among very small children. Among children aged 6 - 12 years, refusal to use the toilet is said to be due to deep-seated mental disturbances which are very difficult to deal with. Other children do most of their defecation on the toilet but pass a small stool into their clothes each day. Kanner (1953) calls this partial encopresis. In these cases, too, the feces are of normal consis- tence. These children state that they experience the urge to defecate but are prevented from going to the toilet by haste, by fear of the dark, by not daring to ask permission to leave the classroom, etc. 17 Even though encopretic children may protest that they cannot control their bowel function, many of them have symptom-free periods of varying length, when it is to their advantage. They commonly hide their soiled clothes behind furniture, etc., according to these authors when a parent has scolded them or made them feel ashamed. . Encopresis does occur among psychotic adults or among those who are seriously retarded, especially if they have severe organic lesions in the brain. Otherwise, encopresis appears to be extremely rare among adults. In general, methods of treatment for encopresis have varied with the alleged cause of the symptom. Mostly, it has been considered either as an obstruction or as a psychiatric problem. Believers in the former cause have emptied the large intestine with laxatives, enemas, supposi- tories, or manual evacuation. Believers in the latter cause advocate psychological or psychiatric treatment, possibly combined with other measures. 2.3 Advances in Biofeedback Conditioning for Encopresis 2.3.1 Motility Recordings The anorectal area does not readily lend itself to the methods usually employed for the study of the more proximal portion of the colon, such as direct observation of the exposed viscera of animals or persons under anesthesia, fluoroscopic examination, or routine pressure record- ings by balloons, or open-tipped tubes lying passively in this area. Manometric recordings of lower bowel motility have also been difficult to interpret because this segment frequently displays no 18‘ spontaneous activity for periods as long as six (6) hours. Attempts to stimulate normal activity have been met with inconsistent results, and the activity observed has not been clearly related to this segment's primary function, defecation. Schuster et a1 [9] describes an internal anal sphincteric response that can be elicited at will, is regularly reproducible, and is analogous to the physiological concomitants of defecation. This response is essentially that reported in 1877 by Gowers [10], who found that in- sufflation of air into the rectum produces relaxation of the internal anal sphincter. Schuster et al [11] has designed an investigation to define, in the human, the normal physiology of the sphincter response, the neural path- ways involved, and the effect of various disorders of bowel function upon this response. The apparatus used to measure sphincter function consisted of a balloon assembly attached via polyethylene tubes to Sanborn's differential pressure transducer and a direct-writing electri- cal recorder. See Figure 5. There are, however, two major limitations to this method. First, measurements are obtained only from the internal sphincter. This is a serious drawback, since the anal sphincter is composed of two parts, the internal and the external sphincters. Second, this technique requires that the recording device must be held in place manually. Schuster et al [12] extended the investigation to permit simul— taneous recordings from both internal and external anal sphincters. The apparatus used to measure sphincter function consisted of a hollow steel cylinder 22 mm in outer diameter, 21.5 mm in inner diameter, and 10 cm long, surrounded by two balloons which created two separated compartments, 19 which recorded separately from the internal and external sphincter. See Figure 6. With this technique, it can be shown that rectal distention produces simultaneous internal sphincter relaxation and external sphinc— ter contraction. 2.3.2 Operant Conditioning Biofeedback Since Miller [13] reported the results of operant conditioning of visceral responses in the curarized rats, others have used biofeedback to control different bodily responses. The application of biofeedback techniques in treating fecal incontinence was first described by Engel et a1 [1] in 1974. He described the means by which six patients with severe fecal incontinence and manometric evidence of external sphincter impairment were taught to produce external sphincter relaxation. These responses were induced by rectal distention. The feedback was provided to the patient by permitting him to watch the polygraph tracings of his sphincteric responses as they were being recorded. Verbal reinforcement was also used at the beginning of the process, then gradually diminished. During follow-up periods, four of the patients remained completely con— tinent, and the other two showed definite improvement. The Engel experi- ment showed that recto-sphincteric responses can be brought under volun- tary control in patients with chronic fecal incontinence, even when the problem is secondary to organic lesions. Engel [14] showed that al- though the recto-sphincteric reflexes are neurally mediated responses of the anal sphincters to rectal distention, these responses can be brought under voluntary control. This study was done on a patient who complain— ed of chronic severe fecal incontinence (about five years) of solid stools following rectal surgery. This patient was first trained to 20 Sigmoid#_ Recto-Sigmoid Junction RECTUM Internal Anal Sphincter \ //External Anal Sphincter / To Transducers > r r To Pulley——o' 47 . . / Strin ed to plast1c 0%, tube #111 fl '— Table Top fl E Q: I —:, ;Plastic Tubes ’ II Erlenmeyer Flash Containing Water\\\\\ III MWWOCUZDN—fi Figure 5. Schematic Diagram of Recording Technique. [A. Balloons ig_situ without weight attached to caudad tube.] [8. Counterweight traction applied to caudad tube.] 2l \0 l‘. Internal Anal - Sphincter 0 _ '0 (7 b __Externa1 Anal 0 by sphincter ll Figure 6. Measurement Device for Internal and External Sphincters. 22 relax her internal sphincter and was subsequently trained to contract her external anal sphincter. Following internal sphincter training she began to have normal bowel movements; following external sphincter train- ing, she beCame continent. The feedback used was in the form of poly- graph tracings. Cerulli et a1 [15] treated fifty patients with severe daily fecal incontinence through biofeedback techniques. The training made use of a three-balloon system (as the one described by Schuster [12]) connected to a physiograph. Twenty-four patients had incontinence associated with previous anorectal surgery, while eleven had had spinal surgery. Patients were taught to develop reflex transient contraction of the ex- ternal sphincter in response to rectal distention. The physiograph pro- vided the feedback to the patient. Forty-five patients achieved a good response to biofeedback training, as evidenced by disappearance of incon- tinence or by a decrease in frequency of incontinence by 90 percent. Olness et al [16] described how fifty children and adolescents who had severe fecal incontinence associated with either imperforate anus surgery in infancy or longstanding functional constipation were given biofeedback training for the purpose of achieving analsphincter control. The feedback was in the form of oscilloscope tracings which the children learned to produce by contracting small air-filled balloons positioned at the internal and external anal sphincters. Forty-seven of these patients learned to have voluntary bowel movements, and thirty eliminated soiling accidents. Wald [17] reported on fourteen children, aged 5 to 17 years, with meningomyelocele and significant fecal soiling who underwent anorectal manometry using a three-balloon system connected to a physiograph. On 23 the basis of manometric criteria, eight patients were taught to contract the external anal sphincter or nearby gluteal muscles in response to various volumes of rectal distention. Four of the eight patients who were treated with biofeedback had a good clinical response with dis- appearance of soiling or a greater than 75 percent improvement in the frequency of soiling. The feedback was in the form of physiographic tracings. Chapter III. SYSTEM ORGANIZATION 3.l Characteristics of the System The developed system obtains, analyzes, and feeds back human sphincter responses.. The basic feature of this system is related to the treatment of fecal incontinence (encopresis) by operant conditioning through the use of a biofeedback system. This biofeedback system is composed of four different parts, which are: l) the pressure measurement device, 2) the data acquisition stage, 3) the data analysis, .4) the graphic generation and visual feedback path. A block diagram of the system is shown in Figure 7. The pressure response of the external sphincter is detected by a two-balloon system, as the one described in Chapter II, connected through a pressure transducer to an amplifier. The amplified signal is then routed to an A/D converter which transforms the analog voltage into a binary representation. This binary representation is analyzed by an Apple II minicomputer and then used to generate the animated figures employed as the biofeedback path. 3.2 The pressure measurement device. The pressure measurement device is formed of two different compo- nents, the balloons and the pressure transducer. 24 25 cwpuasoo HH wFQa< cmozcmccch oczmmmga Lougm> -cou o\< 23.5%... :25; 2153.5 (.{1\ 8...; Biofeedback System Figure 7. 26 The balloons were selected using two different criteria. One was size, volume, and capacity required for the patient; and the other was cost and availability. Based on these two requirements, the triple lumen/double balloon (Blakemore tube, Inmed Corporation, 2950 Pacific Drive, Norcross, Georgia 30071) was chosen. Figure 8 shows the chosen balloon. The first balloon is intended for insertion into the anus at approximately the location of the inernal sphincter; the second balloon is to be positioned at the location of the external sphincter. See Figure 9. The pressure transducer is a Statham model P23AC, and the follow- ing are the specifications provided by the manufacturer: excitation voltage of 12 volts, input resistance of 314 ohms, output resistance of 314 ohms. A 105 ohms resistor simulates a pressure of 16.50 cm Hg, and a 1.5x105 ohms resistor simulates a pressure of 11.0 cm Hg. The trans- ducer is a strain-sensitive device in which resistance wire elements are arranged in the form of a wheatstone bridge. Because of the lack of a pressure/voltage response curve given by the manufacturer, it was necessary to develop one. Two different methods were used, the first being a bivariate curve fitting conducted on a Texas Instruments TI59 desk calculator (Applied Statistics Module, Texas Instruments Incorporated, Dallas, Texas). The second one used experimental data to generate an approximate curve equation. The exper- imental data was obtained by a series of measurements of the output voltage of the pressure transducer due to a known pressure. The equation of the pressure/voltage response is: P =-a exp (-bR) where P is the pressure in mm Hg, R is the resistance in ohms, and a and 27 Figure 8. Triple Lumen/Double Balloon 28 Internal Balloon External Balloon Figure 9. Schematic Diagram of Recording Technique 29 b are constants to be determined. Substituting the set of experimental data into this equation, a pair of equations with two unknowns was obtained. -The system was solved, yielding the following equation: P é 371.25 exp (8.1x10-3 R) Both methods gave very similar results, which are tabulated in Table 2. Table 3 provides the output voltage of the pressure transducer as a function of the input pressure. Figure 10 shows the pressure transducer. 3.3 Data Acquisition Data acquisition is handled by means of a high sensitivity amplifier and an A/D converter. The input signal to the amplifier may vary depending on the sphincteric response elicited by the mode of the anorectal muscles. Table 4 shows the sphincteric muscles' responses. The amplifier was designed to have a zero voltage output when the pressure input was less than 5 mm Hg and a maximum voltage output when the pressure input was 30 mm Hg. The data sheets of the A0571 show that ifa nominal full scale of 10.24 volts is desired, the less significant bit has a magnitude of 9.76 m volts. Considering these factors, the gain of the amplifier was obtained as follows: . _ Vout . 10.24, = Gain 7 Vin 6.78xlOTT 15103 A standard differential amplifier stage and a non-inverter amplifier stage were used to realize the desired voltage gain. The combina- 30 Table 2. Approximated Transducer Response * The last two values of resistance are given by the specification sheets of the P23AC pressure transducer. . Pressure mm Hg R K-ohms l 729.640547 5 531.172433 10 445.690969 15 395.696869 20 360.221305 25 332.704319 30 310.221305 40 274.74574 50 247.228755’ 60 224.745741 70 205.736623 80 189.270176 90 174.745741 .100 161.733191 110 150 (G) 165 100 (G) 31 Table 3. Output Voltage of the Pressure Transducer Pressure mm Hg Voltage in m volts 1 0.005 5 ' - 0.045 10 0.100 15 0.296 20 0.400 25 0.560 30 0.678 Table 4. Sphincteric Muscles Responses Depending on the Mode of the Anorectal Muscles Mode! Internal Sphincter External Sphincter Normal Strongly contracted Slightly contracted - (10 mm Hg) (less than 5 mm Hg) Defecation Relaxation Relaxation (-40 mm Hg) (almost 0 mm Hg) Continence --- Contracted (5 to 30 mm Hg) 32 Figure 10. Pressure Transducer 33 tion of reSistor values shown in Figure 11 provided the desired gain factor. The off-set nulling control of the CA3140T is used to calibrate the output gain of the amplifier once the balloons are inflated. Hallgren [18] designed a high speed A/D converter for the APPLE II computer which was modified to be used in this project. Figure 12 shows the modified A/D converter circuit diagram. The A0571 is a ten-bit successive approximation A/D converter consisting of a DAC, voltage reference, resistors, clock comparator, and output buffers. The A0571 will accept analog inputs of O to +10 volts (unipolar) or :5 volts (bipolar). Unipolar was used in this design. All data and control lines were isolated through the 74LS36AN a hex-non inverting three state buffers. The A0571 has a conversion time of 25 microsec, thus making it theoretically possible to sample at rates up to 40,000 samples/sec. The APPLE II execution time, however, reduces the sampling rate to only 10,000 samples/sec. The MC14013B flip-flops were used to latch the three bit address, which determined the analog signal that was to be digitized, as well as to provide a strobe pulse to the A/D converter, indicating when the conversion cycle begins. The APPLE II, being an eight-bit machine, requires the ten bits from the A/D converter to be read in two steps. The data ready (DATA RDY) line from the A0571 signals the APPLE II that the conversion cycle has finished and that the data is available to be picked up. Thus, the APPLE 11 transfers the two most significant bits, followed by the eight least significant bits, from the A/D converter to memory. The software portion of the A/D converter is handled using a machine 34 .m.c..ag< s».>.p_mcam 59.: .FF 523m.a .> m—1 2 _ mELO cw me mLOHmwmmL _.F<¥ .> m—1 : m m ovpm mF+ x cm .: oepmcoo a\< umogm say: nn—ov— .-—— --- '1 mu _.o> m 9 VI «3;:— mo—u=< Vl' . Tl 3.2.. 2- —~mo< O “a o a: HIHHIIIIE _ ._\m_ 0 ma — .522: ”1.5.1 1 m“ 0 a _ wan-. . a _2—\2 _ XL’J. lflflww\\1~. Auv Na - - _.J\m. 0 .9 . filL a 533.1%? 0 a pllllL 36 language subroutine which provided high speed transfer of data from the A/D converter to memory. Figure 13 shows the flow chart of the machine language subroutine used to digitize the pressure response of the exter~ nal sphincter, and a listing of the subroutine can be found in Appendix A. This subroutine is used in several programs that will be described later. Its main function is to transfer the data from the A/D converter to the memory of the APPLE II, allowing other programs to make use of the digi- tized information. The subroutine is named READER; 3.4 Data Analysis and Graphics Generation As can be seen in Chapter II, feedback in past experiments has been provided by showing the pressure response of the sphincters on an oscilloscope or a polygraph. The APPLE II personal computer supplies three different modes of displaying information on the video display to which it is connected; these are: Text, Low-Resolution Graphics, High- Resolution Graphics. The use of the computer facilitates the generation of animated figures, which are more attractive for the patient than the usual tracings. Once the digitized data is stored in the memory of the APPLE II, it can be used by different programs either to analyze it or to generate various kinds of dynamic displays. The data analysis is done by two different programs written in APPLESOFT Basic. One of them is used to equate the input voltage to the computer equal to zero, which is called CALIBRATION. The other is used 37 Call from . BASIC L 3 Save registers Increment and storage rocessor status location .______5_ Define data and video storage locations Load and save ‘1 8 LSB and Initiate estore accumulator A/D conversion 1 Load Return to::> C BASIC ' conversion status IS conversion finished? Restore data and save 2 MSB L Figure 13. Flow Chart for the Machine Language Program to Digitize Sphincteric Muscle Response (READER) 38 in the diagnostic phase of the system to find out whether the patient is likely to have a successful training regimen. Figures 14 and 15 show the flow chart diagrams of these programs, and they are listed in Appendix B (CALIBRATION) and in Appendix C (PRESSURE). Graphics generation is accomplished by four different programs, three of them written in APPLESOFT Basic and the last in Machine language. All four generate animated graphic displays, the three written in APPLESOFT making use of the subrbutine READER. Figures l6, l7, and 18 show the flow chart diagrams for the APPLESOFT Basic programs. Program listings are in Appendices D (SQUARE), E (COLOR LINE), and F (GLASS). The program SQUARE displays a vertical bar that grows, depend- ing on the pressure exerted by the muscle on the preSSure transducer. Figure 19 shows the shape displayed by the program SQUARE. COLOR LINE displays a horizontal line that grows and changes colors depending on the pressure exerted. See Figure 20. Program GLASS displays an empty glass which can be filled, according to the pressure exerted. See Figure 21. The program written in machine language (EXACT) is the fastest and most accurate of the four programs. It displays two lines, one vertical, which is the pressure reference set by the researcher, and one horizontal, which is a sampling of the pressure exerted by the patient. Figure 22 shows the flow chart diagram for the machine language program EXACT; it is listed in Appendix G. EXACT is used in two different phases of the training program, as will be explained in Chapter IV. Figure 23 shows the shape displayed by the program. All programs provide the capability to sample sphincteric responses only when either the patient or the researcher request them. 39 C 3 it CALL,Reader Obtain sample L Calculate voltage & display it want to continue? C Q FigureM, Flow Chart for Applesoft Basic Program to Calibrate Input (CALIBRATION) 4O C D I CALL Reader Obtain sample «1; Calculate voltage & display it Do you t t'n ? wan to con 1 ue YES Figure 15. Flow Chartfor Applesoft Basic Program to Diagnostic Initial Response (PRESSURE) 41 START I Clean Video Display area I Call program READER l Calculate pressure & display result Do you want to continue? YES Re store registers Figure 16. Flow Chart for Applesoft Basic Program that Displays a Square (SQUARE) g42 START Clean video display area .__t__ Call program READER 6 v Calculate pressure iii; Select color Do you want to continue? YES Restore registers Figure 17. Flow Chart for Applesoft Basic Program that ' Displays a Color Line (COLORLINE) 43 START Clean video display area 4 Call program READER __$____ Calculate pressure & display result Do you want to continue? Restore registers Figure 18. Flow Chart for Applesoft Basic Program that Displays a Glass (GLASS) 44 Shape Displayed by the Program SQUARE Figure 19. 45 Figure 20_ Shape Displayed by the Program COLORLINE 46 :0 "CIE MT TG CERTIHIIE : =I} ’13 MT TIE CERTIHUE‘F 1}" “WT le- CERTIHUE 'f Figure 21. Shape Displayed by the Program GLASS START Save registers & rocessor status E Define data storage location 4. Define video storage location .1. Initiate A/D conversion Load conversion status conversion finished? 47 Restore data & save 2 MSB of data Are MSB equal to zero? Rotate one bit right and store again Is this bit ,equal to one? Rotate one bit right and store again Figure 22, Flow Chart for Machine Language Program with High Speed and Accuracy (EXACT) Figure 22, cont'd. Jumphto weighting subroutine. D 48 NO Is this bit equal to one? V Jump to weighting subroutine Increment storage location J Load and save 8 LSB of data Are they equal to zero? l Figure 22, cont'd. Rotate one bit right and store Is this bit equal to one? Jump to weighting subroutine l Display sample on TV screen Do you want to continue? Restore accumulator and registers 50 Figure 22, cont'd. START sub- routine wgting> Define storage location J. Fill memory according to next table: Bit No. # Bytes Content 10 12 FF 9 6 FF 8 4 FF 7 3 PF 6 2 PF 5 1 PF 4 1 OF 3 1 OC 2 1 O4 1 l 01 l Increment storage location (:Return main:> 51 'E . CII. 3.3 l i» g I l a a m r. “can; 3'? at {PIE SlIflBL TIE REF .mm Shape Displayed by Program EXACT Figure 23. Chapter IV. EXPERIMENTATION PROTOCOL A computer-based biofeedback control system was developed to help in the treatment of fecal incontinence by operant conditioning. All patients are intended to go through a series of three phases of training. Phase 1 is a diagnostic procedure during which the severity of impairment of rectosphincteric reflexes is objectively determined. For this purpose, a three balloon arrangement, as the one described in Chapter III, is inserted into the rectum. The first two balloons are positioned at approximately the location of the internal and external sphincters. The third balloon, called the rectal balloon, is positioned above the double balloons, at a level of approximately 10 cm above the anal margin. The balloon situated at the location of the external sphincter is connected to a pressure transducer (described in Chapter III, Section 3.2), and the electrical output of this device is amplified and sampled by the APPLE II. In normal subjects, momentary inflation of the rectal balloon causes a reflex contraction of the external sphincter. This contraction produces a variation in the output of the pressure transducer so that the program PRESSURE can provide the researcher with the value of pressure exerted. The magnitude of the pressure provides the researcher with knowledge of the patient's ability to reach a normal response level. The minimum pressure required is 5 mm Hg. 52 53 After the diagnostic studies are completed and before training studies are initiated, it is important for the researcher to explain in detail to each patient capable of understanding, the nature of the normal rectosphincteric reflex and the way in which his response differs from normal. 1 During Phase 2, the initial stage of training, instantaneous feedback, obtained by a two balloon system, is provided to the patient by allowing him to watch the figures displayed on the T.V. monitor. Four different programs are used in this phase, SQUARE, COLOR LINE, GLASS, and EXACT. The program EXACT should be used to set goals for the patient to reach in every session. Each program supplies a different figure and information referent to pressure. During this stage of training the patient is verbally reinforced: he is praised for every normal response obtained and encouraged to modify an abnormal response. Phase 3 is the final stage of training, and its goals are twofold. First, the patient is trained to refine his sphincteric response; i.e., to approximate the amplitude of a normal sphincteric response and to synchronize sphincteric responses so that the external- sphincter contraction occurs simultaneously with the internal- sphincter relaxation. This refinement of motor control is accomplished through verbal reinforcement in conjunction with the very accurate feedback representation provided by the program EXACT. The second goal of Phase 3 is to wean the patient from any dependency on the system. In this stage of training the visual feedback is periodically withheld, so that the patient is unable to see the displayed shapes. 54 After a series of trials the patient is permitted to observe his performance. Each 1aboratory_session comprises about two hours, sufficient to allow the patient to have an average of fifty (50) training trials. Figure 24 shows a block diagram of the system protocol. 55 UZHZHdMB Ozm xomnooow Hoswfl> UHoSSUHB .N oncommou ocflwon ou BUflxm Eowmoum omD .H UZHZHdMB AdZHm aWIIIIIIIIIIIIIIIl. Empmxm Focucoo xowaumoeowm .em mtzmwm MMDmmmmm moan: ucoEo>oumEH 0Humocmcflo .4 a pumzow mm mEmHmoum memo om: coflmmom Loco “ovum .m xomnooom o>auomuupm pan HMEMOMCA no no oms ou wuocuo map «mCOmflummfioo ome Op can mamom pom Op BUéxm mamumoum can wo om: oxmz .N mmw manponom can Hooouonm mcflcaouu pom .H UZHZHdME ddHBHZH a. uncommon oauouo:fl:mmouoou Hmmsum: onp :0 coflumcmmem coaflmuoo opfl>oum allllL mosvflcnoou Hmcoflummflumno lance wuB mxocnpooMOHn how >MHHMDU ucoflumm on“ mooo mmDmmmmm Emumoum mCAm: oaumocmmflo UZHZHdMB BMfiBm Chapter V. RESULTS AND CONCLUSIONS Although the system has not been tested on a patient at the time of this writing, a trial was conducted on a voluntary normal subject. This subject was placed in his right lateral position, and the Blakemore double balloon was inserted into the rectum. One of the balloons was positioned to a level of 5 cm from the anal margin, and the other was positioned at the external sphincter. Polyethylene tubing from the second balloon led to the P23AC pressure transducer. Three recordings were obtained: 1) in the resting state 2) during balloon distention of the rectum 3) during voluntary contraction of the anal sphincters. The following results were obtained: A) During the resting state without stimulation (no air in the rectal balloon), a steady base line with respiratory excursions was recorded from the external sphincter balloon. B) Transient distensions of the rectum (lasting 2 - 5 seconds) resulted from introducing approximately 50 cc of air in the rectal balloon and produced an abrupt increase in pressure in the external sphincter balloon. This pressure rise in the external balloon varied -from 5 mm Hg to 30 mm Hg in amplitude (average of 15 mm Hg) and 2 - 5 seconds in duration (average of 3 seconds). 56 57 C) Intermittent distentions produced a pressure rise which was no higher (average of 6 mm Hg, range 2 - 15 mm Hg), although more prolonged (average 9 seconds, range 5 - 22 seconds) than with transient distention. D) Threshhold. The minimal amount of air required in the rectal balloon to elicit a recognizable pressure change was 15 cc. E) Voluntary contraction of the anal sphincter resulted in a rise in pressure in the external sphincter balloon. F) Voluntary contraction of gluteal muscles resulted in an abrupt rise in pressure in the external sphincter balloon. A comparison test was done to verify which feedback, the oscilloscope tracings or the animated graphics, was more attractive for the subject. The test was performed with five different subjects, ranging in age from two to 32 years. In all cases the animated graphics were selected. The system was readily used by the novice subject. Even though the equipment underwent extremely limited testing, the highly favorable responses obtained provide enough evidence about the promising potential for its use in an actual clinical setting. During the experimentation three minor problems were found. The first occurred when the balloons leaked, necessitating frequent running of the program to calibrate the system (CALIBRATION). This problem can be overcome by obtaining a better quality balloon. The second problem was noted when the uncalibrated input voltage went to the negative side, resulting in the output not being a true representation of the input. To overcome this problem it will be necessary either to construct a zero crossing detector or to use the analog input of the A/D converter as bipolar. 58 Third, voluntary contraction of the gluteal muscles produced an increase of pressure in the balloon. To overcome this problem, if the patient is unable to cooperate in controlling this contraction (i.e., not contracting these muscles), the balloon system must be reconfigured. Because the training requires insertion of an anal probe device, which may cause discomfort (and in some cases, pain), it should be emphasized that other appropriate therapeutic methods should be tried before the patient is referred for biofeedback training. Biofeedback training is not recommended as the preferred initial therapy for very young children (under two years of age) because of their difficulty in understanding the procedure and acting as cooperating participants. The computer-based biofeedback system is economical both to produce and to operate; it is readily used by a novice operator and by a subject. Because people in general already have-close familiarity with visual media (particularly television), patients are expected to respond easily and positively to the color computer animated graphics. For all of these reasons, the system shows very favorable potential as an alternative therapeutic modality in the treatment of patients with encopresis. Glossary of Medical Terms Glossary of Medical Terms The following are the medical terms and their descriptions which are used throughout this thesis. See [19] for bibliographic reference. caudal: inferior or, in the case of quadruped, posterior. cephalad: in a direction toward the head or the anterior pole. encopresis: involuntary passage of feces. flatus: expired air; gas in the stomach or intestine; eructation. intraluminal intratubal: within any tube. . manometric: related to a manometry. manometry: measurement of pressure of gases by means of an instrument (manometer). meningomyelocele: a protrusion of the membranes and spinal cord through a defect in the vertebral column. motility: the power of spontaneous movement. nervous system: the system of tissues which coordinates an animal's various activities with each other and with external events by means of nervous impulses conducted rapidly from part to part via nerves. The nervous system can be divided into two parts. The Central Nervous System (CNS), consisting of brain and spinal cord, stores and processes information and sends messages to muscles and glands. The Peripherial Nervous System, consisting of 12 pairs of cranial nerves arising in and near the medulla oblongata of the brain and the 31 pairs of spinal nerves arising at intervals from the spinal cord, carries messages to and from the central nervous system. The Autonomic Nervous System, normally considered part of the peripherial nervous system, controls involuntary actions such as heartbeat and digestion. It is divisible into two complimentary 59 60 parts: the sympathetic system prepares the body for "fight or flight," and'Unaparasympathetic system controls the body's vegeta- tive functions. Most internal organs are innervated by both parts. obstipation: intestinal obstruction; severe constipation. pathology: the medical science and practice that deals with all aspects of disease, but with special reference to the essential nature, the causes and development of abnormal conditions, as well as the structural and functional changes that result from the disease pro- cesses. psycotherapeutic: psycotherapy. Treatment of mental disease based primarily upon verbal or non-verbal communication with the patient, in contrast to treatments utilizing chemical and physical measures. rectophincteric: the sphincter muscles action over the rectum. sphincter: an accumulation of muscular circular fibers or specially arranged oblique fibers, the function of which is to reduce partially or totally the lumen of a tube, the orifice of an organ, or the cavity of a viscus. Glossary of Engineering Terms Glossary of Engineering Terms Analog: Analog measurements, as opposed to digital measurements, use a continuously variable physical quantity (such as length, voltage, or resistance) to represent values. Digital measurements use precise, limited quantities (such as presence or absence of voltages or magnetic fields) to represent values. A/D Converter: System employed to convert an analog input to a digital output. AND: A binary function which is "on" if and only if all of its inputs are "on." BASIC: Acronym for "Beginner's All-Purpose Symbolic Instruction Code." BASIC is a higher-level language, similar in structure to FORTRAN but somewhat easier to learn. It was invented by Kemney and Kurtz at Dartmouth College in 1963 and has proved to be the most popular language for personal computers. Binary: A number system with two digits, "0" and "1," with each digit in a binary number representing a power of two. Most digital com- puters are binary, deep down inside. A binary signal is easily expressed by the presence or absence of something, such as an electrical potential or a magnetic field. Binary Function: An operation performed by an electronic circuit which has one or more inputs and only one output. All inputs and outputs are binary signals, See AND OR, and Exclusive-0R. Bit: A Binary digII, The smallest amount of information which a com- puter can hold. A single bit specifies a single value: "0" or "1.“ Bits can be grouped to form larger values (see Byte and Nybble). Byte: A basic unit of measure of a computer's memory. A byte usually comprises eight bits. Thus, it can have a value from 0 to 255. Each character in the ASCII can be represented in one byte. The Apple's memory locations are all one byte, and the Apple's addresses of these locations consist of two bytes. Class A Amplifier: Method of operation for the amplifier in which the collector output current flows for the full 3600 of the input 61 62 signal, without any part of the signal being cut off. Class AB Amplifier: The collector output current flows between 1800 to 3600, or one-half of full input cycle. Data (datum): Information of any type. Display: As a noun: any sort of output device for a computer, usually a video screen. As a verb: to place information on such a screen. Flip Flop: Digital electronic circuit that has a "memory." Format: As a noun: the physical form in which something appears. As a verb: to specify such a form. Graphic: Visible as a distinct, recognizable shape or color. Graphics: A system to display graphic items or a collection of such items. Hardware: The physical parts of a computer. Hexadecimal: A number system which uses the ten digits 0 through 9 and the six letters A through F to represent values in base 16. Each hexadecimal digit in a hexadecimal number represents a power of 16. In this manual, all hexadecimal numbers are preceded by a dollar sign ($). High-level Language: A language which is more intelligible to humans than it is to machines. Hz (Hertz): Cycles per second. A bicycle wheel which makes two revolu? tions in one second is running at 2H2. The Apple's microprocessor runs at 1,023,000Hz. Input: As a noun: data which flows from the outside world into the computer. As a verb: to obtain data from the outside world. Input/Output (I/O): The software of hardware which exchanges data with the outside world. Instruction: The smallest portion of a program that a computer can execute. In 6502 machine language, an instruction comprises one, two, or three bytes; in a higher-level language, instructions may be many characters long. Integrated circuit: A small (less than the size of a fingernail and about as thin) wafer of a glassy material (usually silicon) into which has been etched an electronic circuit. A single IC can con- tain from ten to ten thousand discrete electronic components. 105 are usually housed in DIPs (see above), and the term IC is someei times used to refer to both the circuit and its package. 63 Interface: An exchange of information between one thing and another, or the mechanisms which make such an exchange possible. Interpreter: A program, usually written in machine language, which understands and executes a higher-level language. Interrupt: A physical effect which causes the computer to jump to a special interrupt-handling subroutine. When the interrupt has been taken care of, the computer resumes execution of the interrupted program with no noticeable change. Interrupts are used to signal the computer that a particular device wants attention. Machine language: The lowest level language which a computer under— stands. Machine languages are usually binary in nature. Instruc- tions in machine language are single-byte opcodes sometimes followed by various operands. Memory address: A memory address is a two-byte value which selects a single memory location out of the memory map. Memory addresses in the Apple are stored with their low-order bytes first, followed by their high-order bytes. Memory location: The smallest subdivision of the memory map to which the computer can refer. Each memory location has associated with it a unique address and a certain value. Memory locations on the Apple comprise one byte each. Microprocessor: An integrated circuit which understands and executes machine language programs. Mnemonic: An acronym (or any other symbol) used in the place of some- thing more difficult to remember. In Assembly Language, each machine language opcode is given a three letter mnemonic (for ex- ample, the opcode $60 is given the mnemonic RTS, meaning "Relurn fromISubroutine"). OR: A binary function whose value is I'on“ if at least one of its inputs are "on." Peripheral: Something attached to the computer which is not part of the computer itself. Most peripherals are input and/or output devices. Personal Computer: A computer with memory, languages, and peripherals which are well-suited for use in a home, office, or school. Pinout: A description of the fuction of each pin on an IC, often pre- sented in the form of a diagram. Program: A sequence of instructions which describes a process. Software: The programs which give the hardware something to do. 64 Subroutine: A segment of a program which can be executed by a single call. Subroutines are used to perform the smallest sequence of instructions at many different places in one program. Transducer: A detector-transducer stage, which detects the physical variable and performs either a mechanical or an electrical trans- formation to convert the signal into a more usalbe form. Wheatstone bridge: A bridge circuit formed of four terminals, two for input voltage and two for output. It is normally used for the com- parison and measurement of resistances. APPENDICES 65 8E66- 8D E9 8E STA $8EE9 8E69- 8E EA 8E STX $8EEA 8E6C- BC EB 8E STY $8EEB 8E6F* 08 PHP 8E70~ EA NOP 8E71* EA NOP 8E72* EA NOP 8E73~ EA NOP 8E74- A9 05 LDA #$05 8E76- 8D F1 CO STA $COF1 8E79- A9 04 LDA #$04 8E7B- 8D F1 CO STA $COF1 8E7E~ AD F2 CO LDA $COF2 8E81~ 2A ROL 8E82~ BO FA BCS $8E7E 8E84~ 6A ROR BEBS- 29 03 AND #$03 8E87~ 8D 00 8F STA $8FOO 8E8A- EA NOP BEBB- EA NOP 8E8C- AD F4 CO LDA $COF4 8E8F- 8D 01 8F STA $8F01 8E92- EA NOP 8E93- EA NUP 8E94- AD E9 8E LDA $8EE9 8E97- AE EA 8E LDX $8EEA 8E9A- AC EB 8E LDY $8EEB 8E9D~ 28 PLP Appendix A Machine Language Subroutine to Transfer Data [READER] 66 10 PRINT 'THIS PROGRAM HELP YOU TO SET“ 20 PRINT 'YOUR CALIBRATION UALUE = 0 " 25 CALL 36454 30 U1 = PEER (36608):U2 = PEER (36609) 50 UREF = ((Ul * 256) + U2) / 100 60 PRINT 'UREF = '3UREF 70 PRINT 'DO YOU WANT TO CONTINUE ?' 75 PRINT 'IF YES PRESS ’Y'yOTHERWISE PRESS ’N’ ': GET At 80 IF At = ' ' THEN GOTO 25 90 PRINT 'CALIBRATION FINISHED ' .100 END 3 Appendix B Apple Soft Basic to Calibrate [CALIBRATION] 10 20 25 27 29 30 50 55 57 58 59 67 PRINT 'THIS PROGRAM ALLOU YOU TO OBTAIN THE PRINT I'UALUE OF THE SAMPLE PRESSURE CALL 36454 CALL * 922 CALL ~ 922 U1 = PEEK (36608):U2 = PEEK (36609) UREF = ((Ul * 256) + V2) / 100 P = ( ~ 285.31921 X VREF) + 3231.89 POT = ~ 050081093022 * P PRES = 371.25 * ( EXP (POT)) PRINT 'PRESSURE (IN MMHG) = “3PRES 60 CALL ~ 922 70 PRINT 'DO YOU UANT TO CONTINUE ?' 75 PRINT "IF YES PRESS ’Y’vOTHERUISE PRESS ’N’ '3 GET Am 80 IF A$ 3 'Y' THEN CALL ~ 9363 GOTO 25 85 CALL ~ 936 90 PRINT 'SAMPLING FINISHED' 100 END 3 Appendix C Apple Soft Basic to Diagnostic Initial Response [PRESSURE] 10 2O 30 40 50 60 7O 71 72 73 75 80 90 100 .1. 10 115 120 130 140 1.45 .l. 13 68 PRINT 'INICIO DE ENTRENAHIENTO' FOR X = 1 TO 3000 NEXT x CALL _ 936 CALL 36454 U1 = PEEK (36608):U2 = PEEK (36609) UREF = ((01 x 256) + 02) / 25 vu z UREF / 4 R = < _ 285.31921 X 00) + 3231.89 POT = ~ 0.0081093022 X R PRES = 371.25 x ( EXP (POT)) GR : COLOR= 7 FOR J = 0 To UREF HLIN 10,30 AT J NEXT J PRINT "PRESSURE (IN NNHG) = '3PRES PRINT -no YOU HANT To CONTINUE ?': GET AN$ IF AN$ = 'Y' THEN GOTO 50 PRINT ”THE SESSION HAS FINISHED' TEXT : HOME END Appendix 0 Apple Soft Basic Display Program [SQUARE] “V a 10 20 3O 40 50 60 70 80 90 100 110 120 130 140 145 150 69 TEXT 3 HOME PRINT 'INICIO DE ENTRENAMIENTO” FOR X = 1 TO 3000 NEXT X CALL ~ 936 CALL 36454 = PEEK (36608)3U2 = PEEK (36609) UREF = ((Ul * 256) + U2) / 30 BR 3 COLOR= J FOR J z 0 T0 UREF HLIN OvJ AT 24 NEXT J PRINT "DO YOU UANT TO CONTINUE ?'3 GET AN$ IF AN$ = 'Y' THEN GOTU 50 PRINT I'THE SESSION HAS FINISHED' TEXT 3 HOME END Appendix E AppTe Soft Basic D1'sp1ay Program [COLORLINE] 10 15 20 30 '50 ‘90 95 100 110 120 130 140 150 160 170 180 190 200 210 250 L7: 2a..) 1260 13370 70 SR COLOR= 7 HLIN 15,30 AT 30 ULIN 30,8 AT 15 ULIN 3098 AT 30 CALL 36454 91 = PEER (36608):u2 = PEEK (36609) UREF = ((01 X 256) + 02) / 50 FOR J = 0 TO UREF COLORz 9 HLIN 1692? AT 29 — J NEXT J PRINT 'DO YOU HANT TO CONTINUE 2': SET AN$ IF AN$ = 'N" THEN GOTO 250 FOR J z 0 TO UREF COLOR= 0 HLIN 16,29 AT 29 « J NEXT J , BOTO 90 TEXT : HOME CALL ~ 936 PRINT ”THE SESSION HAS FINISHED“ ENO Appendix F AppTe Soft Basic DispTay Program [GLASS] 7] 5 FOR T 8 1 T0 20 10 2O 30 40 50 6O 70 80 90 100 150 160 170 180 190 200 210 220 230 240 250 260 265 270 280 290 300 310 320 350 355 360 400 405 410 450 455 460 500 505 510 550 555 560 600 605 610 650 655 657 660 670 680 690 695 700 710 PRINT '@QQGQGQGQQQQQGGGQ@GQQQGQGQQGQQGGGGGQGQG' HTAB 93 VTAB (12): PRINT 'BIOFEEDBACK TRAINNING' VTAB (24)3 PRINT 'G@090999999990890QQGQGCGGQGGGGQQGGQQGGQ' NEXT T TEXT HOME 3 TEXT PRINT 'THE PROGRAM IS CLEANNING' PRINT ' THE VIDEO STORAGE ' PRINT ' AREA ' CALL 36368 HOME 3 TEXT PRINT 'THE VIDEO STORAGE AREA IS CLEAN' PRINT 'THE FOLLOUING INFORMATION IS' PRINT 'THE AVAILABLE PRESSURE REFERENCES 3 ' PRINT ' SMMHG IS EQUAL TO ' PRINT ’ IOMMHG IS EQUAL T0 PRINT ' ISMMHG IS EQUAL TO PRINT ' 20MMHG IS EQUAL TO PRINT ' 25MMHG IS EQUAL TO PRINT ' 30MMHG IS EQUAL TO > OUIONNH ..... INPUT UHICH Is YOUR SELECTION ?'3PR IF PR 6 OR PR < 1 THEN SOTO 17o HSR IF PR . 1 THEN SOTO 350 IF PR . 2 THEN SOTO 400 IF PR - 3 THEN SOTO 450 IF PR . 4 THEN SOTO 500 IF PR a 5 THEN SOTO 550 IF PR - 6 THEN SOTO 600 HCOLOR- 2 HPLOT 176.0 To 176.159 SOTO 650 HCOLOR- 2 HPLOT 196.0 To 196.159 SOTO 650 HCOL0R= 6 HPLOT 200.0 TO 200.159 SOTO 650 , HCOLOR- 3 HPLOT 210.0 TO 210.159 SOTO 650 HEOLOR: 7 HPLOT 21890 To 218.159 SOTO 650 HCOLOR- 5 HPLOT 223.0 To 223.159 SOTO 650 POKE 49239923 POKE 49235923 POKE 49236923 POKE 4923292 PRINT 'TO CONTINUE PRESS ’Y’9OTHERUISE ’N’ ' S I PR 3 5 PRINT 'REFERENCE (IN MMHG) IS THE VERTICAL '35 PRINT 'THE SAMPLE IS IN THE MIDDLE' CALL 35994 PQKE 49233923 POKE 4923692 HOME 3 TEXT PRINT ‘THE EXPERIMENT HAS FINISHED' END Appendix G Machine Language to show an Exact Representation [EXACT] (Page 1 of 6) 72 Appendix G, cont'd. 8C9A- 80 09 8E STA ‘8E09 8C90- 8E 0A 8E STX ‘8EOA 8CAO- 8C 00 8E STY ‘8E00 8CA3- 08 PHP 8CA4- EA NOP 8CA5- A9 01 LDA 0‘01 8CA7- 80 F0 8E STA ‘BEFO 8CAA- A9 02 LDA 0‘02 8CAC- 80 F1 8E STA ‘8EF1 8CAF- A9 03 LOA 0‘03 8C01- 80 F2 8E STA ‘8EF2 8004- A9 04 LDA 9‘04 8C06- 80 F3 8E STA ‘8EF3 8C09- A9 06 , LDA 0‘06 8CBB- 80 F4 8E STA ‘8EF4 8CBE- A9 0C LOA O‘OC 8CCO- 80 F5 8E STA ‘8EF5 8CC3- A9 08 LOA 4‘08 8CC5- 80 F6 8E STA ‘8EF6 8CC8- A9 0F LOA O‘OF 8CCA- 80 F7 8E STA ‘8EF7 8CCO- A9 FF LOA O‘FF BCCF- 80 F8 8E STA ‘8EF8 8C02- A9 00 LDA 0‘00 8C04- 80 F9 8E STA ‘8EF9 8C07- EA NOP 8C08- A9 00 LDA 0‘00 BCDA- 85 0A STA ‘OA 8COC- A9 8F LDA #‘8F 8COE- 85 00 STA ‘00 8CEO- EA NOP 8CE1- A9 28 LOA 0‘28 8CE3- 85 0C STA ‘OC 8CE5- A9 22 LDA 4‘22 8CE7- 85 00 STA ‘00 SCE9- EA NOP 8CEA- AC F9 8E LDY ‘8EF9 8CEO- EA NOP 8CEE- 20 00 F0 JSR ‘FBDD 8CF1- 20 0C F0 JSR ‘FDOC BCF4- C9 09 CMP 0‘09 8CF6- F0 14 BEQ ‘800C 8CF8- 20 00 F0 JSR ‘FBDD 8CFO- 20 00 F0 JSR ‘FBDD 8CFE- 20 00 F0 JSR ‘F000 8001- A0 09 8E LOA ‘8E09 8004- AE 0A 8E LOX ‘8EOA 8007- AC 00 8E LOY ‘8E00 800A- 28 PLP 8000- 60 RTS 800C- 20 F3 80 JSR ‘80F3 800F- EA NOP 8010- A2 20 LOX 0‘20 8012- A9 00 LOA 0‘00 8014- 20 E1 80 JSR ‘80E1 8017- 20 F3 80 JSR ‘80F3 801A- EA NOP 8010- EA NOP 801C- EA NOP 8010- EA NOP I Appendix G Machine Language to Show an Exact Representation [EXACT] (Page 2 of 6) 73 Appendix G, c0nt[g;_ EA NOP 801E- EA NOP 801F- EA NOP 8020- EA NOP 8021- EA NOP 8022- EA NOP 8023- EA NOP 8024- EA NOP 8025- AC F9 8E LDY ‘8EF9 8028- A9 05 LDA 0‘05 802A- 80 F1 CO STA ‘COF1 8020- A9 04 LDA 0‘04 802F- 80 F1 CO STA ‘COF1 8032- AD F2 CO LDA ‘COF2 8035- 2A ROL 8036- 00 FA 0CS ‘8032 A 8038- 6A ROR 8039- 29 03 AND 0‘03 8030- 91 0A STA (‘0A)9Y 8030- C9 00 CMP 0‘00 803F- F0 1E 0E0 \ ‘805F 8041- 01 0A LDA (‘0A)9Y 8043- 6A ROR 8044- 91 0A STA (‘0A)9Y 8046- 90 09 DEC ‘8051 8048- AE F4 8E LDX ‘8EF4 8040- A0 F8 8E LDA ‘8EF8 804E- 20 E1 80 JSR ‘80E1 8051- 01 0A LDA (‘0A)9Y 8053- 6A ROR 8054- 90 09 0CC ‘805F 8056- AE F5 8E LDX ‘8EF5 8059- AD F8 8E LDA ‘8EF8 8050- 20 E1 80 JSR ‘80E1 805F- A6 0A LDX ‘OA 8061- E8 INX 8062- 86 0A STX ‘OA 8064- A0 F4 C0 LDA ‘COF4 8067- 91 0A STA (‘0A)9Y 8069- C9 00 CMP 0‘00 8060- F0 70 BEQ 08000 8060- 20 FC 80 JSR ‘80FC 8070- 90 09 BCC ‘8070 8072- AE F3 8E LDX ‘8EF3 8075- AD F8 8E LDA ‘8EF8 8078- 20 E1 80 JSR ‘80E1 8070- 20 FC 80 JSR ‘80FC 807E- 90 09 0CC ‘8089 8080- AE F2 8E LDX ‘8EF2 8083- AD F8 8E LDA ‘8EF8 8086- 20 E1 80 JSR ‘80E1 8089- 20 FC 80 JSR ‘SDFC 808C- 90 09 0CC ‘8097 808E- AE F1 8E LDX ‘8EF1 8091- AD F8 8E LDA ‘8EF8 8094- 20 E1 80 JSR ‘80E1 8097- 20 FC 80 JSR ‘BDFC 809A- 90 09 00C ‘80A5 809C- AE F0 8E LDX ‘BEFO 809F- A0 F8 8E LDA ‘8EF8 9 Appendix G Machine Language to Show an Exact Representation [EXACT] (Page 3 0f 6) 74 Appendix G, cont'd. 809F- AD F8 8E LDA ‘8EF8 BDA2- 20 E1 80 JSR ‘80E1 80A5- 20 FC 80 JSR ‘BDFC 80A8- 90 09 000 ‘8003 80AA- AE F0 8E LDX ‘8EFO ODAD- A0 F7 8E LDA ‘8EF7 8000- 20 E1 80 JSR ‘80E1 8003- 20 F0 80 JSR ‘BDFC 8006- 90 09 000 ‘8001 8008- AE F0 8E LDX ‘8EFO 8000- AD F6 8E LDA ‘8EF6 800E- 20 E1 80 JSR ‘80E1 8001- 20 F0 80 JSR ‘80F0 8004- 90 09 000 ‘800F 8006- AE F0 8E LDX ‘8EFO 8009- A0 F3 8E LDA ‘8EF3 8000- 20 E1 80 JSR ‘80E1 BDCF- 20 FC 80 JSR ‘80FC 8002- 90 09 000 ‘8000 8004- AE F0 8E LDX ‘8EFO 8007- A0 F0 8E LDA ‘8EFO . 800A- 20 E1 80 JSR ‘80E1 8000- EA' NOP 800E- 40 ED 80 JMP ‘SCED 80E1- A0 00 LDY 0‘00 80E3- 91 OC STA (‘00)9Y 80E5- E0 00 CPX 0‘00 80E7- F0 09 BEQ ‘80F2 80E9- CA DEX SDEA- A4 00 LDY ‘00 80EC- 08 INY 80ED- 84 00 STY ‘00 _80EF- 40 E1 80 JMP ‘80E1 80F2- 60 RTS 80F3- A9 28 LDA 0‘28 80F5- 85 00 STA ‘00 80F7- A9 22 LDA 0‘22 80F9- 85 00 STA ‘00 80F0- 60 RTS BDFC- A0 00 LDY 0‘00 80FE- 01 0A LDA (‘0A)9Y 8E00- 2A ROL 8E01- 91 0A STA (‘0A)9Y 8E03- 60 RTS 8E04- 00 0RK 8E05- 00 0RK 8E06- 00 0RK 8E07- 00 0RK 8E08- 00 0RK 8E09- 80 90 9A STY ‘9A9D 8E00- 00 0RK 8E00- 00 0RK 8EOE- 00 0RK 8EOF- 00 0RK 8E10- 80 E9 8E STA ‘8EE9 8E13- 8E EA 8E STX ‘8EEA 8E16- 80 E0 8E STY ‘8EEO 8E19- 08 PHP 8E1A- EA NOP 8E10- EA NOP 1 Appendix G Machine Language to Show an Exact Representation [EXACT] (Page 4 0f 6) Appendix G, cont'd; BEIC— A9 '8E1E~ 85 8E20— A9 8E22- 85 8E24- A9 8526- 8D 8E29- A9 8E28~ 8n 8E2E- EA 8E2F- EA 8E30~ A9 8E32~ A2 8E34- 81 8E36— A4 8538- CB 8E39~ 84 8E3B- DO 8E38~ A4 8E3F- CB 8E40~ 84 8E42- AD 8E45* CS 8E47~ no 8E49- An 8E4C- AE 8E4F~ AC 8E52~ 28 8E53— 60 8E54~ 00 SESS— 00 00 00 20 00 FF EC 3F ED 00 00 00 00 00 F3 00 00 ED 00 E7 E9 EA EB 8E SE SE SE SE SE 75 LDA STA LDA STA LDA STA LDA STA NOP NOP LDA LDX STA LDY INY STY BNE LDY INY STY LDA CMP BNE LDA LDX LDY F‘LF' RTS BRK RAN 0$00 $00 0$20 $00 0$FF $8EEC 0$3F $8EED 0$00 0$00 ($0C!X) $00 $00 $8E30 $08 $OD $8EED $00 $8E3O $8EE9 $8EEA $8EEB A endix G Machine Language to Show an Exact pp Representation [EXACT] (Page 5 of 6) 76 Appendix G. cont'd. 8E10- 80 E9 8E STA $8EE9 8E13- 8E EA 8E STX $8EEA 8E16- SC EB 8E STY $8EEB 8E19- 08 PHP 8E1A- EA NOP 8E10- EA NOP 8E10- A9 00 LDA #$00 8E1E- 85 OC STA $00 8E20- A9 20 LDA 0$20 8E22- 85 OD STA $00 8E24- A9 FF LDA 0$FF 8E26- 80 EC 8E STA $8EEC 8E29- A9 3F LDA 0$3F 8E2B- 80 ED 8E STA $SEED 8E2E- EA NOP 8E2F- EA NOP 8E30- A9 00 LDA #$00 8E32- A2 00 LDX 0$00 8E34- 81 OC STA ($OCyX) 8E36- A4 00 LDY $00 8E38- 08 INY 8E39- 84 OC STY $00 8E3B- 00 F3 BNE $8E3O 8E3D- A4 00 LDY $00 8E3F- 08 INY 8E40- 84 OD STY $00 8E42- AD ED 8E LDA $8EED 8E45- C5 00 CMP $00 8E47- 00 E7 BNE $8E30 8549- AD E9 8E LDA $8EE9 8E4C- AE EA 8E LDX $8EEA' 8E4F- AC EB 8E LDY $8EEB 8E52- 28 PLP 8E53- 60 RTS “‘0— 6 Appendix G Machine Language to show an Exact Representation [EXACT] (Page 6 of 6) 77 3 TEXT 3 HOME 10 11 12 15 17 20 22 24 25 26 27 28 PRINT 'THIS PROGRAM HILL GIVE YOU ALL THE ' PRINT 'INFORMATION NEEDED TO EXECUTE A ' PRINT 'BIOFEEDBACK TRAINNING SESSION ' FOR X a 1 TO 2500 NEXT X CALL - 936 CALL - 922 CALL - 922 CALL - 9363 PRINT 'THE SYSTEM CONSIST ON THREE DIFFERENT PRINT “SUB-SYSTEMS9 UHICH ARE 3 ‘ PRINT ' ' PRINT 'CALIBRATION (TO ZERO THE INPUT). PRINT 'DISPLAY (TO RUN THE SESSION). PRINT 'PRESSURE (TO OBTAIN PRESSURE). CALL - 922 PRINT 'TO RUN THEM MAKE USE OF THE FIRST LETTER' CALL - 922 CALL - 922 INPUT 'UHICH IS YOUR SELECTION ? 'FSEL‘ IF SEL‘ = '0' THEN GOTO 50 IF SEL‘ = '0' THEN GOTO 100 IF SEL‘ = ’P' THEN GOTO 200 CALL- - 936 PRINT ‘INVALID CODE. YOU MUST USE ’0’9’0’9OR ’P" CALL - 936 PRINT 'TRY AGAIN '3 GOTO 35 PRINT ' YOU MUST TYPE 3 PRINT ' BLOAD LECTOR(‘8E66) ' PRINT ' LOAD CALIBRATION ' PRINT ' RUN ' PRINT '00 YOU UANT TO CONTINUE ?'3 GET AN‘ IF AN‘ = 'Y' THEN GOTO 25 . GOTO 250 PRINT ' YOU MUST TYPE 3 ' PRINT ' DLOAD COMPLETO(‘809A) ' PRINT ' 0LOAD 0LANCO(‘8E10) ' PRINT ' LOAD BASICO3 ' PRINT ' RUN ' PRINT 'DO YOU UANT TO CONTINUE ? ' IF AN‘ 8 'Y' THEN GOTO 25 GET AN‘ GOTO 250 PRINT ' YOU MUST TYPE 3 ' PRINT ' BLOAD LECTOR(‘8E66) ' PRINT ' LOAD PRESSURE ' PRINT ' RUN ' PRINT 'DO YOU UANT TO CONTINUE 7'3 GET AN‘ IF AN‘ I 'Y' THEN GOTO 25 GOTO 250 PRINT 'END OF THE PROGRAM ' END Appendix H Systems Manager [HELLO] BIBLIOGRAPHY 10. 11. BIBLIOGRAPHY Engel, B.T., Nikoomanesh, P., and Schuster, M.M. 1974. Operant conditioning of rectosphincteric responses in the treatment of fecal incontinence. New England Journal of Medicine 290:646-649. Miller, N. E., Barber, T. X., DiCara, L. V. , Kaniya, J. ,Shapiro, D., and Stoyva, J. 1973. Biofeedback and Self Control. Chicago: Kimmel, H.D. l967. Instrumental conditioning of autonomically mediated behavior. Psychological Bulletin 67(5):337-345. Weiss, T., Engel, B.T. 1971. Operant conditioning of heart.rate patients with premature ventricular contractions. Phychosoma 33:301-321. Engel, B.T., and Bleecker, E.R. In;Press: .Applications of operant conditioning techniques to the control of cardiac arrhythmias. In: Contemporary Trends in Cardiovascular Psycthhysiology. Chicago. Aldine- Atherton. Scott, R.N., et al. 1973. A shaping procedure for heart-rate conditioning in chronic tachycardia. Precepts of Motor Skills. 37:327-338. . . Blanchard, E.B., and Young, L.D. 1974.:.C1iniCal applications of biofeedback training. Archives of General ngchiatpy30(5):573-589. Prigatano, G.P., and Johnson, H.J. 1972. Biofeedback control of the rate variability to phobic stimuli. A new approach to treating spider phobia. In: Proceedings of the Annual Convention of the American Psychological Association. PP. 403-404. Washington, D.C.: American Psychological Association. Schuster, M.M., Hendrix, T.R., and Mendeloff, A.I. 1961. Studies on the internal anal sphincter reflex. Clinical Research 9:155. Gowers, w.R. 1877. .The automatic action of the sphincter ani. In: Proceedings of the Royal Society, Vol. 26, p. 77. Schuster, M.M., Hendrix, T.R., and Mendeloff, A.I. 1963. The internal anal sphincter response: manometric studies on its normal physiology, neural pathways, and alteration in bowel disorders. Journal of Clinical Investigation 42:196-207. 78 79 Bibliography. cont'd. 12. 13. 14. 15. 16. 17. 18. 19. 20. Schuster, M.M., Hookman, P., Hendrix, T.R., and Mendeloff, A.I. 1965. Simultaneous manometric recording of internal and external anal sphincteric reflexes. Bulletin of John Hopkins Hospital 166:79. Miller, N.E. 1969. Learning of visceral and glandular responses. Science 163:434-445. Engel, B.T. 1978. The treatment of fecal incontinence by operant conditioning. Biomedica 2:101-108 Cerulli, M.A., Nikoomanish, P., and Schuster, M.M. 1979. Progress in biofeedback conditioning for fecal incontinence. Gastroenterology_76:742—746. Olness, K., McParland, F.A., and Piper, J. 1980. Biofeedback, a new modality in the management of children with fecal soiling. Journal of Pediatrics 96(3-1):505-509. Wald, A. 1981. Use of biofeedback in treatment of fecal inconti- nence in patients with meningomyelocele. Pediatrics 68 1 : Hallgren, R. 1980. Exploiting the personal computer in the research laboratory. In: IEEE Transactions on Biomedical Engineering, Vol. BME-27, N0. 3, March 1980. Stedman's Medical Dictionary.l973. 22nd Edition. Baltim0re Williams and Wilkins. Duthie, H.L. 1971. Anal continence Gut 12:844. IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII lllll[HI1111111111[11111111111111