Marc S. Cohen

Comparing Interpersonal Interactions with a Virtual Human to Those with a Real Human

This paper provides key insights into the construction and evaluation of interpersonal simulators¿systems that enable interpersonal interaction with virtual humans. Using an interpersonal simulator, two studies were conducted that compare interactions with a virtual human to interactions with a similar real human. The specific interpersonal scenario employed was that of a medical interview. Medical students interacted with either a virtual human simulating appendicitis or a real human pretending to have the same symptoms. In Study I (n = 24), medical students elicited the same information from the virtual and real human, indicating that the content of the virtual and real interactions were similar. However, participants appeared less engaged and insincere with the virtual human. These behavioral differences likely stemmed from the virtual humans limited expressive behavior. Study II (n = 58) explored participant behavior using new measures. Nonverbal behavior appeared to communicate lower interest and a poorer attitude toward the virtual human. Some subjective measures of participant behavior yielded contradictory results, highlighting the need for objective, physically-based measures in future studies.

Treatment of Pediatric Urolithiasis Between 1984 and 1994

PURPOSE We report our experience with the management of pediatric urolithiasis during a 10-year period. Our aim was to assess the impact of new technology in the treatment of pediatric urolithiasis. MATERIALS AND METHODS We retrospectively reviewed the records of all patients up to age 18 years in whom urolithiasis was treated from 1984 to 1994. In 37 cases 24-hour urine collections were available for metabolic evaluation. RESULTS A total of 100 pediatric patients was treated for urolithiasis. Mean followup was 36 months. A total of 79 patients underwent 115 procedures for symptomatic urolithiasis and 21 were treated nonoperatively. In 42 patients structural anomalies of the urinary tract required additional management. Metabolic abnormalities in 48 patients included hypercalciuria in 19, defined as greater than 4 mg./kg./24 hours calcium by 24-hour urine collection. Only 24 of the 100 patients had no identifiable predisposing factors. Procedures included shock wave lithotripsy in 42 cases, basket extraction with or without ureteroscopy in 20, percutaneous nephrostolithotomy in 11 and litholapaxy in 12. Open surgery included cystolithotomy in 10 cases and other forms of open lithotomy in 15. Thus, open surgical removal was necessary in 1 of 5 cases. CONCLUSIONS Compared to the traditional mode of stone treatment, fewer patients required open surgery. Our results indicate that a comprehensive approach to the care of pediatric patients with urolithiasis requires attention to metabolic and structural abnormalities.

Chronic scrotal hypothermia: results in 90 infertile couples.

We studied the use of a testicular hypothermia device worn daily for at least 16 weeks in 64 men with subfertile semen and elevated testicular temperature, who had had an infertile marriage for 2 or more years in which the wife was judged fertile. Improvement in 1 or more semen parameters was seen in 42 patients (65.6 per cent). Semen analysis was converted into the motile oval index, a numerical value representing the count, motility and normal morphology. The motile oval index helps to predict pregnancy outcome. Of 21 patients with pre-treatment motile oval indexes greater than 4.8 million per ml. 11 (52.4 per cent) produced pregnancy. Patients with lower starting indexes did not fare as well. Of 20 patients who met the criteria, and who wore the device for less than 2 weeks or not at all and had no other treatment 1 (5.0 per cent) produced pregnancy. Mean hypothermia time to date of missed menses was 4.2 months. Six patients with nonobstructive azoospermia showed no semen change with the testicular hypothermia device.

Needle biopsy of testes: A safe outpatient procedure

A total of 287 testes biopsies were performed in the office under local anesthesia, using a modified needle and technique to collect the tissue which was then fixed in Bouins solution. Adequate tissue was obtained in all specimens for histopathologic diagnosis. In 3 patients small hematomas developed and were treated conservatively. Five patients complained of orchialgia, but none required narcotic analgesia. No sperm antibodies, extravasation, or serious complications were encountered. We believe this technique is safe, simple, and cost-effective.

Laparoscopically Assisted Percutaneous Renal Biopsy

We performed laparoscopically assisted percutaneous renal biopsy on 4 patients with azotemia or renal dysfunction who were believed to be unsuitable candidates for percutaneous renal biopsy. Tissue adequate for diagnosis was obtained in all 4 cases. Complications included subcutaneous emphysema in 1 patient and a small splenic capsular tear in 1, which was managed laparoscopically and did not require transfusion. Bleeding from the renal biopsy occurred in 1 patient and was easily managed laparoscopically. We recommend laparoscopically assisted percutaneous renal biopsy as an alternative method of renal biopsy in patients who can tolerate general anesthesia and who are not candidates for percutaneous renal biopsy.

Robotic surgery in male infertility and chronic orchialgia.

Purpose of review The use of robotic assistance during microsurgical procedures is currently being explored in the treatment of male infertility and patients with chronic testicular pain. Whether the addition of this technology would allow a corresponding improvement in outcomes as when the operating microscope was introduced in microsurgery is yet to be seen. Recent findings The present review covers new robotic microsurgical tools and applications of the robotic platform in microsurgical procedures such as vasectomy reversal, varicocelectomy, denervation of the spermatic cord for chronic testicular pain and microsurgical vascular anastomosis. Preliminary animal studies appear to show an advantage in terms of improved operative efficiency and improved surgical outcomes. Preliminary human clinical studies appear to support these findings. The use of robotic assistance during robotic microsurgical vasovasostomy appears to decrease operative duration and significantly improve early postoperative sperm counts compared with the pure microsurgical technique. Summary As with any new technology, long-term prospective controlled trials are necessary to assess the true cost–benefit ratio for robotic assisted microsurgery. The preliminary findings are promising, but further evaluation is warranted.

Video Technique for Human Robot-Assisted Microsurgical Vasovasostomy

Previous studies have shown that robot-assisted microsurgical vasovasostomy (RAVV) has technical advantages over pure microscopic vasovasostomy (MVV) in animal and human models. This study presents a video technique and initial results for RAVV in 20 human cases compared with 7 MVV cases by a single fellowship-trained microsurgeon from July 2007 to June 2009. A three-layer 10-0 and 9-0 suture anastomosis was performed with up to 22 months follow-up (mean 3 months). Mean operative duration for the RAVV cases was 109 and 128 minutes for MVV (p = 0.09). At 2 months postoperatively, all patients were patent. Mean sperm count was 54 million in RAVV and 11 million in MVV (p = 0.04). The use of robotic assistance in microsurgical vasovasostomy may have potential benefit over MVV in decreasing operative duration and significantly improving early semen analysis measures. Further evaluation and longer follow-up is needed to assess its clinical potential.

Urothelial Hyperplasia and Neoplasia. III. Detection of Nitrosamine Production with Different Bacterial Genera in Chronic Urinary Tract Infections of Rats

Various agents have been implicated in inducing urothelial cancer. Although drugs, occupational and environmental carcinogens are more widely accepted as playing a major role as urothelial carcinogens, several investigations suggest that bacteria may play a role. The mechanism of how bacteria may interact with the host to augment the development of urothelial carcinoma is not well understood. Clinically, investigators have linked the development of infection, urinary stones and indwelling catheters with urothelial cancer. Other investigators have suggested that the mechanism may be related to the production of carcinogenic compounds (nitrosamines) which can be detected during urinary tract infection. In our laboratory, we showed that rats with chronic urinary tract infections produced increasing urinary levels of N,N dimethylnitrosamine over a 24 week period and that the production correlated with hyperplasia and early neoplasia of the bladder epithelium. Three bacterial genera were used and two of these (Escherichia coli and a protein sp.) showed production of increasing levels of urinary nitrosamine and correlated with infection. The purpose of this current study is to determine if other bacterial genera and strains can also produce similar increasing nitrosamine levels in the rat model of chronic urinary tract infection and thus provide evidence that a number of bacterial genera and strains can produce nitrosamines in vivo. Also, the histology of the chronically infected bladder was examined for hyperplasia and neoplasia.

Interpersonal Scenarios: Virtual \approx Real?

This paper reports on a study to examine the similarities and differences in experiencing an interpersonal scenario with real and virtual humans. A system that allows medical students to interview a life-size virtual patient using natural speech and gestures was used as a platform for this comparison. Study participants interviewed either a virtual patient or a standardized patient, an actor trained to represent a medical condition. Subtle yet substantial differences were found in the participants’ rapport with the patient and the flow of the conversation. The virtual patient’s limited expressiveness was a significant source of these differences. However, overall task performance was similar, as were perceptions of the educational value of the interaction.

Computation of Localized Flow for Steady and Unsteady Vector Fields and Its Applications

This paper provides key insights into the construction and evaluation of interpersonal simulators - systems that enable interpersonal interaction with virtual humans. Using an interpersonal simulator, two studies were conducted that compare interactions with a virtual human to interactions with a similar real human. The specific interpersonal scenario employed was that of a medical interview. Medical students interacted with either a virtual human simulating appendicitis or a real human pretending to have the same symptoms. In study I (n=24), medical students elicited the same information from the virtual and real human, indicating that the content of the virtual and real interactions were similar. However, participants appeared less engaged and insincere with the virtual human. These behavioral differences likely stemmed from the virtual humans limited expressive behavior. Study II (n=58) explored participant behavior using new measures. Nonverbal behavior appeared to communicate lower interest and a poorer attitude toward the virtual human. Some subjective measures of participant behavior yielded contradictory results, highlighting the need for objective, physically-based measures in future studiesThis paper provides key insights into the construction and evaluation of interpersonal simulators - systems that enable interpersonal interaction with virtual humans. Using an interpersonal simulator, two studies were conducted that compare interactions with a virtual human to interactions with a similar real human. The specific interpersonal scenario employed was that of a medical interview. Medical students interacted with either a virtual human simulating appendicitis or a real human pretending to have the same symptoms. In study I (n=24), medical students elicited the same information from the virtual and real human, indicating that the content of the virtual and real interactions were similar. However, participants appeared less engaged and insincere with the virtual human. These behavioral differences likely stemmed from the virtual humans limited expressive behavior. Study II (n=58) explored participant behavior using new measures. Nonverbal behavior appeared to communicate lower interest and a poorer attitude toward the virtual human. Some subjective measures of participant behavior yielded contradictory results, highlighting the need for objective, physically-based measures in future studies