Journal of Medical Systems, Vol. 27, No. 2, April 2003 ( C  2003) Low-Cost Instrumentation for the Diagnosis of Hirschsprung’s Disease Sadık Kara, 1 Duygu ˙ Istek, 2 and Mustafa Okandan 3,4 In Hirschsprung’s disease, the internal anorectal sphincter fails to relax in response to rectal distension, which strongly indicates the absence of rectoanal inhibitory reflex (RAIR). Hirschsprung’s disease is a very common case particularly encountered in the newborns in our region. Development of a manometric system targeted specifically for the diagnosis of this disease at a reasonable cost is an urgent need identified by our regional colorectal surgeons. These surgeons indicated that commercially available anorectal manometers are too expensive to acquire. Therefore, in our research we tried to develop a low-cost single balloon-transducer system, which only provides information about RAIR, and hence diagnoses the Hirschsprung’s disease. The hardware part of our instrumentation is made of a latex balloon, pressure trans- ducer, amplifier, and A/D converter circuits, which all collects the pressure readings and sends the data to the computer. The manometer system software, programmed based on Delphi, displays these readings and patient information on a computer screen. This designed system was successful enough to perform manometric recording of RAIR in the anorectal ampulla of rabbits and rats. KEY WORDS: anorectal manometry; Hirschsprung’s disease. INTRODUCTION Anorectal manometry is a test used to assist colorectal surgeons and gastroen- terologists in the diagnosis and treatment of various anorectal disorders such as fecal incontinence, constipation, pelvic floor dyssynergia, and Hirschsprung’s dis- ease. Hirschsprung’s disease is the most common cause of neonatal obstruction of the colon and accounts for about 33% of all neonatal obstructions. (1) This disease results from the absence of ganglion cells in the bowel wall, extending proximally from the anus for a variable distance. Incomplete parasympathetic innervation in 1 Erciyes University, Department of Electronic Engineering, Biomedical Engineering Group, 38039 Kayseri, Turkey. 2 Department of Health, Research and Educational Hospital, Ankara, Turkey. 3 Independent Biomedical Technology Consultant, Kayseri, Turkey. 4 To whom correspondence should be addressed; e-mail: kara@erciyes.edu.tr. 157 0148-5598/03/0400-0157/0 C  2003 Plenum Publishing Corporation