Wrist Joint

Subjects’ Monofilament and Two-Point Discrimination scores for the index and thumb fingertips were compared with and without noise. Specifically, sensory scores without noise were recorded at the beginning (pre) and end (post) of the testing session. Sensory scores for the pre and post test were compared to ensure no learning effect and no residual effect of noise after the exposure during the one day testing session. In between the pre and post sensory tests without noise, sensory scores with noise were recorded while subthreshold vibrotactile noise was applied to four different locations at three noise intensities. The subthreshold vibrotactile noise was turned on immediately before each sensory test and was turned off immediately after each sensory test (lasting approximately 1 minute each). The testing session lasted for approximately two hours for each subject.
Subthreshold vibrotactile noise was white noise bandwidth filtered at 0 to 500 Hz, applied with a C-3 Tactor (Engineering Acoustics, Inc. Casselberry, Florida). Due to the characteristics of the C-3 Tactor, the vibration amplitude could have been larger for 100-300 Hz which includes the sensitive range of the Pacinian corpuscles. The noise was applied to one of four locations in the paretic upper limb (Figure 1): 1) dorsal hand approximately 2 cm proximal to the index finger knuckle; 2) dorsal hand approximately 2 cm proximal to the thumb knuckle; 3) dorsal wrist, medial to the radial styloid process; and 4) volar wrist, medial to the radial styloid process. These locations were arbitrarily chosen with the intention of developing a future wearable rehabilitation device for stroke survivors. Since the long-term goal of the research is to improve dexterity and grip control, noise locations that would interfere with gripping, such as the fingertip or palm, were avoided. Presentation of noise locations was block randomized.
Noise intensities were set to 40%, 60%, or 80% of the sensory thresholds specific for each location. The order of testing different noise intensities was randomized within each location block. To determine the sensory threshold, the noise intensity was increased and decreased until the subject was barely able to distinguish between an “off” and an “on” presentation of the vibrotactile noise (i.e., the method of ascending and descending limits [22 (link)]). Subjects’ mean sensory threshold occurred when the Tactor was driven by current of 0.17 A peak-to-peak (Table 1). There is a linear relationship between the current and amplitude of the vibration. According to the data sheet from the manufacturer, 0.17 A peak-to-peak corresponds to a maximum amplitude of 260 μm. Subthreshold noise intensities were chosen not only so that subjects could not distinguish between trials with and without noise [21 (link)], but also because suprathreshold noise has been shown to degrade performance [23 (link)].
The Monofilament and Two-Point Discrimination Tests were administered using standard testing measures. For the Monofilament score, beginning with the baseline 2.83 Monofilament (indicating the threshold for “normal sensing”), the Monofilament was applied to the fingertip at least three times and the smallest Monofilament for which the subjects responded “yes” and could identify the correct finger that was touched marked the score [29 ]. The Two-Point Discrimination test was conducted so that subjects were asked to respond either “one” for a single point and “two” for two points separated by a small distance [29 ]. One and two point stimuli were alternated randomly. The smallest distance where the subjects responded correctly three consecutive times to identifying two separated points was used for their Two-Point Discrimination score. A score of 2.83 [30 ] and 5 mm [31 (link)] was considered normal for the Monofilament test and Two-Point Discrimination tests, respectively.

Clinical evaluations were performed on emergency room patients with hypotension who were older than 18 years and met the inclusion criteria. After explaining the study to the patient or relative, written consent was obtained. The patient’s demographic details, vitals, clinical details, and diagnosis were entered in the data collection proforma. Patients who required ABG as a part of routine care per treating physician were sampled. An arterial sample (0.5–1 mL) was collected using a heparinized syringe from the radial artery at the wrist level. The venous blood sample was obtained from the cubital or dorsal hand veins. Both samples were collected with minimum delay (less than 10 min). Both samples were analyzed as soon as possible using a blood gas analyzer Nova Biomedicals Stat profile pHOX ultra.

The EMA data collections conducted in the UAS began in February, 2020, and consisted of 1-week of intensive repeated assessments in panel members 50 years of age or older (a primary focus of the UAS is on health and retirement). The bursts consist of momentary assessments of mood, pain, stress, and social relationships collected 6x/day along with other assessments (e.g., end-of-day daily diaries and voice recordings of participants describing the day’s occurrences). Invitations to fill out the EMA consent survey were made available in batches to UAS panelists (see S1 Appendix for text of email invitation). For each batch of invitations, the UAS system made an online screening survey available through the panelists’ profiles. Within 3 days of the study invitations, the study administrator followed up with an email to encourage participation. The first email described the study as an upcoming UAS research project focusing on health and activities. A link to the online screening survey was included in the email. Additional reminder emails were sent to those panelists who did not respond to the study invitation, spaced approximately one week apart after the initial invitation. Nonresponsive panelists were re-contacted again at the next batch of recruitment for the burst. A total participant payment of up to $100 was offered. For the analyses presented in this paper, we only considered panelists’ response until February 2021.
The screening survey asked panelists about their eligibility, contained information about the details of study participation, and informed panelists about the compensation associated with study participation. The primary inclusion criteria were having a smartphone with Android or iOS operating system (no minimum level of the operating systems was required) and with a voice and data plan billed on a monthly basis. There were two study protocols that differed in the following ways. The first protocol, which was used through April 3^rd, 2020, included the use a wrist-worn accelerometer throughout the burst. The second protocol, which started May 18^th, 2020, mentioned the accelerometry, but said it was temporarily suspended due to the novel coronavirus pandemic. In addition, in the second protocol participants were asked to provide brief voice recordings twice during the burst. These design components add burden to the study beyond the momentary assessments and should be taken into account when considering the resulting uptake rates. At the end of the study description (with either version), panelists were given the option of “Yes, I am interested in participating,” “No, I am not interested in participating,” and “Not sure, I need more information to decide.”
Those who expressed interest in participating were then provided with detailed instructions on installing the study application on their phone and were informed that the study team would contact them with more information regarding participation. Although no specific operating systems were part of the inclusion criteria, in fact, Android 5.0 or iOS 10.3 were the lowest level of the operating systems required for installation of the app. For those who indicated that they were not interested in participating, the survey asked for the reasons for the lack of interest. For those who indicated uncertainty in their interest in participating, additional descriptive material about the study was displayed on the follow up page in the screening survey. If the panelists still were unsure, then a research team member contacted the panelists to provide further details and to enroll eligible panelists who expressed interest in participating in the study.

Data came from the Seniors-ENRICA-2 cohort [29 (link)]. Participants were recruited between 2015 and 2017 by stratified random sampling of all community-dwelling individuals aged 65 years and older holding a national healthcare card and living in two districts of the city of Madrid (Spain) and four large surrounding towns. Initially, a computer-assisted telephone interview was conducted to collect socio-demographic, lifestyle and morbidity data. Next, two home visits by study staff were done to perform a physical examination, obtain a diet history, place a wrist accelerometer, and obtain serum samples.