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Simon DA, Raza S, Shachar C, Glenn Cohen I. Using digital technologies to diagnose in the home: recommendations from a Delphi panel. NPJ Digit Med 2024; 7:18. [PMID: 38253682 PMCID: PMC10803339 DOI: 10.1038/s41746-024-01009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Rapid advances in digital technology have expanded the availability of diagnostic tools beyond traditional medical settings. Previously confined to clinical environments, these many diagnostic capabilities are now accessible outside the clinic. This study utilized the Delphi method, a consensus-building approach, to develop recommendations for the development and deployment of these innovative technologies. The study findings present the 29 consensus-based recommendations generated through the Delphi process, providing valuable insights and guidance for stakeholders involved in the implementation and utilization of these novel diagnostic solutions. These recommendations serve as a roadmap for navigating the complexities of integrating digital diagnostics into healthcare practice outside traditional settings like hospitals and clinics.
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Affiliation(s)
| | - Sara Raza
- Health Law and Policy Clinic, Harvard Law School, Cambridge, USA
| | - Carmel Shachar
- Health Law and Policy Clinic, Harvard Law School, Cambridge, USA
| | - I Glenn Cohen
- Petrie-Flom Center for Health Law Policy, Biotechnology & Bioethics, Harvard Law School, Cambridge, USA
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Simon DA, Shachar C, Cohen IG. Unsettled Liability Issues for "Prediagnostic" Wearables and Health-Related Products. JAMA 2022; 328:1391-1392. [PMID: 36136366 DOI: 10.1001/jama.2022.16317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
This Viewpoint examines the murky legal treatment of various health-related wearable or other general wellness products for patients, physicians, and manufacturers, and recommends solutions.
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Affiliation(s)
- David A Simon
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
| | - Carmel Shachar
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
| | - I Glenn Cohen
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
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3
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Simon DA, Evans BJ, Shachar C, Cohen IG. Should Alexa diagnose Alzheimer's?: Legal and ethical issues with at-home consumer devices. Cell Rep Med 2022; 3:100692. [PMID: 35882237 PMCID: PMC9797943 DOI: 10.1016/j.xcrm.2022.100692] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 01/10/2023]
Abstract
Voice-based AI-powered digital assistants, such as Alexa, Siri, and Google Assistant, present an exciting opportunity to translate healthcare from the hospital to the home. But building a digital, medical panopticon can raise many legal and ethical challenges if not designed and implemented thoughtfully. This paper highlights the benefits and explores some of the challenges of using digital assistants to detect early signs of cognitive impairment, focusing on issues such as consent, bycatching, privacy, and regulatory oversight. By using a fictional but plausible near-future hypothetical, we demonstrate why an "ethics-by-design" approach is necessary for consumer-monitoring tools that may be used to identify health concerns for their users.
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Affiliation(s)
- David A. Simon
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, MA 02138, USA
| | - Barbara J. Evans
- University of Florida Levin College of Law, Gainesville, FL 32611, USA,University of Florida Herbert Wertheim College of Engineering, Gainesville, FL 32611, USA
| | - Carmel Shachar
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, MA 02138, USA
| | - I. Glenn Cohen
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, MA 02138, USA,Corresponding author
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4
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Simon DA, Shachar C, Cohen IG. Skating the line between general wellness products and regulated devices: strategies and implications. J Law Biosci 2022; 9:lsac015. [PMID: 35855400 PMCID: PMC9280986 DOI: 10.1093/jlb/lsac015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/04/2022] [Indexed: 05/21/2023]
Abstract
Health technology is advancing at a rapid clip, with many of these technologies appearing on consumer products like smartphones and tablets. Federal regulators have responded to these changes with a flexible approach that allows firms to manufacture a 'general wellness product' ('GWP') without being subject to regulation typically applied to 'devices' that diagnose or treat a disease or condition. Using currently available medical products and devices from across a spectrum of diseases, we describe how firms can use this existing regulatory framework to develop innovative products by 'skating the line' between mostly unregulated GWPs and regulated devices. On the one hand, we find that skating the line offers a variety of benefits, including potential improvements to product development, innovation, and patient access to medical technologies. On the other hand, we show that this technique has potential costs to patient safety, competition, and data sharing. Skating the regulatory line between GWP and devices, in other words, offers important benefits but is not without risks. Any further regulatory action to address such risks should be careful to leave significant unregulated space for product development.
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Simon DA, Cohen IG, Balatbat C, Offodile AC. The hospital-at-home presents novel liabilities for physicians, hospitals, caregivers, and patients. Nat Med 2022; 28:438-441. [PMID: 35177864 DOI: 10.1038/s41591-022-01697-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David A Simon
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, MA, USA
| | - I Glenn Cohen
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, MA, USA. .,Harvard Law School, Cambridge, MA, USA.
| | | | - Anaeze C Offodile
- Department of Plastic Surgery, Division of Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Affiliation(s)
- David A Simon
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
| | - Carmel Shachar
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
| | - I Glenn Cohen
- Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics, Harvard Law School, Cambridge, Massachusetts
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Liddell K, Simon DA, Lucassen A. Patient data ownership: who owns your health? J Law Biosci 2021; 8:lsab023. [PMID: 34611493 PMCID: PMC8487665 DOI: 10.1093/jlb/lsab023] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/17/2021] [Accepted: 04/05/2021] [Indexed: 06/13/2023]
Abstract
This article answers two questions from the perspective of United Kingdom law and policy: (i) is health information property? and (ii) should it be? We argue that special features of health information make it unsuitable for conferral of property rights without an extensive system of data-specific rules, like those that govern intellectual property. Additionally, we argue that even if an extensive set of rules were developed, the advantages of a property framework to govern health information would be slight: propertization is unlikely to enhance patient self-determination, increase market efficiency, provide patients a foothold in the data economy, clarify legal uses of information, or encourage data-driven innovation. The better approach is to rely less, not more, on property. We recommend a regulatory model with four signature features: (i) substantial protection for personal health data similar to the GDPR with transparent limits on how, when, and by whom patient data can be accessed, used, and transmitted; (ii) input from relevant stakeholders; (iii) interoperability; and (iv) greater research into a health-data service, rather than goods, model.
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Abstract
Telehealth has the potential to address health disparities, but not without deliberate choices about how to implement it. To support vulnerable patients, health policy leaders must pursue creative solutions such as public-private partnerships, broadband infrastructure, and value-based payment. Without these initiatives or others like them, health disparities are likely to persist despite telehealth's tantalizing potential.
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Simon DA, Fleishman NR, Choi P, Fraser JD, Fischer RT. Torsion of an Accessory Spleen in a Child With Biliary Atresia Splenic Malformation Syndrome. Front Pediatr 2020; 8:220. [PMID: 32432066 PMCID: PMC7212802 DOI: 10.3389/fped.2020.00220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/14/2020] [Indexed: 11/29/2022] Open
Abstract
Torsion of an accessory spleen is an exceedingly rare cause of abdominal pain in pediatric patients. The diagnosis is frequently challenging as presentation is variable and diagnostic imaging can be aspecific. The current case describes an unusual presentation of a torted accessory spleen in a 5-year-old girl with biliary atresia splenic malformation syndrome who initially presented with non-specific abdominal symptoms and fever. The diagnosis was made following fine-needle aspiration of a suspected intraabdominal abscess. The case highlights the diagnostic challenge of accessory splenic torsion and stresses the importance of its inclusion on the differential diagnosis of pediatric patients, especially those with known splenic or laterality abnormalities, presenting with both acute and sub-acute abdominal symptoms.
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Affiliation(s)
- David A Simon
- Department of Pediatrics, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States
| | - Nathan R Fleishman
- Department of Gastroenterology and Hepatology, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States
| | - Pamala Choi
- Department of Pediatric Surgery, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States
| | - Jason D Fraser
- Department of Pediatric Surgery, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States
| | - Ryan T Fischer
- Department of Gastroenterology and Hepatology, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States
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Abstract
Introduction: While functional gallbladder disorder is a well-recognized and defined condition in adults, its pediatric analog, biliary dyskinesia, lacks uniformity in diagnosis. Yet, biliary dyskinesia is among the most common conditions resulting in cholecystectomy in youth and its frequency continues to rise. The primary aims of the current review were assess the efficacy of cholecystectomy in children diagnosed with biliary dyskinesia and the utility of cholescintigraphy in predicting outcomes. Results: All previous studies assessing outcomes in youth with biliary dyskinesia have been retrospective and therefore of low quality. There is a lack of uniformity in patient selection. Short term follow-up reveals partial response in 63.4-100% with complete resolution in 44.2-100%. Only 4 studies have reported long-term outcomes with complete symptom resolution in 44-60.7%. The published research generally indicates that the gallbladder ejection fraction (GBEF) as determined by cholescintigraphy lacks utility in predicting cholecystectomy outcome utilizing the commonly used cut-off values. There are data suggesting that more extreme cut-off values may improve the predictive value of GBEF. Conclusion: There is a lack of consensus on the symptom profile defining biliary dyskinesia in youth and current literature does not support the use of cholescintigraphy to select patients for cholecystectomy. There is a substantial portion of pediatric patients diagnosed with biliary dyskinesia who do not experience long-term benefit from cholecystectomy. Well-designed prospective studies of surgical outcomes are lacking. Increasing the uniformity in patient selection, including both symptom profiles and cholescintigraphy results, will be key in understanding the utility of cholecystectomy for this condition.
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Affiliation(s)
- David A Simon
- Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Craig A Friesen
- Division of Pediatric Gastroenterology, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Jennifer V Schurman
- Division of Developmental and Behavioral Sciences, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Jennifer M Colombo
- Division of Pediatric Gastroenterology, Children's Mercy Kansas City, Kansas City, MO, United States
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Fan X, Roberts DW, Olson JD, Ji S, Schaewe TJ, Simon DA, Paulsen KD. Image Updating for Brain Shift Compensation During Resection. Oper Neurosurg (Hagerstown) 2019; 14:402-411. [PMID: 28658934 DOI: 10.1093/ons/opx123] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 06/15/2017] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In open-cranial neurosurgery, preoperative magnetic resonance (pMR) images are typically coregistered for intraoperative guidance. Their accuracy can be significantly degraded by intraoperative brain deformation, especially when resection is involved. OBJECTIVE To produce model updated MR (uMR) images to compensate for brain shift that occurred during resection, and evaluate the performance of the image-updating process in terms of accuracy and computational efficiency. METHODS In 14 resection cases, intraoperative stereovision image pairs were acquired after dural opening and during resection to generate displacement maps of the surgical field. These data were assimilated by a biomechanical model to create uMR volumes of the evolving surgical field. A tracked stylus provided independent measurements of feature locations to quantify target registration errors (TREs) in the original coregistered pMR and uMR as surgery progressed. RESULTS Updated MR TREs were 1.66 ± 0.27 and 1.92 ± 0.49 mm in the 14 cases after dural opening and after partial resection, respectively, compared to 8.48 ± 3.74 and 8.77 ± 4.61 mm for pMR, respectively. The overall computational time for generating uMRs after partial resection was less than 10 min. CONCLUSION We have developed an image-updating system to compensate for brain deformation during resection using a computational model with data assimilation of displacements measured with intraoperative stereovision imaging that maintains TREs less than 2 mm on average.
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Affiliation(s)
- Xiaoyao Fan
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - David W Roberts
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire.,Department of Su, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.,Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.,Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Jonathan D Olson
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Songbai Ji
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire.,Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
| | | | - David A Simon
- Medtronic, PLC, Brain Therapies, Neurosurgery, Louisville, Colorado
| | - Keith D Paulsen
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire.,Department of Su, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.,Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
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Abstract
OBJECTIVE Preoperative magnetic resonance images (pMR) are typically coregistered to provide intraoperative navigation, the accuracy of which can be significantly compromised by brain deformation. In this study, the authors generated updated MR images (uMR) in the operating room (OR) to compensate for brain shift due to dural opening, and evaluated the accuracy and computational efficiency of the process. METHODS In 20 open cranial neurosurgical cases, a pair of intraoperative stereovision (iSV) images was acquired after dural opening to reconstruct a 3D profile of the exposed cortical surface. The iSV surface was registered with pMR to detect cortical displacements that were assimilated by a biomechanical model to estimate whole-brain nonrigid deformation and produce uMR in the OR. The uMR views were displayed on a commercial navigation system and compared side by side with the corresponding coregistered pMR. A tracked stylus was used to acquire coordinate locations of features on the cortical surface that served as independent positions for calculating target registration errors (TREs) for the coregistered uMR and pMR image volumes. RESULTS The uMR views were visually more accurate and well aligned with the iSV surface in terms of both geometry and texture compared with pMR where misalignment was evident. The average misfit between model estimates and measured displacements was 1.80 ± 0.35 mm, compared with the average initial misfit of 7.10 ± 2.78 mm between iSV and pMR, and the average TRE was 1.60 ± 0.43 mm across the 20 patients in the uMR image volume, compared with 7.31 ± 2.82 mm on average in the pMR cases. The iSV also proved to be accurate with an average error of 1.20 ± 0.37 mm. The overall computational time required to generate the uMR views was 7-8 minutes. CONCLUSIONS This study compensated for brain deformation caused by intraoperative dural opening using computational model-based assimilation of iSV cortical surface displacements. The uMR proved to be more accurate in terms of model-data misfit and TRE in the 20 patient cases evaluated relative to pMR. The computational time was acceptable (7-8 minutes) and the process caused minimal interruption of surgical workflow.
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Affiliation(s)
| | - David W Roberts
- Geisel School of Medicine, Dartmouth College, Hanover.,Norris Cotton Cancer Center, and.,Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and
| | | | - Songbai Ji
- Thayer School of Engineering, and.,Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and
| | | | - David A Simon
- Medtronic PLC, Surgical Technologies, Louisville, Colorado
| | - Keith D Paulsen
- Thayer School of Engineering, and.,Geisel School of Medicine, Dartmouth College, Hanover.,Norris Cotton Cancer Center, and
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Abstract
The horseshoe abscess is a rare variant of flexor tendon sheath infections. It involves the tendon sheaths of the first and fifth digits, which communicate through the deep potential space of the wrist. Neural compression is possible, leading to an acute carpal tunnel syndrome. The approach to such patients should include empirical antibiotic coverage and urgent consultation with a hand surgeon to facilitate operative management.
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Affiliation(s)
- David A Simon
- Division of Orthopaedic Surgery, University of Ottawa, ON
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Simon DA, Bjork RA. Metacognition in motor learning. J Exp Psychol Learn Mem Cogn 2001; 27:907-12. [PMID: 11486923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Research on judgments of verbal learning has demonstrated that participants' judgments are unreliable and often overconfident. The authors studied judgments of perceptual-motor learning. Participants learned 3 keystroke patterns on the number pad of a computer, each requiring that a different sequence of keys be struck in a different total movement time. Practice trials on each pattern were either blocked or randomly interleaved with trials on the other patterns, and each participant was asked, periodically, to predict his or her performance on a 24-hr test. Consistent with earlier findings, blocked practice enhanced acquisition but harmed retention. Participants, though, predicted better performance given blocked practice. These results augment research on judgments of verbal learning and suggest that humans, at their peril, interpret current ease of access to a perceptual-motor skill as a valid index of learning.
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Affiliation(s)
- D A Simon
- Department of Kinesiology, McMaster University, Ontario, Canada.
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Abstract
STUDY DESIGN In vitro accuracy assessment of a novel virtual fluoroscopy system. OBJECTIVES To investigate a new technology combining image-guided surgery with C-arm fluoroscopy. SUMMARY OF BACKGROUND DATA Fluoroscopy is a useful and familiar technology to all musculoskeletal surgeons. Its limitations include radiation exposure to the patient and operating team and the need to reposition the fluoroscope repeatedly to obtain surgical guidance in multiple planes. METHODS Fluoroscopic images of the lumbar spine of an intact, unembalmed cadaver were obtained, calibrated, and saved to an ). A was used for the sequential insertion of a light-emitting diode-fitted probe into the pedicles of L1-S1 bilaterally. The trajectory of a "virtual tool" corresponding to the tracked tool was overlaid onto the saved fluoroscopic views in real time. Live fluoroscopic images of the inserted pedicle probe were then obtained. Distances between the tips of the virtual and fluoroscopically displayed probes were quantified using the image-guided computer's measurement tool. Trajectory angle differences were measured using a standard goniometer and printed copies of the workstation computer display. The surgeon's radiation exposure was measured using thermolucent dosimeter rings. RESULTS Excellent correlation between the virtual fluoroscopic images and live fluoroscopy was observed. Mean probe tip error was 0.97 +/- 0.40 mm. Mean trajectory angle difference between the virtual and fluoroscopically displayed probes was 2.7 degrees +/- 0.6 degrees. The thermolucent dosimeter rings measured no detectable radiation exposure for the surgeon. CONCLUSIONS Virtual fluoroscopy offers several advantages over conventional fluoroscopy while providing acceptable targeting accuracy. It enables a single C-arm to provide real-time, multiplanar procedural guidance. It also dramatically reduces radiation exposure to the patient and surgical team by eliminating the need for repetitive fluoroscopic imaging for tool placement.
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Affiliation(s)
- K T Foley
- Image-Guided Surgery Research Center; Department of Neurosurgery, University of Tennessee, Memphis, Tennessee, USA.
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Abstract
STUDY DESIGN Accuracy requirement analysis for image-guided pedicle screw placement. OBJECTIVES To derive theoretical accuracy requirements for image-guided spinal pedicle screw placement. SUMMARY OF BACKGROUND DATA Underlying causes of inaccuracy in image-guided surgical systems and methods for quantifying this inaccuracy have been studied. However, accuracy requirements for specific spinal surgical procedures have not been delineated. In particular, the accuracy requirements for image-guided spinal pedicle screw placement have not been previously reported. METHODS A geometric model was developed relating spinal pedicle anatomy to accuracy requirements for image-guided surgery. This model was used to derive error tolerances for pedicle screw placement when using clinically relevant screw diameters in the cervical (3.5 mm), thoracic (5.0 mm), and thoracolumbar spine (6.5 mm). The error tolerances were represented as the permissible rotational and translational deviations from the ideal screw trajectory that would avoid pedicle wall perforation. The relevant dimensions of the pedicle model were extracted from existing morphometric data. RESULTS As anticipated, accuracy requirements were greatest at spinal levels where the relevant screw diameter approximated the dimensions of the pedicle. These requirements were highest for T5, followed in descending order by T4, T7, T6, T3, T12, L1, T8, T11, C4, L2, C3, T10, C5, T2, T9, C6, L3, C2, T1, C7, L4, and L5. Maximum permissible translational/rotational error tolerances ranged from 0.0 mm/0.0 degrees at T5 to 3.8 mm/12.7 degrees at L5. CONCLUSIONS These results, obtained by mathematical analysis, demonstrate that extremely high accuracy is necessary to place pedicle screws at certain levels of the spine without perforating the pedicle wall. These accuracy requirements exceed the accuracy of current image-guided surgical systems, based on clinical utility errors reported in the literature. In actual use, however, these systems have been shown to improve the accuracy of pedicle screw placement. This dichotomy indicates that other factors, such as the surgeon's visual and tactile feedback, may be operative.
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Affiliation(s)
- Y R Rampersaud
- Division of Neurosurgery and Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada.
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DiGioia AM, Jaramaz B, Blackwell M, Simon DA, Morgan F, Moody JE, Nikou C, Colgan BD, Aston CA, Labarca RS, Kischell E, Kanade T. The Otto Aufranc Award. Image guided navigation system to measure intraoperatively acetabular implant alignment. Clin Orthop Relat Res 1998:8-22. [PMID: 9917587 DOI: 10.1097/00003086-199810000-00003] [Citation(s) in RCA: 292] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
There has been little clinical research to examine the effects of patient positioning and pelvic motion on the alignment of the acetabular implant during total hip replacement surgery. Until now, no tools were capable of accurately measuring these variables during the actual procedure. As part of a broader program in medical robotics and computer assisted surgery, a clinical system has been developed that includes several enabling technologies. The hip navigation system (HipNav) continuously and precisely measures pelvic location and tracks relative implant alignment intraoperatively. HipNav technology is used to gauge current clinical practice and provide intraoperative feedback to surgeons with the goal of improving the precision and accuracy of acetabular alignment during total hip replacement. This system provides surgeons with a new class of image guided measurement tools and assist devices. These tools successfully were introduced into the clinical practice of surgery with results showing the following: (1) There exist unpredictable and large variations in the initial position of patients' pelves on the operating room table and significant pelvic movement during surgery and during intraoperative range of motion testing; (2) current mechanical acetabular alignment guides do not account for these variations, and result in variable and in the majority of cases unacceptable acetabular alignment; and (3) press fitting oversized acetabular components influences the final cup orientation.
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Affiliation(s)
- A M DiGioia
- Center for Orthopaedic Research, University of Pittsburgh Medical Center Shadyside, PA 15232, USA
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Abstract
Imaging, sensing, and computing technologies that are being introduced to aid in the planning and execution of surgical procedures are providing orthopaedic surgeons with a powerful new set of tools for improving clinical accuracy, reliability, and patient outcomes while reducing costs and operating times. Current computer assisted surgery systems typically include a measurement process for collecting patient specific medical data, a decision making process for generating a surgical plan, a registration process for aligning the surgical plan to the patient, and an action process for accurately achieving the goals specified in the plan. Some of the key concepts in computer assisted surgery applied to orthopaedics with a focus on the basic framework and underlying technologies is outlined. In addition, technical challenges and future trends in the field are discussed.
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Affiliation(s)
- D A Simon
- Sofamor Danek-Surgical Navigation Technologies, Broomfield, CO 80303, USA
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Groarke L, Simon DA, McCollum CN. Tissue viability. Leg ulcer care: auditing the service in the community. Nurs Stand 1996; 10:56. [PMID: 8868680 DOI: 10.7748/ns.10.45.56.s53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Simon DA, Freak L, Kinsella A, Walsh J, Lane C, Groarke L, McCollum C. Community leg ulcer clinics: a comparative study in two health authorities. BMJ 1996; 312:1648-51. [PMID: 8664719 PMCID: PMC2351389 DOI: 10.1136/bmj.312.7047.1648] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To compare the outcome and cost of care for leg ulcers in community leg ulcer clinics in Stockport District Health authority with Trafford District Health Authority as a control. DESIGN Detailed cost and efficacy studies conducted prospectively over a three month period in both districts both before and one year after the introduction of five leg ulcer clinics in Stockport. SETTING Two large district health authorities of broad socioeconomic mix and total population of 540,000. PATIENTS All patients receiving treatment for an active leg ulcer, irrespective of the profession or location of their carer. MAIN OUTCOME MEASURES The proportion of ulcerated limbs completely healed within three months and total cost of leg ulcer care. RESULTS The introduction of community clinics in Stockport improved healing of leg ulcers from 66/252 (26%) in 1993 to 99/233 (42%) in 1994 (P < 0.001) compared with in Trafford, where 47/203 (23%) healed in 1993 and only 43/213 (20%) in 1994. This improved result in Stockport was achieved while the annual expenditure on care of leg ulcers was reduced from 409,991 pounds to only 253,371 pounds. In the same year the cost of leg ulcer care in Trafford increased from 556,039 pounds to 673,318 pounds. CONCLUSION In the first year after the introduction of community clinics, before most patients in Stockport had access to these clinics, healing of leg ulcers was already improved whereas costs were reduced.
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Affiliation(s)
- D A Simon
- University Department of Surgery, University Hospital of South Manchester West Didsbury
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Simon DA, McCollum CN. Approaches to venous leg ulcer care within the community: compression, pinch skin grafts and simple venous surgery. Ostomy Wound Manage 1996; 42:34-8, 40. [PMID: 8703294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The traditional approach to leg ulcer care is both expensive and achieves poor outcomes. The outcome of treatment for patients with venous ulceration has been improved using a more scientific and research-based approach to patient assessment, adequate compression bandaging, use of other procedures such as pinch skin grafting and simple venous surgery, and the delivery of these innovations in patient care to the community as a whole. Multi-layer compression bandaging is superior to standard (one-layer) bandaging because it can easily be adapted to a wide range of ankle circumferences and leg sizes to provide sustained, graduated compression. Pinch skin grafting is cost-effective, accelerates healing, and, following adequate training, may be performed by specialist nurses in the community. Simple venous surgery may be offered under local anaesthesia when only the superficial veins are incompetent; however, deep venous surgery has yet to prove itself in clinical practice. Implementation of dedicated community leg ulcer clinics using these research-based findings will result in a substantially reduced prevalence of venous leg ulceration.
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Abstract
The goal of intrasurgical registration is to establish a common reference frame between presurgical and intrasurgical three-dimensional data sets that correspond to the same anatomy. This paper presents two novel techniques that have application to this problem, high-speed pose tracking and intrasurgical data selection. In the first part of this paper, we describe an approach for tracking the pose of arbitrarily shaped rigid objects at rates up to 10 Hz. Static accuracies on the order of 1 mm in translation and 1 degree in rotation have been achieved. We have demonstrated the technique on a human face using a high-speed VLSI range sensor; however, the technique is independent of the sensor used or the anatomy tracked. In the second part of this paper, we describe a general purpose approach for selecting near-optimal intrasurgical registration data. Because of the high costs of acquisition of intrasurgical data, our goal is to minimize the amount of data acquired while ensuring registration accuracy. We synthesize near-optimal intrasurgical data sets, based on an analysis of differential surface properties of presurgical data. We demonstrate, using data from a human femur, that discrete-point data sets selected using our method are superior to those selected by human experts in terms of the resulting pose-refinement accuracy.
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Affiliation(s)
- D A Simon
- Robotics Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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Tolman KG, Detweiler MK, Harrison CA, Rollins DE, Simon DA, Brady C, McCormack GH, Bryant EC. Effect of rioprostil on aspirin-induced gastrointestinal mucosal changes in normal volunteers. J Clin Pharmacol 1988; 28:76-80. [PMID: 3127431 DOI: 10.1002/j.1552-4604.1988.tb03104.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Rioprostil, a 15-deoxy-16-methyl prostaglandin E1, was evaluated for its effect on aspirin-induced gastrointestinal mucosal changes in normal volunteers. Fifty-six normal male volunteers were evaluated by endoscopy in a double-blind, placebo-controlled study. Aspirin was given at a dose of 975 mg four times per day. Rioprostil was given at doses of 60, 120, and 300 micrograms four times per day. Rioprostil, at both antisecretory and subantisecretory doses, prevented or reduced aspirin-induced injury. Increased stool frequency was the most common side effect and appeared to be a dose-related effect of rioprostil occurring at only antisecretory doses.
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Affiliation(s)
- K G Tolman
- Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132
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Simon DA, Carner EA. An off-site day treatment program for mentally impaired nursing home residents. Gerontologist 1987; 27:585-7. [PMID: 3678896 DOI: 10.1093/geront/27.5.585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Asscher AW, Johnson SE, Simon DA. Effect of urinary pH on the renal clearance of cephaloridine. Postgrad Med J 1970:Suppl:55-7. [PMID: 5488209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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