The Deep Phreatic Thermal Explorer ( DEPTHX ) is an autonomous underwater vehicle designed and built by Stone Aerospace , an aerospace engineering firm based in Austin , Texas . It was designed to autonomously explore and map underwater sinkholes in northern Mexico, as well as collect water and wall core samples. This could be achieved via an autonomous form of navigation known as A-Navigation. The DEPTHX vehicle was the first of three vehicles to be built by Stone Aerospace which were funded by NASA with the goal of developing technology that can explore the oceans of Jupiter 's moon Europa to look for extraterrestrial life .
57-846: DEPTHX was a collaborative project for which Stone Aerospace was the principal investigator . Co-investigators included Carnegie Mellon University , which was responsible for the navigation and guidance software, the Southwest Research Institute , which built the vehicle's science payload , and research scientists from the University of Texas at Austin , the Colorado School of Mines , and NASA Ames Research Center . In 1999, Bill Stone had been involved in an underwater surveying project in Wakulla Springs , Florida . For that project, Stone had devised
114-423: A cavern . The mapping of Cenote Zacatón was particularly notable because its depth was previously unknown, as human divers had not been successful in attempts to reach the bottom. DEPTHX created the first map of the bottom of Zacatón, which has a depth of over 1,000 feet [300 m]. DEPTHX was the first robotic system of any kind to implement three-dimensional simultaneous localization and mapping (SLAM). It
171-415: A dietary supplement of an acidic quality in the experiment after two months at sea, when the ship was already afflicted with scurvy. He divided twelve scorbutic sailors into six groups of two. They all received the same diet but, in addition, group one was given a quart of cider daily, group two twenty-five drops of elixir of vitriol ( sulfuric acid ), group three six spoonfuls of vinegar , group four half
228-461: A different purpose to construct focus on identifying a specific effect. Clinical trials involving new drugs are commonly classified into five phases. Each phase of the drug approval process is treated as a separate clinical trial. The drug development process will normally proceed through phases I–IV over many years, frequently involving a decade or longer. If the drug successfully passes through phases I, II, and III, it will usually be approved by
285-558: A digital wall mapper that was propelled by a diver propulsion vehicle and steered by divers which was designed to create a 3-D map of Wakulla Springs using an array of sonars, as well as a suite of other sophisticated sensors. The success of this project, the Wakulla Springs 2 Project, attracted the interest of planetary scientist Dan Durda from the Southwest Research Institute, who wished to create
342-419: A landmark study carried out in collaboration with Richard Doll on the correlation between smoking and lung cancer . They carried out a case-control study in 1950, which compared lung cancer patients with matched control and also began a sustained long-term prospective study into the broader issue of smoking and health, which involved studying the smoking habits and health of more than 30,000 doctors over
399-477: A less ellipsoidal design, however these designs were abandoned due to concerns that such a shape would be difficult to maneuver out of the potentially tight spots it might encounter during the exploration of unknown territory. It was also during this time that the DEPTHX team did a field campaign at Cenote Zacatón using a drop sonde to acquire some initial data for the software team, which itself contributed to
456-557: A national regulatory authority approves marketing of the innovation. Similarly to drugs, manufacturers of medical devices in the United States are required to conduct clinical trials for premarket approval . Device trials may compare a new device to an established therapy, or may compare similar devices to each other. An example of the former in the field of vascular surgery is the Open versus Endovascular Repair (OVER trial) for
513-434: A panel of expert clinical investigators, including what alternative or existing treatments to compare to the new drug and what type(s) of patients might benefit. If the sponsor cannot obtain enough test subjects at one location investigators at other locations are recruited to join the study. During the trial, investigators recruit subjects with the predetermined characteristics, administer the treatment(s) and collect data on
570-499: A period of several years. His certificate for election to the Royal Society called him "... the leader in the development in medicine of the precise experimental methods now used nationally and internationally in the evaluation of new therapeutic and prophylactic agents ." International clinical trials day is celebrated on 20 May. The acronyms used in the titling of clinical trials are often contrived, and have been
627-465: A pint of seawater, group five received two oranges and one lemon , and the last group a spicy paste plus a drink of barley water . The treatment of group five stopped after six days when they ran out of fruit, but by then one sailor was fit for duty while the other had almost recovered. Apart from that, only group one also showed some effect of its treatment. Each year, May 20 is celebrated as Clinical Trials Day in honor of Lind's research. After 1750
SECTION 10
#1732801805932684-412: A placebo to a person suffering from a disease may be unethical, "active comparator" (also known as "active control") trials may be conducted instead. In trials with an active control group, subjects are given either the experimental treatment or a previously approved treatment with known effectiveness. In other cases, sponsors may conduct an active comparator trial to establish an efficacy claim relative to
741-779: A role in clinical trials. While working for the Rothamsted experimental station in the field of agriculture, Fisher developed his Principles of experimental design in the 1920s as an accurate methodology for the proper design of experiments. Among his major ideas include the importance of randomization —the random assignment of individuals to different groups for the experiment; replication —to reduce uncertainty , measurements should be repeated and experiments replicated to identify sources of variation; blocking —to arrange experimental units into groups of units that are similar to each other, and thus reducing irrelevant sources of variation; use of factorial experiments —efficient at evaluating
798-420: A similar cutoff age) are often excluded from trials because their greater health issues and drug use complicate data interpretation, and because they have different physiological capacity than younger people. Children and people with unrelated medical conditions are also frequently excluded. Pregnant women are often excluded due to potential risks to the fetus . The sponsor designs the trial in coordination with
855-467: A similar piece of technology to explore the oceans of Europa, but one that could drive itself autonomously. Stone accepted the challenge, and several collaborative proposals were submitted to NASA. It wasn't until 2003 that NASA would finally fund DEPTHX as a three-year, $ 5 million project. The vehicle underwent several different design concepts over the next couple of years as engineers at Stone Aerospace explored various options. Initial designs focused on
912-540: A single disease entering and leaving the platform), and basket trial (one medical product for multiple diseases or disease subtypes). Genetic testing enables researchers to group patients according to their genetic profile, deliver drugs based on that profile to that group and compare the results. Multiple companies can participate, each bringing a different drug. The first such approach targets squamous cell cancer , which includes varying genetic disruptions from patient to patient. Amgen, AstraZeneca and Pfizer are involved,
969-491: A single research center or multiple centers , in one country or in multiple countries. Clinical study design aims to ensure the scientific validity and reproducibility of the results. Costs for clinical trials can range into the billions of dollars per approved drug, and the complete trial process to approval may require 7–15 years. The sponsor may be a governmental organization or a pharmaceutical , biotechnology or medical-device company. Certain functions necessary to
1026-459: A team to obtain the best strategic advantage for the project. In the context of a clinical trial, a PI may be an academic working with grants from NIH or other funding agencies, or may be effectively a contractor for a pharmaceutical company working on testing the safety and efficacy of new medicines. There were 20,458 PIs on NIH R01 grants in US biomedical research in 2000. In 2013, this number
1083-423: A treatment can have nonspecific effects. These are controlled for by the inclusion of patients who receive only a placebo. Subjects are assigned randomly without informing them to which group they belonged. Many trials are doubled-blinded so that researchers do not know to which group a subject is assigned. Assigning a subject to a placebo group can pose an ethical problem if it violates his or her right to receive
1140-418: Is common in the sciences, it is used widely for the person or persons who make final decisions and supervise funding and expenditures on a given research project. A co-investigator (Co-I) assists the principal investigator in the management and leadership of the research project. There may be a number of co-investigators supporting a PI. In the context of United States federal funding from agencies such as
1197-420: Is researcher and how. PPI can improve the quality of research and make it more relevant and accessible. People with current or past experience of illness can provide a different perspective than professionals and compliment their knowledge. Through their personal knowledge they can identify research topics that are relevant and important to those living with an illness or using a service. They can also help to make
SECTION 20
#17328018059321254-467: The Antarctic environment. Principal investigator In many countries, the term principal investigator ( PI ) refers to the holder of an independent grant and the lead researcher for the grant project, usually in the sciences, such as a laboratory study or a clinical trial . The phrase is also often used as a synonym for "head of the laboratory" or "research group leader". While the expression
1311-609: The National Institutes of Health (NIH) or the National Science Foundation (NSF), the PI is the person who takes direct responsibility for completion of a funded project, directing the research and reporting directly to the funding agency. For small projects (which might involve 1–5 people) the PI is typically the person who conceived the investigation, but for larger projects the PI may be selected by
1368-571: The Therapeutic Trials Committee to advise and assist in the arrangement of properly controlled clinical trials on new products that seem likely on experimental grounds to have value in the treatment of disease. The first randomised curative trial was carried out at the MRC Tuberculosis Research Unit by Sir Geoffrey Marshall (1887–1982). The trial, carried out between 1946 and 1947, aimed to test
1425-409: The cohort study and the case-control study , provide less compelling evidence than the randomized controlled trial. In observational studies, the investigators retrospectively assess associations between the treatments given to participants and their health status, with potential for considerable errors in design and interpretation. A randomized controlled trial can provide compelling evidence that
1482-466: The UK also follow ICH guidelines. Journals such as Trials , encourage investigators to publish their protocols. Clinical trials recruit study subjects to sign a document representing their " informed consent ". The document includes details such as its purpose, duration, required procedures, risks, potential benefits, key contacts and institutional requirements. The participant then decides whether to sign
1539-412: The ability of a trial to detect a difference of a particular size (or larger) between the treatment and control groups. For example, a trial of a lipid -lowering drug versus placebo with 100 patients in each group might have a power of 0.90 to detect a difference between placebo and trial groups receiving dosage of 10 mg/dL or more, but only 0.70 to detect a difference of 6 mg/dL. Merely giving
1596-454: The active comparator instead of the placebo in labeling . A master protocol includes multiple substudies, which may have different objectives and involve coordinated efforts to evaluate one or more medical products in one or more diseases or conditions within the overall study structure. Trials that could develop a master protocol include the umbrella trial (multiple medical products for a single disease), platform trial (multiple products for
1653-583: The catastrophic result of Anson 's circumnavigation attracted much attention in Europe; out of 1900 men, 1400 had died, most of them allegedly from having contracted scurvy. John Woodall , an English military surgeon of the British East India Company , had recommended the consumption of citrus fruit from the 17th century, but their use did not become widespread. Lind conducted the first systematic clinical trial in 1747. He included
1710-407: The clinical trial to follow. There are two goals to testing medical treatments: to learn whether they work well enough, called "efficacy", or "effectiveness"; and to learn whether they are safe enough, called "safety". Neither is an absolute criterion; both safety and efficacy are evaluated relative to how the treatment is intended to be used, what other treatments are available, and the severity of
1767-509: The country where approval of the therapy is sought. These authorities are responsible for vetting the risk/benefit ratio of the trial—their approval does not mean the therapy is 'safe' or effective, only that the trial may be conducted. Depending on product type and development stage, investigators initially enroll volunteers or patients into small pilot studies , and subsequently conduct progressively larger scale comparative studies. Clinical trials can vary in size and cost, and they can involve
DEPTHX - Misplaced Pages Continue
1824-553: The discipline began to take its modern shape. The English doctor John Haygarth demonstrated the importance of a control group for the correct identification of the placebo effect in his celebrated study of the ineffective remedy called Perkin's tractors . Further work in that direction was carried out by the eminent physician Sir William Gull, 1st Baronet in the 1860s. Frederick Akbar Mahomed (d. 1884), who worked at Guy's Hospital in London , made substantial contributions to
1881-456: The disease or condition. The benefits must outweigh the risks. For example, many drugs to treat cancer have severe side effects that would not be acceptable for an over-the-counter pain medication, yet the cancer drugs have been approved since they are used under a physician's care and are used for a life-threatening condition. In the US the elderly constitute 14% of the population, while they consume over one-third of drugs. People over 55 (or
1938-562: The document. The document is not a contract, as the participant can withdraw at any time without penalty. Informed consent is a legal process in which a recruit is instructed about key facts before deciding whether to participate. Researchers explain the details of the study in terms the subject can understand. The information is presented in the subject's native language. Generally, children cannot autonomously provide informed consent, but depending on their age and other factors, may be required to provide informed assent. In any clinical trial,
1995-412: The effects and possible interactions of several independent factors. Of these, blocking and factorial design are seldom applied in clinical trials, because the experimental units are human subjects and there is typically only one independent intervention: the treatment. The British Medical Research Council officially recognized the importance of clinical trials from the 1930s. The council established
2052-499: The efficacy of the chemical streptomycin for curing pulmonary tuberculosis . The trial was both double-blind and placebo-controlled . The methodology of clinical trials was further developed by Sir Austin Bradford Hill , who had been involved in the streptomycin trials. From the 1920s, Hill applied statistics to medicine, attending the lectures of renowned mathematician Karl Pearson , among others. He became famous for
2109-421: The first time they have worked together in a late-stage trial. Patients whose genomic profiles do not match any of the trial drugs receive a drug designed to stimulate the immune system to attack cancer. A clinical trial protocol is a document used to define and manage the trial. It is prepared by a panel of experts. All study investigators are expected to strictly observe the protocol. The protocol describes
2166-418: The intervention's efficacy was generally lacking. For instance, Lady Mary Wortley Montagu , who campaigned for the introduction of inoculation (then called variolation) to prevent smallpox , arranged for seven prisoners who had been sentenced to death to undergo variolation in exchange for their life. Although they survived and did not contract smallpox, there was no control group to assess whether this result
2223-410: The national regulatory authority for use in the general population. Phase IV trials are performed after the newly approved drug, diagnostic or device is marketed, providing assessment about risks, benefits, or best uses. A fundamental distinction in evidence-based practice is between observational studies and randomized controlled trials . Types of observational studies in epidemiology , such as
2280-408: The number of subjects, also called the sample size, has a large impact on the ability to reliably detect and measure the effects of the intervention. This ability is described as its " power ", which must be calculated before initiating a study to figure out if the study is worth its costs. In general, a larger sample size increases the statistical power, also the cost. The statistical power estimates
2337-499: The overall design changes. The final design was decided upon in 2006, at which point construction of the vehicle began. The completed vehicle was about 7 feet (2.1 m) in diameter and weighed about 3,300 pounds (1,500 kg). It had redundant navigation systems including 54 sonars, an inertial measurement unit , doppler velocity logger , as well as depth gauges and accelerometers . Propulsion systems were also redundant, having six thrusters and two equivalent battery stacks. It
DEPTHX - Misplaced Pages Continue
2394-606: The process of clinical trials, where "he separated chronic nephritis with secondary hypertension from what we now term essential hypertension . He also founded the Collective Investigation Record for the British Medical Association ; this organization collected data from physicians practicing outside the hospital setting and was the precursor of modern collaborative clinical trials." Ideas of Sir Ronald A. Fisher still play
2451-407: The research more grounded in the needs of the specific communities they are part of. Public contributors can also ensure that the research is presented in plain language that is clear to the wider society and the specific groups it is most relevant for. Although early medical experimentation was performed often, the use of a control group to provide an accurate comparison for the demonstration of
2508-418: The safety and relative effectiveness of a medication or device: While most clinical trials test one alternative to the novel intervention, some expand to three or four and may include a placebo . Except for small, single-location trials, the design and objectives are specified in a document called a clinical trial protocol . The protocol is the trial's "operating manual" and ensures all researchers perform
2565-494: The scientific rationale, objective(s), design, methodology, statistical considerations and organization of the planned trial. Details of the trial are provided in documents referenced in the protocol, such as an investigator's brochure . The protocol contains a precise study plan to assure safety and health of the trial subjects and to provide an exact template for trial conduct by investigators. This allows data to be combined across all investigators/sites. The protocol also informs
2622-564: The study administrators (often a contract research organization ). The format and content of clinical trial protocols sponsored by pharmaceutical, biotechnology or medical device companies in the United States, European Union, or Japan have been standardized to follow Good Clinical Practice guidance issued by the International Conference on Harmonisation (ICH). Regulatory authorities in Canada , China , South Korea , and
2679-832: The study treatment causes an effect on human health. Some Phase II and most Phase III drug trials are designed as randomized, double-blind , and placebo -controlled. Clinical studies having small numbers of subjects may be "sponsored" by single researchers or a small group of researchers, and are designed to test simple questions or feasibility to expand the research for a more comprehensive randomized controlled trial. Clinical studies can be "sponsored" (financed and organized) by academic institutions, pharmaceutical companies, government entities and even private groups. Trials are conducted for new drugs, biotechnology, diagnostic assays or medical devices to determine their safety and efficacy prior to being submitted for regulatory review that would determine market approval. In cases where giving
2736-456: The subject of derision. Clinical trials are classified by the research objective created by the investigators. Trials are classified by their purpose. After approval for human research is granted to the trial sponsor, the U.S. Food and Drug Administration (FDA) organizes and monitors the results of trials according to type: Clinical trials are conducted typically in four phases, with each phase using different numbers of subjects and having
2793-430: The subjects' health for a defined time period. Data include measurements such as vital signs , concentration of the study drug in the blood or tissues, changes to symptoms, and whether improvement or worsening of the condition targeted by the study drug occurs. The researchers send the data to the trial sponsor, who then analyzes the pooled data using statistical tests . Examples of clinical trial goals include assessing
2850-443: The surgical setting, case-controlled studies will be replaced. Besides being participants in a clinical trial, members of the public can be actively collaborate with researchers in designing and conducting clinical research . This is known as patient and public involvement (PPI). Public involvement involves a working partnership between patients, caregivers, people with lived experience, and researchers to shape and influence what
2907-546: The treatment of abdominal aortic aneurysm , which compared the older open aortic repair technique to the newer endovascular aneurysm repair device. An example of the latter are clinical trials on mechanical devices used in the management of adult female urinary incontinence . Similarly to drugs, medical or surgical procedures may be subjected to clinical trials, such as comparing different surgical approaches in treatment of fibroids for subfertility . However, when clinical trials are unethical or logistically impossible in
SECTION 50
#17328018059322964-501: The trial in the same way on similar subjects and that the data is comparable across all subjects. As a trial is designed to test hypotheses and rigorously monitor and assess outcomes, it can be seen as an application of the scientific method , specifically the experimental step. The most common clinical trials evaluate new pharmaceutical products, medical devices, biologics , diagnostic assays , psychological therapies , or other interventions. Clinical trials may be required before
3021-516: The trial, such as monitoring and lab work, may be managed by an outsourced partner, such as a contract research organization or a central laboratory. Only 10 percent of all drugs started in human clinical trials become approved drugs . Some clinical trials involve healthy subjects with no pre-existing medical conditions . Other clinical trials pertain to people with specific health conditions who are willing to try an experimental treatment. Pilot experiments are conducted to gain insights for design of
3078-698: Was 21,511. At the same time, the success rate for an applicant to receive an R01 grant went down from 32% in 2000 to 17% in 2013. Clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines , drugs , dietary choices , dietary supplements , and medical devices ) and known interventions that warrant further study and comparison. Clinical trials generate data on dosage, safety and efficacy. They are conducted only after they have received health authority/ethics committee approval in
3135-411: Was also the first such system to make its own decisions on where and how to collect samples. From these samples, at least three new divisions of bacteria were discovered. The success of the DEPTHX mission led to the funding of the follow-on project, ENDURANCE . The ENDURANCE vehicle reused the frame and a number of systems from the DEPTHX vehicle, but was considerably reconfigured for the needs of
3192-481: Was due to the inoculation or some other factor. Similar experiments performed by Edward Jenner over his smallpox vaccine were equally conceptually flawed. The first proper clinical trial was conducted by the Scottish physician James Lind . The disease scurvy , now known to be caused by a Vitamin C deficiency, would often have terrible effects on the welfare of the crew of long-distance ocean voyages. In 1740,
3249-562: Was outfitted with a variable buoyancy system, and finally with the science payload that included the ability to take in water and solid core samples for later analysis, as well as an onboard microscope to analyze water samples in real time. During the DEPTHX 2007 deployment, the vehicle was able to create 3-D maps of four cenotes in Sistema Zacatón in Tamaulipas , Mexico . This was the first autonomous system to explore and map
#931068