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This article describes the concept of Medical Device Interface Data Sheets (MDIDSs) to document and characterize medical device interface data requirements, the processes for creating MDIDSs, and its role in supporting patient safety and cybersecurity of current systems while enabling innovation in the area of next-generation medical Internet of Things (IoT) platforms for integrating sensors, actuators, and applications (apps).

In this article, we describe the role of "clinical scenario" information to assure the safety of interoperable systems, as well as the system's ability to deliver the requisite clinical functionality to improve clinical care. Described are methods and rationale for capturing the clinical needs, workflow, hazards, and device interactions in the clinical environment. Key user (clinician and clinical engineer) needs and system requirements can be derived from this information, therefore, improving the communication from clinicians to medical device and information technology system developers. This methodology is intended to assist the health care community, including researchers, standards developers, regulators, and manufacturers, by providing clinical definition to support requirements in the systems engineering process, particularly those focusing on development of Integrated Clinical Environments described in standard ASTM F2761. Our focus is on identifying and documenting relevant interactions and medical device capabilities within the system using a documentation tool called medical device interface data sheets and mitigating hazardous situations related to workflow, product usability, data integration, and the lack of effective medical device-health information technology system integration to achieve safe interoperability. Portions of the analysis of a clinical scenario for a "patient-controlled analgesia safety interlock" are provided to illustrate the method. Collecting better clinical adverse event information and proposed solutions can help identify opportunities to improve current device capabilities and interoperability and support a learning health system to improve health care delivery. Developing and analyzing clinical scenarios are the first steps in creating solutions to address vexing patient safety problems and enable clinical innovation. A Web-based research tool for implementing a means of acquiring and managing this information, the Clinical Scenario Repository™ (MD PnP Program), is described., Competing Interests: The authors declare no conflicts of interest.

Medical device and health information technology systems are increasingly interdependent with users demanding increased interoperability. Related safety standards must be developed taking into account these systems' perspective. In this article, we describe the current development of medical device standards and the need for these standards to address medical device informatics. Medical device information should be gathered from a broad range of clinical scenarios to lay the foundation for safe medical device interoperability. Five clinical examples show how medical device informatics principles, if applied in the development of medical device standards, could help facilitate the development of safe interoperable medical device systems. These examples illustrate the clinical implications of the failure to capture important signals and device attributes. We provide recommendations relating to the coordination between historically separate standards development groups, some of which focus on safety and effectiveness and others focus on health informatics. We identify the need for a shared understanding among stakeholders and describe organizational structures to promote cooperation such that device-to-device interactions and related safety information are considered during standards development., Competing Interests: The authors declare no conflicts of interest.

Purpose: To compare the effect of storing Descemet-stripping automated endothelial keratoplasty (DSAEK) tissue with anterior lamellar corneal tissue (ALCT)-on versus -off., Methods: An in vitro model was used with corneoscleral rims and DSAEK quality paired corneas. After microkeratome-assisted excision of ALCT, 4 pairs of corneas (8 eyes) were stored with the ALCT left on the stroma (on) and the others with ALCT off the stroma (off) for 24 hours in Optisol GS solution. A vital dye assay was used to identify devitalized and necrotic endothelial cells with alizarin red S and trypan blue., Results: Corneal endothelial cell damage was observed in the ALCT-off specimens, whereas almost no staining was observed in the ALCT-on samples. In addition, the ALCT-off donor corneas were clinically edematous and opaque, whereas the ALCT-on corneas were clear. Moreover, Descemet membranes of ALCT-off samples were found to be loose and easily detached from the stroma, with many Descemet striae observed in the specimens., Conclusions: This study shows that endothelial damage occurs in ALCT-off corneas. We hypothesize that the absence of the Bowman layer may contribute to the damage, because it has been shown that the Bowman layer provides a barrier function. These data suggest that it is important to keep the ALCT/Bowman layer on the stromal side of the DSAEK graft as long as possible to avoid stromal swelling and endothelial damage.

Purpose: To qualitatively assess the endothelial damage on Descemet-stripping automated endothelial keratoplasty (DSAEK) donor tissue resulting from a gentian violet marking pen., Methods: An in vitro model was used, by using corneoscleral rims, DSAEK quality corneal donor tissue, and a gentian violet marking pen. After making a mark on the stromal side of a microkeratome-prepared DSAEK corneal button to confirm appropriate orientation of the donor tissue after insertion into the anterior chamber, the corneal tissue was returned to Optisol GS solution for 1 hour. A vital dye assay was used to identify devitalized and necrotic endothelial cells with alizarin red S and trypan blue., Results: Corneal donor tissue evaluated with the gentian violet marking pen showed positive trypan blue staining, limited to the area marked with the gentian violet ink., Conclusions: Marking the DSAEK donor stromal surface with a gentian violet marker damages the endothelium. Surgeons should limit the size of the mark or use an insertion technique that avoids confusion about orientation of the donor cornea.

Purpose: To qualitatively assess the extent and pattern of endothelial trauma on corneal donor Descemet-stripping automated endothelial keratoplasty (DSAEK) buttons resulting from DSAEK insertion forceps., Methods: An in vitro model was used with corneoscleral rims, DSAEK quality corneal donor tissue, and DSAEK insertion forceps. After insertion of the donor button through the corneoscleral rim, a vital dye assay was used to identify devitalized and necrotic endothelial cells (with alizarin red S and typan blue)., Results: Corneal buttons evaluated with the forceps delivery model showed that, for each arm of the forceps, there were 2 parallel bands of purple/red staining. In addition, orthogonal wrinkles of scattered blue devitalized nuclei were seen in a parallel arrangement., Conclusions: The DSAEK insertion forceps resulted in a reproducible pattern of endothelial damage. A thorough understanding of iatrogenic endothelial trauma could result in improved forceps design and perhaps help mitigate the high rate of donor dislocation and graft failure in the future.

Most hospital policies prohibiting the use of wireless devices cite reports of disruption of medical equipment by cellular telephones. There have been no studies to determine whether mobile telephones may have a beneficial impact on safety. At the 2003 meeting of the American Society of Anesthesiologists 7878 surveys were distributed to attendees. The five-question survey polled anesthesiologists regarding modes of communication used in the operating room/intensive care unit and experience with communications delays and medical errors. Survey reliability was verified using test-retest analysis and proportion agreement in a convenience sample of 17 anesthesiologists. Four-thousand-eighteen responses were received. The test-retest reliability of the survey instrument was excellent (Kappa = 0.75; 95% confidence interval, 0.56-0.94). Sixty-five percent of surveyed anesthesiologists reported using pagers as their primary mode of communications, whereas only 17% used cellular telephones. Forty-five percent of respondents who use pagers reported delays in communications compared with 31% of cellular telephone users. Cellular telephone use by anesthesiologists is associated with a reduction in the risk of medical error or injury resulting from communication delay (relative risk = 0.78; 95% confidence interval, 0.6234-0.9649). The small risks of electromagnetic interference between mobile telephones and medical devices should be weighed against the potential benefits of improved communication.

Leukemia is a disease characterized by the malignant transformation of hematopoietic stem cells. Previous studies have shown that the Wilms' tumor antigen-1 (WT1) transcription factor is expressed at elevated levels in hematopoietic stem cells of leukemia patients compared with normal stem cells. In the past, we have generated cytotoxic T lymphocytes (CTL) specific for WT1, and we have shown that they killed WT1-expressing leukemia cell lines and inhibited the in vitro colony-forming activity of leukemia cells of patients. We used a xenotransplantation model to address whether WT1-specific CTL can selectively inhibit engraftment of malignant but not normal stem cells. CD34+ hematopoietic cells isolated from individuals with chronic myeloid leukemia or normal hematopoiesis were treated with WT1-specific CTL and injected into immunodeficient non-obese diabetic-severe combined immunodeficient mice. After 5 to 8 weeks, engraftment of leukemic or normal human cells was analyzed using immunohistology, flow cytometry, and polymerase chain reaction amplification of human sequences. The data showed that exposure of chronic myeloid leukemia CD34+ cells to WT1-specifc CTL completely prevented the development of leukemia in the recipient mice, whereas CTL treatment did not inhibit engraftment of normal CD34+ stem cells. The experiments indicate that WT1-specific CTL can discriminate between stem cells that give raise to leukemia and normal hematopoiesis in the xenogenic transplantation model. This supports the use of CTL with this specificity for treatment of leukemia patients undergoing stem-cell transplantation.

Background: We have previously developed and used limiting dilution analysis to measure frequencies of alloreactive cytotoxic T cell precursors (CTLp) and interleukin (IL)-2-producing T helper cells (IL-2/HTLp) to assess the risk of graft-versus-host disease in bone marrow transplantation (BMT). However, no test has been available to measure precursor frequencies of the important IL-4-secreting subset., Methods: We have now established a limiting dilution analysis to measure the frequency of IL-4-producing T helper cells (IL-4/HTLp) using the IL-4-responsive indicator cell line CT.h4S and have applied this assay to measure alloreactive IL-4/HTLp frequencies in BMT donor-recipient pairs. These frequencies were then analyzed in the context of clinical data to assess the relationship between the number of donor anti-recipient IL-4-secreting T cells and disease outcome., Results: Frequencies of IL-4/HTLp have been studied in HLA-identical siblings, HLA-"matched" unrelated, and HLA-mismatched combinations and found to range from approximately 1/500,000 in HLA-identical sibling pairs to -1/2,000 in HLA-DR-mismatched pairs. These frequencies were independent of those for IL-2/HTLp and showed a negative correlation with those for CTLp. Clinical follow-up of 30 patients showed that high IL-4/HTLp frequencies are associated with a reduced risk of severe graft-versus-host disease. High IL-4/HTLp frequencies may also indicate an increased risk of leukemia relapse., Conclusions: Our data suggest that measurement of IL-4/HTLp frequencies provides information distinct from that obtained with CTLp and IL-2/HTLp. This new assay provides a valuable additional method for optimizing donor selection in unrelated BMT.

Between May 1989 and February 1994, we performed 48 volunteer unrelated donor BMTs for first chronic phase chronic myeloid leukemia using in vivo T cell depletion for acute graft-versus-host disease (aGvHD) prophylaxis. In 40 cases, adequate material was available to measure the frequency of antirecipient MHC cytotoxic T lymphocyte precursor (CTLp) cells in the blood of potential donors. This supplemented standard serological typing, one-dimensional isoelectric focusing for class I proteins, and allogenotyping for DR and DQ alleles using DNA RFLP analysis in the donor selection process. All recipients were conditioned with cyclophosphamide 120 mg/kg, TBI 1320 cGy, and intravenous Campath 1G. GvHD prophylaxis consisted of CsA, short-course methotrexate, and intravenous Campath 1G. Minimum follow-up in all surviving recipients was 100 days. The development of aGvHD and the probability of leukemia-free survival were compared between the high frequency group (CTLp > 1 in 100,000) (n = 15) and the low frequency group (CTLp < 1 in 100,000) (n = 25). There was a trend for increasing grade of aGvHD, which was statistically significant in the high frequency group when compared with the low frequency group (P = 0.003). Both a high frequency of CTLp (relative risk [RR] = 9.0, P = 0.016) and HLA mismatch (RR = 6.7, P = 0.023) were predictors of severe aGvHD (grade III or IV). Multivariate analysis showed that CTLp group (RR = 3.4, P = 0.015) and CMV status (RR = 3.9, P = 0.008) were predictors of leukemia-free survival. Further investigation showed an interaction between the two, such that CMV seropositive recipients in the high frequency group had a relative risk of 9.4 (P = 0.0001) of treatment failure (death or relapse) when compared with other combinations. We conclude that with our present GvHD prophylaxis regimen, CTLp frequency analysis predicts post-BMT outcome and is a valuable aid in donor selection.

Donor/recipient histocompatibility antigen differences initiate acute graft-versus-host disease (GVHD) after bone marrow transplantation. Frequency analysis, using limiting dilution techniques, of functionally defined (helper or cytotoxic) antirecipient T lymphocyte precursors in the peripheral blood of the donor has been shown to be an accurate predictor for the development of moderate-to-severe acute GVHD. Here, we describe a sensitive assay for measuring alloreactive helper (IL-2-producing) T lymphocyte precursor (HTLp) frequencies, and compare the ability of this assay and the cytotoxic T lymphocyte precursor (CTLp) assay to detect HLA- class II and class I differences and to predict clinical outcome in a cohort of unrelated donor/recipient BMT pairs. Twenty-two pairs underwent unrelated donor BMT. Patients with high (> 1:100 x 10(3)) HTLp or CTLp frequencies had a higher incidence of moderate-to-severe (grades II-IV) acute GVHD (80% and 100%, respectively) than pairs with low (< 1:100 x 10(3)) frequencies (40% and 57%, respectively). Ten (45%) patients have died, but all patients with both a low HTLp and low CTLp frequency remain alive. The HTLp and CTLp assays provided similar predictive information for outcome. Given that the HTLp assay is more rapid and less labor intensive, it offers an additional or alternative functional method for donor selection in unrelated donor BMT.

Of 143 consecutive patients who survived at least 6 months after bone marrow transplantation (allogeneic [n = 131]; syngeneic [n = 5]; or autologous [n = 7]) and whose pulmonary function was evaluated before and on at least 2 occasions after BMT, 29 (20%) developed a chronic pulmonary syndrome without evidence for an infectious etiology. Twenty-eight (97%) presented with cough and 22 (76%) with dyspnea; abnormal chest signs were crackles in 23 (79%) and wheeze in 22 (76%). Chest roentgenogram showed pulmonary infiltrates in 15 (52%) cases but was normal in 14 (48%). All patients had major reductions in lung volumes (forced expiratory volume in 1 sec [FEV1]; relaxed vital capacity [VC]; and alveolar volume [VA]), and/or diffusing capacity (pulmonary diffusing capacity [TLCO] and single-breath carbon monoxide coefficient [KCO]). The obstructive component varied with only 18 (62%) patients developing overt airways obstruction (FEV1/VC < 75%), and in 6 of this group the fall in lung volumes preceded the onset of airways obstruction. Open lung biopsy (n = 4) showed both bronchiolitis obliterans and chronic patchy interstitial pneumonitis. The development of this syndrome was associated with acute (P < 0.001) and chronic (P < 0.0001) graft-versus-host disease of other organ systems. Twenty-four (83%) patients had a partial or complete response to immunosuppressive agents. Six (21%) have died, five (17%) of pulmonary complications. We suggest that this syndrome may be a manifestation of chronic GVHD involvement of the lung.

Umbilical cord blood has been used to effect hematological reconstitution and there are sufficient stem cells available in the cord blood obtainable from a single placenta to reconstitute an adult patient. Umbilical cord blood might therefore, have widespread potential use in the field of bone marrow transplantation. We compared alloreactivity of paired samples of adult and cord peripheral blood mononuclear cells, by measuring frequencies of both alloreactive T helper cells and cytotoxic T cell precursors (CTLp), using limiting dilution analysis. In addition we compared the phenotype of adult and neonatal PBMC, using monoclonal antibody staining. Cord PBMC in general showed higher frequencies of alloreactive Th than adult PBMC, with statistically significant differences in 6 out of 10 experiments. There was no statistically significant difference between adult and cord CTLp frequencies. Adult and cord PBMC surface phenotype was similar, except that cord blood contained fewer lymphocyte function-associated-3 (LFA-3) positive (memory) cells.

It is generally accepted that patients with chronic myelogenous leukemia in chronic phase under the age of 50 years who have HLA-identical siblings, should be offered bone marrow transplantation within the first year of diagnosis. The projected disease-free survival for these patients is 70% to 80% at 4 years, and most of these will prove to have been cured. Results of bone marrow transplantation for patients with more advanced disease are less promising. For transplant conditioning there is no important difference between cyclophosphamide plus total-body irradiation and busulphan plus cyclophosphamide. Nonenlarged spleens require neither splenectomy nor additional radiotherapy. The use of cyclosporine and methotrexate is currently the optimal approach to graft-versus-host disease prevention. Fewer good results are obtained with "matched" volunteer marrow donors. Use of the polymerase chain reaction to monitor residual BCR-ABL transcripts after bone marrow transplantation may prove useful in identifying patients at increased risk for relapse. Autografting may offer the prospect of prolonged life or even cure for patients without suitable allogeneic donors.

Retrospectively we analyzed the histocompatibility data and clinical results of bone marrow transplantation in 51 patients who received marrow from unrelated donors (UD) from 1977 to 1987 at one of four UK BMT centers. We compared the results with those obtained in 51 transplants carried out at the same centers using HLA-identical (ID) sibling donors. Of the UD/recipient pairs 32 (63%) were serologically identical for HLA A, B, and DR antigens, and 37% showed varying degrees of mismatch. UD-BMT primary diagnoses were: severe aplastic anemia or Fanconi's anemia (n = 17), acute leukemia (n = 11), chronic myeloid leukemia (n = 21), and other conditions (n = 2). T cell depletion of the graft was associated with a significant improvement in survival in both UD and ID-BMT. Graft failure was more common in recipients of UD than of ID transplants (13 [25%] vs. 5 [10%] P = 0.05) but there was no significant difference in the frequency of acute or chronic graft-versus-host disease. Actuarial survival was superior for recipients of ID transplants (UD vs. ID: 49% vs. 78%, respectively, at 3 months; 32% vs. 63% at one year). Reduced survival for recipients of UD-BMT was confirmed in case control regression analysis (relative risk 3.0, P = 0.01). Nevertheless in patients whose only alternative is a partially mismatched family donor we think that UD-BMT is justified.

Thirty patients undergoing lidocaine spinal anesthesia for transurethral resection of the prostate (TURP) were studied to evaluate the effectiveness of low-dose intrathecal morphine (ITM) for postoperative analgesia. In a double-blinded fashion, groups of ten patients received either 0.1 mg morphine, 0.2 mg morphine, or placebo (control group) intrathecally with lidocaine 75 mg. Standard postoperative analgesics were available to all patients. Patients receiving 0.1 mg or 0.2 mg morphine reported significantly less postoperative pain as assessed by an inverse numerical visual pain scale and required significantly fewer postoperative analgesic interventions than the control group. There was no difference between the 0.1 mg ITM and 0.2 mg ITM groups with regard to severity of postoperative pain or analgesic requirements. The incidence of nausea and vomiting was significantly higher in the group receiving 0.2 mg ITM than in the control group. Six patients (60%) in the 0.2 mg ITM group, two patients (20%) in the 0.1 mg ITM group, and one patient (10%) in the control group experienced nausea and vomiting. No clinically evident respiratory depression occurred in any of the subjects. The authors conclude that administration of 0.1 mg or 0.2 mg of morphine intrathecally is effective in reducing postoperative pain following TURP and that 0.1 mg ITM is not associated with nausea and vomiting.

Hemorrhagic cystitis is a well known complication of allogeneic bone marrow transplantation (BMT) and is normally attributed to the use of high-dose cyclophosphamide in the preparative regimen. Hemorrhagic cystitis occurring late after BMT is unlikely to be due to the effects of this conditioning, and probably has an infective etiology. Three patients undergoing BMT for chronic granulocytic leukemia (CGL) developed terminal dysuria and hematuria at 38, 56, and 149 days post-BMT. Electron microscopy (EM) of urine voided at these times revealed large numbers of papovavirions, which were subsequently identified as BK virus. Urine samples inoculated onto human embryonic lung fibroblasts induced infection of the cells and replication of the virus as detected by EM of tissue culture fluid. Urine from one of these patients was examined by standard cytological techniques, and EM of urothelial cells showed nuclear inclusions consisting of nonencapsulated virus particles of diameter 40 nm, consistent with papovavirus. Five further patients were found to be excreting BK virus without symptoms of cystitis, although one of these patients did experience abnormalities of liver function that were otherwise unexplained. BK virus has already been implicated in hepatic dysfunction posttransplant, and in cystitis in nonimmunosuppressed children. We postulate that it may also be involved in the etiology of late hemorrhagic cystitis after BMT.

HLA "matched" unrelated donor bone marrow transplants are associated with an increased incidence and severity of graft-versus-host disease in comparison with HLA-identical sibling transplants. This is presumably due to HLA and non-HLA histocompatibility differences between donor and recipient. Using a limiting dilution assay, we have previously demonstrated a relationship between cytotoxic T lymphocyte precursor frequency and HLA disparity. In this study we have compared CTL-p frequencies with clinical GVHD, and demonstrate for the first time a significant correlation (P less than 0.005) between high CTL precursor frequency prior to BMT and severity of acute GVHD after HLA A, B, DR "matched" unrelated donor transplants using T cell depleted marrow. This assay system may be of value in the final selection of HLA "matched" unrelated donors for BMT.