David Waldron

A Review and Adaptation of Methods of Object Tracking to Telemetry Capsules

Abstract This review considers techniques employing radio frequency (RF) as well as ultrasound signals for tracking. Medical capsules have been employed since the SOs to measure various physiological parameters in the human body. Examples are temperature, pH, or pressure inside the gastrointestinal (GI) tract. The development and subsequent incorporation of new technology into reasonably priced, commercially available devices have made ultrasound and RF devices readily accessible for medical diagnosis. Some applications for telemetry capsules are drug delivery, and collection of tissue/fluid samples. Samples are taken from the GI to understand or treat diseases where diagnosis can only be made by taking a biopsy from the intestinal walls. Such biopsies have traditionally been performed using customized endoscopes. In order for a telemetry capsule to be effective in the above named tasks, accurate knowledge of the location of the capsule within the body during tests is necessary. As such, methods for calcu...

Fulminant small bowel enteritis: A rare complication of Clostridium difficile-associated disease

To the Editor: A 54-year-old male was admitted to a community hospital with a 3-month history of diarrhea up to 8 times a day associated with bloody bowel motions and weight loss of 6 kg. He had no past medical history or family history of note. A clinical diagnosis of colitis was made and the patient underwent a limited colonoscopy which demonstrated continuous mucosal inflammation and ulceration that was most marked in the rectum. The clinical and endoscopic findings were suggestive of acute ulcerative colitis (UC), which was subsequently supported by histopathology. The patient was managed with bowel rest and intravenous steroids. However, he developed toxic megacolon on day 4 of his admission and underwent a total colectomy with end ileostomy. On the third postoperative day the patient developed a pyrexia of 39°C, a septic screen was performed, and the central venous line (CVP) was changed with the tip culturing methicillin-resistant Staphylococcus aureus (MRSA). Intravenous gentamycin was commenced and discontinued after 5 days, with the patient remaining afebrile and stable. On the tenth postoperative day the patient became tachycardic (pulse 110/min), diaphoretic (temperature of 39.4°C), hypotensive (diastolic of 60 mm Hg), and with a high volume nasogastric aspirates noted (2000 mL). A diagnosis of septic shock was considered although the etiology was unclear. The patient was resuscitated with intravenous fluids and transferred to the regional surgical unit for Intensive Care Unit monitoring and management. A computed tomography (CT) of the abdomen showed a marked inflammatory process with bowel wall thickening along the entire small bowel with possible intramural air, raising the suggestion of ischemic bowel (Fig. 1). However, on clinical assessment the patient elicited no signs of peritonism, his vitals were stable, he was not acidotic (pH 7.40), urine output was adequate, and his blood pressure was being maintained without inotropic support. Furthermore, his ileostomy appeared healthy and well perfused, although a high volume (2500 mL in the previous 18 hours), malodorous output was noted. A sample of the stoma output was sent for microbiological analysis. Given that the patient was not exhibiting evidence of peritonitis with normal vital signs, a conservative policy of fluid resuscitation was pursued with plans for exploratory laparotomy if he disimproved. Ileostomy output sent for microbiology assessment was positive for Clostridium difficile toxin A and B utilizing culture and enzyme immunoassays (EIA). Intravenous vancomycin, metronidazole, and rifampicin via a nasogastric tube were commenced in conjunction with bowel rest and total parenteral nutrition. The ileostomy output reduced markedly within 2 days and the patient’s clinical condition improved. Follow-up culture of the ileostomy output was negative for C. difficile toxins. The patient was discharged in good health on full oral diet 12 days following transfer. Review of histopathology relating to the resected colon and subsequent endoscopic assessment of the retained rectum confirmed the initial diagnosis of UC, rather than a primary diagnosis of pseudomembranous colitis. Clostridium difficile is the leading cause of nosocomial diarrhea associated with antibiotic therapy and is almost always limited to the colonic mucosa.1 Small bowel enteritis secondary to C. difficile is exceedingly rare, with only 21 previous cases cited in the literature.2,3 Of this cohort, 18 patients had a surgical procedure at some timepoint prior to the development of C. difficile enteritis, while the remaining 3 patients had no surgical procedure prior to the infection. The time span between surgery and the development of enteritis ranged from 4 days to 31 years. Antibiotic therapy predisposed to the development of C. difficile enteritis in 20 of the cases. A majority of the patients (n 11) had a history of inflammatory bowel disease (IBD), with 8 having UC similar to our patient and the remaining 3 patients having a history of Crohn’s disease. The etiology of small bowel enteritis remains unclear. C. difficile has been successfully isolated from the small bowel in both autopsy specimens and from jejunal aspirate of patients with chronic diarrhea, suggesting that the small bowel may act as a reservoir for C. difficile.4 This would suggest that C. difficile could become pathogenic in the small bowel following a disruption in the small bowel flora in the setting of antibiotic therapy. This would be supported by the observation that the majority of cases reported occurred within 90 days of surgery with attendant disruption of bowel function. The prevalence of C. difficile-associated disease (CDAD) in patients with IBD is increasing. Issa et al5 examined the impact of CDAD in a cohort of patients with IBD. They found that more than half of the patients with a positive culture for C. difficile were admitted and 20% required a colectomy. They reported that maintenance immunomodulator use and colonic involvement were independent risk factors for C. difficile infection in patients with IBD. The rising incidence of C. difficile in patients with IBD coupled with the use of increasingly potent immunomodulatory therapies means that clinicians must have a high index of suspiCopyright

Small bowel obstruction secondary to migration of a fragment of lithobezoar: a case report

IntroductionSmall bowel obstruction is a common world-wide condition that has a range of etiological factors. The management is largely dependent on the cause of the obstruction. Small bowel obstruction caused by foreign body ingestion is rare; many items have been reported as responsible, but there are no reports implicating polyurethane foam.Case presentationWe report the case of a 44-year-old Irish male who presented following ingestion of polyurethane foam. He was asymptomatic on presentation but developed a small bowel obstruction shortly thereafter.ConclusionPatients presenting following ingestion of polyurethane foam should be scheduled for elective laparotomy, gastrotomy, and retrieval of the cast on the next available theatre list - given that they are suitable for surgery.

Review of the potential of a wireless MEMS microsystem for biomedical applications

Purpose – Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would replace invasive techniques in the diagnosis of function disorders in the GI tract. However, problems such as signal loss and uncertainty of the pills position limited their use in a clinical setting. In this paper, a review of the capabilities of microelectromechanical systems (MEMS) for the fabrication of a wireless pressure sensor microsystem is presented.Design/methodology/approach – The circuit requirements and methods of data transfer are examined. The available fabrication methods for MEMS sensors are also discussed and examples of wireless sensors are given. Finally, the drawbacks of using this technology are examined.Findings – MEMS for use in wireless monitoring of pressure in the GI tract have been investigated. It has been shown that capacitive pressure sensors are particularly suitable for this purpose. Se...

Atypical midcycle pain

A 16-year-old female presented with acute-onset abdominal pain and an initial diagnosis of midcycle pain. Subsequent pelvic ultrasound and diagnostic laparoscopy showed a large mass in the pouch of Douglas. The patient underwent a laparotomy and excision of a mass from a loop of jejunum. This case highlights the difficulties in diagnostic differentiation relating to large pelvic masses in young females.

Low power programmable prototype sensor for remotely pressure monitoring

In this paper, a miniaturized, low power, bidirectional wireless communication system has been developed to be used for in vivo pressure monitoring. The system prototype consists of miniature FSK transceiver integrated with Microcontroller unit (MCU) in one small package, chip antenna, and capacitive interface circuitry based on Delta-sigma (SigmaDelta) modulator. At the base station side, the same transceiver chip is communicating with a PC through a graphical user interface (GUI) to either sends/receives commands/data. Industrial, Scientific and Medical (ISM) band RF (433 MHz) was used to achieve half duplex communication between the two sides. A digital filtering has been used in the capacitive interface to reduce noise effects forming capacitance to digital converter (CDC). All the modules of the mixed signal system are integrated in a printed circuit board (PCB) of size 22.46 x 20.168 mm.

The solution to a big hole: dermal collagen graft

ConclusionPorcine dermal collagen graft is a safe biological material that is readily incorporated into the host tissue resulting in a permanent repair. It is especially useful in hostile wounds. The advantages of this graft emphasise the potential use of this biomaterial in a wider range of surgical applications. The disadvantages of this material are that it is only available in a single size of 10 × 15 cm and is very expensive at 20AC2,073.83 per sheet.