Doctor Lewis Zimmerman was a noted 24th century Human scientist and holo-engineer, responsible for the creation and development of the Emergency Medical Hologram, or "EMH", and considered to be the father of modern holography. He was also the model for the image of the EMH Mark I, a fact that he found to be a great source of embarrassment when wide scale use of the Mark I was discontinued and the holograms later re-utilized to perform menial tasks.
Long-Term Medical Hologram research
In an attempt to further the capabilities of the EMH, Zimmerman sought to create a new Long-term Medical Holographic program, and selected Julian Bashir as the template. Zimmerman traveled to Deep Space 9 to begin his work. He interviewed many residents of the station, to get a complete picture of Bashir.
In Quark's, Bashir asked Zimmerman to not invite his parents to the station. Zimmerman did the opposite and asked Richard and Amsha Bashir to come to the station immediately. Zimmerman later stumbled across the fact that Bashir had been genetically-engineered as a child, and had to withdraw Bashir from consideration as a suitable template.
Zimmerman was briefly involved with Leeta when he asked her to work in the bar on Jupiter Station. They were on their way to a transport when Rom appeared and told Leeta he loved her. Zimmerman was initially disappointed until he met a female passenger. He asked her if she was familiar with the Earth text, the Kama Sutra. (DS9: "Doctor Bashir, I Presume")
Dr. Zimmerman lived and worked at Jupiter Station constantly, and rarely left. His only companions were holographic figures, including a fly named Roy, an iguana called Leonard, and his personal assistant Haley (who was the first sentient hologram Zimmerman programmed). He was especially close to Haley and considered her more than a hologram.
In preparation, he began dictating his last will and testament, leaving his entire collection of holographic art, including the 21st century masterpiece "Woman in Four Dimensions", to Reginald Barclay, as well as his holographic research about miniature holograms for espionage purposes, on the grounds that Barclay was the only person who appreciated them. Barclay, himself, affectionately referred to Zimmerman as "Doctor Z". (VOY: "Life Line")
In an attempt to find a cure, Barclay contacted the USS Voyager via the Pathfinder Project. Voyager carried a Mark I EMH, The Doctor, whose unique knowledge and abilities Barclay hoped would help. Analyzing Zimmerman's medical records, The Doctor noted some similarities between Zimmerman's condition and the Vidiian Phage, which he had been partially able to treat in the past and which gave him hope that he could do the same to Zimmerman. Reasoning that other doctors would not be experienced with the treatments, The Doctor requested that he be sent to the Alpha Quadrant to administer the treatment himself.
Zimmerman initially refused to be treated by The Doctor, whom he saw as inferior to the later Mark III and Mark IV EMHs, reprogramming The Doctor's equipment and transferring him to other parts of the station, forcing The Doctor to reconfigure his appearance to a Tarlac masseuse to even try and get close to Zimmerman to examine him. Lieutenant Barclay recruited Counselor Deanna Troi to mediate between the EMH and Dr. Zimmerman and try to resolve their differences, Troi reflecting that part of Zimmerman's problem was his anger over the final fate of the Mark Is given how much he had personally invested in them. The situation became so frustrating that Barclay, Troi, and Hayley created a fake glitch in The Doctor's program to encourage the two to work together, Zimmerman being forced to acknowledge that The Doctor was more than a Mark I when he was informed that Voyager wouldn't accept a Mark IV EMH in The Doctor's place as they would simply want their friend back, as he had believed that a Mark I was incapable of making that kind of impact on others.
Beginning his work on The Doctor, Zimmerman initially contemplated making various additions to the EMH's programming, but when The Doctor protested at Zimmerman's inability to accept him as he was, Zimmerman's anger and frustration at what had happened to the Mark Is came to the fore, ranting about the negative reaction of Starfleet to the other Mark I EMHs and his own grief at the garbage cleaners they had become. As Zimmerman sank into a chair in depression, The Doctor offered an awkward moment of comfort to him, reminding Zimmerman that he was still doing the job he was designed for and was actually rather good at it. This encounter marked the first steps in their near-father/son relationship, with The Doctor confessing that he'd hoped Zimmerman would be proud of his achievements if the two of them ever met, and Zimmerman admitting that, for all his anger about the fate of the other Mark Is, he was grateful that at least one of them was still doing what Zimmerman had designed them for. Before The Doctor departed, Zimmerman slightly grudgingly posed for a photograph with his "son", and said that The Doctor could drop them a communication the next time his ship got the chance to do so. (VOY: "Life Line")
The holonovel Photons Be Free was written with acknowledgment made to Dr. Zimmerman. During the subsequent court case to defend The Doctor's rights as a person, Barclay noted that The Doctor's attempt to save Zimmerman was reminiscent of a son seeking the father's approval. (VOY: "Author, Author")
Lewis Zimmerman was played by actor Robert Picardo.
Executive Producers and Star Trek: Voyager co-creators Rick Berman, Michael Piller and Jeri Taylor spared a thought for the creator of the holographic doctor character while the series was in the early developmental stages. In a summary of notes Taylor wrote (dated 6 August 1993), she reported, "We spoke of a programmer who created the doctor but made him a bit bland." However, Taylor and her executive producing partners initially intended Reginald Barclay to fulfil this "programmer" role, imagining that he had created the holographic doctor in his own image. (A Vision of the Future - Star Trek: Voyager, p. 182)
In the pre-production of Voyager and the scripts which were written for VOY Season 1, "Doc Zimmerman" was intended to be the name of The Doctor. An early, British ad promoting the series still referred to him by this name, as well as the TV Guide article promoting the new series. He was named for Herman Zimmerman, a production designer for TNG, DS9, and the four TNG movies.
Zimmerman's first name was spelled "Louis" in the script for "Doctor Bashir, I Presume", though the spelling "Lewis" was seen on-screen in "Projections" and was also used in scripts for Star Trek: Voyager (at least in the case of "The Swarm").
Ronald D. Moore commented on Zimmerman's lack of rank insignia in "Doctor Bashir, I Presume", despite wearing a Starfleet uniform: "This is a mistake, but an understandable one. Dr. Zimmerman's appearance was guided by his appearance on the Voyager episode in which he was recreated on the holodeck. In that episode, he didn't wear a rank insignia either, and our costumers simply followed that choice in doing our episode. Why he didn't have one on Voyager is a good question." (AOL chat, 1997)
Zimmerman returns to DS9 in "So a Horse Walks into a Bar...".
His mirror universe counterpart (β) is depicted as a Terran scientist working for the Klingon-Cardassian Alliance to develop a telepath in the novella The Mirror-Scaled Serpent. The Ocampa Kes, who had become trapped in the Alpha Quadrant after a brief encounter with the Caretaker, was sent to him to be experimented upon.