Screening of Mild Cognitive Impairment Through Conversations With Humanoid Robots: Exploratory Pilot Study.

BACKGROUND: The rising number of patients with dementia has become a serious social problem worldwide. To help detect dementia at an early stage, many studies have been conducted to detect signs of cognitive decline by prosodic and acoustic features. However, many of these methods are not suitable for everyday use as they focus on cognitive function or conversational speech during the examinations. In contrast, conversational humanoid robots are expected to be used in the care of older people to help reduce the work of care and monitoring through interaction. OBJECTIVE: This study focuses on early detection of mild cognitive impairment (MCI) through conversations between patients and humanoid robots without a specific examination, such as neuropsychological examination. METHODS: This was an exploratory study involving patients with MCI and cognitively normal (CN) older people. We collected the conversation data during neuropsychological examination (Mini-Mental State Examination [MMSE]) and everyday conversation between a humanoid robot and 94 participants (n=47, 50%, patients with MCI and n=47, 50%, CN older people). We extracted 17 types of prosodic and acoustic features, such as the duration of response time and jitter, from these conversations. We conducted a statistical significance test for each feature to clarify the speech features that are useful when classifying people into CN people and patients with MCI. Furthermore, we conducted an automatic classification experiment using a support vector machine (SVM) to verify whether it is possible to automatically classify these 2 groups by the features identified in the statistical significance test. RESULTS: We obtained significant differences in 5 (29%) of 17 types of features obtained from the MMSE conversational speech. The duration of response time, the duration of silent periods, and the proportion of silent periods showed a significant difference (P<.001) and met the reference value r=0.1 (small) of the effect size. Additionally, filler periods (P<.01) and the proportion of fillers (P=.02) showed a significant difference; however, these did not meet the reference value of the effect size. In contrast, we obtained significant differences in 16 (94%) of 17 types of features obtained from the everyday conversations with the humanoid robot. The duration of response time, the duration of speech periods, jitter (local, relative average perturbation [rap], 5-point period perturbation quotient [ppq5], difference of difference of periods [ddp]), shimmer (local, amplitude perturbation quotient [apq]3, apq5, apq11, average absolute differences between the amplitudes of consecutive periods [dda]), and F0cov (coefficient of variation of the fundamental frequency) showed a significant difference (P<.001). In addition, the duration of response time, the duration of silent periods, the filler period, and the proportion of fillers showed significant differences (P<.05). However, only jitter (local) met the reference value r=0.1 (small) of the effect size. In the automatic classification experiment for the classification of participants into CN and MCI groups, the results showed 66.0% accuracy in the MMSE conversational speech and 68.1% accuracy in everyday conversations with the humanoid robot. CONCLUSIONS: This study shows the possibility of early and simple screening for patients with MCI using prosodic and acoustic features from everyday conversations with a humanoid robot with the same level of accuracy as the MMSE.

Fracture of self-expandable metallic stent inserted for unresectable gastric cancer at the esophagogastric junction: successful retrieval of distal fragment by gastrotomy.

Endoscopic stenting is useful for amelioration of gastrointestinal stenosis. This procedure benefits severely compromised patients who cannot afford surgery. Although the self-expandable metallic stent (SEMS) is safe, it is also associated with several complications such as perforation, migration, and fracture. Migration of a SEMS is not particularly rare; however, fracture of a SEMS is relatively rare. An 88-year-old man underwent stenting for dysphagia at another hospital. He was being treated for gastric cancer at the esophagogastric junction. After appropriate stenting, he regained his ability to eat and was discharged the hospital. Only 2 months later, however, he again lost his ability to eat and visited our hospital. Abdominal X-ray and computed tomography revealed a stent fracture. The proximal fragment was in the esophagus, and the distal fragment was in the stomach. An emergency operation involving gastrotomy and gastrostomy was performed. Open gastrotomy was performed to remove the fractured distal stent, and percutaneous tube gastrostomy was placed through the same gastric incision for nutrition support. The surgery was successful, and he was again able to eat. In this report, we discuss the occurrence of SEMS fracture within a short time periods after insertion.

[A Case of Gastric Granular Cell Tumor Resected by a Surgical Robot].

A 46-year-old man was referred to further treatment for a 20 mm submucosal tumor at the gastric angle found during a medical check-up. Endoscopic ultrasonography and chest abdominal contrast-enhanced CT revealed the tumor was located at the 4th(proper muscular)layer of the posterior wall of the gastric antrum and slightly enhanced. No metastasis was found. Although a biopsy failed to reveal an accurate diagnosis, GIST was clinically suspected. A robotic distal gastrectomy was planned to manage the residual gastric stricture. The intraoperative findings indicated possible passage of the remnant stomach; therefore, local resection was performed. The patient's postoperative course was uneventful, and he was discharged on postoperative day 9. A histopathological examination confirmed the diagnosis of a PAS-positive, S100-positive granular cell tumor with no nuclear atypia. These findings suggest that use of the robotic approach could help determine the stomach resection extent.